A record keeping question for reloading

[David Milisock]

The best information I can find has the Garand designed for the 173 grain - 7 caliber olive and a 9 degree boattail projectile, using IMR 1185 propellant (IMR 4831) . That changed to a 152 grain flat base using IMR 4895 propellant. .

This makes sense as the lighter bullet, slower powder would have the port pressure to high.

So the question for those knowledgable in all thing Garand is, was there a gas system, recoil system change required for this change of projectile?

I as as I'm starting my elk load development and this is critical information.

[RCS]

The M1 Rifle was designed to use the 30 caliber M1 cartridge from post WW1, during WW1, the 30-06 cartridge was the main issued cartridge. After the 30 cal M1 cartridge was in service, it was decided to use a lower power, shorter range cartridge called the 30 cal M2. The 30 cal M2 entered service in 1938 but the 30 M1 cartridge was also used in other weapons for a period of time. The early examples of the 30M2 had a stannic stain (silver-gray color) bullet during the pre WW2 period to identify it from the 30 M1 cartridge. Mr Garand was not really in favor of the 30M2 cartridge as he felt it did not have enough reserve energy for the M1 rifle, but things worked out.

Photo shows: 30-03, 30-06, 30 M1 and 30 M2 with stannic stain bullet (pre WW2)

[David Milisock]

The timing is interesting, the Garand was adopted in 36 with the 30m1 ball, starts to be issued in 37 and Macarthur gets the ball rolling with the 30M2, which was adopted in 38.

The 30M1 was using IMR 4831 a significantly slower powder than the 30M2, IMR4895. My question was did they only change the powder to make the 152 grain 30M2 projectile work or did they also change the gas and or recoil system? Clearly after 38 it was all 30M2 and faster powder.

For my reload development if there is been no recoil gas system change them my starting slow powder will be IMR 4831 not IMR 4895. There is a huge difference in burn rate, same town but really far apart neighborhoods.

FYI the 30M1 bullet weight makes the Garand very close to a midrange elk rifle, my goal because I can. :-)

[RCS]

Mac Arthur was not involved with the 30 M2 cartridge, he was more involved in the 30 cal selection over the 276 cal

[David Milisock]

Well let's dig him up and ask if they changed the gas system. 😀

[RCS]

Were talking about the M1 in 276 cal and the M1 in 30M1 cal as to which would be selected

This has nothing to do with the system as both have the same gas system

[David Milisock]

Actually I'm looking into the change over from 30M1 to 30M2 and the evidence does at ths time point to a powder burn rate change along with the projectile change. I've got more reading to do but the weight of the documentation and chronological details suggests that at this time. I'm meeting with a 93 year old next week who worked for Dupont during the war and I'll pick his brain. After the war he ran a gun shop and in fact he sold me my Garand.

[Smokey]

The 173 gr bullet with IMR4831 would have too high a port pressure for the Garand. More likely the propellant was something like IMR4320, or IMR4895. M1 ball was actually based on the Swiss GP11 and had similar ballistics. While M2 ball deliberately had a shorter range, it was supplanted during WWII with the black tip armor-piercing ammo for general issue to US combat troops. Interestingly, accurate barrel life for the armor piercing was twice as many rounds as the 152gr flat base ammo.

[David Milisock]

Smokey the trail of powder, projectile and rifle design changes can make your head spin. I read one account where a sniper preferred the black tip AP the best for accuracy. Go figure. Although after reading how they did the powder configurations on a per lot load basis points to why the 30 Carbine had some cold weather issues.

[David Milisock]

As far as I can tell there is no direct correlation to the powder used when the Garand was developed to any known IMR or other powder. That powder used during development was IMR1185. As designed for the 30 M1 ball.

To understand the thought process we need to go back to the 1906 development of a 150 grain 30.06 load using MR21 which as an IMR equal IMR4198 as our base burn rate for a 150 grain projectile. Heavier projectiles would require a slower powder to maintain safe pressure.

The 1926 load development of a new cartridge took place before the design and adaptation period of the M1 Garand as a military rifle it uses a 174 grain projectile and utilized IMR 1185 powder which basic concepts dictate it had to be a significantly slower powder than MR21 (IMR4198). Standard 30 M1 Ball was the result and was inventoried from 1926 until 1938 some say 1941. The was the standard 30 caliber cartridge for the military and obviously what the Garand was designed for.

Then in 1937 (for reason I won't discuss) they started development of what became the 30M2 Ball which uses a 150 grain projectile and again they changed powder which simple basic concepts dictate, it had to be faster than the IMR1185, we know this powder as it is clearly documented as having an IMR 4895 number. Sold as surplus after the war, when that stock ran out it was reformulated for civilian use and marketed in 1962.

The Garand was originally designed with a gas trap, for IMR1185 powder and 174 grain projectiles. 18,000 rifles in service (I believe), these rifles had the gas trap removed as rifles needed repair. The rifle was redesigned and by 1940 had the new gas system in place and by 41 the Army was fully supplied. The Garand rifles being manufactured from then on as well as those in early theaters of operation had to function with 30M1 Ball and 30M2 ball.

Macarthur noted no issues with gas trap rifles in his reports. The theaters of operation from 12/41, Asian, Africa in 42 and maybe Italy in 43 (but I doubt the latter) utilized both 30M1 Ball as well as 30M2 ball. I can hardly believe the inventoried 30M1 ball lasted that long but some say it was manufactured into 41.

I can find zero documented load data utilizing IMR4895 with 175 or 180 grain projectiles that produce the stated 2647 velocity and operating pressures of 47,000 or even 50,000 PSI. I find data but no properly tested and written data with pressure reading and velocity measurements.

I have documented load data producing 47,000 and 48,000 PSI with 180 grain projectiles with velocities from 2650, 2694 to 2780 utilizing IMR 4064 and IMR 4831 and IMR 4350. All of these powders can produce results (but most likely not in all rifles) that duplicate the development loads and can do so without utilizing maximum loads, in most cases 70% to 75% load pressure. I sincerely doubt that IMR 4831 is a proper load.

The best I can estimate is that IMR1185 produced a burn rate somewhere (on the Hodgen burn rate chart) between Reloader 12 and IMR 4320.

So for my 180 grain hunting loads I'll use my known target loads as a comparison of op rod function and start my loads with IMR 4064, I clock the loads and watch for signs of pressure. Change in extraction angle, excessive op rod action, primer and firing pin marks.

I'll continue my research.

As a side note military loads took the lots of manufactured powder, tested them and then mixed them to achieve the required properties, then loaded the cartridges from that lot of powder, changing charge weights as the tested results dictated. What happened is that the charge weight of these military loads varied from lot to lot.

The difference in the civilian counterparts of these military powders is that the powder production processes were more controlled to provide the same results from exact measured amounts of the powder. Ergo hand loaders could rely on getting really similar results from a measure amount of powder.

[Smokey]

The Garand action is pretty strong, so I pay more attention to pressure at the muzzle where the gas port is. Too slow a propellant will give higher pressure there with possible damage to the operating rod. With nothing else to go on, I use a combination of published load data and Quickload, which plots pressure along the length of the barrel. I started with a "standard" M2 Ball load and got the peak and port pressures. That pretty closely tracked the peak pressures and velocities from several reloading manuals (all were a little different). I then worked handloads for different bullet weights and propellant combinations to give similar peak and port pressures. With a heavier bullet and slower passage time from the gas port to the muzzle, I dropped the port pressure a little.

[David Milisock]

I'd call your post good advice, which is as scarce as hens teeth on the internet.

I want the load to do the job but causing a rifle failure is not a reasonable goal. IMR1185 sounds like the powder but I haven't solved the time travel problem so I can get my hands on some. Historically I have defined a range in burn rate and ultimately it will come down to the port pressure, the powders which provide it and the bullet powder combination the rifle likes.

I'm methodical and patient so I'll get there safely, the other options are undesirable.😀

[David Milisock]

Smokey I just emailed Quickload to see 8f they have a stable Windows 10 64 bit version of Quickload thanks for jogging my memory on that software.

[RDS]

I will check my reference material but I believe M2 ball ammo was also loaded with ball powder during WWII and post WWII. Olin Chemicals developed ball powder by recycling surplus WWI gun powder which was in great supply prior to the beginning of WWII. The process was patented by Olin. Olin Chemical owned Winchester(firearms) and Winchester/Western (ammo) at the time.

[David Milisock]

RDS thanks for the information, I did read some stuff about the ball powder development in my research but did not see (or missed) the M2 Ball loadings.

[RDS]

David
American Rifleman March 1986 issue has the following article by John R. Clarke "Reloading for the M1 Rifle". It is on pages 50,51,52,53, and 78. Loading data for Sierra MatchKing bullets in weights of 150gr, 180gr,190gr, 200gr and Sierra 168gr International bullet. You will find it and interesting read even if published 33 years ago.

[David Milisock]

Thanks, American Rifleman articles have always been a great resource, I'll check it out.

This study has been interesting for me, unfortunately I have found a great deal of information on the internet containing unsafe loads for the 03, Garand and especially the 30 Carbine. I mean improperly labeled over maximum safe pressure loads. Carbine loads in excess of 43,000 PSI, Garand loads exceeding 55,000 PSI with slow powders. Bad stuff!