Brass: Military vs. Comercial

[JustMe2]

Greg C you need to do some serious reading about how to reload for a semi-auto firearm. It is not the same as a bolt action. Get a copy of Sierras Reloading manual and maybe some others and it will explain how reloading for a semi-auto and bolt are very different. You can't use just any powder for a semi like you can for a bolt rifle - the burn rate of the powder must match where your gas port hole is drilled in your semi-autos barrel (it's called timing). Also, you'll need to start crimping, if you don't already for your other firearms, etc., etc. You are not ready to start reloading for a semi-auto yet.

 

[Hugnot]

For years I used a mild load of H380 with 168's in my .308 bolt match gun with GI 7.62 LC match brass . At that time H380 was about the slowest burning powder recommended for gas guns. Slower burning propellents can elevate gas port pressures. My thoughts would be load some powder in the A2520, A2460, H4895 or RS Tac burn range with 150 - 168 grain bullets using recommended load data - like manual info. Weighing charges is absolutey essential. Verify each step for compliance with established load data & procedure.

Real good 1st step, Greg C - your concern was expressed.

 

[Ol' Red]

Gregg, you are weighing your charges right? Not just filling until it is a compressed load? I may have misunderstood what you were saying, and apologize if so.

 

[Lionel Boyd Johnson]

Military 7.62x51 brass is made for semi- and full- automatic firearms. The brass may be both thicker and harder. It may also have a taller base around the primer, before it begins to thin toward the mouth. Bottom line is you must treat it differently than commercial .308 brass. Segregate your brass by head stamp and work up a load for each. If a "book" starting load is up into the neck, it is obviously too much for your lot of mil brass. One of my .308 bolt action rifles shoots much better groups with LC Match brass. Another does not. OK by me. -Ed

 

[Chrsm]

Don't treat mil spec brass 762x51 the same as factory 308!!!
Volumetric They hold different amounts of powder that will change pressure!!!(with the same recipe)
You might need a short base die, if the mil spec was fired through a military firearm!
The 308 vs 762x51 is more of a internal thing than then let's say the 556 vs 223 witch is more a external thing.
This is all based on my own experience.
There are a lot of people out there that know a lot more than me!

 

[Gregg C]

Gregg, you are weighing your charges right? Not just filling until it is a compressed load? I may have misunderstood what you were saying, and apologize if so.

Oh my goodness, yes. All three of the cases in the photo have the same charge...48.0 hrs of H380. And while I might be comfortable with that in the commercial brass to start, I'm certainly not comfortable with a start load that's compressed, as that charge is in the FC NATO case.

 

[Trnelson]

Not sure where to post this, as I'm loading this for an AR308, but I think it might be of interest, and I'm certain that some folks here can steer me right.
Got me an AR 308, and bought a bunch of surplus ammo, to both break the rifle in and get a supply of brass. I've had real good results in my Win Model 88 308 with H380, so ordered up an 8lb bottle. I have never loaded for an AR, and know very little about the system.
Decided I'd start my initial loading\testing at the bottom. Lyman lists 48.0 for a 150 gr Jacketed SP. Top load, Compressed, at 52grs. Picture is 3 brands of brass. Far right is Federal Cartridge NATO 7.62x51. Middle case is PPU NATO 7.62x51. The case on the left is commercial 308Win from Winchester.
My question is, would you recommend dropping the charges visually to about the same level in the mil spec cases as the Win case to start ? This will of course necessitate having a different load for each group of cases. I'm not looking for crazy accuracy, but reliable, consistent, functioning of the rifle system. Any comments or anecdotes welcome. Looking to learn. Thanks in advance.View attachment 367544

Sir, with all due respect I would not advise going forward currently, regardless of what brass you choose to work with eventually. Reloading for an AR-308 requires a few considerations to function safely and reliably, without excessively wearing upon the operating system. Choose an appropriate powder makes things easier, H-380 might be a bit too slow IMO and can over-gas and have excessive bolt carrier velocity and subsequent wear. With 168g bullets I'd choose something like IMR4064, IMR 4166, IMR 4895. Varget is about as slow as I'd recommend. What works well in one may not function in another rifle. Know what your port diameter is before you start. Gas port diameter, bolt carrier weight, buffer weight, spring rate determine the gas or unlock timing of the weapon. IMO, an adjustable gas block is a necessity. A heavier buffer or an adjustable bolt carrier, (I don't prefer using an adjustable bolt carrier) and a heavier buffer spring make tuning your gun to properly function with the load much easier. I am happy to help in any fashion that I can going forward

 

[Teri Anne]

Not sure where to post this, as I'm loading this for an AR308, but I think it might be of interest, and I'm certain that some folks here can steer me right.
Got me an AR 308, and bought a bunch of surplus ammo, to both break the rifle in and get a supply of brass. I've had real good results in my Win Model 88 308 with H380, so ordered up an 8lb bottle. I have never loaded for an AR, and know very little about the system.
Decided I'd start my initial loading\testing at the bottom. Lyman lists 48.0 for a 150 gr Jacketed SP. Top load, Compressed, at 52grs. Picture is 3 brands of brass. Far right is Federal Cartridge NATO 7.62x51. Middle case is PPU NATO 7.62x51. The case on the left is commercial 308Win from Winchester.
My question is, would you recommend dropping the charges visually to about the same level in the mil spec cases as the Win case to start ? This will of course necessitate having a different load for each group of cases. I'm not looking for crazy accuracy, but reliable, consistent, functioning of the rifle system. Any comments or anecdotes welcome. Looking to learn. Thanks in advance.View attachment 367544

It appears to me that it is once again someone trying to turn molehills into mountains. I have had, and still do a lot of military .308 brass. Most of mine is Lake City Match brass which is about as good as it gets. Yes, military brass has a heavier wall construction than commercial, but that is a plus not a minus when it comes to reloading. Why? It can be reloaded, in my case up to 7 or 8 times before the necks crack as opposed to 3 to 4 times for commercial brass. If you anneal it can even last longer. I will freely admit that I do not load to max pressure, I load for best accuracy which is never close to a compressed load. No matter if it's commercial or military my loads wander out of the barrel at between 2400 and 2600 fps, after all I am looking for accuracy not a race horse. I shoot 165 and 168 gr bullets for both match and hunting with the .308 and find that I can shoot them both without a change in zero, which is very handy. My go to powders are IMR 4320 and IMR 4895 approximating the 7.62 MM Lake City match. I have more than one .308 and the rounds work the same in all of them, let's simply say sub MOA. Bottom line is that the case capacity has less to do with accuracy than what you dump into the case. The less you dump in the case the lower the pressure the longer the individual cases last.

 

[AvonShooter]

Something is just not right or I am missing the big picture. 48.0 starting and the cases look full? Reloder 15 is close on burn chart and load is 43.1 to 49.0c. From the pics, my guess is load data problem, not commercial vs military brass.