M1 Garand query

[Jeremy2171]

Garand safe commercial ammunition was not needed earlier because mil surp was plentiful and the mumberbof Garands in private hands was relatively low.

When CMP raised the number of Garands a person could purchase per year and mil surp ammunition availability diminished, it became profitable for manufacturers to produced Garand safe ammunition.

I cracked the forcing cone on a S&W Model 19 shooting a steady duet of 158 hrain full power 357 Magnum loads. Many folks say you van only crack the forcing cone with full power 110-125 grain maximum loads.

Obvious I have a data point outside what it considered the “norm”.

So, I tend to not over stress my firearms

That's an opinion that people never shot commercial ammo in the 60-70s etc.

Regardless...if commercial ammo operates at similar pressures as milsurp.

What's the harm?

 

[cfullgraf]

That's an opinion that people never shot commercial ammo in the 60-70s etc.

Regardless...if commercial ammo operates at similar pressures as milsurp.

What's the harm?

Agreed.

But as I understand powders developed recently produce acceptable chamber pressures but maintain higher pressures throughout the entire combustion process. This results in higher muzzle velocity, at least in bolt action hunting rifles. So, with the Garand, the loads on the gas cylinder and op rod system is higher. So, not all commercial ammunition may be Garand safe.

I can’t give you studies, just that I followed the CMP forums for many years.

I see no reason to risk knowingly risk damaging a Garand and there is enough information that at least some ammunition can damage a Garand.

Shoot what you want in your rifle, I’ll shoot what I want in mine.

 

[P5 Guy]

 

[P5 Guy]

The GCA (Garand Collectors Association) in conjunction with the CMP (Civilian Marksmanship Program) did a very comprehensive article on the Garand M1 rifle referencing The Book of the Garand and Hatcher's Notebook.
Hodgdon bought a boxcar full of the powder used in the M1 ammunition selling it in paper bags of one pound for seventy five cents. H4895.

 

[Reloadron]

If you read CMPs warning it basically says commercial ammo is fine as was the previous warning for the last 20 years.

Yeah and I get that. With me you are preaching to the choir. The problem is there is no shortage of people who don't get that which is why I say if seeing a box of 30-06 ammunition labeled Garand Safe (advertising) offers a feeling of it's better then let them go for it. Pretty much my point in my post. Personally for those wanting the most out of their Garand rifles I say roll your own.

Ron

 

[S.Crockett]

I once saw a guy get scolded for shooting commercial 150grn soft-point "hunting" ammo in his M1. Remington brand, I think it was.

The upshot of the lecture, from one of our club's M1 collectors, was that if it's not ammo you bought directly from the CMP, it better say "Garand- or M1-safe" on the box.

 

[Jeremy2171]

I once saw a guy get scolded for shooting commercial 150grn soft-point "hunting" ammo in his M1. Remington brand, I think it was.

The upshot of the lecture, from one of our club's M1 collectors, was that if it's not ammo you bought directly from the CMP, it better say "Garand- or M1-safe" on the box.

And there is the problem... a so-called "collector" not having a clue then berating someone else over what he doesn't understand....typical FUD. (Fear, Uncertainty and Doubt)

And to this day FUD is used to sell stuff, and to disparage the competition.

 

[Reloadron]

I once saw a guy get scolded for shooting commercial 150grn soft-point "hunting" ammo in his M1. Remington brand, I think it was.

The upshot of the lecture, from one of our club's M1 collectors, was that if it's not ammo you bought directly from the CMP, it better say "Garand- or M1-safe" on the box.

Every time any mention of the M1 Garand comes up the issue of "Garand Safe" ammunition comes up. There are endless white papers and articles on the subject. So who would be a noted authority on the subject? I figure it this way. The M1 Garand rifle is actually a very complex piece of machinery. Hell just look at an illustrated parts breakdown of the thing. Makes me wonder if John Garand had a fetish for complexity? Since he designed the rifle he and others did plenty of testing of this new rifle. The government as a whole just loves testing things all the way from NDT (Non Destructive Testing) to flat out destructive testing. The M1 Garand rifle was no exception to the rule. When it comes to testing rifles and ammunition I figure Julian S. Hatcher was an expert and I place stock in his writings. Hatcher's Notebook is a hell of an interesting read on military firearms and ammunition. Here is a little factual information about Garand and Hatcher.

General Hatcher wrote this book in 1948, and covers everything you need to know about the development, testing, operation, and performance of the M1. A must read for those trying to navigate through all the modern internet noise. Some key points from Hatcher:

1. The M1 was designed for use with the M1 Ball Cartridge. This was a 172gr, boat tail design, loaded to 2650 fps at 48,000 max pressure. It also had an extreme range of 5,500 yards. All the M1 rifle testing done prior to adoption was with M1 Ball ammo. M1 Ball was also the designated service ammunition when the M1 Rifle was finally adopted in 1936. That extreme range proved problematic as existing National Guard shooting ranges did not have “safe zones” for this extreme distance. As a result, “training amunition” was developed as a shorter range alternative to the M1 Ball, That training ammunition eventually became the 150 gr M2 Ball cartridge, later to become the standard service cartridge in 1939.
2. As far as the M1 rifle being too weak to handle the chamber pressure of modern 30–06 ammo, nothing could be further from the truth. Quoting Hatcher: “….up to the present writing (April 1948), the Ordnance Department has no record of any M1 in which the receiver has been burst or the or the lugs blown off the bolt,,,,,,,the receiver of the Garand M1 is practically indestructible.”
3. John Garand himself wanted to determine the ultimate strength of the M1 rifle. He took the standard M1 proof cartridge, which developed 70,000 psi , then added enough proof powder to develop loads, in 5,000 psi increments, to fire in a completed rifle. It wasn’t until he fired a 120,000 (!) psi load that any damage was encountered—some surface cracking of the left lug of the bolt. One rifle that experienced this bolt damage at 120,000 psi then successfully fired 5,000 rounds of of service ammunition without any further deterioration.
4. Finally, a December 1941 M1, serial #422349, was used for the ultimate test. Starting again with the standard proof load of 41 grains of powder, it was loaded with increasingly heavier powder charges. At 51 grains, the Japanese 7.7mm M1939 rifle had it’s receiver blown to bits. At 52.5 grains of powder (all the case could hold) was then tried in the M1 rifle. The pressure of that round was unknown because of the fear that the equipment used to measure pressure would be damaged. It’s clear that the 52.5gr charge was well over 120,000psi chamber pressure. At that pressure. the base of the cartridge case actually melted, sending gasses into the magazine. This splintered the stock, and blew out the base of the trigger group. Some gas got into the ejector hole causing the bottom of the bolt to bulge. Parts damaged due to this was limited to the stock, extractor and bolt, the trigger housing, and the bullet guide. Replacing those parts resulted in a perfectly fine, functional rifle.

The M1 does not need to be babied….avoid greater than 180 grain ammo , avoid the slower powders and heavier bullets when reloading….and shoot the heck out of your M1.

While I have the hardcover version of Hatcher's Notebook there are .pdf copies online that can be downloaded. The above quote was taken from here to give credit where credit due. The important part is the references to John Garand and Julian Hatcher.

Next be it with hand loads or factory loads there are a few important things overlooked and seldom covered in all of the chat about Garand Safe ammunition. From our friends at SAAMI.

COPPER CRUSHER SYSTEM This system employs a copper crusher cylinder that is compressed by a piston fitted to a piston hole into the chamber of the test barrel. The pressure developed by the gases from the burning propellant acts through the piston hole, allowing the gases to force the piston upward, and thereby permanently compressing the copper crusher cylinder. The Sporting Arms and Ammunition Manufacturers' Institute has adopted the pressure units designation of "Copper Units of Pressure" (abbreviated CUP) for this system. This designation applies only to values obtained using the particular crushers, tarage tables and methods outlined in this Standard. PIEZOELECTRIC TRANSDUCER SYSTEM This system employs a piezoelectric transducer flush mounted in the chamber of the test barrel. Pressure developed by the gases from the burning propellant exerts force on the transducer through the cartridge case wall causing the transducer to deflect, creating a measurable electric charge. This electrical charge is converted into a reading of pressure. The Sporting Arms and Ammunition Manufacturers' Institute has adopted the pressure units designation of "pounds per square inch" (abbreviated psi) for this system. This designation applies to values obtained with transducers and methods as outlined in this Standard.

In my humble opinion technology is really nice because while the older method did provide numbers it really could not produce a graph pitting pressure against time. Earlier in the thread Jeremy2171 asked several times as to M1 Garand gas port pressure. That typically looks like this:


In this case the cool part is not the peak pressure which I see as about 1100 PSI but how fast that peak pressure arrives at its peak which is right about 500 uSec or simply put really, really, really fast. This crap gets boring but for those still awake during my rambling. The bullet exits the muzzle at about 2650-2700 feet per second. That means that only a little less than 50 microseconds elapse between when the rear of the bullet passes the gas port and when the bullet fully exits the muzzle. Matter of fact Caliber .30 Match M72 ball ammunition pushing a 173 grain match bullet should produce a muzzle velocity of about 2640 FPS.
1.5 inches = 0.125 feet
0.125 feet × ( 1 second / 2650 feet ) = 0.000 047 seconds
0.125 feet × ( 1 second / 2700 feet ) = 0.000 046 seconds
During that brief time, the gas cylinder is part of the highly pressurized space behind the accelerating bullet and the pressure within the cylinder is increasing very rapidly. The large momentum of the operating rod renders it effectively motionless during this period. So the velocity of the operating rod moving actually becomes a direct function of how fast the peak pressure is archived which goes back to how fast the powder burns way back before the bullet even passes over that little hold in tha barrel about 1.5 inches aft of the muzzle exit.

No the operating rod will not dismount and leave the rifle and hit you between the eyes or bend or damage as a result of excessive chamber pressure. The operating rod can dismount but not as a result of excessive chamber pressures.

While I handload for my M1 Garands I also load for my M1A. IMR® 4895,Hodgdon® 4895, AccurateArms® 2495 are my go to powders. Varget id OK but I want a slightly faster powder, especially for my M1A gun. Anyway as to the M1 Grand I just feel the use of "Garand Safe" is little more than advertising hype for all of what I tried to cover here. Now if someone shares a different view then cool with me. I am not looking to change minds here, merely expressing my view and why I have the view I have. One more thing, I keep my bullet weights below 180 grains.

Thank You & Have A Nice High Road Day....

Ron