Primer pockets getting tighter

B

Bob Kingsbury

New member
Seems very rare, but my primer pockets are getting very tight.
lapua brass in 6ppc. Same primers for the last two years. Case heads are flat
as is the bolt face. They are tight enough that once in awhile a primer cannot
be seated to the bottom. I reamed some pockets with a wilson pocket reamer
and they seat fully and smoothly, but otherwise they are well flattened.
 
Joel, hey buddy, where were you for the big bath this year. It actually rained inside my loading trailer when the
roof vent blew off. Your correct about wet primers.
Nope, not the decapping rod, pockets are full depth, the sidewalls are the problem, I'm lost.
 
Bob,never heard of it...or had happen to me...... but could`nt you deprime a fired case without resizing...... then check primer fit....
if too tite.... chamber to small
if fit o.k. sizing die too tite....???
I`m eager to hear the true answer....
OMHO
bill larson
 
This happenned to me a number of years ago, it turned out I had a lot # of cases that did have convex case head faces. You could see a distinct shiney ring around the primer pocket after several firings.

I made a little lathe set-up and faced them all, and the problem went away.

Later, Lapua started making them flat again, and I stopped facing them.

But, if your case heads are indeed flat, I have no answer.............jackie
 
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I am glad to hear someone else has this problem besides me. All I ever hear about are pockets getting to big so I figured it was just my imagination.
I dont know how to tell if my heads are indeed flat or not so I cant answer that one. But I was having this happen last year but not so much this year yet. Maybe its because I started shooting some stiffer loads this year.
 
Vern, easy. Get a small straight edge, like a 6" scale, and hold it against the case face while looking into a light. If they are convex, you will see it...........jackie
 
Vern.
I saw the same thing on my 2nd lot of brass. I could feel the convex thing. They went in the scrap bucket real quick.
I figured every thing should be the same.....

I almost said get some new glasses.....Just a joke Vern. Just a joke...
 
Its ok zippy not a problem. Sounds like your sense of humor is like mine.

I could figure the flat thing I guess my mind reverted back to SQUARE.
How do we verify a case head is square since the body tapers and we are working in .001?

Since I dont have a lathe I would suppose that I could use the wilson case trimmer and just turn the case around? That is if I needed to flatten the head of the case?
 
Vern the best way you can accuratly square a case head is single point it in a lathe. I would not use a trimmer.

What I did was bore a piece the exact same taper as a 220 Russian case, (picture a Wilson case holder), and pushed the case in, took the light cut, popped it out, and then another. Once your set up, you can do 100 in about 45 minutes. Of course, you do need access to a lathe.
 
Jackie your right so since I dont have a lathe I go back to the original question. Will it work by inserting it backwards in a wilson case trimmer providing all the cases were trimmed to length prior trimming the heads square?
 
Should work.
Push the case in straight.....
Got an arbor press, right. Put the case holder on top of a deep socket. As you push the case in, make sure everything is straight......
I use deep sockets to install and remove small bearings, pins, posts, er, whatever. Everything has to be straight.
 
Zip I am a loss for the need of a socket.
If we use the case holder to hold a case and the mouth is square when we trim it if we simply turn the case holder around shouldnt it be able to trim the case head square? I realize all cases would have to be trimmed to length, then the trimmer readjust the trimmer cut length.

HOWEVER when I asked about case head squareness so many years ago everyone said all of that PSI would square any case head.
IF that were true why do these posts exist. I think sometimes theory about what does and doesnt happen are often no more than theory and opinion.
 
The socket gives someplace for the brass to go. A spacer/hole.
You are correct. I guess you don't need it. I was thinking you had to flip the brass around.
Ah!!!! But, the brass still needs a spacer. So you don't bugger up the case mouth.
 
Vern said:
Jackie your right so since I dont have a lathe I go back to the original question. Will it work by inserting it backwards in a wilson case trimmer providing all the cases were trimmed to length prior trimming the heads square?
Click to expand...


Vern, I have used this technique for years; it works well. Don't overdo the depth of cut. The cutter will begin to shave off brass just at the edge of the primer pocket and extend outward as the cut progresses. There is no need to extend the cut beyond the solid head part. In other words, don't extend the cut all the way to the case head rim. Hope that makes sense. The words aren't flowing well this morning; must need more coffee. Yeah, that's it; more coffee. :p

Gene Beggs
 
Thanks Gene and thank you again for sharing your vast knowledge with me yesterday.
Hope to see you in the tunnel later this year.
 
My case heads are flat now, but may well have been domed at one point. The problem surfaced quite progressively and I
thought it was an occasional fat primer. More and more cases developed tight pockets and rather than pitch them, I decided
to see what would happen. I faced the heads lightly followed by a primer pocket uniformer to establish common depth. Then
with a .1735 chucking reamer ground flat on the end with the corners just broken, I removed the extra material. Primers
now seat nicely and in 200 rds, they haven't tightened back up and what is surprising, I have no soot ring on my bolt face.
Primers also appear to flatten more uniformly than before, but not excessively flat. Thinking now, I may face all my cases
before fireforming.
 
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