who can answer this? Primers

Scouts_Out

Private
Minuteman
Mar 6, 2011
10
0
39
Texas
When seating primers, not seating deep enough will obviously cause failure to ignite, but if seated too deep/hard will it cause weaker ignition? testing loads on 22-250, 30-06 and 260 over the weekend I encountered a couple new problems first being odd fluctuations in velocities and poor accuracy. With all three rifles (all bolt guns) there were lesser velocities on some rounds, ladder testing the loads and increasing in charge weights, I first thought I was near max load because .5gr increases weren't showing the usual increases in velocity but kept shooting because there was no sticky bolts, no ejector marks, and no cratering. As I was logging the data I remembered once seating the Primer too lightly and the resulting click (got me thinking that i subconciosly sqeezed a little "extra",) could it be that I pushed the anvil just a little further on some rounds resulting in weaker ignition...

Side note, I usually spend most of my time priming pre-occupied with the impending doom of my OCD powder weighing methods... I do benchrest prep on cases, and ensure seating depth, neck tension and the like are uniform... the only area I "relax" on is priming, am I setting myself up for failure by not applying the attention to detail priming apparently requires or could it be, I need to sort primers...
 

Joe Kidd

NRA Lifer
Minuteman
Mar 26, 2013
57
0
North Carolina
My approach to priming is simple, always done on a hand tool. I seat till the primer just "touches" then I rotate the case 180 degrees and slightly bump again. I get good uniformity with this method. Seating too hard can break the primer pellet and cause some odd ignition issues.
 

RADcustom

Registered Coonass
Full Member
Minuteman
Jun 1, 2008
1,881
4
Louisiana
I'm betting it's something else. You didn't mention what brand of primer you were using but, you might try a different one. How confident are you that your chronograph was giving good information? Primers seated a little deep may cause some odd signs like premature flattening or cratering but, not what you are seeing. YMMV
 

Scouts_Out

Private
Minuteman
Mar 6, 2011
10
0
39
Texas
CCI LR, CCI #34, Fed 210M, Rem 91/2... I live too far from any Ranges and not good enough to compete, so I spend alot of time in the pasture testing different powder primer combos. I was trying some faster powders than usual, looking for backup loads...

as far as the chrono, its no Oehler, but ballistics data for the 260 (using velocities from that chrono) puts me within 4-5inches, first shot between 550-600yds... I assume thats good considering my level as a shooter.

The biggest possibility is I've only been reloading for a little more than a year, with great results... may have gotten complacent? mixed brass with another batch? who knows, I just don't feel as certain about the primer seating is why I asked.

Thanks for the replies!
 

Jig Stick

Gunny Sergeant
Full Member
Minuteman
Aug 27, 2010
1,439
3
41
Pittsburgh PA
I personally think you get better consistency using a ram prime on your press. Very easy to set up. And once it is, all you do is run your ram all the way up, every time, case after case, and the seating is uniform through out. There is none of this "feel" needed like when using a hand primer. Just my .02