Problem with 223 loads in AR-15

[spriz]

Recently discovered an issue with my 223 loads that I've been running through my AR-15. What's happening is after firing a few rounds (finished firing before going empty) and attempting to clear the chamber, the bolt acts as if it was stuck shut, and a great deal of force is necessary to retract it. Now I experienced this same problem in my AR-10, but found out that my sizing die needed adjusted to fully resize the casing, which solved the issue. However, I know my resizing die for 223 is functioning as it should, and my casing's length is no longer than 1.76" per my reloading book. In the past these loads have been working great, but occasionally I would run into this. My load consists of various brass mostly LC, Winchester, and S&P loaded with 77 grn sierra matchking hpbt. Anyone have any suggestions?

 

[NCsmitty]

I doubt that your OA case length is bothering, but the case length to the case shoulder probably needs to be shortened a few thousands. Drop your FL die an eighth of a turn and try the case in the rifle, it may now unlock and eject normally. Before the bolt was locking up against a slightly too long case. You simply have to fit the case to the chamber by moving the shoulder back a bit in the fl die.
You found that to be the problem in your AR-10, why not the AR-15?



NCsmitty

 

[rcmodel]

Are you crimping in the seating die?

If so, you are getting imperceptible shoulder buckles on some of the cases that will lock an AR-15 up tighter then a gnats panties.

The cure is don't crimp, or crimp if you must using a Lee FCD collet crimp die that is not dependent on case length.

It also might be that you are crimping by accident if your seating die is screwed in too far.

rc

 

[Walkalong]

Agreed. Sounds like slight shoulder buckles, or not quite sized enough.

 

[spriz]

Thanks for the input. I had a feeling it might be at the shoulder, just never measured it. I'll try adjusting the die again and see what happens. Oh and to reply to rcmodel, no I am not crimping.

 

[rcmodel]

Color some of the sticky ones with a magic marker and chamber them.

That will tell you right quick what is too tight where.

rc