Primer seating issue

[cbacejr]

I was loading new Alpha 6mm Dasher brass and ran into an issue where the primers were not seating completely. I’m using a RCBS Rock-Chucker press and thought I was seating them firmly.

When I was trying to set the bullet seating depth I was getting inconstant results. When I measured them with my caliper some were longer or shorter than others.

When I looked some of the primers were not fully seated. I ran them thru the press again and on some you could plainly feel a little give.

Has anyone else run into this?

Is there a better tool that gives more consistent results?

 

[SSL]

I was loading new Alpha 6mm Dasher brass and ran into an issue where the primers were not seating completely. I’m using a RCBS Rock-Chucker press and thought I was seating them firmly.

When I was trying to set the bullet seating depth I was getting inconstant results. When I measured them with my caliper some were longer or shorter than others.

When I looked some of the primers were not fully seated. I ran them thru the press again and on some you could plainly feel a little give.

Has anyone else run into this?

Is there a better tool that gives more consistent results?

I haven't primed rifle cartridges directly from a press for years. Though many do, I never really trusted the consistency. I much prefer hand priming so I can feel the seating and visibly check each primer - or even just run a finger over the seated primer to check. Good opportunity to double check case condition. Lots of alternatives out there, but my preference is the RCBS hand primer. I have two, each with the universal holder. One is set for large primers and the other is for small primers. May not be your choice, but there are a lot others to look at too.

 

[D-4297]

No mention of cases used but I found years ago that using a pocket tool , and "squaring" the pocket eliminated a lot of primer insertion issues , and I haven't had a primer seating issue for at least seven years now . Even with different cases and primers .
I seat my primers using a very old R.C.B.S model A2 that has the Primer tool mounted to the press . Works great .

 

[AlNyhus]

Check the bottom of the primer pockets....there may be a radius between the side and the bottom that prevents the primer from bottoming out in the pocket. There can also be some taper in the sides. If that's the case, uniforming the pockets will take care of this.

 

[Straightshooter1]

I was loading new Alpha 6mm Dasher brass and ran into an issue where the primers were not seating completely. I’m using a RCBS Rock-Chucker press and thought I was seating them firmly.

When I was trying to set the bullet seating depth I was getting inconstant results. When I measured them with my caliper some were longer or shorter than others.

When I looked some of the primers were not fully seated. I ran them thru the press again and on some you could plainly feel a little give.

Has anyone else run into this?

Is there a better tool that gives more consistent results?

You didn't say just which primers you're seating???

As mentioned and as I recall, my Alpha brass's primmer pockets did have a radius from the bottom to the side of the pocket. Depending on the primers one is using (different ones with different heights), that radius does tend to interfere with getting primers fully seated. I always uniform my pockets anyway, so that's never a problem.

Addendum: Alpha primer pockets ARE tight and I couldn't use my usual RCBS uniformer as it wouldn't fit. I had to go get a 21st Century uniformer that worked well since the shaft is .001" smaller in diameter.

 

[JFrank]

In addition to the posts above I’ll note that Alpha dasher brass primer pockets ‘are’ a wee bit tight, not all primers are the same diameter either. Personally I started with a smaller primer and set them with a 21st century hand primer. They were still on the snug side but the final results were positive, seating to the anvil plus a tiny crush.. stopping at the radius shot very well.

 

[bozo699]

I was loading new Alpha 6mm Dasher brass and ran into an issue where the primers were not seating completely. I’m using a RCBS Rock-Chucker press and thought I was seating them firmly.

When I was trying to set the bullet seating depth I was getting inconstant results. When I measured them with my caliper some were longer or shorter than others.

When I looked some of the primers were not fully seated. I ran them thru the press again and on some you could plainly feel a little give.

Has anyone else run into this?

Is there a better tool that gives more consistent results?

I hate the grammar and safety police but I just can’t help it on this one! I assume or hope you didn’t seat the primers deeper with the powder and bullet still in place!….with that being said I don’t use Alpha brass so don’t know but others that have posted seem to have valid answers. Like JFrank I use a 21st century hand primer and have fantastic results. I haven’t seated for decades with a press but they do work.
Wayne

 

[K22]

I stopped using the primer seating arm on the press over 30 years ago, maybe longer. The reason: inconsistent seating evidenced by off center primers and the resultant marred primer cups and flipped primers.

While the RCBS hand primer tool was a significant improvement, the arms kept breaking (fatigue failures) which RCBS replaced free of charge several times.

I became weary of this failure / replacement cycle, so I made the investment in a Sinclair hand priming tool, and it has performed outstandingly. Having literally primed over 25,000 rifle and pistol cases with this tool, I have had zero problems. This tool is extremely precise and durable.

 

[M-61]

I hate the grammar and safety police but I just can’t help it on this one!

I don’t. Grammer would include the proper nomenclature which is needed to determine what the OP is really talking about. (Headspace is one thing, COAL something else as examples.) Then safety. Of course you’re not required to reply but if you read something where the OP is doing something totally unsafe ( insane) it’s kind of nice to let them know they’re on the path to self destruction.
Spelling, punctuation etc is a matter of personal preference.

 

[64Rambler]

If you're not used to Alpha brass, there's a bit of a speed bump in the primer pocket. You have to get the front tires over, keep moving and then get the rear tires over to get to the stop.

 

[robert8904]

I use a small swab with alcohol and moly powder to lube primer pockets. Greatly reduces the force needed to seat primers and gives me much easier feel and control over seating depth. I get a very thin, almost invisible coating which is all that's needed. Even small primer Alpha brass becomes easy to prime. I use an RCBS bench mounted priming tool.

 

[quest450]

lubing primer pockets could potentially be the missing link......I'm definitely doing that next time I prime my brass