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Merc
08-06-2019, 01:52
I sat down to reload a bunch of .30-06 using the M2 military 150 gr FMJFB bullets I bought a while ago. Up until now, I’ve been shooting the 150 gr commercial FMJBT bullets. Here they are side by side.

46402

The commercial bullet FMJBT is on the left. Both are .308 but the ogive on the M2 is much different. Sierra’s specs indicate the overall length of the cartridge with the commercial bullet should be 3.250” while all the military surplus cartridges with the M2 bullet that I have from the 1950s all measure .075” longer at 3.325”.

Does anyone have the overall length specs for a cartridge with a M2 FMJFB bullet?

Parashooter
08-06-2019, 09:28
46403

The BT bullet pictured in post #1 is designed for the 7.62 NATO cartridge, saving some overall length by placing more of the projectile inside the neck. M2 ball cartridge, a close copy of M1906 ball, has bullet seated only part-way in neck to preserve same OAL as M1903 ball cartridge for reliable feed from M1903 rifle magazine.

Merc
08-07-2019, 05:37
So, the proper OAL for a cartridge fired by a M1903 and a M1917 rifle is 3.34”?

Parashooter
08-07-2019, 07:38
So, the proper OAL for a cartridge fired by a M1903 and a M1917 rifle is 3.34”?
That would be the maximum length, a limit imposed by magazine dimensions. With some bullets, that length can't be achieved with adequate seat depth for reliable tension and alignment - a shorter OAL is then "proper". For example, if we seat that Sierra 150 BT to 3.34" OAL, we only have some .13" of shank bearing inside the neck of a 2.494" case. That's not really adequate to keep the bullet firmly in place - we have to seat it deeper. (This is reflected in the locations of the cannelures.) Check the Sierra data for some of their longer bullets, like the 175 MK, and you should find the OAL listed as 3.340".

A handy general rule is that we like to see at least one "caliber" of bullet shank (not counting the tail of a BT) seated inside the neck. For instance, .3" for a 30 caliber and .22" for a 22 caliber. There are lots of exceptions for special circumstances.

Tuna
08-07-2019, 07:40
And the bullet for the M2 round should be a flat based bullet. While the one in your photo on the right is closer to an M2 bullet is not a true flat base. If I remember right 3.34 is the Maximum over all length for the 30-06.

Merc
08-07-2019, 09:30
So, an OAL of 3.325” should be safe with a M2 bullet. It is the OAL of the old cartridges from the 1950s.

46404

The above label was on the package of M2 bullets that I bought.

Sunray
08-07-2019, 10:53
.30 M2 used a 152 grain, flat based, bullet not a 150. A 150 is close enough though. Two grains either way won't matter. There's a tolerance given in Hatcher's Book of the Garand. .30 M1 ammo used a 174.5 grain BT bullet at 2640 FPS. The M1 Rifle was designed to use and tested using .30 M1 ammo. However, the ogive makes no difference of any kind.
.30 AP used a 168 grain bullet and was used in the same weapons as .30 M2.
3.340" is the Max OAL for .30-06. It works out of any .30-06 rifle. Minimum OAL according to SAAMI(that came after the U.S. Ordnance Board set the dimensions), is 2.940".
3.325” will be perfectly safe. I think that box of bullets may be from some place other than the U.S. though. Don't really think it matters either. The milsurp 147's made for 7.62Nato work just fine out of a .30-06 too.

Merc
08-07-2019, 01:18
3.325” will be perfectly safe.

I’m glad to hear that since I already hand loaded about seventy .30-06 cartridges with M2 bullets using that OAL spec.

JOHN COOK
08-08-2019, 05:09
It works out of any .30-06 rifle. Minimum OAL according to SAAMI(that came after the U.S. Ordnance Board set the dimensions), is 2.940".
3.325” will be perfectly safe. I think that box of bullets may be from some place other than the U.S. though. Don't really think it matters either. The milsurp 147's made for 7.62Nato work just fine out of a .30-06 too.
Last edited by Sunray; 08-07-2019 at 02:05.

Sunray, please feel free to correct me becayse I maybe reading this wrong. Isn't the 2.940 dimension actually the cartridge case length ???? I don't think the 2.940 refers to OAL ( over all length))

john in SC

Merc
08-08-2019, 12:16
John,

The 30-06 case length is 2.494”. I seem to only reload 30-06 these days so that dimension is firmly etched in my brain.

Merc

Merc
08-08-2019, 12:41
An observation concerning the maximum 3.34” OAL vs. my current 3.325” OAL. I suspect the M2 bullet’s cannelure is positioned for the maximum length of 3.34” because I noticed that it sits slightly below the case rim when the bullet is seated at 3.325” OAL and prevents me from crimping the case. The next time I reload, I’ll try to add some length and see what the OAL is when the cannelure lines up properly with the neck rim. Hopefully, it will be somewhere at or below 3.34”.

JOHN COOK
08-08-2019, 05:19
Mec, I didn't quote all the correct statement. This is what i was referring to


I could have interpreted this statement to mean OAL (over all length) Max 3.340 and Min 2.940. I feel sure he was referring to a completed cartridge, but 2.940 can't be correct for a completed cartridge. Not nit picking but someone not familiar with the 30:06 round could be misled. Although I don't think they would.

john SC

Merc
08-10-2019, 06:25
I fired 10 uncrimped rounds with my ‘03 that were reloaded with M2 bullets. First time for both. All shots were close to the aim point but all case necks were covered with black soot.

I read all I could find on other forums on the causes and what could be done to correct it. Some say crimping will help while others say there’s no need to crimp. Other possible causes: powder charge is too light, the length is too short or long, the neck was sized wrong or the primer is wrong.

The BT bullets don’t leave soot on the case necks in my other rifles (M1917 and 03A3) but I didn’t have any BTs or any of my other rifles with me to compare.

The only difference between cases with the M2s and the BTs is the bullet type and the M2s have a slightly longer length. Same powder, same primers, same cases sized with RCBS FL Dies.

I’m going to fire some of the M2s with my M1917 and some BTs with my ‘03 to see if the problem follows the bullet.

Merc
08-13-2019, 03:41
Back to the range on Monday with my ‘03 and shooting uncrimped BTs and M2s. No soot on BT case necks, soot on M2 case necks. So, is crimping the M2 case necks the next step?

PWC
08-13-2019, 08:34
What is your powder? Soot is probably a result of load. Mine shoots best with upper end loads, no soot with either FB or BT.

I may have missed what the load was except for the bullet.

Merc
08-13-2019, 01:08
I’ve been using Hodgdon BL-C(2) which evidently isn’t the cleanest powder around although I can’t complain about the accuracy. Three of the four rifles I shoot are .30-06, the fourth is a .303 British.

madsenshooter
08-13-2019, 02:44
Fire your BL-C(2) with a magnum primer, or a CCI#34, which is milspec primer for 7.62 Nato designed to fire ball powder. I've used a lot of ball powders in 30-06, they are hard to ignite compared to stick powders. I'd often get little dents in the cases from unburnt powder falling into the chamber upon extraction of the case, then the next round chambering on top of that. Switching to magnums or #34s cleared that right up. Since you're getting sooty necks, your load is relative low pressure as is, so you shouldn't have to adjust the charge and work up again, just try a few to see how it goes. On the otherhand, you might already be using magnums or #34s. In that case, go a little higher with the charge.

Merc
08-14-2019, 02:27
Fire your BL-C(2) with a magnum primer, or a CCI#34, which is milspec primer for 7.62 Nato designed to fire ball powder. I've used a lot of ball powders in 30-06, they are hard to ignite compared to stick powders. I'd often get little dents in the cases from unburnt powder falling into the chamber upon extraction of the case, then the next round chambering on top of that. Switching to magnums or #34s cleared that right up. Since you're getting sooty necks, your load is relative low pressure as is, so you shouldn't have to adjust the charge and work up again, just try a few to see how it goes. On the otherhand, you might already be using magnums or #34s. In that case, go a little higher with the charge.

I’m using large rifle primers but will switch to magnum or #34 primers. I see Brownells carries the #34s.

I crimped 20 necks right in the center of the M2 crimp groove and went to the range today to see if there was any difference. No change. The BL-(2) is still depositing soot on the necks but all shots were accurately placed.