Uberti SAA Piercing Primers

C

Cowboy7

Member
Rating - 100%
6   0   0
Location
Toronto, ON
Hey all,

I've got a brand new Uberti SAA in .357 Mag that is occasionally piercing primers. The firing pin seems to protrude quite a bit through the frame in the fully down position, and is creating pretty deep indents in primers (more cylindrical than hemisperical). Of the 10 .357 rounds I put through it, 2 had damaged primers after firing, and of the 50 .38 rounds, 1 damaged primer.

The damage appears to be small nick on the surface of the primer where the firing pin is impacting, and the indent is then coloured black by the primer's contents, along with a circle around the firing pin hole in the frame. The primers remain seated and intact besides this perforation, and the cases remain airtight and fire fine. The surface of the firing pin looks and feels fine, I believe it is properly smoothed. I can take some pictures of things if needed.

Could this be caused by an overly long firing pin? If not, has anyone run into this before or know the cause?

Thanks in advance.
 
Pictures would help, I have a similar but even worse problem with an old Great Western Arms .45 Colt, the primer is deformed and protrudes out enough to jam the cylinder as it rotates. I thought maybe the mainspring was too strong so I slacked it off by loosening the screw that holds it on the frame, no change. My gun has a disc through which the firing pin hits the primer (recoil shield) and it is depressed..I think a new part is in order.


 
OP- Are these factory rounds or reloads? I had some reloads that were doing this in my S&W 586. Turns out the .357s were overly hot with very soft primers. Some of the primers would blow out and jam the cylinder. I've never had the same problem with factory rounds.
 
Factory rounds. Remington .357 125gr JSP, UMC .38 130gr FMJ.

Primers are still seated fine in the cases, everything about the rounds looks fine except the hole in the primer indent and the black residue. Frame doesn't show any signs of stress, just a ring of that black stuff around the hole through which the firing pin protrudes.

Will take pictures when I get home today.
 
Since it's brand new it's obviously time for some warranty work. Or if you don't want to wait that long you could pay a local gunsmith to look it over and bob the nose of the firing pin by a little if it turns out that is what you need.
 
I'm all out of patience for warranty at the moment, as I've already had to send in two brand new guns from other manufacturers for warranty, both of which have taken over 4 months to get sorted out. I'd rather avoid sending something away for months that I've already waited a year to get my hands on. Warranty service times are shameful for Canadian customers of too many foreign manufacturers.

Here are the images:




 
That's what I'm thinking. I just wanted to get a second opinion from here to make sure that the firing pin was the probable culprit.

I'll upload a picture of the frame from the side to show how much the firing pin protrudes tonight.
 
I hear you on the warranty wait times. That's why I suggested warranty OR getting a local smith to do the work.

If you want to identify the issue and then fix it yourself you'll want to have some way of measuring and modifying the pin. A picture won't do us any good. We all know what the pin looks like sticking out of the recoil shield liner. Instead you need to have a way to measure the protrusion to within a thou then find out what it SHOULD be and then work the pin down shorter and re-profile and polish the nose. A file is fine for the initial shortening. But then you'll want to CAREFULLY round the nose of the pin evenly and accurately to re-produce the shape.

It's also possible that your FP has the right protrusion but perhaps it's too sharp or too blunt with sharp edges. As shown in Skinny's photo you want it to be neatly rounded and polished.
 
I measured 4 revolvers at lunch by inserting a feeler gauge between the cylinder face and the firing pin. It's the only way I could think to do it since I don't have the proper firing pin measuring tool. Colt 3rd gen SAA 0.015", Uberti Cattleman (SAA clone) 0.020", second Cattleman 0.025", and an Uberti Remington 1858 cartridge conversion, which actually protruded past the rear face of the cylinder. All are 45LC, none of them pierce the primers. I suspect you may have an overly strong hammer spring. I had the opposite with first Cattleman, spring was weak causing light strikes and a very touchy, hair trigger, which I suspect was because the spring didn't put very much pressure on the sear. I replaced the spring with a replacement from Numrich, no more misfires, much better feeling trigger, not so touchy.

B
 
OK, picked up a feeler gauge today, firing pin protrusion appears to be about 0.050" with a cylinder gap of 0.063".

According to this source, those measurements look good to go. Although, based on my measurements, I am below the recommended case head clearance (0.006") assuming a nominal 0.060" rim thickness for .357. I measured one of the cases with the pierced primers to have a rim thickness of 0.058" though, so it was closer to proper clearance.

So, I have 0.005" to give on the firing pin protrusion before it's out of spec, and mine does look a little rough compared to Skinny's. I think I'll go at it with a strop and round it off and see where that gets me.
 
That would be a reasonable start. It's best to sneak up on the issue by starting with the least invasive action like you're doing. Especially if you find that it has a sharpness to it compared to Skinny's picture.

My own hammers on my Pietta and S&W guns that have hammer mounted firing pins are even a little more rounded than Skinny's.
 
You must log in or register to reply here.
Back
Top Bottom