primer pinholes

[armike]

i am new to reloading and have had some primers with small pinholes where the firing pin hit or i get indents back out. any ideas.
Mike

 

[Greg110]

Seroiusly over pressure!?

 

[rstreich]

Got pictures?

Most likely you just need to bush your firing pin. Remington?

 

[treeman]

what primers are you useing? rem 6-1/2's are bad about peircing. which if it in the center of the fireing pin will cut a crater in the center of the f.pin. if they peirce at the edges of the cup will cut the bolt face. neither of these are a good thing. if you are useing rem 6-1/2 change to a rem benchrest[7-1/2] or cci-400/450, hope this helps, treeman

 

[armike]

i was using cci 400 primers, i talked to cci yesterday and they said i should cut back on my load. the load i saw the pinhole in was lc brass with a 65grain gameking over 25.0 grains of h335.only ona had a pinhole others had dimples back out. lee die and cci told me the lc case has less capacity but from the info on this site showed this not to be the case.i also now believe my lee scale is .5 grain off to the light side. i wieghed a 50 and 65 grain bullet and they both show to be .4 to .5 grain on the light side.also a gentleman at the range had a chrony and the load was pushing 3046 fps and it should have been around 2850-2900 according to the sierra manual ar section. their gun and mine both have 20" barrels.i also loaded a 50 grain v-max over 25.0 grains of h335 and saw small dimples.
velocities were around 3250.

 

[armike]

oh yeh it's a rock river 20" h-bar flat top topped with a 4.5-16 konus pro scope. i put on a free float forearm and MI low profile gas block.at 100 yards i can usually get 3-4 holes touching with flyer or two. i attribute most of the flyers to my shooting but i learn and improve with every range session.

 

[280man]

Which Sierra manual are you using? I use the fifth edition that has AR-15 specific data and I have found it to be very good. If I recall they say to reduce your load by 10% if you are using military brass also CCI builds a military primer that is harder yet I think its a #43

 

[Winchester69]

CCI builds a military primer that is harder yet I think its a #43

The CCI military primer for 5.56 NATO is #41. The #34 is for 7.62 NATO.
.