Surplus IMR4895, I finally figure it out; what it is.

[Clark]

I bought 32 pounds of surplus IMR4895 pull down powder from the 1960s. I got it from Hi-Tech ammo in 2000 for $8/#
http://iidbs.com/hitech/

The velocities seen on the chrono and the threshold of primer pocket growth did not match the Quickload predictions of velocity and pressure.

A week ago I was getting ready to go elk hunting and I had primers falling out at the range with .308, 45 gr surplus IMR4895 Sierra 2125 moly coated 150 gr boat tail hunting bullets 2.784" just barely do not touch the lands. 20" barrel, 2940 fps, extractor groove growth was .001 to .003".

This should not happen, not even per IMR's conservative data.

Either the powder is aging, and/or the bulk powder was always way faster than the canister equivalent.


I went back to all my range reports for 6 years in 30-06, 308, 8mm, and 257 Roberts Ackley.

It seems that Quickload predicts everything nicely over the last 6 years if I interpolate between H322 and Re10X.
The surplus IMR4895 is faster than the H322, but slower than the Re10X.

And all these years, I have been saying that my surplus IMR4895 is just as good as store bought IMR4895 in the purple can, just because the groups are just as good

I guess you get what you pay for.

 

[donttellthewife]

Sounds to me like you should dump that bad old powder, and being the environmentalist that I am, I'll be happy to help
Seriously, if you have surplus surplus I have surplus cash, just trying to keep the 1919a4 beltfed fed.

 

[Peter M. Eick]

I was under the impression that with surplus powders you had to work up a new load for each "batch" of powder because they do not hold the tolerances of the powder as tightly as in canister grade stuff.

Your data seems to support this concept that the surplus you bought is close but not exactly the same as canister 4895.

Why not just work back up to your same velocities and keep shooting it up?

 

[flutedchamber]

If I had primer falling out and substantial extractor groove growth, the first thing I would do is cut back on the load by at least 5%, or more if signs warranted. The reloading programs are great, but you must remember that they were developed with canister grade powder.

 

[Dr. Dickie]

+1 on donttellthewife
I always heard the same thing. Surplus powder is inconsistant as heck, and you must work up charges for each lot you get.
Course, I have never messed with the stuff, and THEY say all kinds of crazy stuff. But this time, seems like THEY might be right.

 

[USSR]

Clark,

Is that 45gr load of surplus IMR4895 with a .308 or .30-06?

Don

 

[Clark]

That was with .308.
Sorry, I edited THAT ommision later.

I can use the 16 pounds I have left, I just have to remember that H322 or Re10X is the load data for the work up.

And I've gotta stop sighting in and working up loads for elk hunting at the range THE SAME DAY I leave for elk hunting

 

[Dr. Dickie]

For .308 I use 41.5 gr of IMR 4895; 150 gr boattail
45 to 46 for .30-'06.
I would drop back to the the 41 gr range and see if that is better.

 

[USSR]

Clark,

I don't know where you got your 45.0gr of IMR4895 from (I suspect it is a .30-06 load), but that is a WAY overload in a .308 Winchester. Under no circumstances should you exceed 43.0gr with that bullet. I use alot of surplus IMR4895 in a .308, and 42.2gr with a 170gr bullet is a warm load in a bolt rifle. It's no wonder that you are blowing primers.

Don