Infantry weapons, n-th time

[tomo pauk]

I wasn't really arguing the merits of the .280. I was just noting (and perhaps I am remembering badly) that the .280 was pretty comparable to the .303 in velocity and trajectory if not in energy. The point was that the British would not have been giving up any great range capability by changing to a new cartridge.

Agreed all the way.

 

[Shortround6]

"the British would not have been giving up any great range capability by changing to a new cartridge. "

That was the intention.

Notice the different trigger group/unit. Tapered "rails' on the left rear of the receiver were for the long range dial sight,

Taden gun used a non disintegrating belt that seems to have pushed through rather than pulling the cartridge back before feeding.

 

[The Basket]

Flintlock and musket are still viable weapons . Even spears.
7.62x54R was not replaced. Doesn't mean it shouldn't have.

 

[Ivan1GFP]

Flintlock and musket are still viable weapons . Even spears.
7.62x54R was not replaced. Doesn't mean it shouldn't have.

Hello The Basket,
The Flintlock / Musket / Spear are vastly inferior in performance in comparison to their modern equivalents.
The same cannot be said of the 7.62 x 54R. It is quite comparable in performance to equivalent rounds in current use by other nations.
It may offend your sense of aesthetics, but that is hardly a good enough reason for replacement.

- Ivan.

 

[The Basket]

The Soviets did replace the rimmed cartridge with the 7.62x39 which itself was replaced by 5.45x39. So the 7.62x54R was no longer in the main infantry weapon.
But we go back to the main issue of machine gun v infantry rifle. The RPD and other AK machine guns were not cutting it as they didn't have the extreme ranges that was expected. So we get the PK.

It's a huge cost to replace one round to another especially for very specialised roles such as machine gun or DRM so using the 54R makes perfect sense as it's in production and also it means that the millions of Mosins also can be brought back to use.
However both the French and British had similar issues and scrapped their obsolete rounds in the 1920s and 1950s.
The Italians kept the bottle nosed Carcano 6.5x52 until the adoption of the Garand so keeping hold of an obsolete cartridge for production reasons can backfire.

 

[Ivan1GFP]

The Soviets did replace the rimmed cartridge with the 7.62x39 which itself was replaced by 5.45x39. So the 7.62x54R was no longer in the main infantry weapon.
But we go back to the main issue of machine gun v infantry rifle. The RPD and other AK machine guns were not cutting it as they didn't have the extreme ranges that was expected. So we get the PK.

It's a huge cost to replace one round to another especially for very specialised roles such as machine gun or DRM so using the 54R makes perfect sense as it's in production and also it means that the millions of Mosins also can be brought back to use.
However both the French and British had similar issues and scrapped their obsolete rounds in the 1920s and 1950s.
The Italians kept the bottle nosed Carcano 6.5x52 until the adoption of the Garand so keeping hold of an obsolete cartridge for production reasons can backfire.

Hello The Basket,
I believe you have a very odd interpretation of events.

At no point did the Soviets stop using the 7.62 x 54R as a military cartridge in at least some of their infantry weapons, so how was it "replaced"? I do not believe that keeping the caliber in production in order to allow the continued availability of millions of Mosin Nagants is a likely reason. Note that during this time a LOT of effort was spent to replace the Mosin Nagant as the sniper rifle. The Soviets do not seem to have any big issues with creating very specialized cartridges for a specialised weapon. How many nations do you know of that have built a "rifle" for use under water? If they had thought the 7.62 x 54R was not suitable as the new sniper round, they would have replaced it instead of building the SVD around it. Sniper ammunition tends to be manufactured to different specifications than other round in the same caliber anyway, so it would have been easy to just create a whole new caliber if they had wanted to.

The point I had brought up earlier with Tomo Pauk was that if a country intends to replace just the caliber of the infantry rifle and retain their older and larger caliber for LMG use, it appears that they are more likely to go with something smaller than if they intend to replace the caliber for both infantry rifles AND LMG with the new caliber. The course chosen by the Soviets seems to fit that pattern pretty well.

- Ivan.

 

[The Basket]

SVD is not a sniper rifle.
The Vintorez is a sniper rifle and uses specialist rounds.
The main rifle of the WarPac was either 7.62x39 or 5.45x39, not 54R.

Ths Sniper Mosin used 54R so it would make sense to keep the round in specialist roles. But virtually every other country changed from a rimmed to a non rimmed cartridge. Either France and UK was wrong and the Soviets were right or vice versa.

It is hugely impractical to change calibres and rifles because you make everything before obsolete and have to start from scratch. So it is usually done very rarely and never on a whim. So the Soviets didn't obsolete the 54R as the British and French did. That's a decision they made and its easy to see why.

Whether this is true I don't know but Mosins are been stockpiled by the Ukraine in case of Russian invasion. Which is stopping them entering the milsurp market. So the idea of the Soviets having huge numbers of Mosins for emergencies or shipping them as military aid is not unknown.

 

[Ivan1GFP]

Hello The Basket,
Your recollection of history is quite interesting.

SVD is not a sniper rifle.
The Vintorez is a sniper rifle and uses specialist rounds.
The main rifle of the WarPac was either 7.62x39 or 5.45x39, not 54R.

The Soviets certainly thought of the SVD as a sniper rifle regardless of your opinion.
The Vintorez (VSS) is a 1980's era gun. The SVD pre-dates that by around 25 years and served as the primary sniper gun for quite some time. I believe the first example in US hands was captured in Vietnam in the early 1960;s.
My own experience with the SVD is that its accuracy potential is about the same as a match tuned M14. I believe with good ammunition it should shoot around 0.75 MOA to 1 MOA. The problem is that good quality 7.62 x 54R is pretty hard to get in the US and so are the .310 diameter bullets in a weight that is appropriate to a x54R target load.
Soldier of Fortune had an article describing a test of a SVD that was chambered in .308 Winchester. Accuracy they got in testing is about what I described above.
The biggest limitation on shooting the SVD accurately is that the standard optics are quite poor. 4X isn't really enough power for good precision work and the scope has a fairly small objective and isn't very bright.
The trigger is a little odd. IIRC, it has a very long pull and doesn't stack. It takes some getting used to but there is nothing really wrong with it.

Ths Sniper Mosin used 54R so it would make sense to keep the round in specialist roles. But virtually every other country changed from a rimmed to a non rimmed cartridge. Either France and UK was wrong and the Soviets were right or vice versa.

I believe my Son would call this kind of argument an "appeal to popularity".
If you think about it from a logical standpoint, Where each nation was starting from might also influence its decisions.
The French were starting with a 8 mm Lebel. They switched to a 7.5 mm rimless round before WW2 and the era of assault rifles we are discussing here.
The British were starting with a .303 rimmed round and wanted to go with a .280 intermediate cartridge but ended up with the 7,62 NATO. They ended up with a cartridge with better ballistic capabilities than their older rimmed round.
Neither the French nor British rimmed rounds were at the same performance level as the German 7.92, US .30-06 or the 7.62 NATO rounds. The Soviet 7.62 x 54R fro a performance standpoint IS at the same performance level as a 7.62 NATO, 7.92 x 57 or .30-06.

The argument that you are making is like this:
Your neighbours all bought new cars, so you should too.
My response is:
The neighbours bought new cars because their previous cars could not do what they wanted.
Mine is running fine and does what I want, so I think I will keep it.

- Ivan.

 

[The Basket]

By that logic the Soviets should have kept the Mosin.
And to say the 8mm Lebel or 303 is underpowered or lacking compared to the German 7.92 is nonsense.
In the military context it matters zero.

 

[Ivan1GFP]

By that logic the Soviets should have kept the Mosin.
And to say the 8mm Lebel or 303 is underpowered or lacking compared to the German 7.92 is nonsense.
In the military context it matters zero.

Hello The Basket,
So if I understand you correctly, a lack of performance in a military rifle cartridge "matters zero" but the presence of a rim on the cartridge case is a better reason to replace it. That doesn't seem to make much sense.
This kind of reasoning also has a lot of other implications, but I believe folks can come to their own conclusions.

Regarding the Mosin Nagant as a sniper rifle, the Soviets chose to replace it with a more modern weapon and did so with the Dragunov. By what logic should they have kept the Mosin?

- Ivan.

 

[Shortround6]

Sniping and the evolution of sniper rifles is a subject for books (or several of them).

Long range sniping requires a special skill set on the part of the shooter (and often support from a 'spotter') that makes comparison of sniper rifles and cartridges from different time periods and countries rather difficult.
Sniping was carried out in WW I (and actually in the US civil war if not before) but the ranges were much less (usually, there are few a exceptions) than what is considered "normal" today.

The use of a certain cartridge or rifle for "sniper use" doesn't prove much of anything one way or another as expected engagement ranges changed. Tactics/methods changed and even the expected objectives of the different sniper programs changed.

Sniper selection could vary from "Smith is a pain in the ass, give him one of the unit sniper rifles and let him do his own thing, out of sight, out of mind and maybe we will get lucky and the enemy will kill him" to "Jones is the best shot to come through basic training in several months, lets send him to special training and see if he has what it takes to be a sniper".

On cartridges the shape of a cartridge has darn little to do with the accuracy of cartridge, bullet, barrel combination once you go further back than the neck. Or at least very little difference in practical accuracy if you are not competing in the bench rest game where 0.010 difference in 5 shot group size is the difference between 1st and 5th place.

Bullet quality and barrel quality are by far the determining factors in accuracy. Both made tremendous strides in the last 100 years. At least in large quantity production.

However the rimmed cases, especially the ones with a lot of taper, make designing automatic guns more difficult. Obviously they did make successful guns using rimmed tapered cartridges but it often took a bit of extra work.

For belt fed guns if you use a push though type belt you can make the receiver about 1 to 2 inches shorter (depending on cartridge) than a gun that has to pull the cartridge to the rear to clear the belt before pushing it forward to chamber it. This means the receiver can be shorter and lighter.
This does not apply to magazine fed weapons. However a rimless case needs a smaller magazine than an equivalent rimmed case for the same number of rounds.

The amount of case taper needed depends somewhat on the type and quality of the case material and the requirements for extraction. Tapered cases also tend to put more pressure on the bolt face. Really straight cases tend to stick more although the 7.62 NATO doesn't seem to have a lot of trouble in gas operated guns (I am not saying no trouble) The G3 and it's brothers/cousins use fluted chambers that float the outside of the case on a layer of gas to avoid the sticking problem (or tearing the extractor through the rim leaving the case in the chamber).

 

[yulzari]

The rimmed .303 in 1888 was an easier manufacturing choice but crucially, spacing on the rim left chamber dimensions less critical so made manufacturing a reliable rifle easier, let the chamber be looser and ammunition dimensions less critical as the chamber both needed less precise machining and could cope with wider variations in size. Anyone familiar with the Long Lee's predecessors chambers will realise how far factory machining came in 40 years. My Martini Henry is dated 1887. It made sense in 1888. Soon after one would have chosen rimless but there was a logic at the time and remained viable but only survived as a legacy. Post South African War research was always into rimless replacement but a passing war rather got in the way. Incidentally the amenability of the Lee to variable ammunition was no help to the over finely made Ross Rifle and led the RFC and RNAS to get specially selected .303 supplies for their aerial machine guns.

In short, the .303 was rimmed for a reason. That reason went away but it remained and worked well for 80 years in British use and 100 in Indian use. It wasn't broken so it wasn't fixed.

The very original 1888 pattern Lee Metford continues today as the arm of the Duke of Atholl's Army.

 

[The Basket]

Hello The Basket,
So if I understand you correctly, a lack of performance in a military rifle cartridge "matters zero" but the presence of a rim on the cartridge case is a better reason to replace it. That doesn't seem to make much sense.
This kind of reasoning also has a lot of other implications, but I believe folks can come to their own conclusions.

Regarding the Mosin Nagant as a sniper rifle, the Soviets chose to replace it with a more modern weapon and did so with the Dragunov. By what logic should they have kept the Mosin?

- Ivan.

The ability of a cartridge say 8mm Lebel or 303 is going to be better than the average squaddie who can shoot it.
So extreme accuracy or range becomes pointless beyond a certain range as only a very small percentage of troops can shoot that good. Also standard wartime production ammo was not always the best quality so even if the rifle and shooter can do the ranges, the ammo cannot. This is not talking about snipers but general infantry.

A good example is that the M1917 could hold 6 rounds and the P14 held 5. So there is an advantage to having a more modern cartridge. Also a machine gun or rifle can fire rimmed cartridges but this has to be engineered into the rifle or magazine. A look at a bren gun with different calibres will say this.

If change is not necessary then why didn't the Soviets keep the Mosin? Or keep the 7.62x54R and make a new rifle?

 

[Shortround6]

The very original 1888 pattern Lee Metford continues today as the arm of the Duke of Atholl's Army.

The 2nd company Governor's Foot Guard of Connecticut has a number of 30-40 Krags. 2nd Company Governor's Foot Guard of Connecticut

Although the "service" rifle is the 1903 Springfield.

I was a member for over 35 years.

Not sure what the "arms" of ceremonial units have to do with the discussion though.

 

[Shortround6]

Incidentally the amenability of the Lee to variable ammunition was no help to the over finely made Ross Rifle and led the RFC and RNAS to get specially selected .303 supplies for their aerial machine guns.

At one point in WW II US .30-06 ammo was separated into three classes.
Grade 1 was aircraft machine gun.
Grade 2 was ground machine gun.
Grade 3 was for rifles.

This was based entirely on brass quality and functioning ( Head separations or case splits, extractors pulling through rims and so on) and had nothing to do with either power or accuracy. I have no idea how long this grading lasted for.

Please remember that in WW I the heat treatment of 1903 springfield receivers was done by "eye". A rack of receivers was put in an oven and heated up until the receivers reached a certain color as judged by the furnace operator before being taken out and quenched. It was either in late 1917 or 1918 that they got instruments that allowed them to actually measure the temperature of the receivers.
Rifle brass is heated up and allowed to cool at least once in manufacturing and often twice (or more?) to prevent it from becoming too brittle and splitting/cracking on firing. However that is the forward part of the case. The rear part of the case was often in a water bath to keep it somewhat harder than the front, too soft a rim and the extractor pulls though and/or the primer pocket enlarges, the primer falls (is blown) out and high pressure gas gets back into the action.

Even rudimentary modern manufacturing techniques/methods and tools are the stuff of science fiction to a 1880s-1915 metallurgist.
The solutions to problems they found through trial and error in some cases no longer apply. The problem/s have simply disappeared due to better manufacturing techniques and tools.

 

[Ivan1GFP]

On cartridges the shape of a cartridge has darn little to do with the accuracy of cartridge, bullet, barrel combination once you go further back than the neck. Or at least very little difference in practical accuracy if you are not competing in the bench rest game where 0.010 difference in 5 shot group size is the difference between 1st and 5th place.

Bullet quality and barrel quality are by far the62 determining factors in accuracy. Both made tremendous strides in the last 100 years. At least in large quantity production.

Hello Shortround6,
In the practical sense, I believe you are correct. Differences in cartridge shape are most likely to have a greater than 0.010 inch difference in AVERAGE group size though.
I am sure that you already know this: When the US military switched from .30-06 to 7.62 NATO, one of the interesting side effects was that the accuracy of service rifles increased noticeably. One might attribute this also to the change in the rifle from M1 Garand to M14, but the accuracy improvement also showed up in Navy M1 Garands that had been converted to 7.62 NATO (properly converted rather than just sleeved).
It appears that in general, the higher loading density and shorter powder column in the 7.62 case resulted in GENERALLY better accuracy.
The reason for so many qualifiers such as "generally" and "average" is that there exist plenty of exceptional rifles in both calibers.

The amount of case taper needed depends somewhat on the type and quality of the case material and the requirements for extraction. Tapered cases also tend to put more pressure on the bolt face. Really straight cases tend to stick more although the 7.62 NATO doesn't seem to have a lot of trouble in gas operated guns (I am not saying no trouble) The G3 and it's brothers/cousins use fluted chambers that float the outside of the case on a layer of gas to avoid the sticking problem (or tearing the extractor through the rim leaving the case in the chamber).

The issue of case taper and fluted chambers for better primary extraction does tend to depend on the case material (plated or lacquered steel versus brass) and quality, but it also depends very much on factors relating to the operating "system" of the firearm itself.
Ideally, the unlocking and primary extraction starts AFTER the chamber pressure has dropped to very near outside ambient pressure.
In many guns, this is not what actually happens.
The German G3 / CETME system for example uses a "roller lock" that requires that two rollers which are resisting the rearward movement of the bolt be moved into recesses to allow the bolt to move. The problem is that although the mechanical leverage is very high, there IS some movement of the bolt as soon as the cartridge fires and "primary extraction" is starting at peak chamber pressure. The G3 / CETME is really a delayed blowback operated gun.
On other guns, there is a certain amount of "dwell time" designed into the system.
On the M1 Garand for example, the gas port is about 1.5 inches from the end of the barrel.
Gas pressure is applied to the operating rod when the bullet has passed the gas port which means that it has only another 1 inch or so to go before the barrel is open to the atmosphere.
In that amount of time, the Operating Rod needs to move back about 1/4 inch (IIRC) before it even begins to cam open the bolt so by the time it reaches the bolt, there should be no chamber pressure.
On the M14, this dwell time is pretty marginal to non-existent but can be adjusted by selectively fitting certain pieces.
The easiest way to check this is to measure the cartridge headspace on fired cases using the RCBS Precision Mic.
If the action is unlocking with some pressure, I believe this can be seen by the somewhat random stretch of the spent cases.
There are of course some other guns (such as SVT-40) that use a fluted chamber because the operating cycle is so violent.

- Ivan.

 

[Shortround6]

In the practical sense, I believe you are correct. Differences in cartridge shape are most likely to have a greater than 0.010 inch difference in AVERAGE group size though.
I am sure that you already know this: When the US military switched from .30-06 to 7.62 NATO, one of the interesting side effects was that the accuracy of service rifles increased noticeably. One might attribute this also to the change in the rifle from M1 Garand to M14, but the accuracy improvement also showed up in Navy M1 Garands that had been converted to 7.62 NATO (properly converted rather than just sleeved).
It appears that in general, the higher loading density and shorter powder column in the 7.62 case resulted in GENERALLY better accuracy.
The reason for so many qualifiers such as "generally" and "average" is that there exist plenty of exceptional rifles in both calibers.

I may have exaggerated slightly.

But there are often other factors at work that confuse things. Most .30-06s use a 1-10 twist while 7.62 NATO/.308 are more varied. Often 1-11 or 1-12. Throats are often different leading to different distances/jumps for the bullet to travel before hitting rifling (the sleeved M1s to .308 have problem here, a 12mm increase in bullet travel before hitting rifling even if everything else was the same). Due to changes in propellent powders most .30-06 loads have more empty space than .308 loads which allows for more variation in the powder location, unless using bulky slow burning powders in the .30-06 and these are the ones that can screw up the gas port pressure.
The length to diameter ratio changed between the two cases but only the length really changed.

I have two 6.5mm rifles, one is a 6.5mm/308 (.260 Rem) and the other is a 6.5mm Rem benchrest.

From left to right: 6mm SAW, 6.5 Grendel, 6.8 SPC, 7mm Bench Rest, .280/30 British, 7mm-08, 7mm Second Optimum (Liviano), .276 Pedersen, .308×1.75", 7.62×51 NATO.

Like the 4th round from the left only a bit smaller bullet. Just like the 6.5mm-08 is just a slightly smaller bullet 7mm-08.
I was NOT filling the 6.5mm-08 up to the base of the bullet with most of the loads I was using the most so the whole powder density thing may not have worked right.
The two guns use different rates of twist, I don't know if or what the differences in the chamber throat are. Neither chamber requires neck turning.
And this is a "sample" of only one barrel in each caliber which is way too small to be statistically valid. Top Bench rest shooters will often order ten barrels at a time, test fire all ten and keep only the 3-4 best.

Some people claim you can over spin bullets which degrades accuracy, not anywhere near as bad as under spinning them though

In my case the rifle with the short case is more accurate than the rifle with the long case, BUT, one is a Winchester action, one is a Remington, both are Hart barrels, they have different stocks (one glass/one wood), there is a 2in difference in barrel length between the two guns and the two barrels do not have identical contours.
I use 30.5 grains of 4895 in the short case and 36.5 grains of 4895 in the big case. In part due to the fact that the old powder measure I use will throw charges of 4895 to within +/- 1/10th of grain all day long. Doesn't deal with ball powder at all (jams the powder measure) so the long case has room for the power to move around.

So personally I have have a few interesting points of data but too many variables to claim any sort of conclusion.

BTW the 6.5-08 once shot a 596 out of 600 aggregate at 600yds. and held the range record (800-64Xs out of 800, 600 yd target reduced for 300yds)for years at a local 300yd range, so it is not an inaccurate rifle.

 

[yulzari]

The 2nd company Governor's Foot Guard of Connecticut has a number of 30-40 Krags. 2nd Company Governor's Foot Guard of Connecticut. Although the "service" rifle is the 1903 Springfield. I was a member for over 35 years.

Not sure what the "arms" of ceremonial units have to do with the discussion though.

Just an amusing aside. Technically the Duke of Atholls Highlanders are an actual army and neither civilian nor British. BTW I see that the last .303 cartridge to be approved for British use was the Round .303 inch Ball L1A1 which was made in the mid 1980's.

 

[Ivan1GFP]

Hello Shortround6,
I had already come to the conclusion that you were quite an experienced and knowledgeable rifleman.
I also suspect that for most things firearms related, we would tend to agree in general principles though perhaps not in degree.

The conclusion of difference in accuracy between .30-06 and 7.62 NATO, however, is not mine.
Civilians unless they work in the firearms industry will most likely never be able to test the thousands of guns needed to be able to come to this kind of conclusion.
My own experience would suggest that there is no significant difference but I also have not chosen to test the M1 Garand in .308 cal. The accuracy I have been able to get in .30-06 is quite good and was very easy to achieve. I believe the current limitation is the optics I am able to mount on the M1. Results are better with the M14 types, but it is also easier to mount a big telescope on the M14/M1A.

But there are often other factors at work that confuse things. Most .30-06s use a 1-10 twist while 7.62 NATO/.308 are more varied. Often 1-11 or 1-12. Throats are often different leading to different distances/jumps for the bullet to travel before hitting rifling (the sleeved M1s to .308 have problem here, a 12mm increase in bullet travel before hitting rifling even if everything else was the same). Due to changes in propellent powders most .30-06 loads have more empty space than .308 loads which allows for more variation in the powder location, unless using bulky slow burning powders in the .30-06 and these are the ones that can screw up the gas port pressure.
The length to diameter ratio changed between the two cases but only the length really changed.

I believe that some of these factors are not as prominent as they might seem. First of all, although the typical rifling twist for a .308 is 1-12, National Match and Target guns are usually re-barreled to a faster twist which is typically 1-10 as well.
I believe the throat dimensions at least for the .30 cal service guns are either the same or very close. The easy way to check would be to compare the Throat Erosion Gauges used for the M1 and M14.
I do agree with you that with a lot of air space inside the cartridge case, there is a variation of velocity depending on whether the powder is at the front or back of the case. (Powder at the back gives higher velocities.)
This gets to be quite important when the case volume is VERY large and the powder charge is small such as (IIRC) 28 grains of powder in a .45-70 case. I seem to remember that although there were no noticeable differences in shot impact location at 100 yards, the velocity difference was 75-100 fps. It is obviously much much less with a larger powder charge in a smaller case and it becomes even less observable with a bottle necked case.
Another thing to remember is that with a gas-operated service rifle, the shot to shot variation in velocity will be a bit higher than a simple bolt gun. With a very consistent load, the Standard Deviations only go down to about 15 FPS and even that may be high enough to mask a lot of the variation in velocity caused by powder location. I should probably check to see if the same loads have a better SD in a bolt gun but my understanding is that good target load there will have SD down around 9-10 FPS or better. With higher SD, I don't think it would matter very much.

With target loads in .308, it is possible with some single base powders to get about 100% loading density but I also have not noticed that this improves things. I believe that many other factors are more important than a LITTLE air space in the case.

- Ivan.

 

[The Basket]

Just an amusing aside. Technically the Duke of Atholls Highlanders are an actual army and neither civilian nor British. BTW I see that the last .303 cartridge to be approved for British use was the Round .303 inch Ball L1A1 which was made in the mid 1980's.

The. 303 was used quite recently by the Canadian Rangers and Bangladesh police. So Lee-Enfield rifles certainly has stuck around. Would be interesting to know where these last rounds went.