I had three light primer strikes this afternoon while practicing for an upcoming three gun match.  They were the only problems I encountered out of the 200 rounds I fired out of my carbine.  I had one, cleared the chamber, had another with that round, cleared the chamber again, fired one round, and then had the third light primer strike, then the gun ran smoothly until I was finished.  After I finished running my little prepared gauntlet of badguys, I collected the three suspect rounds, cleaned them off, inspected them, reloaded them, and fired all three without incident.  My question is, does anyone have any idea why I may have gotten these three light primers strikes so close together, and what preventative action can I take to avoid such occurances in the future?  I was doing double taps if that helps.  The gun has approximately 500 rounds through it and is due for a cleaning.  It's a basic Rock River Arms Carbine with Bushmaster lightweight barrel.  All other parts are RRA.

Thanks in advance.

You do not state if factory or reload ammo. Too bad you did not save them and "drop" them in a gauge. Possibly slight large and second time chambered allowed full bolt closure to allow fire pin to contact proper?


Preventitive action,,, buy a case gauge and "drop" all your ammo prior to the event, helps weed out those "bum" rounds. Nothing like a malfunction while the timer is running.

Quoted: You do not state if factory or reload ammo. Too bad you did not save them and "drop" them in a gauge. Possibly slight large and second time chambered allowed full bolt closure to allow fire pin to contact proper? Preventitive action,,, buy a case gauge and "drop" all your ammo prior to the event, helps weed out those "bum" rounds. Nothing like a malfunction while the timer is running.

Doh, my mistake!!!!

It's real deal mil-spec M193, stamped W C C 78

Quoted: Not using a match trigger or light springs right?

Nope, completely stock, save for the Bushmaster barrel.  The trigger is a little rough, almost to the point of sticking, but not quite.  I'm going to clean it and take it back out tomorrow, and will report back if I have anymore problems.  The gun has functioned admirably up until the back to back light primer strikes, with the exception of a few mag related feed failures in the first 100 rounds or so.  Three problems back to back just kinda threw me a little.

I would guess you have a tired hammer spring.  It would probably be adequate forever with commercial .223.

Sam

I suspect the hammer spring also.  Rock River seems to use a lighter spring than some others, possibly because most of the Factory rifles are fitted w/their match trigger (just a hunch,though). Get another brand spring and see if the problem occurs again.

Quoted: I'll bet you have a loose primer down in your fire control parts.  Depending on where it is, it can interfere with trigger movement or even completely lock up the FCG. -Troy

As in a primer blew out and fell into my lower?