Good general .223 AR load or XM193 clone?

[Baron]

Hey all - as I explained in my other thread, I'm trying to work up a ballistic clone of XM193. It would be nice to know that I can replicate XM193 if the SHTF, etc., but I'm wondering if I'd be better served by a gentler load for general purpose.

I'm using 55 gr. FMJs, H335, and CCI 450 magnum primers. My Lee reloading manual specifies standard primers and H335 from 23.0 grains to 25.3, so with the magnum primers I have tested from 23.0 to 24.4 in my 16" chrome-lined midlength Rock River. I shot all these loads today over my chrono in addition to XM193 and was dismayed to find that even 24.4 grains of powder only yielded 2875 fps compared to XM193's 3145.

But, 2875 is no slouch. Provided I'm not going to war anytime soon, a 2875 fps load will be easier on the gun and I imagine on the suppressor that will hopefully clear ATF in one month. The 2875 load grouped and POIed similar to XM193 - how does 2875 compare to your general AR .223 load? What are your numbers like? What is a good balance between a general load that's easy on the gun and consistent, realistic practice load?

Thanks, all.

 

[dodge]

You should also remember that they probably tested the XM913 in a 20" barrel as where you're using a 16" barrel. Your load maybe more like 3075 fps out of a 20 " barrel. I believe that the rule of thumb is 25 fps for every inch of barrel that is different from the test gun. So by figuring in the deference between the barrel lengths you're not that far off with your load. You can get that much deference between guns of the same barrel length.

 

[Baron]

Good point - unfortunately I chronoed XM193 at 3145 yesterday out of my 16" barrel! Oh well - I may use something like 2875 as a plinking load, but I do want to know what it takes to get to 3145.

 

[Galil5.56]

3145 fps is pretty snappy for 16". I do have some worked up loads using AA2460 that make an avg 3170 fps from an Israeli made IMI Galil ARM that has an 18" barrel, but they exceed today's data (these loads were from 1994). Using today's max for AA2460 would give me about 3030 fps.

My normal plinker load used WW748/55 FMJBT, and achieved 3005 fps from the Galil. Sierra lists 25.7 as max with a 55 grain bullet and H335, so perhaps if you can work it up to this, I think your chrono will give you about 2975-3050 as my best guess.

 

[Bartkowski]

Saw this in a thread the other day, it might help you a little.

http://www.frfrogspad.com/miscellq.htm#duplicate