Small Arms Thread
Re: Small Arms Thread
seems to me wherever any forms of artillery gets involved (mortar,shell) or even portable artillery (RPG,grenades) it outscores the damage from bullets by Huge margins. there are likely soldiers who went through wars without directly hitting anyone with their rifle bullets.
no wonder the good armies like khan bring along massive amts of artillery to every fight if they can. in ww2 the american 8" howitzers were famous for the massed barrages and the soviets threw everything in the kitchen sink ranging from tube guns, tank cannons in high elevations, AT guns to katyushas into their all-out barrages before every attack.
http://upload.wikimedia.org/wikipedia/c ... isplay.jpg
this ugly bad boy could lob a shell only 16km but the shell itself was 90kg weight.
the Pakis have a few pieces of this and used to shell some of our border camps with this 90kg shell. it was a much feared weapon because anyone caught in the open would suffer due to the big radius of lethal shrapnel.
the worrying part is the lizard also believes in using artillery to overwhelm problems and unlike us, is not sitting on thumbs wrt to improving their bite.
no wonder the good armies like khan bring along massive amts of artillery to every fight if they can. in ww2 the american 8" howitzers were famous for the massed barrages and the soviets threw everything in the kitchen sink ranging from tube guns, tank cannons in high elevations, AT guns to katyushas into their all-out barrages before every attack.
http://upload.wikimedia.org/wikipedia/c ... isplay.jpg
this ugly bad boy could lob a shell only 16km but the shell itself was 90kg weight.
the Pakis have a few pieces of this and used to shell some of our border camps with this 90kg shell. it was a much feared weapon because anyone caught in the open would suffer due to the big radius of lethal shrapnel.
the worrying part is the lizard also believes in using artillery to overwhelm problems and unlike us, is not sitting on thumbs wrt to improving their bite.
Re: Small Arms Thread
Vic, what if the enemy is dispersed and it is not known what to bomb and shell.
The Iraqis were fighting conventionally and hence presented targets for Americans. Hence most Iraqi (military) casualties might have been air/arty inflicted. In Afghanistan too, air/arty is extensively used, but that is to compensate for lack of boots on the ground. If one started to use a Hellfire or mortar fire against every bike mounted terrorist, then technically yes, Air/Arty kill rates improve, but the expense will surely hit sooner or later. Even the world largest economy will bleed itself.
And the best part is the Taliban choose the time & place of battles, so they have the strategic initiative.
Marksmanship and other skills are still the deciding factor, rather than gizmos.
The Iraqis were fighting conventionally and hence presented targets for Americans. Hence most Iraqi (military) casualties might have been air/arty inflicted. In Afghanistan too, air/arty is extensively used, but that is to compensate for lack of boots on the ground. If one started to use a Hellfire or mortar fire against every bike mounted terrorist, then technically yes, Air/Arty kill rates improve, but the expense will surely hit sooner or later. Even the world largest economy will bleed itself.
And the best part is the Taliban choose the time & place of battles, so they have the strategic initiative.
Marksmanship and other skills are still the deciding factor, rather than gizmos.
Re: Small Arms Thread
wise words here.tsarkar wrote:Vic, what if the enemy is dispersed and it is not known what to bomb and shell.
The Iraqis were fighting conventionally and hence presented targets for Americans. Hence most Iraqi (military) casualties might have been air/arty inflicted. In Afghanistan too, air/arty is extensively used, but that is to compensate for lack of boots on the ground. If one started to use a Hellfire or mortar fire against every bike mounted terrorist, then technically yes, Air/Arty kill rates improve, but the expense will surely hit sooner or later. Even the world largest economy will bleed itself.
And the best part is the Taliban choose the time & place of battles, so they have the strategic initiative.
Marksmanship and other skills are still the deciding factor, rather than gizmos.
let me type out 3 quotes from 2 books
1. From SLA Marshall's famous book "men Against Fire" - page 19
2, From "Acts of War" page 171The belief in push-button war is fundamentally a fallacy. But it is not a new fallacy. It is simply an age old fallacy in modern dress. There is one controlling truth from all past wars which applies with equal weight to any war of tomorrow. No nation on earth possesses such limitess resources that it can maintain itself in a state of perfect readiness to engage in war immediately and decisively and win a total victory soon after the outbreak without destroying its own economy, pauperizing its own people, and promoting interior disorder
3.Acts of war - page 209Veterans frequently comment on the surprisingly ineffective nature of so much fire. After scrambling back in from a patrol amidst a hail of fire, Charles Carrington recorded "Home, with one man wounded and for the twentieth time I marvelled ho much ammunition can be spent without killing a man". Fred Majdalany said of Cassino that "The remarkable thing about modern shelling is not how many it kills, but how few," and Martin Lindsay, inspecting heavily shelled German positions near Caen complained "I walked round the battlefield and found that only three huns were killed by our barrage. They were all dug in and not a single dug-out had a direct hit" "One of the things that amazed me is ow many bulets can be fired during a firefight without anyone getting hurt" remarked Douglas Graham a medi withj 3rd battalion, 1st Marines, in Vietnam
fears of the effects of enemy weapons have a siilar tendency towards iogicality; soldiers do not necessariy fear most those weapons which do the most damage. Dollard's subjects feared bombs most of all, then trench mortars, artillery shells, bayonet and knife.
<snip>
In strictly rational terms mortar and artillery fire should be the most alarming fo it has been the greatest killer although not necessarily the most cost effective killer..
Re: Small Arms Thread
I got this info from here
http://icasualties.org/OEF/Fatalities.aspx
Total causality of NATO starting from Jan 2011 to Dec 25 2011 is 558
in this IED causes 240 casualty and small arms including RPG is 112.
that mean 20.9% casualty is from small arm fire, and IED 43%. My assumption is the casualty differ based on nature of war, terrain & tactics deployed.
interestingly only one person die of sniper
http://icasualties.org/OEF/Fatalities.aspx
Total causality of NATO starting from Jan 2011 to Dec 25 2011 is 558
in this IED causes 240 casualty and small arms including RPG is 112.
that mean 20.9% casualty is from small arm fire, and IED 43%. My assumption is the casualty differ based on nature of war, terrain & tactics deployed.
interestingly only one person die of sniper
Re: Small Arms Thread
From idrw - no source as usual
F-Insas Rifle Design Clears Audit, To Go Into Production From Jan 2012
F-Insas Rifle Design Clears Audit, To Go Into Production From Jan 2012
The defence ministry may no longer have to search for an advanced rifle to arm the Indian infantry soldier of the future under the F-Insas project. Rifle Factory Ishapore (RFI) claims to have come up with an advanced variant of the existing 5.56 mm Insas rifle that will go into production from January, 2012. “The rifle is an extremely modern weapon that will meet with the requirements of the future infantryman.
Our designs have already cleared the audit and production is expected to start from January,” a source said.
RFI has already manufactured over a million Insas rifles for distribution among security personnel in India. The Insas was first introduced before the Kargil war and several variants have since been developed. When the Future Infantry Soldier as System (F-Insas) project was launched by the defence ministry, the Defence Research and Development Organisation (DRDO) and Ordnance Factory Board (OFB) got together to develop weapons for the soldier of the future.
Under the F-Insas project, the infantryman will be kitted with state-of-theart equipment including weapons, protective gear and communications systems. The soldier’s uniform would include bullet-proof clothing and the visor on his helmet would display maps and gunsights. The future soldiers would also carry palmtops and other advanced communications gear.
Among the weapons for the F-Insas project is a multi-calibre carbine for Close Quarter Battle (CQB) and a rifle. OFB has already developed the Milap multi-calibre carbine and handed it over to the Army for field trials. The carbine is modular in structure and can fire 5.56 mm, 7.62 mm and also 6.8 mm rounds. It also has an under belly grenade launcher for air-burst grenades. The OFB believes that this weapon that is expected to cost nearly . 50,000 apiece will solve the Army’s problems for days to come.
For the rifle, the defence ministry is on the lookout for something on the lines of the Israeli Tavor. In fact, nearly 5,000 Tavors have already been imported for use by the Special Forces. RFI sources say that the F-Insas developed by them at Ishapore would meet the ministry’s requirements and there would be no need to go in for further imports.
The efforts that have gone in for this project has bagged S K Rath of RFI the best general manager award from OFB. Although details were not available, sources revealed that the new rifle will be modular and have several advanced components. It may even have a computer chip inside.
“The first phase of the F-Insas programme should be completed by 2012. We believe that the rifle developed by RFI will meet the requirements of the Army,” an official said.
Re: Small Arms Thread
Not exactly a ringing endorsementThe OFB believes that this weapon that is expected to cost nearly . 50,000 apiece will solve the Army’s problems for days to come.
Re: Small Arms Thread
Hmm days and days and days hopefully
Re: Small Arms Thread
Everyone missed this info from the news
the F-Insas developed by them at Ishapore would meet the ministry’s requirements and there would be no need to go in for further imports.
This may be the weapon
and also the modern sub-machine carbine (MSMC)
the F-Insas developed by them at Ishapore would meet the ministry’s requirements and there would be no need to go in for further imports.
This may be the weapon
and also the modern sub-machine carbine (MSMC)
Re: Small Arms Thread
^^
The knack of jingos here to sniff out news from obscure places would put even sniffer dogs to shame (no insult to either jingos or canines intended).. and you really thought that BR missed this video from early 2009? Already posted here several times my friend.
The knack of jingos here to sniff out news from obscure places would put even sniffer dogs to shame (no insult to either jingos or canines intended).. and you really thought that BR missed this video from early 2009? Already posted here several times my friend.
Re: Small Arms Thread
[
Seems like an advanced variant of INSAS to improve it or remove some complaints. Can it be Kalantak?url]http://idrw.org/?p=6126#more-6126[/url]
Rifle Factory Ishapore (RFI) claims to have come up with an advanced variant of the existing 5.56 mm Insas rifle that will go into production from January, 2012
Re: Small Arms Thread
I think that DDM mixes 3 issues in this report:-
1. Advanced variant of INSAS - maybe something like Kalantak in 5.56x45
2. MSMG or Milap carbine 5.56x30
3. Research on F-INSAS to make modular weapon
1. Advanced variant of INSAS - maybe something like Kalantak in 5.56x45
2. MSMG or Milap carbine 5.56x30
3. Research on F-INSAS to make modular weapon
Re: Small Arms Thread
It's heartening to see PSUs coming up with multiple desi designs i.e. Kalantak/excalibur (5.56X45), MSMC ( 5.56X30), Trichy assault rifle (7.62X39) and future modular assault rifle aka F-INSAS rifle. It would be a big mistake if IA goes for imports this time and kills the indigenous effort.
Kalantak/excalibur
MSMC
Trichy Assault Rifle
Cheers....
Kalantak/excalibur
MSMC
Trichy Assault Rifle
Cheers....
Re: Small Arms Thread
Wonder why we don't see more photos of the Trichy Assault Rifle. This is the only image I could find online, same as the one above posted by neerajb. Unique rail design bolted on the right side.
Re: Small Arms Thread
OFB has attempted some work on small arms but almost everything has been rejected by Army.
1. INSAS 5.56x45 variant Excaliber – rejected
2. INSAS 5.56x45 carbine variant- rejected
3. MINSAS 5.56x30 – rejected
4. Anti Material rifle – Vidhwansak rejected by Army but 100 ordered by BSF. Army unable to find a better one for last 13 years
5. A-7 cone of AK-47/AKM-rejected
6. Trichy rifle- no new news
7. Bolt action 7.62x51 rifle – no news at all
8. Katantak – modified 5.56x45 INSAS carbine – no new news about any order being placed
Now we have this piece about a new INSAS variant, let us see what it means
1. INSAS 5.56x45 variant Excaliber – rejected
2. INSAS 5.56x45 carbine variant- rejected
3. MINSAS 5.56x30 – rejected
4. Anti Material rifle – Vidhwansak rejected by Army but 100 ordered by BSF. Army unable to find a better one for last 13 years
5. A-7 cone of AK-47/AKM-rejected
6. Trichy rifle- no new news
7. Bolt action 7.62x51 rifle – no news at all
8. Katantak – modified 5.56x45 INSAS carbine – no new news about any order being placed
Now we have this piece about a new INSAS variant, let us see what it means
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Re: Small Arms Thread
Gun-smithing has always been a noble profession. In modern times names like John Moses Browning, John Garand, Dieudonné Saive, Eugene Stoner and Mikhail Kalashnikov, have changed the way armies around the world fight. Handing the requirement of Indian Army's requirement to idiots at OFB will nothing but fill the coffers of foreign nationals via arms purchase.vic wrote:OFB has attempted some work on small arms but almost everything has been rejected by Army.
1. INSAS 5.56x45 variant Excaliber – rejected
2. INSAS 5.56x45 carbine variant- rejected
3. MINSAS 5.56x30 – rejected
4. Anti Material rifle – Vidhwansak rejected by Army but 100 ordered by BSF. Army unable to find a better one for last 13 years
5. A-7 cone of AK-47/AKM-rejected
6. Trichy rifle- no new news
7. Bolt action 7.62x51 rifle – no news at all
8. Katantak – modified 5.56x45 INSAS carbine – no new news about any order being placed
Now we have this piece about a new INSAS variant, let us see what it means
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- Posts: 113
- Joined: 27 Oct 2010 07:19
- Location: Unkel Sam's pot garden
Re: Small Arms Thread
nothing unique about that rail ..looks like a cheap Ak side rail mountVictor wrote:Wonder why we don't see more photos of the Trichy Assault Rifle. This is the only image I could find online, same as the one above posted by neerajb. Unique rail design bolted on the right side.
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Re: Small Arms Thread
A small florida based company "KELTEC" founded in 1991 does a 100 times better job than the mighty OFB. OFB has been the most disheartening companies of the PSU defence sector companiesneerajb wrote:It's heartening to see PSUs coming up with multiple desi designs i.e. Kalantak/excalibur (5.56X45), MSMC ( 5.56X30), Trichy assault rifle (7.62X39) and future modular assault rifle aka F-INSAS rifle. It would be a big mistake if IA goes for imports this time and kills the indigenous effort.
Cheers....
Re: Small Arms Thread
I don't know much about small arms, but would be interested in finding out what a 100 times better job means. OFB being disheartening is directly related to other companies being better so please say what this 100 times better means exactly. In general USA itself is 100 times better than India and Americans are 100 times better than Indians.Sandeep_ghosh wrote: A small florida based company "KELTEC" founded in 1991 does a 100 times better job than the mighty OFB. OFB has been the most disheartening companies of the PSU defence sector companies
I mean how does one look at a gun and say "This one is 17.5 times better than that, and the other one is 95 times better". Clearly, "100 times better" is a rhetorical statement. But what does it mean in real terms that one could take your list to the OFB managing director and tell him "Look you stupid git - this little Florida company makes this weapon. Why can't you incompetent twits do something twice as good which will still be 50 times worse than this product?"
In fact I meet OFB people at Aero India and I am fully capable of asking such a question (albeit less insulting than on here) if you provide me with the details.
Last edited by shiv on 04 Jan 2012 08:00, edited 1 time in total.
Re: Small Arms Thread
I have read that as early as the civil war in America the main differentiating factor was the artillery of the North, seems to be that stand off weapons leave a loss impact on the psychology. Pilots dropping bombs don't know who their victims are and what has happened to them, but a sniper will see the victim through the scope and rescuers.Singha wrote:seems to me wherever any forms of artillery gets involved (mortar,shell) or even portable artillery (RPG,grenades) it outscores the damage from bullets by Huge margins. there are likely soldiers who went through wars without directly hitting anyone with their rifle bullets.
no wonder the good armies like khan bring along massive amts of artillery to every fight if they can. in ww2 the american 8" howitzers were famous for the massed barrages and the soviets threw everything in the kitchen sink ranging from tube guns, tank cannons in high elevations, AT guns to katyushas into their all-out barrages before every attack.
http://upload.wikimedia.org/wikipedia/c ... isplay.jpg
this ugly bad boy could lob a shell only 16km but the shell itself was 90kg weight.
the Pakis have a few pieces of this and used to shell some of our border camps with this 90kg shell. it was a much feared weapon because anyone caught in the open would suffer due to the big radius of lethal shrapnel.
the worrying part is the lizard also believes in using artillery to overwhelm problems and unlike us, is not sitting on thumbs wrt to improving their bite.
I guess thats we need to increase our artillery. Even the 105 mm gun, with improvement in explosive materials in recent year, we can definitely improve the ammunition to take down Bunkers in the Hills.
Re: Small Arms Thread
In India , if we ever had soldier like this, he would have been in a 100 fake encounter cases by an assorted list of persons, but here here Uncle and Indian media is proud of this US soldier.
With 255 kills, he's deadliest Seal sniper in US history
With 255 kills, he's deadliest Seal sniper in US history
Re: Small Arms Thread
^^
+1
+1
Re: Small Arms Thread
OT
^ No Sir.
A fake encounter is still a fake encounter.
I respect Indian media better then the US media in cases like these.
And the assorted list though annoying is essential.
^ No Sir.
A fake encounter is still a fake encounter.
I respect Indian media better then the US media in cases like these.
And the assorted list though annoying is essential.
Re: Small Arms Thread
Indian 'AK-47' too fast for its own good
:
:
Called the Trichy Assault Rifle (TAR), the gun is being developed at the Tiruchirapalli Ordnance Factory in Tamil Nadu. The faster firing capacity was the USP for the Indian AK. It could fire 800 bullets in a minute as against 600 from the Russian rifle.
:
:
Re: Small Arms Thread
So the OFB did not try the gun before submitting to trials? Looks like someone goofed and is now claiming its the high rate of fire that is causing the jam. What good is the high rate of fire if it jams and thus becomes inoperable.
Re: Small Arms Thread
I would not be so unfair ramana. There is a post earlier in this thread that speaks of a Florida company that is 100 times better than OFB. If you watch the video, the company rep demonstrates their latest pump action double barrelled shotgun in two models. One is the original and the second is the modified. And he goes on to say that the modified one does not have the defects noted by users in the original. The mechanical defect is similar in effect to the OFB rifle and involves the trigger going dead during fast pump/reload. One could ask (rhetorically speaking of course) - "Did this 100 times better company not try the gun before actually selling it to users, let alone sending for trials? Of what use is such a gun if the trigger goes dead when you need to be pumping out bullets? "ramana wrote:So the OFB did not try the gun before submitting to trials? Looks like someone goofed and is now claiming its the high rate of fire that is causing the jam. What good is the high rate of fire if it jams and thus becomes inoperable.
Re: Small Arms Thread
I agree it was too strong. However the jamming under high rate of fire should have been known to developers before the trials. Its that sort of not complete development that leads to bad blood on all sides.
Also they should explore having a set of qualified machine shops for outsourcing developmental work to beat the tender and bid system. Tenders etc should be for high rate manufacturing. For ~120 articles there should be a rapid procurement initiative.
Also they should explore having a set of qualified machine shops for outsourcing developmental work to beat the tender and bid system. Tenders etc should be for high rate manufacturing. For ~120 articles there should be a rapid procurement initiative.
Re: Small Arms Thread
Smells like an recoil spring and/or extractor spring not being stiff enough. There are rifles capable of firing > 800 rpm. Or perhaps they could add a gas regulator and slow down the rate of operation.VinodTK wrote:Indian 'AK-47' too fast for its own good:
:
Called the Trichy Assault Rifle (TAR), the gun is being developed at the Tiruchirapalli Ordnance Factory in Tamil Nadu. The faster firing capacity was the USP for the Indian AK. It could fire 800 bullets in a minute as against 600 from the Russian rifle.
:
:
Re: Small Arms Thread
What is the point of having a gun that fires 800 (or even 600) rounds a minute when a mag has only 30 and any half decently trained soldier will not use full auto all the time (if at all). Mostly burst fire (either by mode or by depressing the trigger in auto mode) is used.VinodTK wrote:Indian 'AK-47' too fast for its own good:
:
Called the Trichy Assault Rifle (TAR), the gun is being developed at the Tiruchirapalli Ordnance Factory in Tamil Nadu. The faster firing capacity was the USP for the Indian AK. It could fire 800 bullets in a minute as against 600 from the Russian rifle.
:
:
Re: Small Arms Thread
Higher rate of fire decreases the bullet grouping radius in auto.
Re: Small Arms Thread
Gurneesh wrote:Indian 'AK-47' too fast for its own goodQuite right.:
:
Called the Trichy Assault Rifle (TAR), the gun is being developed at the Tiruchirapalli Ordnance Factory in Tamil Nadu. The faster firing capacity was the USP for the Indian AK. It could fire 800 bullets in a minute as against 600 from the Russian rifle.
:
:
What is the point of having a gun that fires 800 (or even 600) rounds a minute when a mag has only 30 and any half decently trained soldier will not use full auto all the time (if at all). Mostly burst fire (either by mode or by depressing the trigger in auto mode) is used.
But if an Indian designed gun fires at 500 rpm, it will be immediately rejected by IA as being too slow !!!
And IA will buy AK 21634 from Rodina. Never mind that the AK xvsss has NEVER need fired / tested at temperature above 20 Deg C !!!
K
Re: Small Arms Thread
The news item says that they already have regulator gasbags who will slow down the rate of modification and productionArmenT wrote: Smells like an recoil spring and/or extractor spring not being stiff enough. There are rifles capable of firing > 800 rpm. Or perhaps they could add a gas regulator and slow down the rate of operation.
Re: Small Arms Thread
Hmm ..Interesting point.koti wrote:Higher rate of fire decreases the bullet grouping radius in auto.
Re: Small Arms Thread
Can some guru explain the physics behind the stoppages? My understanding of rotating bolt mechanism is this
What is tilting breach by the way?
Cheers....
What is tilting breach by the way?
Cheers....
Re: Small Arms Thread
^^^^
Basically, the stoppage is happening because the old cartridge is not getting ejected out quickly enough. If you look at the movie you posted, after the cartridge is fired, the bullet is pushed out and some of the gas is piped off to operate a piston mechanism above the barrel. The piston in turn, is connected to a bolt carrier. The bolt carrier moves backwards (at around 0:57 of the clip) and in the process, it starts to rotate the bolt (around 1:00) which unlocks the bolt from the breech and allows it to move backwards. The bolt carrier also rotates the hammer backwards (at 1:09-1:15) as it continues to move back. As the bolt carrier moves backwards, an extractor removes the spent cartridge from the firing chamber (approx 1:12 of your clip), as well as opening a side port. The spent cartridge gets pushed out of the side port due to upward spring pressure from the magazine (around 1:18). Meanwhile, the bolt carrier continues to move backwards till it reaches its backward most point, where the recoil spring again pushes it forwards. At this point, the bolt carrier picks up a new cartridge from the magazine during its forward movement and it rams that new cartridge home into the firing chamber. As it does this, the bolt rotates the other way and locks into place.
Now, if the old cartridge is not picked up correctly (say, due to worn extractor or crappy cartridge quality), then it will not be ejected out of the side port properly and the bolt carrier will pick up a new cartridge and attempt to ram it into the firing chamber. However, since the old one is not yet ejected, it will stay in front of the new cartridge and the weapon will not close properly. Another cause could be that the recoil spring is extra strong and so the bolt doesn't move all the way back to its backward most point and the recoil spring pushes it forward earlier than expected. In this case, the old cartridge does not have a chance of getting ejected from the side port because it does not fully get exposed to the side port.
By the way, rotating bolt isn't unique to AK. M16 and SA80 also use it and the mechanism is pretty well known. It was invented in 1836 by a Prussian gunsmith named Dreyse. The main objection that Anton Kalashnikov had about the OFB's A-7 rifle was that it cloned the entire AK's mechanism exactly without paying royalty. It is perfectly OK to use a rotating bolt with a different mechanism.
As for the tilting block mechanism, I wonder if that bit is DDM. As far as I know, tilting block mechanism was used in single-shot weapons only, most notably the Martini-Henry rifle (clones of which still continue to be made by Paki gunsmiths in Dera Adam Khel). Here's an article I wrote about tilting block mechanisms a while back.
Basically, the stoppage is happening because the old cartridge is not getting ejected out quickly enough. If you look at the movie you posted, after the cartridge is fired, the bullet is pushed out and some of the gas is piped off to operate a piston mechanism above the barrel. The piston in turn, is connected to a bolt carrier. The bolt carrier moves backwards (at around 0:57 of the clip) and in the process, it starts to rotate the bolt (around 1:00) which unlocks the bolt from the breech and allows it to move backwards. The bolt carrier also rotates the hammer backwards (at 1:09-1:15) as it continues to move back. As the bolt carrier moves backwards, an extractor removes the spent cartridge from the firing chamber (approx 1:12 of your clip), as well as opening a side port. The spent cartridge gets pushed out of the side port due to upward spring pressure from the magazine (around 1:18). Meanwhile, the bolt carrier continues to move backwards till it reaches its backward most point, where the recoil spring again pushes it forwards. At this point, the bolt carrier picks up a new cartridge from the magazine during its forward movement and it rams that new cartridge home into the firing chamber. As it does this, the bolt rotates the other way and locks into place.
Now, if the old cartridge is not picked up correctly (say, due to worn extractor or crappy cartridge quality), then it will not be ejected out of the side port properly and the bolt carrier will pick up a new cartridge and attempt to ram it into the firing chamber. However, since the old one is not yet ejected, it will stay in front of the new cartridge and the weapon will not close properly. Another cause could be that the recoil spring is extra strong and so the bolt doesn't move all the way back to its backward most point and the recoil spring pushes it forward earlier than expected. In this case, the old cartridge does not have a chance of getting ejected from the side port because it does not fully get exposed to the side port.
By the way, rotating bolt isn't unique to AK. M16 and SA80 also use it and the mechanism is pretty well known. It was invented in 1836 by a Prussian gunsmith named Dreyse. The main objection that Anton Kalashnikov had about the OFB's A-7 rifle was that it cloned the entire AK's mechanism exactly without paying royalty. It is perfectly OK to use a rotating bolt with a different mechanism.
As for the tilting block mechanism, I wonder if that bit is DDM. As far as I know, tilting block mechanism was used in single-shot weapons only, most notably the Martini-Henry rifle (clones of which still continue to be made by Paki gunsmiths in Dera Adam Khel). Here's an article I wrote about tilting block mechanisms a while back.
Last edited by ArmenT on 15 Jan 2012 10:20, edited 1 time in total.
Re: Small Arms Thread
Dude, Glad you are recovered and roaring.ArmenT wrote:^^^^
Basically,
Re: Small Arms Thread
ArmenT, Glad you are recovering. So you think its a case of too stiff a spring causing the ejection delay and subsequent jamming?
If so the spring stiffness can be lowered by heat treatment and is not too big a deal.
Can we make out anything from this site:
http://www.thefirearmblog.com/blog/2011 ... ult-rifle/
If so the spring stiffness can be lowered by heat treatment and is not too big a deal.
Can we make out anything from this site:
http://www.thefirearmblog.com/blog/2011 ... ult-rifle/
Re: Small Arms Thread
The news item about the OFB rifle clearly states that no matter how trivial the solution to the jamming problem any solution will require bureaucracy to step in, with calling for tenders, a 3 month notice and the examining all the tenders along with the "earnest money" deposit etc. This is what will lead to endless killing delays. The actual solution is already known and it is also known that the solution will reduce rate of fire to 650 rpm.
Re: Small Arms Thread
The doc is right in that the main issue is bureaucracy and red tape. It looks like the OFB chaps know how to fix the issue easily, but need to wait months to implement it.
One more reason for jamming I forgot to mention could be the cartridge quality. If you fire a somewhat weaker cartridge, it will not push the bolt back all the way and therefore the recoil spring will push it forward a bit ahead of time and jam it. Now, a good design will account for a decent range of cartridge qualities and design the stiffness of the recoil spring accordingly. The OFB could have been using a higher grade of cartridge for testing and not seen the issue come up. But during acceptance testing, they could have been using ammo which has origins from different factories and therefore has more variance in power.
Incidentally, the M16 had similar teething issues. During the initial development phase, Colt had used Remington cartridges using Dupont made stick powder, and designed their springs accordingly. Then the military changed their cartridge manufacturer to Olin, which used ball powder instead, which burned with a different profile than dupont's stick powder. Result: The firing rate went from the designed rate of 800 rpm up to 1000 rpm and caused jamming issues during testing.
One more reason for jamming I forgot to mention could be the cartridge quality. If you fire a somewhat weaker cartridge, it will not push the bolt back all the way and therefore the recoil spring will push it forward a bit ahead of time and jam it. Now, a good design will account for a decent range of cartridge qualities and design the stiffness of the recoil spring accordingly. The OFB could have been using a higher grade of cartridge for testing and not seen the issue come up. But during acceptance testing, they could have been using ammo which has origins from different factories and therefore has more variance in power.
Incidentally, the M16 had similar teething issues. During the initial development phase, Colt had used Remington cartridges using Dupont made stick powder, and designed their springs accordingly. Then the military changed their cartridge manufacturer to Olin, which used ball powder instead, which burned with a different profile than dupont's stick powder. Result: The firing rate went from the designed rate of 800 rpm up to 1000 rpm and caused jamming issues during testing.
Re: Small Arms Thread
I am sure we have all seen this one:
http://www.ndtv.com/video/player/ndtv-i ... ory/213685
Can anyone identify the weapon at approx 2:23-2:25 min and the assault rifle carried by the man bringing up the rear at 2:35-2:40 ?
Assistance much appreciated.
http://www.ndtv.com/video/player/ndtv-i ... ory/213685
Can anyone identify the weapon at approx 2:23-2:25 min and the assault rifle carried by the man bringing up the rear at 2:35-2:40 ?
Assistance much appreciated.