WC844 vs H335

[goodoleboy]

I recently purchased some once-fired surplus 5.56 brass and some SS109 projectiles and I am planning on loading some today. The only thing I am missing/undecided on is what type of powder to use. I don't want to buy any pull-down surplus powder till I expend my H335 (which I have read is about the same as WC844). I found a pdf of the US Army Technical Manual TM-0001-27 that recommends 26.1 gr. of WC844 to load mil-spec M855.

I guess my question is, how much/if any do I need to adjust the H335 powder charge to duplicate 26.1 gr. of WC844? Or, at least to get in the 2900-3000 fps envelope if I were using a 20 in. bbl?

Thanks in advance

[chadbag]

I recently purchased some once-fired surplus 5.56 brass and some SS109 projectiles and I am planning on loading some today. The only thing I am missing/undecided on is what type of powder to use. I don't want to buy any pull-down surplus powder till I expend my H335 (which I have read is about the same as WC844). I found a pdf of the US Army Technical Manual TM-0001-27 that recommends 26.1 gr. of WC844 to load mil-spec M855.

I guess my question is, how much/if any do I need to adjust the H335 powder charge to duplicate 26.1 gr. of WC844? Or, at least to get in the 2900-3000 fps envelope if I were using a 20 in. bbl?

Thanks in advance

Have you looked in any other manuals or data?

I would start a little lower and work some up in say .3 grain intervals until you get to 26.1 and see what you get

[goodoleboy]

Have you looked in any other manuals or data?

I would start a little lower and work some up in say .3 grain intervals until you get to 26.1 and see what you get

I did a little more research and settled on 24.8 gr of H335. By my estimates, that (on paper at least) should put me at about 3025 fps.

I got started today, did some case trimming and priming. I will finish up soon and take it to the range as soon as I can.

[jaholder]

FULL STOP HERE!!!

Do not repeat do not use the Army ammo data sheets blind for loading ammo, even with the specified milspec powders.

Many of these powders have a widely varying burn rate and each lot has to be tested (burn calorimeter) at the AAP to determine actual load per round for that lot of powder. Then loaded samples are tested for pressure and velocity.

Case in point: I bought some M72 match ammo years ago for my garand. I cracked a few of those open and found them loaded with 48 grains of stick powder not unlike IMR 4895 and a 173 grain bullet. These ran right a slow 2475 fps. Data sheets stated 50 grains IMR 4895, 173 grain bullet for 2640fps. Now cross reference this data against any of the current bullet maker's data for 175 grain match bullets and .30/06 and see if you're not overpressure using 50 grains of 4895?

If you've bought surplus powder, there should be some data regarding burn rate provided. Start low and work up.

[chadbag]

FULL STOP HERE!!!

Do not repeat do not use the Army ammo data sheets blind for loading ammo, even with the specified milspec powders.

Many of these powders have a widely varying burn rate and each lot has to be tested (burn calorimeter) at the AAP to determine actual load per round for that lot of powder. Then loaded samples are tested for pressure and velocity.

Case in point: I bought some M72 match ammo years ago for my garand. I cracked a few of those open and found them loaded with 48 grains of stick powder not unlike IMR 4895 and a 173 grain bullet. These ran right a slow 2475 fps. Data sheets stated 50 grains IMR 4895, 173 grain bullet for 2640fps. Now cross reference this data against any of the current bullet maker's data for 175 grain match bullets and .30/06 and see if you're not overpressure using 50 grains of 4895?

If you've bought surplus powder, there should be some data regarding burn rate provided. Start low and work up.


Exactly!

This is even true for canister grade powders. They can vary lot to lot or have changed over time so older manuals may not be that great for new lots of regular commercial powder. Always start low and work up.

Chad