Primer seating, how critical for a ladder test?

[thefitter]

This question is related to another thread. I primed my first batch of brass yesterday and had trouble with quite a few primers seating.

The brass is new once fired FGMM. The primers are CCI BR. The press is a RCBS bench mounted primer press. I deburred the flash hole and used a uniformer on the pockets. I'm now thinking I should have bought a swage and swaged everything first also. But they are not military crimped so I did not think it was necessary.

Some of the primer pockets were too tight and shaved off some of the cup of the primer. Most seem to be seated all the way down but some are a little higher and some have a half moon crease in them.

I planned to do a ladder test to find a good load for this rifle. How critical are the primers position to that equation? Should I wait to do my ladder? Should I first swage all the pockets for uniformaty and then load?

I don't want to go through all the work of loading for a ladder for 175, 168 and 155 if the FU primers are going to throw off my data?

Thanks

 

[Chiller]

Re: Primer seating, how critical for a ladder test?

the old saying garbage in....garbage out.......???

 

[Chiller]

Re: Primer seating, how critical for a ladder test?

control as many of the items as you can. The more "unknowns" the more you need to question your results.

 

[MitchAlsup]

Re: Primer seating, how critical for a ladder test?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: thefitter</div><div class="ubbcode-body">Some of the primer pockets were too tight and shaved off some of the cup of the primer. Most seem to be seated all the way down but some are a little higher and some have a half moon crease in them.</div></div>

There is this thing called a primer pocket uniformer that makes this kind of problem go away.

 

[Low Sioux]

Re: Primer seating, how critical for a ladder test?

IF you are using the press to seat primers, which it sounds like you are, you need to make sure you push the seating arm into the ram as far as it will go--until it stops. If you just push it in to where you think its centered you will end up with the problems you describe.

 

[vman]

Re: Primer seating, how critical for a ladder test?

There are a few way to remedy this problem.

1) purchase a hand primer... even the ones with trays feed fine
2) move to a better brass such as Lapua, that requires no primer pocket work
3) purchase pocket uniforming tool and run it in your cases