Piercing Primers, 327 Federal Mag

[41 Rem Mag]

Hope someone has some ideas, I recently picked up a new Ruger Blackhawk in 327 Fed Mag. it is stainless and has a 5 1/2" barrel. After shooting it several times I noticed some of the primers were pierced and had powder residue on the primer around the firing pin indent. I am shooting a XTP 100 grain bullet over 10.8 grains of 2400, this is middle of the range for 2400 powder, 10.0 is the starting load and 11.5 is max. Not all of the primers are pierced, most are not, guessing 7 or 8 out of 100. The primers I was using are CCI and I have changed to Winchester small pistol mag primers, will see if that changes anything. I also have a GP100 in 327 mag and have not noticed it doing the same. The Blackhawk was new and the firing pin seems to be smooth and I can not see anything unusual. I will say, overall I was a little disappointed with the quality of the Blackhawk, just little things like fit and finish were not what I had expected from Ruger. Thanks Greg

 

[buck460XVR]

I wa under the impression the CCI primers had harder cups than others already. Sharp edge on the firing pin? Maybe one needs to try small rifle primers.

 

[tightgroup tiger]

I agree with Buck, If you are getting pierced primers then you have a firing pin problem, I'm using Win small pistol primers and they seem to work well for me with my heavy loads of Lill Gun in my SP101. I haven't pierced any yet but I am ready to go to small rifle primers if I do.
So far so good for me though, really makes me wonder about your Blackhawk's firing pin, your load isn't that hot.

I remember when the first Speer data for the 327 fed mag came out that they recommended small rifle primers, also like Buck said, but again your loads aren't that hot. I typically use about .2 gr under max in mine and have never had a pierced primer with the wins. (that's all I've ever used for over 40yrs so I can't speak of the other primer companys. )
I think I'd be going to see a gunsmith.

overall I was a little disappointed with the quality of the Blackhawk

Yea, I'd be disappointed also. My blackhawks were made in the early 1970's and they have been for me, superb. There is no reason yours should be piercing primers with the load your using.

 

[GJgo]

Possibly it's not the shape of the pin but the protrusion? Maybe it's set too long & needs to be machined shorter. I had to do this on my SKS, it came with .055" protrusion & was blowing primers left & right. Shortened to .035" & it works great.

 

[243winxb]

Try a magnum primer, may have thicker cups.

 

[Jim K]

"Pierced" primers are rarely the result of high pressure, soft primers, or a bad firing pin. They are the result of a light hammer, a weak firing pin spring, or a light firing pin.

What happens is that after the firing pin ignites the primer, the internal pressure within the primer tries to push the primer metal back against the firing pin. Ordinarily, the inertia of the firing pin and the strength of the spring combine to keep the "dimple" from being flattened and the primer shows the familiar dent. But if there is not enough resistance, the primer dent will be forced back out, and if the firing pin is forced back far enough to expose the firing pin hole, a disc shaped piece of the primer will be forced back into the firing pin hole and we have a "pierced" primer.

So when you get "pierced" primers, forget the loads and the shape of the firing pin (unless it looks like a hat pin); look to the mainspring (hammer spring in this case) or the hammer itself (such as lightening, dehorning, etc.).

Jim

 

[41 Rem Mag]

Thanks

Thanks for your reply guys, it gives me some things to look at. I have already changed to WSPM primers and increased the load to 11.0 grains, so far I have not seen and damaged primers but have only shot 30 or 40 of them. Thanks for the tip on the main spring and hammer, as I said, I bought the gun new and have ran maybe 500 rounds through it, so looking at the springs would not have been anything I would have considered. New gun, low round count springs should be good....... Thanks again, Greg

 

[Vern Humphrey]

One thing to look out for -- Brian Pearce wrote an article not long ago about blown primers blowing the hammer to full cock on an SAA. The result was the hammer then fell (since the shooter still had the trigger back) and the gun literally went full auto.

 

[Jim K]

I never heard of that happening with an SAA, but it has been known to happen with a percussion revolver with rusted out nipples. I once saw an original '51 Navy rip off three shots that way. I am pretty sure a percussion gun can't be a machinegun legally, but that one fired "more than one shot with a single pull of the trigger."

Jim