Loading M2 in 30-06?

S

Shadow9mm

New member
If one wanted to load m2 ap in 30-06 using h4350 where would somone start?

My understanding is that these bullets are longer for their length than traditional bullets due to the steel cores being much less dense and large that they use up a lot more case capacity. Would you use something like solid copper bullets data? Or would you jump up to the next weight class? Seeing as these are scarce it would be a shame to waste any.

I also understood that due to the steel core, they do not compress nearly as well as lead core or even solid coppet amd had a tendency to wear out barrels extra fast. Would this imply higher bearing surface presure?

My understanding was the COL on these was 3.340, does that sound right?

They would be loaded for a modern bolt action rifle, not a garand.
 
I would work up the load as usual, instead of using data for heavier bullet. If you try to skip working up the load to save, don't. Cheap as I am, I still burn min 10 rounds for a new load, 30 rounds if I need accuracy.

-TL

Sent from my SM-N960U using Tapatalk
 
First off, 3.340" is the standard (SAAMI) max loaded length for the .30-06. SO, yes, that sounds right.

The M2 AP bullet is slightly longer than the 150gr ball and has a nominal weight of 162-168gr. Loaded to the cannelure, the same amount of bullet sticks out of the case, but the AP bullet base is a little deeper inside the case.

IMR 4350 is a bit slow for a Garand, the Army used IMR 4895. In a bolt gun it should give you no trouble. Work up your loads in the usual way.
 
M2 AP is between (closer to?) M1 ball and M2 ball, is it not? Since this is NOT for an M1 rifle, but rather a bolt gun, personally I'd use 30-06 data for 168 or 175 SMKs as my starting point.
That's just me, though.
 
MZ5 said:
M2 AP is between (closer to?) M1 ball and M2 ball, is it not? Since this is NOT for an M1 rifle, but rather a bolt gun, personally I'd use 30-06 data for 168 or 175 SMKs as my starting point.
That's just me, though.
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I was looking at hornady data, which covers several bullets in the 165-168g weight range, one of which are the mono-metal variety.
 
One note, all public and club ranges that I am aware of do not allow any type of steel core or AP ammo. It might pay to check around before loading a large batch.
 
blackhawk44 said:
One note, all public and club ranges that I am aware of do not allow any type of steel core or AP ammo. It might pay to check around before loading a large batch.
Click to expand...
Im clear. Go to at least 1 private range where its not prohibited, provided you dont dont shoot the steel targets. And i have a friend with some land outside city limits.
 
Hatcher said that post WWII, before match ammo was back in production, service rifles were shot with "selected lots" of issue ammo and that AP frequently did best.

But Phil Sharpe shot out a barrel in 300 rounds of AP.

Which old time source do you credit?
Or is there more up to date information on the www?
 
M2AP became a standard issue for combat during the war, and I doubt the army would have done that if it shot out barrels quite as rapidly as Phil Sharp claimed. Too many field service headaches. However, the last loadings of it were at a higher pressure, 54,000 psi, by copper crusher (equivalent to SAAMI CUP pressure units) according to the tech manuals. So it exceeded SAAMI pressure limits for 30-06, and, from a comparison of SAAMI crusher and transducer numbers, would have been running at close to 65,000 psi by the transducer, more like 270 Winchester does. So, some additional barrel wear would be expected with it.

The construction of sectioned 30 cal AP bullets shows gilding metal just over 0.030" thick directly surrounding the penetrator. Early versions used tungsten penetrators, IIRC, and weighed 168.5 grains with a tolerance of minus three grains. But those were prohibitively expensive to produce in wartime, so later M2 AP had steel penetrators and weighed 2.8 grains less than their tungsten counterparts (165.7 grains with a tolerance of -3 grains).

In any event, I would use copper solid data with it. Copper solids are both harder and less dense than lead core bullets, so it should be a fair comparison. The Hodgdon starting load of IMR4350 with a 165-grain Hornady GMX is 52 grains, and it is seated slightly shorter than military rounds, which I've measured to be about 3.330"–3.335" most of the time (3.340" is a not-to-exceed number). But at 1.4 inches, the AP bullet is only slightly longer than the Hornady GMX (1.370") that Hodgdon has load data for on its site. Add to this that Hodgdon seats the GMX to 3.225" COL, and your seating depth at 3.330-3.340" is actually going to be longer, adding a safety margin.

The government claims M2 AP is loaded to 2,715 fps at 78 feet from the muzzle of a 24" Velocity and Pressure (V&P) test barrel for this round, and Hatcher says the muzzle velocity was 2,775 fps, and the extreme range was 3500 yards. If I add just 1 fps to Hatcher's calculated MV (which was an estimate anyway) and use a G8 BC of 0.207, I get the correct 78-foot velocity and 3505-yard extreme range, which is very close and so that G8 BC is what I would use for range calculations. The G8 reference projectile, unlike the popular G7, is a flat base design with 10 caliber secant ogive. The ogive is sleeker than the AP ammo, but reducing the BC from 0.2495 (also the bullet's sectional density) to 0.209 has the same effect as adjusting the form factor down, and here it has worked pretty well.

Then comes the question of whether you want to shoot ammo that warm in your gun. Here, your experiments and objectives are your own. Keep in mind the pressures and velocities are for the V&P barrel, which is specially made with a very tightly dimensioned minimum chamber and with the cartridges handled to have the powder back over the flash hole at firing, which produces maximum pressure. In most Garands, which tend to throw the powder forward as they chamber in flat fire, both peak pressure and velocity are likely to be lower in the fielded combat guns by a bit.

Using the Hodgdon data as a surrogate, the 165-grain GMX load of IMR4350 looks like it will be very near Hodgdon's maximum to get to the M2 AP velocity. The Hodgdon velocity will be measured at the SAAMI standard distance of 15 feet. Using the BCs and velocities from above, at 15 feet, the comparable velocity for the AP bullet will be 2764 fps.
 
QuickLOAD thinks you'll lose 70 fps, while GRT thinks you'll lose 66.8 fps with the barrel length difference. So it will be somewhere near those numbers. Again, though, don't expect your gun to match the velocity of the V&P barrels the velocity is based on.

What I do in this situation is copy some Hodgdon starting load data for the same powder as exactly as I can without going to a lot of extra expense. In this case, you would ideally use their GMX data with Hornady's current CX solid bullets to do this, which Hornady says are compatible with GMX load data). Seeing what velocity the copied load data produces in your gun will give you a ratio of your rifle's velocity to their V&P barrel's velocity with that same load. You then apply that ratio to the M2 AP velocities to adjust its numbers to get expectations for your gun.

Note that M2 AP was last loaded by Lake City with WC852 (sold in canister grade as H380). During WWII, it was loaded with 4895, I believe. Your IMR4350 is slower than either, so you should be able to match velocity with lower peak pressure, meaning the IMR4350 is a good choice for a bolt gun, pressure-wise. It will tend to work a Garand op-rod harder than the faster powders, but the bolt gun won't care.
 
The military specifies M2 Ball at a maximum average pressure of 50,000 psi by copper crusher, same as the SAAMI spec for 30-06 in CUP. The military specifies M2 AP at a maximum average pressure of 54,000 psi (by copper crusher), which exceeds the SAAMI spec. However, those numbers are what SAAMI calls Maximum Average Pressure (MAP), which means the maximum average peak value for freshly loaded ammunition, and it is only a not-to-exceed number. There is no requirement for the MAP to be reached. The way the military decides on the final charge and pressure for any particular lot of ammunition using any particular lot of powder is they load until they meet both the military velocity spec (necessary to keep sight systems calibrated) and the gas port pressure spec (necessary for the gas-operated weapons the ammunition is to be qualified for), and they check that the MAP number has not been exceeded in reaching those goals.

So, the fact the MAP specification pressure for M2 AP is higher than for M2 Ball (and other 30-06 military rounds except for the high-pressure proof load) just means that it is OK for them to be loaded to pressure that high in trying to meet the velocity and gas port pressure specs if it proves necessary. Knowing the spec was developed before WWII, I am guessing they found allowing that extra pressure was necessary for the generally faster burning powders in use at the time in order for that powder to reach the velocity and gas port pressure specs simultaneously.

Next, the spec had to work with IMR4895, which was introduced after the start of WWII. Once you get beyond WWII, at some point, they started using WC852, which is slower and, therefore, produces a lower peak pressure for any given velocity with a given bullet. So, it wouldn't be surprising to find lower peak pressures with that change in powder. I don't know what pressure curves you looked at or who shot the tests or when, but if it was with rounds loaded with WC852, then it is not surprising that the peak doesn't get to 54,000 CUP.
 
Shot them ~ three years ago in a SAAMI spec lab.

AP was all USGI from 42 - 55 dated.

The milsurp ammo pressure and commercial pressures overlapped and were basically similar.

Commercial ammo is safe in garands since it's pressures aren't really different than milsurp ammo.
 
That all falls within spec. The problem with generalizing about these things is that the fact the military spec allows for 54,000 CUP means that if, at some point, they had an unusually fast lot of powder qualify, that particular lot would have higher pressure than average, and you might get some.

Then the question becomes, does it matter? In a sense, it's a moot point, as none of the specified pressures, including the 54,000 CUP, is very near the proof pressure range (67,000 CUP at the bottom end). Therefore, all guns should handle it. The only drawback to the higher pressure loads is they will produce faster throat wear than average. Most folks figure about 5000-round barrel life for a chrome-moly 30-06 barrel at military velocities, and that might shorten to something like 3000 rounds at the higher pressures.

The other thing to be aware of is that cartridges that are old are allowed by SAAMI to experience pressure increases due to bullet and brass bonding. The MAP number is only for freshly loaded ammo. Once it is aged, MAP is no longer the standard, but Maximum Probable Sample Mean (MPSM) is, and that number is three standard errors higher, which works out to 53,200 CUP for 30-06.

Finally, be aware cartridges as old as you were testing three years ago had passed the military 45-year stockpile limit for single-base powders and 20-year limit for double-base powders and may have had their powder's stabilizer consumed and may, therefore, be weaker than they were during their safe stockpiling period. It also may still have been good to go. The way to cross-check is the velocities you got. The military puts M2 AP at 2715 fps ±30 fps at 78 feet from the muzzle. At SAAMI's 15-foot center between screens distance, it would be 2763 fps ±30.5 fps. If you were finding it within that range, then the powder was still up to snuff.
 
Did a touch of weighing today, reasonably consistent imho. Have an even 50.
Avg 163.0g
SD 0.7298
ES 3.8g
Low 160.9
high 164.7

Is there a model in GRT for this bullet, a quick search did not turn up much

Was looking at using Hornady data for 165-168g bullets which include a couple of their solid copper projectiles (cx and GMX). Listed max with H4350 is 58.5g at about 2800fps. supposedly 56.1g will get me 2700fps. but they are also listing a 23.75 in barrel in their test specs and I only have a 21.5in barrel.

Was considering the following for testing. Figured id run them over the chrono, look for pressure signs as I go.
58.5
58.0
57.5
57.0
56.5
56.0
55.5
55.0
54.5
54.0
 
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The Hornady 165-grain Interlock spire point #3040 is flat-based. It is 0.118" shorter than the AP bullet, so you can select it and give it the starting pressure of a solid in the software and either increase it's length to 1.4" or seat it 0.118" below the AP COL, or to about 3.21" to 3.22" and run estimates then.
 
Unclenick said:
That all falls within spec. The problem with generalizing about these things is that the fact the military spec allows for 54,000 CUP means that if, at some point, they had an unusually fast lot of powder qualify, that particular lot would have higher pressure than average, and you might get some.

Then the question becomes, does it matter? In a sense, it's a moot point, as none of the specified pressures, including the 54,000 CUP, is very near the proof pressure range (67,000 CUP at the bottom end). Therefore, all guns should handle it. The only drawback to the higher pressure loads is they will produce faster throat wear than average. Most folks figure about 5000-round barrel life for a chrome-moly 30-06 barrel at military velocities, and that might shorten to something like 3000 rounds at the higher pressures.

The other thing to be aware of is that cartridges that are old are allowed by SAAMI to experience pressure increases due to bullet and brass bonding. The MAP number is only for freshly loaded ammo. Once it is aged, MAP is no longer the standard, but Maximum Probable Sample Mean (MPSM) is, and that number is three standard errors higher, which works out to 53,200 CUP for 30-06.

Finally, be aware cartridges as old as you were testing three years ago had passed the military 45-year stockpile limit for single-base powders and 20-year limit for double-base powders and may have had their powder's stabilizer consumed and may, therefore, be weaker than they were during their safe stockpiling period. It also may still have been good to go. The way to cross-check is the velocities you got. The military puts M2 AP at 2715 fps ±30 fps at 78 feet from the muzzle. At SAAMI's 15-foot center between screens distance, it would be 2763 fps ±30.5 fps. If you were finding it within that range, then the powder was still up to snuff.
Click to expand...
The results of the testing were to disprove the age old myth that commercial ammo is dangerous to garands.

Since commercial ammo numbers and milsurp ammo numbers were very similar that basically says that the myth...is just that....myth.
 
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