What are these?

[Manitobahunter]

I bought a box of primers at a gun show last fall.  The box says Fed 200 small rifle.  I've used them in my .222 without a problem but when I put them through my new .204 I had about 10% of them burn small holes in the primers.  Are these actually small pistol primers and to light for the .204 and it's pressure?  I'm using a middle of the road load in the rifle.  Got my hands on some 205 primers but haven't had a chance to give them a go yet, just waiting for the snow to start melting.

[Grumulkin]

Those primers should work fine in a 204 Ruger.

There are several possibilities:

1.  Your load is really too hot.
2.  There is some irregularity in the firing pin that is piercing the primers.
3.  Mislabeled primers that are really pistol primers (unlikely unless the gun show purveyor bought a bunch cheap and put them in the wrong box).

In any case, shooting cartridges where the primers are getting pierced damages the firing pin so it would be best not to shoot those cartridges.

[Manitobahunter]

It's not the pin punching a hole, it is around the edge of the primer where it burns a small pin hole.  I'm using Rem brass, 32gr seirras and 27gr of IMR4064.  I don't think it is because it is too hot as I had some with starting loads do the same thing.  Tried a couple different powders with same results.  The rifle really likes this load, will shoot dimes at 100 yrds.  No other signs of pressure.

[SHOOTALL]

check the color of the primer mix in the ones you are using with a box of known content , One still sealed or un opened .

[Reed1911]

Those are most likely the leftovers from a bad run. Remington had the same problem once and ended up replacing a bunch of bolt faces and breech faces. Either burn them in something that they will hold up in or trash them. They will pit your bolt or breech face after a while.

[wncchester]

Primer makers order brass strips made to certain specifications of alloy and thickness.  Sometimes the providers fail to meet those standards.  Caps made from a thin, hard alloy tend to blow out at the junction between the walls and bottom of the cup.

All we can do is contact the maker and ask for an exchange.  They are likely to do so and it will save your bolt face from damage.

[Manitobahunter]

After a little looking around I found that Fed 200 primers are a magnum small pistol primer.  Would it be that the cup is too thin for use in a rifle like the 204?

[LaOtto222]

Magnum primers can burn faster/hotter than a regular primer, but I suspect the cup is thin. I do a lot of shooing small rifle primers in 221 Fireball, 222, and 223. I prefer Remington 7 1/2 or CCI BR4 primers because I just do not get pierced primers with them. You mentioned they worked fine in your 222, most likely because the pressure levels in a 222 are not as high as a 204. I know there are lots of folks that swear by Federal primers so they must work OK, but I still prefer the Remington and CCI bench rest primers, I get good results and they do have a thicker cup. Good Luck and Good Shooting