[clearpk999]

So i bought a m700 sps tactical chambered in .223 and here is a list of things i've done to it.

-magpul hunter 700 stock
-mounts, rings, scope
-timney calvin elite trigger

*Here is the problem:
For the last month or two, ive been having some issues at the range. Ive tried two different types of ammunition and the problem persisted. Every 4-10 rounds or so, the firing pin will strike and leave a dimple, however, the gun misfires. It seems like the dimple could be a little light but in comparison to the bullets that do fire, they look pretty similar. I've read a few threads already on this topic and have tried just about everything. I have disassembled the bolt, checked the spring and the firing pin, made sure that the bolt handle is all the way down and snug when i go to fire, and have checked for any debris that may have been obstructing any of the parts in the bolt/reciever. Even after all of this, the problem still presents itself. I have contacted timney to see if they can take a look at the trigger but i want to be sure that there isn't anything obvious that i should look over before i send the trigger in.

Thanks and gig 'em!

 

[Rory]

Have you got any shots of the struck primers? Is this an issue with several types of ammo? It does not sound like a trigger problem to me as the firing pin is being released when you pull the trigger (unless it it is being released under its own accord?). I would look at either ammunition/primer issues or perhaps even firing pin is just too short.

 

[Scorpion8]

Every 4-10 rounds or so, the firing pin will strike and leave a dimple, however, the gun misfires.

Get some of the mis-fired cartridges and some of the fired cases and compare them side-by-side. A .223 will headspace on the case shoulder, so if there is very much visual difference, the non-firing cases may be just a tad too short. Are these reloads or remanufactured rounds, perchance?

 

[clearpk999]

Thanks for the recommendations. I was using some cheap factory ammo. I switched to Remington's 223 ammo and the problem is gone!

 

[Scorpion8]

I was using some cheap factory ammo.

Good lesson-learned. Offhand, what was it?

 

[Deadshot2]

Good lesson-learned. Offhand, what was it?

I shoot cheap ammo all the time and don't have any problems. It comes right out of MY factory which is an unused bedroom


A lot of cheap ammo is improperly sized and has excessive headspace clearance. The ejector spring pushes the case as far as it can forward into the chamber, sometimes without the extractor "hook" even engaged in the extractor ring. When one pulls the trigger all you get is a dimple because the firing pin doesn't (and never will) protrude far enough to really hit the primer.

If one has a press and a collet type bullet puller there is a solution. Pull the bullet part way out of the case and then reseat it longer so it touches the lands. This will force the case to stay back against the bolt face and unless the ammo is a real POS, it will fire. This will then push the shoulder forward and correct the excessive cartridge headspace problem. Then you just properly size the fired case and shoot it until the end of it's life.

Having a case gauge for the caliber will let you check the ammo prior to taking it to the range, even before you buy it if you want to take the gauge to the store, open boxes, and check the ammo before buying. The case gauge will show improperly sized cases with ease.

 

[rlandry6]

It depends on the case gauge. Most including the Wilson only check for headspace and length. Wilson even syas so in the encolsed instructions.
Look at the case gauge and the slotted gauge from Sheridan Engineering. They will tell you what you need to know.

That said, most ammo, even the bulk stuff is going to be sized to fit about any chamber. Head space is what's critical and the gauges will show you that.

 

[rkittine]

It would be interesting to try taking the ones that mis-fired and trying them in another .223. I have seen some sloppy chamber cuts on factory Remington's.

Bob