I searched and couldn't find this posted anywhere. I reload for .30-06. Is there a sweeping generalization I should know about reloading military brass? I've heard through the vine that my favorite load with Remington brass should be reduced by 10% (i.e. 53.7 grains of IMR 4350 in Remington should be loaded no more than 48.3 grains in brass that used to house mil-surp ammo). The rationale I was given is mil-surp brass is thicker and therefore builds more internal pressure than commercial (Remington) brass. Any input would be appreciated.

I've read the same thing. Best I can say is when you change brass just start low and work up looking for pressure signs. I use my chrono while I'm doing this to see how velocities look for my loads. It's a big help.

Thanks! I've got plenty of good hunting rounds (165 Hornady SST for deer-sized game and below, 180 Hornady IB for elk). I have about 100 pieces of military brass that once housed 150 grain FMJ and some Remington Core-Lokt 165's. I'm looking to load those just for trigger time at the range.

I have noticed that Ultramax uses both Federal and military brass in it's .308 loads....

In my experience with 7.62 NATO (.308 Winchester), military brass, it had less case capacity than commercial brass. I had to reduce my powder charges slightly, and starting 10% lower is not a bad suggestion. You can work up if you need to, but if you are only looking for practice ammunition, then you might not have to increase the powder at all if you are getting acceptable accuracy, and the point of impact is not too radically changed.
Chronograph will help as well.

Most 30-06 military brass I've run across is a bit heavier (thicker) than commercial brass, and reducing your loads a bit is wise. Starting 10% lower is prudent.
There is at least one exception- I have a batch of Lake City match brass that weighs exactly the same as Winchester commercial brass.
However, the vast majority of military brass is distinctly heavier.
Another thing to consider is that military brass usually has crimped primers, so you'll have to remove the crimp from the primer pockets to reload it. The RCBS primer pocket swage does the job, and isn't expensive. Fortunately, you only have to remove the crimp once.

If using military brass you will have to remove the primer crimp before repriming. This can be done by swaging, reaming or sometimes a case deburing tool will work. Sometimes the case necks need to be annealed also. Load reductions noted above also apply for stated reasons.

It is a generalization. Usually military brass is heavier than commerical brass, but as others have mentioned, it might not hold true in every case (esp. with military cases marked "match" or those from non-US makers). Only way to know "how much heavier" is to weight test it. Volume comparsion might be more meaninful, but it's not as easy as just putting them on a scale.

Just how old would those 30-06 military cases be?..been awhile for the old -06 as a common US military loading.

Thanks for the input. The ammo was S. Korean, circa 1970's - I think. The brass is in great shape from what I can tell. I've had no splits or blems and I am down to my last 100 or so. It's definitely NOT marked match. The headstamp is "P8 75." I always use a deburring tool and have only had issues re-priming with about 5 cases. If I could only read the language on the side of the box.....

I'll knock it down a few grains. I've got some extra IMR 4831 for the project. Projectiles will be mainly the Remington's, but I've got a few here and a few there of other odd n ends. Thanks again to all!

I have some Frankford arsenal 60 match brass 06. I've used them for 25-06 and my 7mm/06. Yes they are heavier than most commercially available cases. But to be sure anyone loading milsurp brass should weigh them. I have found up to 8gns difference in same lot milsurp brass. The exception was the above FA60Match. 8gns is enough with the heavier brass to cause problems in top loads. I would definately weigh all milsurp brass just to start with cull any 2gns heavy, foreign manufacture I would be very wary of. We have tighter control and acceptance in manufacture.

I've shot a bunch of that Korean late 60's/70's vintage ammo. All of it has been perfectly functional, and the cases hold up for reloading just fine.
One thing to watch out for with the Korean surplus: it's supposed to be non corrosive, and it is, but I believe I've run across 1 or 2 rounds that were exceptions.

That's what I've found. I think out of the original 400 rounds I bought, I've had 3 that were corrosive. The brass has held up pretty well. The funny thing is that my Sig .30-06 shoots this stuff at 1.25" - 1.5" at 100 yards! I'll keep them for range time or if needed. I made the mistake of loading some of the cases before posting my question. I duplicated my pet Hornady load (57.3 grains of IMR 4350) and noted zero signs of pressure! Having read the responses, I'll chalk that up to "living on the edge" and load down going forward.