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Primer Seating Depth!

Posted: Tue Jan 20, 2009 3:58 pm
by Clover_Shooter
Over the summer I had a few reloads that didn't go off! Maybe 6 out of 300. I originally thought the primers or pockets were at fault, but someone said firing spring or pin might be the fault. Another said use a hand primer, I use the one on the RCBS Rock Chucker Press. So at that time I didn't look into it and figured that I would upgrade to the faster firing pin. I haven't done anything yet. Still have a couple of the misfires. Very small indent in primer. So is it the reloads, firing pin or another reloading process!
  • Gun is a Remington
    CCI BR4 primers
    Brass used at least 8 or 10 times
    Full lenght sized
    Primer pockets not uniformed[/list
    Thanks

Re: Primer Seating Depth!

Posted: Thu Jan 22, 2009 9:29 am
by Bunnybuster
Could be the firing pin, but not real probable on a new rifle.

Might be the primer depth, but could also be that some cases have the shoulder pushed back too far, and move forward enough to prevent good impact by the firing pin.

It could also be a bit of contamination on the primers themselves.

Re: Primer Seating Depth!

Posted: Thu Jan 22, 2009 10:03 am
by Ahab
Reloads, as Bunnybuster suggested, the shoulder was pushed too far back. Thats why I only neck size rifle loads. ;)

Re: Primer Seating Depth!

Posted: Thu Jan 22, 2009 3:47 pm
by Clover_Shooter
Thanks, since I had a fairly new rifle and new RCBS Competition dies. I did not think of headspace! I have read about it but never experienced it. Now I need to get a headspace gage and check to make sure that the full length die is adjusted properly. Can I just bump with that or should I be looking at a new neck sizer die also.

Re: Primer Seating Depth!

Posted: Thu Jan 22, 2009 4:03 pm
by Rick in Oregon
Clover: Before you run out and spend money on stuff you may not even need, consider this:

If you did not uniform the primer pockets on your new factory fresh cases, the pockets may be of too narrow of diameter (too small, and typical), and by using the primer seater on the press (a no-no for accurate ammunition), the primers may not be seated all the way to the bottom of the pocket, and were just driven forward a few thou and not igniting properly. If the primer anvil is not in full contact with the bottom of the pocket, eratic ignition is the result. I've seen this in the past, and that led me to hand seaters and proper pocket uniforming.

Chances are your new rifle is headspaced properly, as this is a matter of fact on all new rifles prior to leaving any arms factory. Uniform those pockets first, and see what happens.

By the way, the primer seater on a bench mounted press is NOT the way to seat primers if you want peak accuracy. It will either crush the primer (especially if the pocket is too small) and/or not give you the proper "feel" when the primer is seated and tell you by feel if the anvil is compressed at the bottom of the pocket.

Re: Primer Seating Depth!

Posted: Thu Jan 22, 2009 4:30 pm
by Clover_Shooter
I tried to measure the seated primers but had a hard time getting a repeatable measurment. Will try and find a micrometer to measure them. My list of things to check is getting longer. Not much to do in the winter anyway. Thanks again.

Re: Primer Seating Depth!

Posted: Thu Jan 22, 2009 5:43 pm
by Rick in Oregon
Clover: One more thing....the primer should be from .002 - .005" below the base of the case, not flush, and never raised above. It is rare when a factory unmodified case will give that measurement without pocket uniforming.

Re: Primer Seating Depth!

Posted: Sun Jan 25, 2009 2:52 am
by Orion2see
I ordered a Sinclair priming tool (have not received it yet) in hopes of getting more consistent primer ignition. I will be slower, but hopefully it will enable me to create more accurate .204 ammo.

Re: Primer Seating Depth!

Posted: Sun Jan 25, 2009 1:13 pm
by Silverfox
Orion2see--You won't be sorry about ordering that Sinclair primer seating tool. Ol' Rick in Oregon mentored me into purchasing one of them and it is definitely the way to go for primer seaters. The feel/touch is magnificent and you can adjust the seating depth to within a gnat's eyelash.