primer pockets getting tighter? why?

S

stevelong

Guest
Hello, a fellow match shooter friend has noticed that both his .308 Lapua cases & .222 Lapua cases have been getting harder & harder to get primers stuffed into using an rcbs hand priming tool. Some are two-hand difficult.
WHY?
Number of loadings now are probably somewhere around 10+ up to ? 15-20.
He uses a RCBS "case prep center" that is the ac-powered station.
He cleans the primer pockets each loading with the powered unit & a primer pocket UNIFORMER which shines the pocket base clean without removing much or any metal. He prefers it to the steel-brush insert for pockets.
The uniformer does not seam to touch the pocket WALLS any.
Ideas?
Thanks in advance,
Steve Long.
 
Tight Primer Pockets

The problem may be with the shell holder. It might need cleaning or it is not installed properly. How old is the priming tool? It could worn out.
 
pockets tightening up

FB, yeh, he has both sizes inserted & uses them correctly.
Smitty -Priming tool is not over 5 years old, I'm thinking.
SH -dirty or installed wrong..... really?

Steve.
 
Ran Into This A few Years Back

About four years ago, I had the samething happen tothe 220 Russian cases we use. After about 6 firngs in the "upper load window", the primers became VERY tight.
Here was the culprit. Upon examining the case head face, we found that they were not flat at all, but actually convex. The only part actually hitting the bolt face was the very edge around the primer. The primer pocket was literally getting extruded inward as the pressure was trying to flatten out the face of the case head.

I cured the problem by making a fixture that allowed me to set the cases upin my lathe and face the heads square.This cured the problem 100 percent.

Later cases seemed to be flat, so I stopped facing them, have not had any problems since.

I guess it was just that particular lot of brass that caused the problems.

Lay a precision straight edge on the face of the case and see how flat they really are.......jackie
 
Steve,

Is he using the same priming tool for both cases?

Some of the primer tools will gaul if you don't keep a little bit of grease on them. It can kind of sneak up on you with use.

Try seating some primers in a few new cases, and see what happens. If they're still really tight it might be the primer tool.
 
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steve

Try using a dental tool to clean powder and trash from the shell holder groove.

Let us know what was causing the problem.
 
convex case head

I had the same problem and was fixed in the same manner as Jackie described. However, I am still having that problem if I don't face the case head a bit. I don't use as much brass as he does, and maybe mine are all still from a batch or two that had this convex condition.
Bryan
 
Any chance he's changed primer brand or batch?

The first PMC Russian primers I used had flat corners like regular primers. Later ones had a partially convex face like some older European brands & these buggers tend to spring the lip of the cup out under priming pressure, as far as I can make out. For whatever reason, they're more difficult to seat (except in marginal brass).
 
One other thing to consider

Steve , Are the pockets getting tighter in diameter(or circumference) or are they getting shallower in depth ? If a too long decapping rod is the culprit it will push the pocket out when resizing. If you drive your reloading equipment around from match to match everything will eventually vibrate loose(like decapping stems).
Joel
 
I went through a couple of boxes of Lapua .220 Russian 2 or 3 years back that did that exact thing. The case heads were domed a bit in the center. I put a Wilson .220 Russian case holder in a 6-jaw chuck and just skinned the heads and shot the brass. The latest lots I have used didn't do it.

Mike Swartz
 
One Mans Trash, Another Mans Treasure!!

Years ago Alvin Davidson and I had a conversion about
the primer pockets getting loose on the then available
Sako 220R brass. [late-late 70's early 80's ?] We both
decided the cure would be to convex the bolt face. Neither
Alvin or I decided how much or who would do it first. Well
along comes the next batch of Sako 220R brass and life
got better. Then along comes Allie Uber and every body
finds out how much powder he is stuffing in a case to whip
every body else's butt. Gotta try it, but alas, loose primer
pockets again. I was to cheap [Couldn't afford] to have new
brass for every shoot, so I never beat anybody but myself!
Now, every time I seat a primer in the latest brass I
have, I squint my eyes, grit my teeth [store bought], turn
my head, and go for it. Be carefull what you wish for!

I, as well as others, miss YOU, Alvin-&-Skip You will
allways remain in our hearts and memories!!!

Steve Moore
 
pockets

Hello, thanks for all the posts, we'll be looking at the case heads with a flat edge carefully & see how those look.
Same primer tool, same primers, same shellholder & a different lot of cases works well together, so it's sort of like it's related to THIS particular 100 cases (222 Lapua).
THIS lot of cases in question did not used to prime hard, so it's like something CHANGED.
I like the post that said possibly the depriming rid is going too far in & pushing the web out a skosh.
Thanks again,
if we get a resolution for solid I'll put it in here.
Steve.
 
If you folks can figure out how to get the pockets smaller with firing, I for one would like to know how you do it? I've never been able to go over the 15-20 shot mark, when the stuff was a buck and a half a piece, that information would have been heaven sent.
 
I have some brass that I can insert primers with my thumb. Sad, huh?
 
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