does anyone have 5.56 load data for 50 and 55 grain bullets.
i have worked up a fairly accurate load but I have a short stroking issue in the ar 15.
Federal factory ammo is fine, but very inaccurate, my reloads are accurate but it will not pick up next round in mag, ejects fine.
any ideas?

What powders are you using? With 50-55 gr something between H335 and 748 burn rates will work best.

I use Varget, 8208XBR, W748 and CFE223 without issue in multiple AR15 shaped rifles. If the Federal ammo you shot was 55gr FMJ bear in mind that it’s supposed to shoot a 4 MOA or less group to be “milspec”. Basically the fmj bullets are crap.

I’d suggest using Hodgdon’s website,

http://www.hodgdonreloading.com/data/rifle

I also find the best accuracy at near max loads with good bullets. Remember that “AR15” covers a lot of ground, at least three different common chamber specs and multiple twist rates.

root cause is not enough gas WORK (pressure and volume under a curve)

solutions include:
increasing gas port size
changing powder type and or grains
moving to a shorter length gas port (rifle, mid carbine, shorter)
heavier bullet

I like running rifle length gas systems on an 18" barrel - so i go buy "brown bear" and other junk grade ammo, and drill out the port, by trial and error, until it runs junk ammo, and it tends to work out great on everything else.

it's a 16 inch carbine gas length.
i used 24 g of reloader 10x and 25 grains of h322

I've never had trouble with 748, Varget, Bl C2, or Vhitavouri powders. I've also used some milsurp data powders.

Your powder choice may have something to do with it, but I don't think so, as those are not too unusual choices. It looks like you are on the hotter end of the loads- are you sure its not overgassed and the action is going too fast so that its not feeding right?

Carbine gas set up and hot loads...

What velocities are you getting for your ammo- that will tell you quite a bit about pressures.

quote:

Originally posted by the archer:
it's a 16 inch carbine gas length.
i used 24 g of reloader 10x and 25 grains of h322

Powder. Not enough port pressure. Suspect you're close to max with 24 gr. Try something no faster than H335 or 4895/Varget/RL15.

velocity with the 10x 3050fps
with H322 2900 fps
I'm going to try 223CFE and varget and see what happens

You might also want to check the gas key on the bolt carrier and the gas rings on the bolt. Improperly staked gas key bolts can loosen slightly and cause gas leaks. The rings are a wear item if it’s an older rifle.

quote:

Originally posted by the archer:
velocity with the 10x 3050fps
with H322 2900 fps
I'm going to try 223CFE and varget and see what happens

Ya, those are pretty mild velocities so I'd suspect you're not generating enough gas port pressure. I use H335 with 100% results.

Everyone has given you excellent advice!!!! IMHO

Zeke

hi crbutler,
don't think it's overgassed, factory 55g bullets going 3100 fps, i loaded 10 up with 22.2 of H322
2750 fps and same issue

Overgassed uppers tend toward dropped extraction - extractor lift results in the fired case being dropped before it can eject. So you see a live round wedged against an empty. People erroneously conclude the upper is undergassed.

Extractor lift occurs even with 20" uppers but only rarely rises to a level of failure. Dotgov went with the O-ring solution, first attempt at curing the symptom in M4s.

Undergassed uppers most always fail the one round test - action does not stay open on an empty mag.

thanks Sam I'm gonna try varget and Cfe223 tomorrow and see how it goes.
first build so new to this ar 15 stuff.
been reloading 40 years and never an issue, but i got 1 now!!!

Thank you all for your input.
I'm an obstinate idiot.
I checked everything, then I checked again, the gas block was secure, so I said let me remove it and check for any interference, upon doing so the set screw on the dimple in the barrel was split, held strong enough so there was no play by hand.
replaced the set screw and voi-la it is now properly functioning with with my reloads, mere's the results:
https://imgur.com/a/EuF0wuz

Well, there ya go! Nothing like a simple fix. Shoots very well, too.