ATTENTION AR-15 reloaders! Need help!

meunkemeunke Member Posts: 1,407 ✭✭✭✭✭
Howdy all.

OK, so I've reloaded a batch of .223. I used 55 grain Montana Gold FMJs on cleaned, full resized and trimmed military brass with 26 grains of Varget. I seated the bullets to slightly under 2.255. This was a deep as I could seat them without going totally past the crimp mark. Used CCI small rifle primers.

Anyhoo, these things are within length specs in all dimensions according to my Speer manual, and they work GREAT in my Mini-14. Get approx 2800 FPS.


When used in a Bushmaster AR, they don't work quite as well. About every third round being fed from the magazine doesn't seem to seat all the way into the chamber and allow the bolt to close. Thing is, when used one at a time, they function just fine and the bolt closes just fine.

I used my calipers and checked my loads compared with some Winchester factory FMJs. The factory loads use different bullets, of course, and seem to be 'fatter' and come to a fatter point. They are also 55 grain, but are sunk down to ~2.23 on average. These factory round work just fine in the Bushmaster. The factory brass and my resized brass are the same length.

What the hey? I would think that if the rounds meet the specs described in the manual, they should cycle fine. Do AR platforms require greater seating depth?


  • Alan RushingAlan Rushing Member Posts: 9,002 ✭✭
    edited November -1
    Just a quick thought and question for you ...

    Are you making certain to tap them to the rear of the magazine?

    When I was using .223s I'd found that if any or the rounds were "riding too high" or off the rear of the magazine, that I would experience the same manner of feeding symptoms.

    It might could be something as quick and easy as tapping the magazine rear into the palm lightly?
  • meunkemeunke Member Posts: 1,407 ✭✭✭✭✭
    edited November -1

    Yup, sure did. I always do that with AR and AK mags. Still had the problems. Thanks for the response, though.
  • skyfishskyfish Member Posts: 1,068 ✭✭✭✭
    edited November -1
    Did you try a different magazine. That may be part of the problem. Also, I do believe you have to seat a little deeper, or shorter COL.

    On a side note, Varget with that light of bullet? Velocity seems a little low to me. I've alway used XMR-2015, X-Terminater or TAC and been over 3000fps with a 16" AR. Going to give the new CFE223 powder a try too.
  • shoff14shoff14 Member Posts: 11,994 ✭✭✭
    edited November -1
    The LONGEST overall length for an AR15 is 2.250". I load FMJ to 2.230" and anything else to 2.250". You probably can find some steel magazines that will work up to 2.255" +/- .005".

    Several of the bullet/powder manufacturers have load information just for AR's. I would suggest you look at this information. As far as bullet manufacturers, Hornady and Sierra have service rifle loading information. VihtaVuori and Ramshot have information for service rifles
  • bpostbpost Member Posts: 31,144 ✭✭✭✭
    edited November -1
    Are you shooting them in a tight chambered gun? A base that is a just .0001 too large will not let the bolt fully close, either will a shoulder that is even slightly pushed back. Check the shoulders with a straight edge held up to the light. If you see light, the shoulder is pushed back.
  • steve4102steve4102 Member Posts: 186 ✭✭✭
    edited November -1
    The Mini-14 has a loose sloppy chamber, your AR does not. You are not bumping the shoulder back far enough for the rounds to chamber in your AR. Screw the FL sizing die into the press until they all chamber and extract with ease. Or purchase a case gauge and size to fit the gauge.
  • 243winxb243winxb Member Posts: 258 ✭✭
    edited November -1
    What Steve said. Plus, make sure your not makeing a bulge with the crimper in the seating die. quote: Thing is, when used one at a time, they function just fine and the bolt closes just fine.
    The bolt slaming the round into the chamber can set the shoulder back .001" or more on single loading, no magazine used. When feeding from the magazine, bolt velocity is slowed.
    [url] https://saami.org [/url]
  • Alan RushingAlan Rushing Member Posts: 9,002 ✭✭
    edited November -1
    meunke -

    Agree with steve4102 and 243winxb, that makes lots of sense. [^]

    I'd a couple of .243s, a Win Mod 100 and a bolt action rifle. I couldn't get away with putting the reloads from the bolt action thru the Mod. 100 without having a disgusting number of no fires. [:0] [:(]

    Found (no surprise) that I had to use the smaller die set for the auto loader, so I kept the brass from each rifle segregated and used the brass from each only for it's own rifle. [:0] [:)]

    Made a big difference with case life, reduced the full length resizing and the ammo dependability topped out. I knew then that when I squeezed the trigger ... the rifle would go bang. [:0] [;)]
  • Pistollero1050Pistollero1050 Member Posts: 1,197 ✭✭✭✭✭
    edited November -1
    Had same problem with my AR and Mini-14, I agree with previous posts. The neck gets a bulge in it that won't allow the AR to chamber but mini-14 will. Be carefull when you seat and crimp so as not to enlarge the neck.[;)]
  • dcs shootersdcs shooters Member Posts: 10,969
    edited November -1
    I had about the same problem untill I found slightly bulged shoulders on the ones that wouldn't chamber. Measured brass and found different lengths. Started trimming and cured the problem.
    I bought 1,000 pieces of new IMI brass and had to trim most of it.
    Check your seating die as it might be set too low.
  • krazy4kragskrazy4krags Member Posts: 39 ✭✭
    edited November -1
    If you are reloading for an AR or other similarly tight-toleranced chamber you MUST use small base dies. The regular full length dies do not resize the base of the shell above the rebated rim. This is where the small base die helps you as the chambers on an AR can be finnicky. With these dies the base gets resized along with the rest of it.

    If you are too long on OAL, but your rounds still fit in the magazine and chamber nicely, you don't need to worry about OAL...no, it is likely the base of your brass. Check to see if there aren't scratches on the base portion of your brass. Generally, if you are starting with new brass in the AR and do not reload with small base dies you can probably get 2 or 3 loads through them before the small base dies are needed. IF you mined this brass after firing it from other guns then you should resize with a small base die before loading them for your AR.

    Best Regards,
  • 5mmgunguy5mmgunguy Member Posts: 3,853
    edited November -1
    Use a small base sizing die and a RCBS headspace die. Fire a factory round in the AR check fired length with headspace guage, I have founds some that are .000. most are .002 or .003. I bump the shoulder back .002 with the small dies die, works perfectly. I don't crimp the bullet. Overall length is 2.200.
  • steve4102steve4102 Member Posts: 186 ✭✭✭
    edited November -1
    quote:If you are reloading for an AR or other similarly tight-toleranced chamber you MUST use small base dies.

    Maybe, maybe not. I load for 4 AR-15s, two Ruger Mini's and three Browning BARs, not of them require Small base dies.
  • ga_red_riderga_red_rider Member Posts: 1
    edited November -1
    I would compare neck diameter of the reloaded round against factory ammo. Are you trying to roll crimp them? If so you may be bulging the neck of the case just enough to present a problem in your AR's chamber.
    Lee makes a factory crimp die for about $10 that works great on 223, No neck bulge from it at all. With this crimping die feeding my DPMS has never been an issue of the bolt locking into battery.
  • BUCKAWHOBUCKAWHO Member Posts: 966 ✭✭✭✭
    edited November -1
    Hi...When reloading for an AR, small base dies are a MUST, and be sure all loaded rounds will fit in a WILSON .223 cartridge case gage, also a must for EACH cartridge. Then...No Problems! BT
  • Laredo LeftyLaredo Lefty Member Posts: 13,437 ✭✭✭
    edited November -1
    Are you de-burring the inside and outside of the mouth after trimming? If rough edges are left there it may function fine in your Mini but jam up the closing bolt in the tighter AR chambers.
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