Hottest ammo the Garand can handle

[The Dutchman]

I have read on some previous threads that shooting ammo with a weight greater than 150 grain can damage the operating rod of a Garand in .30-06. My question is this, the original GI ammo used was 150 grain @ 2800 fps. Is it safe to fire Winchester Supreme ballistic silvertip 150 grain with a velocity of 2920fps? Whats the hottest ammo anyone has shot reliable through a Garand without having to get an adjustable gas system or upgrade the recoil spring?

 

[meathammer]

I wondered the same thing and ended up just getting the adjustable gas plug. I have heard opinions from both sides - only shoot surplus or don't worry about it. I think installing the plug is worth it. I still shoot surplus, but I shoot a lot of American Eagle 150 gr. which is rated at about 2910 fps. No ill effects so far.


--meathammer

 

[USSR]

It's not the weight of the bullet that causes damage to a Garand's op rod, it's the high port pressure caused by using slow burning powders that is the problem. There is no problem using bullet weights up to 180 grains, as long as you use a powder in the 4895 - 4064 burn rate range. Since you have no idea as to what powder is used in the Winchester Supreme ammo, I'd stay away from it.

Don

 

[Dave P]

Is it safe to fire Winchester Supreme ballistic silvertip 150 grain with a velocity of 2920fps? Op rods are worth 50-100$ these days.


I sure wouldn't. Either get a adjustable gas plug, or remove the one you have now.

 

[Swampy]

Dutchman,

Already some good advice here.... and I'll throw my own 2 cents in.

As determined by the designers of the M1 and the Army's ballisticians, and then told to the NRA way back in the late 50's-early 60's when M1's were first becoming available to civilian shooters for Highpower comps..... there are some definite ammo issues with the M1 rifle. The M1 is a very sturdy design, but the gas system is made to handle only a very narrow range of pressure as the bullet passes the gas port.

Shooting ammo with too low a gas port pressure will causes short strokes and FTF's. Ammo with too HIGH a gas port pressure can cause "bad things" to happen. Ammo that may be only slightly over the "safe edge" can, over time, cause the op-rod to bend or warp, begin rubbing wood, and sending accuracy South. Going a little higher on the gas port pressure can cause battering of the receiver heel by an over accellerated bolt, cracking it out. Bye-bye receiver. You now own a unitized parts kit. Get way up there and you can do some "instant" damage by immediately bending or breaking a rod.

In order to stay "Gas System Safe" in the M1 the rules are:

1) NEVER shoot bullets HEAVIER than 180 grains
2) NEVER shoot powders SLOWER than IMR-4320

The problem with commercial hunting ammo is that even if you are within rules on bullet weight, there is no way to know what type of powder is in the round. Commercial ammo makers do not use cannister grade powder (having very consistent burn rates from lot to lot) like us handloaders do... they use commercial bulk lot powders that have widely varying burn rates. They simply vary the charge weight of the powder they are using to match the spec velocity of the ammo load they are making that day.

Even if by chance you could determine that the box of hunting ammo you have in your hand today is safe for the m1's gas system (and I DEFY anyone without access to a full ballistics lab to do so) the very next box you buy in your local Sporting Goods dept. may have come from a different lot...and a different lot of powder... burn rate unknown.

Please note: The Winny Supreme 150 grain ammo at 2900+ fps may indeed be safe for the M1. It may not. I don't know either way. Don't have a clue as a matter of fact.... but 2900 fps is plenty hot for a 150 grain 30-06 load. I do know that any type of 30-06 ammo that is marked as "Lite Magnum" or maybe "Plus P" or some such nomenclature derived to denote that this ammo has more velocity than "normal" ammo is NOT going to be something you want in your Garand. The ONLY way to generate the velocities that are being advertised is to use powders that are way too slow for the M1's gas system.

There have been anecdotal reports on various BBS of these types of ammo being fired in the M1 and snapping an op-rod with only one shot, causing bending in others. Are they true??? Who knows... some may be, others not. Why take the risk when you know ahead of time the issues as outlined by THE PEOPLE WHO DESIGNED THE RIFLE???.

Military M2 ball ammo and the M1 rifle are literally "Made for each other", M2 ball having just the right pressure for the M1's delicate gas system.
All I know is that in MY M1's the only factory ammo I will shoot is M2 milsurp.

Now having said all this...... Why not just install a McCann or Schuster adjustable bleed lock screw in your M1 and shoot anything you want.....

Just my thoughts...

Swampy

Garands forever

 

[30Cal]

The M1 was designed to shoot M1 Ball--173gr FMJ doing about 2600fps. M2 Ball didn't show up until after WWII began.

 

[bogie]

Guys. It is NOT a speed race.

It's a 50 year old rifle. It's a piece of history.

Please don't _try_ to break it. I've got a friend who seems obligated to take virtually any object, and test it to destruction.

 

[DMK]

Guys. It is NOT a speed race.

It's a 50 year old rifle. It's a piece of history.

Please don't _try_ to break it. I've got a friend who seems obligated to take virtually any object, and test it to destruction.

I don't think that's the biggest issue. M2 ball is getting harder to find and you can't buy it at your local store. Plus some guys like to hunt with their milsurps. You can't do that with Ball ammo.


How do those adjustable bleed screws work? You do set them like a FAL? Open them up all the way and then slowly close until everything cycles properly? If you change ammo, you need to re-adjust then right?

 

[Swampy]

The M1 was designed to shoot M1 Ball--173gr FMJ doing about 2600fps. M2 Ball didn't show up until after WWII began.

True....

But my statement stands..... M2 ball is designed to give a port pressue that the M1 rifle needs.... and the M1 rifle is designed to use the same port pressure supplied by M2 ball.

Best regards to all,
Swampy

garands forever

 

[Art Eatman]

Any powder has a particular curve of pressure versus time. The peak (roughly) is maybe one-third of the way down the barrel, with the pressure decreasing as the bullet nears the muzzle. My understanding is that the military ammo for the Garand had a pressure at the gas port of 2,000 psi. (I don't pretend to know that as absolute fact.)

The pressure curve for IMR 4895, at the GI loading of some 2,700 ft/sec gives the appropriate pressure, whether or not 2,000 is the specific number. FWIW, the chamber pressure of that load is around 47,000 psi (not CUP).

Ya wanna hunt? Any 150-, 165- or 180-grain bullet can be loaded to that safe condition. All it takes is a bit of judgement and common sense.

Commercial ammo for hunting? I don't know. I guess I'd try to get some information from the manufacturer.

Who knows? Maybe contact one of the outfits like Black Hills or equivalent, and see if they'll load "Garand Ammo". There might well be a pretty good market for it.

Art

 

[Titus]

You may want to check with the manufacturer of the ammo you want to use. I don't know about Winchester, but I can quote myself from a previous thread re: Federal...

I once emailed Federal to ask about American Eagle 150 grain FMJ in a Garand, and they said that while they know people use it for that, it is not loaded with the right powder and doesn't have mil-spec primers. They also said the Gold Match has an appropriate powder but not mil-spec primers.

 

[ocabj]

If you don't want to order M2 surplus from the CMP, you can always get custom Garand-safe ammo from RCBS, Dillon, Redding, Lee, and Hornady.