Primers stand proud ??

[Charlie-NY]

I've got some new Alpha SRP brass in 22 Creedmoor. The pockets are too narrow for my Sinclair pocket uniformer tool to fit without force, so I skipped this step. I loaded all the brass with CCI 450 primers and could easily feel them hit the bottom of the pocket.
While loading up some Berger 85.5 Hybrids, I noticed that the anvil on my calipers revealed a slight amount of light between the anvil and the case head. The primer was protruding ever so slightly. I tried to seat the primer deeper, but it was definitely on the bottom. A quick check of the remainder of the primed cases all had primers that were slightly protruding, maybe just .001"

Has anyone else ever noticed this? Is it more likely the brass or the primers?

Solution?

 

[mgunderson]

Start measuring the primer pocket depth with the back of your caliper. For safety do not try and push the primer in with powder in the case.

 

[gdbleb]

Do you have a swage? Maybe after that you can get the Sinclair PP Uniformer in and deepen the PP pocket. Just an idea.

 

[6ShotsOr5?]

If you check the specs from the primer manufacturers there are some differences in height. Since they are small rifle primers, you might be able to identify and use some shorter primers next time. In case you like this option, I can’t remember which brand is the shortest so either you have homework or another forum member that knows this answer may help you out.

 

[alphapygmy]

I believe PMA Tool recently released a primer pocket uniformer specifically for SRP Alpha brass.

 

[Charlie-NY]

I believe PMA Tool recently released a primer pocket uniformer specifically for SRP Alpha brass.

I see it on their sight but it's hard to see how it differs from their Lapua brass small pocket tool. I can live with the $75 cost as long as it solves the problem.

 

[PatMiles]

I see it on their sight but it's hard to see how it differs from their Lapua brass small pocket tool. I can live with the $75 cost as long as it solves the problem.

Call PMA?

 

[ShtrRdy]

Call PMA?

PMA newsletter says they are going to be at the benchrest nationals for the next three weeks.

 

[old_heli_logger]

Good luck and be careful

 

[Rope2horns]

I've had zero issues with the Alpha brass and CCI450 primers. Mine are .003 below flush. I use a 21st Century priming tool.

 

[memilanuk]

I see it on their sight but it's hard to see how it differs from their Lapua brass small pocket tool. I can live with the $75 cost as long as it solves the problem.

I recently had the same question - I have the Lapua version, but I'm currently running some Alpha OCD brass (308 Win SRP). This is what I got from them via email:

The difference is in the depth. Both of our small uniformers are .002" - .003" smaller in diameter than the others on the market (.1695 vs .1725) for the tighter pockets of Lapua and Alpha brass. Our Lapua uniformers cut significantly deeper than our Alpha uniformers though (.126max vs .124"max).

The funny thing is that our Lapua uniformers started out (14 years ago) cutting at .123-.124 and Lapua has gradually made their primer pockets nearly .003" deeper over that time. Looking at your order history, you have the current depth on your Lapua uniformer. There is no danger in going deeper with the Alpha, it just takes a long time to cut that extra depth.

So now I have some extra deep primer pockets (0.125-0.126"), and by the time the primers (~0.121") hit the bottom (top) of the pocket, then a fair bit of anvil compression... they're something like 10-11 thou below flush. Maybe not ideal, but they seem to work just fine at distance so...

 

[243winxb]

protruding, maybe just .001"

Has anyone else ever noticed this? Is it more likely the brass or the primers?

Seat with RCBS Ram Prime. Its the seating method??

 

[Straightshooter1]

I see it on their sight but it's hard to see how it differs from their Lapua brass small pocket tool. I can live with the $75 cost as long as it solves the problem.

One of the primer pocket uniformers I use is the 21st Century primer pocket uniformer tool. It's fits nicely into the more narrow primer pockets, AND. . . it's easily adjustable. It's a well built tool. You might want to seriously consider it.

21st Century Innovation Primer Pocket Uniformer | Bruno Shooters Supply

Product Details

www.brunoshooters.com

 

[danny]

I've got some new Alpha SRP brass in 22 Creedmoor. The pockets are too narrow for my Sinclair pocket uniformer tool to fit without force, so I skipped this step. I loaded all the brass with CCI 450 primers and could easily feel them hit the bottom of the pocket.
While loading up some Berger 85.5 Hybrids, I noticed that the anvil on my calipers revealed a slight amount of light between the anvil and the case head. The primer was protruding ever so slightly. I tried to seat the primer deeper, but it was definitely on the bottom. A quick check of the remainder of the primed cases all had primers that were slightly protruding, maybe just .001"

Has anyone else ever noticed this? Is it more likely the brass or the primers?

Solution?

I have noticed this sometimes. I have the Sinclair uniformers. Sometimes some pockets may be narrower and some tools may be wider (tolerance stacking). Feed the uniformer in slowly while it is running and the uniformer should open it up. It may grab here and there, but feed it slowly while turning, but whatever you do, do not skip uniforming

Danny

 

[Rsadams]

Let me just ask , are you using an adjustable depth primer seater..???? Sometimes it can fool you if it's out of adjustment.....

 

[Clancy]

Alpha pockets have a little shelf in the bottom. They’re hard to prime the first time.

 

[RegionRat]

Any idea of your primer pocket depth and primer height?


If the pockets are not at least 0.117" deep on SRP, then I would go ahead and run a uniform cut to get them at least that deep. You don't necessarily need the full 0.123" depth.

 

[Doom]

I noticed that the anvil on my calipers revealed a slight amount of light between the anvil and the case head.

You are saying anvil but do you mean the top portion of the primer?

 

[Charlie-NY]

Good luck and be careful

That's some very helpful info. It looks like a BR4 would solve the problem. Not sure a CCI450 is needed but it seems to be what is commonly used in 22 Creed, 6BR, Dashe, etc.

 

[Charlie-NY]

Let me just ask , are you using an adjustable depth primer seater..???? Sometimes it can fool you if it's out of adjustment.....

No - I am seating by feel but can easily feel the primer hit bottom. Additional seating pressure doesn't change primer depth. Using more force would actually affect primer dimensions/shape.