Reasonable .223 load for AR

[sublimaze41]

I have a question and would welcome any feed back. I am trying to have a reasonable expectation of FPS with 55 FMJ w/can and H322 powder, I will be shooting it out of a Colt M4 (civilian version w/ 14.5 inch barrel AND muzzle BREAK)

I have 8 pounds of H322 and thousands of Hornady bullets. I went to the range and chronographed some. The last load is the one I will mention. I loaded 23.4 grains of H322 in once fired .223 case with win primers and seated to a depth of 2.210. The string average was 3011 FPS.

I wanted to load as close to military ball as I could using existing components. Is this unreasonable? Does the shorter carbine barrel contribute loss of speed? Is the powder or seating depth to blame? Am I really at the point where it doesn't matter? Is there room for load increase past 24 grains? Is working pressure higher in 5.56 versus .223 and thus I have room to go up on my load? Should I just be satisfied with 3,000 FPS with a 55grainer in an AR.

Thanks in advance. I would love to have some opinionated responses. I have learned a whole bunch here and it's nice learning this way versus the "school of hard knocks."

 

[taliv]

M193 is ballpark 3150 from a 16" barrel
if you're short another inch and a half, that's maybe worth another 50 fps, yielding 3100.

I don't know what your load book says for max using H322, but if you're at max, then you can be satisfied with 3000, or you can push your luck. if you're not at max, and not seeing pressure signs...

 

[sublimaze41]

Load books list 23 as max except Hornady which lists max as 24 grains.

 

[RecoilRob]

Looks to me like you are getting all you can/should out of H322...maybe even over the line a bit.

Going to a slower powder (H335 or BLC-2) would give you a bit more speed if you really need it. But, then, what would you do with that keg of 322?

I'd stay with your current load....assuming that it is reliable, showing no signs of over-pressure and is accurate. The faster powders are more economical too. 23 vs 26 makes it last longer.

Oh, 3000fps from the 14.5" tube is just about right. Fire them in a 20" AR and you would pick up a couple hundred fps easy.

 

[243winxb]

223Rem FPS in 14.5" barrels

Out of a 14.5" barrel, i would think that is exceptional FPS in your carbine. An M16A1 carbine with a 14.5" barrel, loaded with IMR 4198 (reduce load 10% and work up) 21.5 Gr. (old Dupont) WW 55gr FMJ BT over my chronograph averaged 2766 FPS. You should be very satisfied with that Velocity in your carbine. The 5.56 chamber has a longer leade and a slightly bigger chamber than a 223 Rem.

 

[243winxb]

223 rem rifle versus pistol load data

http://data.hodgdon.com/cartridge_load.asp On the Hodgdon website, load data, check the difference between rifle and pistol in the 223 rem. I dont know what barrels they use, but you can see the difference in vel./fps There is a article on a Kel-Tec pistol with a 9.5" barrel. Factory JHP ammo gave these avg. Vel.; Bullet weights 55gr-2452fps, 50gr- 2556 fps, 40gr-2812fps. Most rifles will vari 35 to 50fps per inch of barrel, lost or gained.

 

[sublimaze41]

I suspected that around 3,000 FPS would be the approximate range within a safe max load. I think I will try a load with maximum charge of 24 grains. I suspect I will only get a modest increase, perhaps to 3050 FPS. I will post the data in a few days. I like the case filled to the base of the bullet and this load will likely do just that.

Thanks for the ideas. I appreciate any and all imput.

 

[sublimaze41]

Thank you everybody who responded. I have loaded some rounds with 23.9 gr of H322 and will chrono them. I am not a "past max" kinda of guy. The extra FPS is just not worth the safety risk with reloading. On the other hand I want to get the stiffest loads I can safely get to cycle the carbine. I am using Hornady bullets and Hornady data, I trust that. It's also nice to hear what others out there are doing as well.

I have a rare rifle that shoots with best with book load as max, most have the best accuracy with middle of the road loads.