All,
I load for my 17 Rem, and I use CCI 400 primers. With a box of 20 rounds, I tend to get 1 or 2 complete punctures by the firing pin through the primer. This has not caused any problems, other than in my mind...a bit of concern when a bit of smoke wafts out of the action. I bought the rifle used and rebarreled it, and I have no idea if a heavier spring was installed for the firing pin.

Has anyone experienced similar results with the CCI 400, or is it just my setup that's causing this? Is the CCI 450 a tougher primer, or another primer that is comparable to the CCI 400? I have a great accurate load worked up with the 400's and Win 760, and some suggest that you should use a 'magnum' primer with ball powder anyway, although as unclenick relayed in another thread, the benchresters shy away from the magnum primers for accuracy.

Any suggestions would be appreciated. Thx.

Never had a problem with them, personally. You may want to check your bolt face. Any escaping gas from the primer may be etching the face around the firing pin hole.

Thx kdub. Initially, I had no problems with the 400 primers. Just recently they began to puncture, and I haven't changed the load a bit. I figure either something has changed with the rifle (hope not), or the primer lot got a bit soft? I'll check the bolt face.

I've used a fair number of CCI 400s recently, some older and some new with no problems.

Remington developed their 7 1/2 primer specifically to stop primer piercing in the 17 Rem. That might tell us something, no?

I'd use the 7 1/2 unless it was unavailable, and then I'd switch to the WSR.

Rocky's on the right track. This article has the details, and if the link doesn't work, use a CCI 450, Remingtion 7½ or Federal 205M.

http://www.jamescalhoon.com/primers_and_pressure.php

Bye
Jack

Good info, Jack. I experienced primer piercing with the CCI 400 primers in my .204. While working up a load, I had no problem until I approached maximum load then I saw the smoke from a pierced primer. The 400 cup thickness is not enough for a hot or near hot load. Honestly, I think CCI should warn reloaders of this possibility with the 400 primers. I switched to CCI BR4 primers and there is no problem at all. I won't risk a problem occuring from using the 400's. I just wish I hadn't bought 1000 of them.

Wow, thanks Rocky and Jack. That info was just the ticket. I had all the ingredients...a Rem 700, a 17 Rem, and a somewhat warm day when I was getting the piercings. I've learned yet more valuable stuff here on Shooters Forum.

Only problems I've experienced in all my years of reloading was a certain batch of Remington 9 1/2's that were used in hot loadings of a wildcat round. Tossed them and haven't had the same problems since. I'm still using the 9 1/2's of other lots from time to time and they work well, especially in reduced plinking loads.

The smallest cases I reload are the .22 Hornet and the .223 Rem. Neither are loaded to max and the CCI BR4 is normally used for target work (don't hunt critters with these, other than turkey with the Hornet). the 400's are for workup and plinking. Maybe that's why they have held up well for me.

Sean.

I think your mention of the hot day may well tell the tipping point. If the load was near marginal to begin with, that could do it. I suppose the CCI #41 probably has the hardest primer cup you can get, but it is a magnum priming mix, being a copy of military primers that have to ignite powder well at very cold temperatures. Hotter primers are not usually thought best for consistency among the bench rest shooters.

A dirty bore in a 17 can raise pressures a surpising amount, too.
Hot day, dirty bore, that might put you over the tipping point.

Thx everyone. Maybe I need to back the load off a bit if I'm going to be shooting in warm weather (normally in 50-60F temps). Last year a had a very few piercings laying in a field plugging squirrels in the sun. Although I never leave an ammo box (those smoke colored ones from Midway that absorb solar heat!) on the dash in the hot sun, nor leave the top on one when in a field in the sun, they still pick up heat. I remember the African PH thread in which many rifles failed from shooters that did leave ammo on the dash.

This particular time, I had just run out of 243 ammo and switched to the 17 Rem, with a clean barrel, and if IIRC, within 5 or 10 shots, had 1 or two piercings, so barrel fouling shouldn't have been the issue, at least this time. It was around 80F though. I try to clean that rifle every 20 rounds anyway since accuracy starts to fall off after that. The load is right at max, at least for one publication - 27.4 grains of Win 760. I'll back it off a bit and see if I still get the accuracy I'm used to with that load.

Good info....thx much. That was an eye-opening article Jack.