Solved a primer mystery

Bubba Jr.

Several months ago I asked the question, "why do Remington primers seat so easily?". I finally got around to investigating the issue. I surmised that the OD of the primers was smaller on the Remington primers. Someone on here (I don't remember who anymore) suggested that the primer shell was made of thinner metal, and you were actually crushing the outer case of the primer during the seating operation.

I got out my small pistol primers this afternoon and confirmed my suspicions. I measured Federal #200 Magnums, CCC #500, Win WSP, and they all measured 0.1750 with my digital calipers. I measured the Remington #1 1/2 primers and they were 0.1745. I know 0.0005" doesn't sound like much, but it would be enough that you would feel a difference when seating them.

Now I still have the question, will they have a tendency to back out of the case while in the magazine during firing of the gun? I still haven't fired any of my reloads that I used the Remington primers in, so I don't have any experience with the issue.

Anyone have that problem with these primers?

nemesisenforcer

I've never had issues with remington primers, but I haven't used many of them in comparison to CCI or winchester either.

rovernut

at one time the only magnum rifle primers I could get wwere remingtons. I"ve been useing them in 300 weatherby, 300 WM, 257 weatherby, 338 WM and 375 H&H. no problems backing out or signs of excess pressure. these loads are all in Remington brass, does this make a difference??

cpermd

Primer brand and primer pocket dimensions all make a difference.

CP

JustC

bolt action or semi-auto?

Tailgunner1954

quote:I measured Federal #200 Magnums, CCC #500, Win WSP, and they all measured 0.1750 with my digital calipers. I measured the Remington #1 1/2 primers and they were 0.1745. I know 0.0005" doesn't sound like much,
Not to bust your bubble, but calipers (regardless of readout methiod) are not accurate enough to be reading to 5 tenths. For that matter a standard micrometer is not capable of splitting tenth's accuratly.
To accuraty measure the kinds of differences your looking at you need a good, direct read, tenths mic, and hold the primers in tweezers while you take your measurments (the heat from your fingers will cause greater expansion than the difference your trying to measure).
Also, you would need to measure a random selection of say 50pcs out of a brick to get a staticticly valid sample.

General measuring rule:
Calipers, within .0050 (thats OK, because as reloaders our tolerances are quite loose).
Standard Micrometer, with in .0010
Tenth's Mic, to .0001
Finer than that you should be using a CMM