223/5.56 77 Grain TMK Best Powder

[treillw]

I managed to get my hands on some 77 grain TMKS for the 5.56.

What is the best powder to pair with them for maximum velocity out of a 10.5" and 14.5" AR?

I see there is a ton of info out there, but didn't know if there is a consensus on some of the best powders for this application.

Thanks!

 

[SKWERLZ]

Tac or 8208

 

[Westy05301]

According to Sierra it is TAC

 

[darkangel_r2]

The fastest 223 powder for heavies will almost always be cfe 223. But SDs can be really bad and it is the farthest thing from temp stable that exists on this earth. Blc2, 2230, tac, 2460, and 2520 can be fast as well. Same story as above though poor sds and temp sensitive. Might not be quite as fast but better SDs with alliant power pro varmint, win 748, and H335. Still relatively temp sensitive though.

But out of a short barrel with those premium projectiles I would suggest a faster burning extruded to deliver the best groups and tolerable sd numbers out of that short pipe.

AR-comp, benchmark, imr xbr, h4895, and varget/swp would be my first choices in that relative order. Benchmark and xbr can even be thrown with some success due to small kernels and consistent shapes. Varget and shooter world precision are the slowest burning but you shouldn't leave them off any list where they are applicable.

IMR 4064, vv 135/140, and reloader 15 can be fast and accurate as well but they are more temp sensitive by comparison so do load dev when its hot out to insure year round safety.

 

[Zero333]

I found on short flame-breathing barrels Alliant AR-Comp is the best choice. Gives excellent velocities in short barrels and is not a flamethrower.

223 / 5.56x45

77 gr TMK ( a fairly long bullet ) seated to fit the mag ( 2.250"-2.260" COAL ). MAX charge weight is gonna be around 21.5 - 22.0 gr. AR-Comp. Got 2,439 from a 12" barrel.

At MAX safe pressures, I assume 2,525+ fps in a 14" bbl.
2,325+ fps from your 10" bbl.

If you're single loading due to longer than mag COAL ( assuming you have the freebore ), you're MAX charge weight probably around 22.5 - 23.0 gr. That's with a 2.450" COAL

I used cci450 primers and F.C. Brass.

Powder Availability really sucks right now, so you can always settle for any of the following powder which should work pretty good for this cartridge and bullet.

Win-748
Accurate 2520
Accurate 2460
Accurate 2015
H-322
H-335
H-4895
Benchmark
Vihtavuori N-530
Viht. N-130
Viht. N-540
Viht. N-140
Reloder 12
Ramshot Wild Boar
Ramshot TAC
Ramshot X-Terminator
IMR-8208xbr

RL-15
IMR-4895
IMR-4064
Accurate 4064
N-140
Varget
CFE-223
Norma 202

Last 8 powders are better suited to the Longer than magazine COAL. They would be compressed loads at mag length.

You can always use Sierra 80 SMK and 80 gr ELD-M data for the 77 TMK.

 

[PopCharlie]

N133, TAC or W748....

 

[CharlieNC]

The fastest 223 powder for heavies will almost always be cfe 223. But SDs can be really bad and it is the farthest thing from temp stable that exists on this earth. Blc2, 2230, tac, 2460, and 2520 can be fast as well. Same story as above though poor sds and temp sensitive. Might not be quite as fast but better SDs with alliant power pro varmint, win 748, and H335. Still relatively temp sensitive though.

But out of a short barrel with those premium projectiles I would suggest a faster burning extruded to deliver the best groups and tolerable sd numbers out of that short pipe.

AR-comp, benchmark, imr xbr, h4895, and varget/swp would be my first choices in that relative order. Benchmark and xbr can even be thrown with some success due to small kernels and consistent shapes. Varget and shooter world precision are the slowest burning but you shouldn't leave them off any list where they are applicable.

IMR 4064, vv 135/140, and reloader 15 can be fast and accurate as well but they are more temp sensitive by comparison so do load dev when its hot out to insure year round safety.

A test with real data appeared in American Rifleman this month showing CFE was comparable to some "stable" powders and only marginally worse than the marvelous Varget.

 

[darkangel_r2]

A test with real data appeared in American Rifleman this month showing CFE was comparable to some "stable" powders and only marginally worse than the marvelous Varget.

Previous testing in 223 showed that it is relatively stable below about 70 degrees but after starts to take off badly after that temp.

As an example.

Temperature Sensitivity of Powders for .223 High Power Service Rifle

Is there a link to the american rifleman report youre referencing?

 

[CharlieNC]

Previous testing in 223 showed that it is relatively stable below about 70 degrees but after starts to take off badly after that temp.

As an example.

Temperature Sensitivity of Powders for .223 High Power Service Rifle

Is there a link to the american rifleman report youre referencing?

I get the paper mag so I don't know if there is an e version, I summarized in excel and can forward to you if needed. For over ten years I have evaluated CFE and other powders in 223 for various barrels and bullets; it always proved best accuracy and with no more apparent temperature issues than others. This shooting Ftr from 40 to 100deg, but I do achieve wide nodes!

 

[darkangel_r2]

I get the paper mag so I don't know if there is an e version, I summarized in excel and can forward to you if needed. For over ten years I have evaluated CFE and other powders in 223 for various barrels and bullets; it always proved best accuracy and with no more apparent temperature issues than others. This shooting Ftr from 40 to 100deg, but I do achieve wide nodes!

Which edition was it, maybe I can find it. And yes please forward me the excel sheet.