Question about pierced primers , any ideas

[onelight]

I have 2 Ruger 327s a single seven and a 4.2 SP101 both will pierce primers about 10% of the time .
The primers I use are WW small pistol . They pierce in 32 s&wl , 32 h&r and 327 the loads are light to moderate here is a pic. of the primers in 32 h&r that were loaded with a 115 rnfp on 3.4 grains of Unique out of 100 rounds 11 pierced . From the Single seven when I look at the firing pin tip it is rounded with light machine marks.
I use these same primers in 20 or 30 hand guns none pierce but my 2 327s . Any ideas on what might cause this ?261394

[metricmonkeywrench]

I have a second Gen Colt in 357 that does the same thing for all Mfgr's primers both standard and Magnum. Same conclusion, for mine the hammer mounted firing pin (original) basically hits big and hard and deep (almost think its trying to turn the primers inside out), looked at the firing pin over and over, nice smooth and well rounded. I haven't see a firing pin protrusion measurement for it but it looks to be no more than my S&W Model 10.

I just accept it and move on until it becomes an issue and I start seeing signs of flame cutting on the firing pin or frame.

http://castboolits.gunloads.com/showthread.php?398909-Corona-Blues-cure&highlight=range

[rancher1913]

might try a harder primer and see if that helps.

[onelight]

Some of the 327 factory loads I have heard are loaded with small rifle primers also some load data for 327 call for small rifle I don't know if Ruger would use a longer firing pin in a gun set up for small rifle primers.
I have a SP101 357 I will compare the pin protrusion with the 327 and see if they are the same.
If I can figure out a way to measure it.

[Thumbcocker]

I have an SP101 in .327. It pierced primers even with .32 long loads. Called Ruger got a call tag. It was returned with cylinder honed and hammer, trigger, and other internals replaced. They also removed my reduced power trigger return spring. The nice lady at Ruger seemed to have no problem helping me so my feeling is that this is not unheard of on these models.

[metricmonkeywrench]

Heres a "tool" for the task. I have a drawing somewhere abouts for a go/No-go for a S&W Model 10. Having the tool is one thing, finding the correct dimensions is another

http://pacifictoolandgauge.com/misc-gunsmith-tools-accessories/14808-firing-pin-indent-protrusion-gauge.html

[onelight]

Thanks , I have several other Ruger revolvers that do not have a problem with a way to measure I can at least compare to the ones that work.

[Valley-Shooter]

It was my understanding that the 327 uses small rifle primers.
Have you used small rifle primers?
I would try that.

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[rintinglen]

Both of my single sevens will do the same thing with either Remington or Winchester small pistol primers. CCI 500 primers seem not to be prone to this problem, nor do WW SP Mag primers. 42,000 PSI loadings put some strain on the primer cup when the hammer fall stretches and thins the metal under the firing pin, though why your mild loadings should exhibit this problem, I do not know. Examine the firing pin tips with a magnifying glass, see if they are more sharply pointed than on your other revolvers. If so, you may be able to lightly sand the tips to round and smooth it. Use a fine sand paper, 600 grit or finer.

[onelight]

I looked them over under magnification hoping to find a burr or something that would be easy to fix but they looked good.
I may just load some of the light loads with small rifle like Valley-shooter suggested and see if it stops the problem that would be an easy fix 😃 am I wrong in thinking the rifle primers have a thicker cup?

[EMC45]

I had the same problem in my S&W Model 30 in .32 Long. I looked closely at my firing pin and there was a little "beak" on it. I stoned it a little and fixed the problem.

[megasupermagnum]

You don't need small rifle primers. Federal and Winchester primers are generally the softest, however, I have not had any piercing problems with either. The problem is almost certainly the guns. It could have started with a bad load that left a mark on your firing pins, or maybe they came that way from the factory. The fix is easy if the guns are relatively new. The firing pins are held in with a screw in bushing on the back of the frame. I made the bit to fit it with a flat screwdriver, and used a Dremel to form it into two points that correspond with the holes in the bushing. All you have to do is unscrew the bushing, inspect and polish your firing pin tips, and reinstall. You will need to remove your grip and hammer too, to gain access. To polish you are going to want something fine like 1000 grit sandpaper, scotch brite, polishing compound, etc. You want to knock off the sharp spot, not remove a lot of metal.

[dimaprok]

At some point I was trying to limit my primers to 1 type so I used S&B rifle primers in my Ruger GP100 for 38 SPL loads because they didn't have any pistol primers in stock and they worked ok, primers were $20/brick at local Cabela's while CCI primers were $30-32 a brick. Sometimes the primers didn't go off, but same thing was happening in Ruger American bolt action 300 BLK, I blamed the primers which disappeared off the shelves in a year or so. I sent Ruger my Ruger American rifle and they determined the gun was at fault and offered me replacement. I don't think Mossberg 223 ever had issue with those primers. Later I learned that semi-auto pistols like Glock does not like rifle primers so I started buying pistol primers again.

[onelight]

You don't need small rifle primers. Federal and Winchester primers are generally the softest, however, I have not had any piercing problems with either. The problem is almost certainly the guns. It could have started with a bad load that left a mark on your firing pins, or maybe they came that way from the factory. The fix is easy if the guns are relatively new. The firing pins are held in with a screw in bushing on the back of the frame. I made the bit to fit it with a flat screwdriver, and used a Dremel to form it into two points that correspond with the holes in the bushing. All you have to do is unscrew the bushing, inspect and polish your firing pin tips, and reinstall. You will need to remove your grip and hammer too, to gain access. To polish you are going to want something fine like 1000 grit sandpaper, scotch brite, polishing compound, etc. You want to knock off the sharp spot, not remove a lot of metal.
The firing pins look good both are nice and round with only normal tiny machine marks checked them both under magnification. But I have not measured them for how far they protrude compared to my other Ruger revolvers.
I know the protrusion is important but I have seen rugers with almost no end shake to excessive end shake that did not have this problem . I am stumped .
I think I will take a box of factory 100 grain load next range trip and see if they pierce the primers.

[samari46]

My Beretta 92FS has a conical style firing pin and useing the ReM-umc el cheapo ammo in 9mm the firing pin pierced the primers. And cost me for a new firing pin and spring. The firing pin tip almost resembles a center punch. Other makes of 9mm showed no problems. When the smith did the replacement pin and spring I asked if he would sell me a spare firing pin which he did. Always good to have a plan B. Frank

[Greg S]

Your firing pin may be scorched from a jet of hot gas eroding the pin causing a dimple. When the pin hits the primer, the dimple grass the primer metal and it tears and cass the problem. The other issue would be to light of a mainspring causing blanking.

[Ed_Shot]

Had a New Model Blackhawk 357/9MM bought 4 years ago that consistantly pierced 1 or 2 primers out of every 6. Small Rifle primers stopped the piercing but I didn't want to pass-it-on with the problem. Sent it back to Ruger and within a week they called to say the firing pin channel was drilled too deep into the frame and they sent me a new Blackhawk. Well.....the replacement pistol they sent pierced 3 out of every 6 primers and it was promptly returned. They replaced the hammer on the second pistol and it hasn't pierced another primer.

[onelight]

Your firing pin may be scorched from a jet of hot gas eroding the pin causing a dimple. When the pin hits the primer, the dimple grass the primer metal and it tears and cass the problem. The other issue would be to light of a mainspring causing blanking.
Could you explain , I do have lighter springs in both. What is blanking ?

[Larry Gibson]

Could you explain , I do have lighter springs in both. What is blanking ?

Did the revolvers pierce primers with the original springs [particularly the hammer springs] in them?

[ioon44]

The only pierce primers I have is out of my 38 S&W which is a H&R model of 1887, the firing pin is really sharp and I have been using Fed 100 primers.

[onelight]

Did the revolvers pierce primers with the original springs [particularly the hammer springs] in them?
No I don't think they did but in each gun I fired 100 rounds of federal 100 grain 327 factory loads to make sure the guns were ok before changing any thing on the guns. I read somewhere for what it is worth that the those Federal loads have small rifle primers , but I don't know that for sure.
On Rugers I go 1 weight down on the hammer and a lighter trigger return . I have done several GP100 ,SP101 , and at least 10 Ruger SA guns . The only problems I have seen are light strikes on 9mm in a convertible Black Hawk and these 2 327s with pierced primers. And they pierce with 32 s&w 32 h&r and 327 all with light to moderate loads.
Same primers in my 38/357 sp101 and 2 GP100s with the same primers and have no problems.:roll:
It would not be hard to put the stock hammer spring back in for a test if the light spring could be the problem.

[rockshooter]

Re: firing pin protrusion- I also have a Single 7 that pierces primers- regardless of primer brand or powder charge. I measured firing pin protrusion at .047" with the gap between the end of the firing pin and the front of the chamber (chamber not held forward) at .006". I'll let Ruger get back up to speed once this virus settles down and contact them about what is within tolerances.
Loren

[onelight]

Re: firing pin protrusion- I also have a Single 7 that pierces primers- regardless of primer brand or powder charge. I measured firing pin protrusion at .047" with the gap between the end of the firing pin and the front of the chamber (chamber not held forward) at .006". I'll let Ruger get back up to speed once this virus settles down and contact them about what is within tolerances.
Loren
I would like to hear the response you get from Ruger. It might be very helpful.
I am going to put the stock hammer spring back in mine and see it if makes any difference. If not I will load 50 with small rifle primers and see if that helps

[onelight]

Update , I put the stock hammer spring back in and fired 50 handloads in 32 H&R with 115 rnfp 3.4 grains Unique with WW small pistol primers I also fired 15 federal 100 grain factory 327.
The pieced primers on the WW primers was 48 out of 50 compared to 11 out of 100 with the lighter hammer spring . The 15 327 factory loads had no pierced primers.
I fired 1 25 yard group with the federal 327 had 1 called flyer the other 4 in a 11/2" group this was in the single seven.

261590
I think I will put the light hammer spring back in and load some with small rifle primers and see what I get unless someone has a better idea .

[megasupermagnum]

You can measure firing pin protrusion if you want, but I just can't imagine it being excessive enough. The way to measure is to swing out the cylinder, and cock the hammer (while holding the cylinder release out). Then take an allen wrench or other flat ended punch and push the firing pin all the way forward from the rear. Then you use feeler gauges or similar to eyeball level with the end of the pin. I see .035" to .045" listed as ideal.

The best fix for this is to remove your firing pin in the manner I posted earlier. Then polish it smooth and round. The more you shoot it as is, the worse your pin will get. At this point it certainly needs a polishing. Either that or send it to Ruger. Once you make the firing pin bushing tool, the job only takes 15-30 minutes.

[onelight]

Thanks megasupermagnum under magnification I am not seeing any flame cutting on the firing pin and you can't tell from the pics but 327 primers have a nice smooth print from the pin.
I will check the firing pin protrusion and see what it is but if small rifle primers don't pierce I have no issues with using them if they test good when shooting. I have no rugers but these two 327s that have this problem one the single seven the other the sp101 I wonder if Ruger has a different FP spec for them to deal with small rifle primers in factory loads . My 357 sp101 has never pierced a primer when loaded with these same primers.

[Greg S]

Blanking is a problem associated with weak mainsprings. Basically, primer flow is so great that it pushes the firing pin off the primer and the primer either completely blanks like it was punched out on a press or it flows into the firing pin hole and ties up the cylynder.

If you have a high powered loope, look at the firing pin indentations on your primers. You should see a smooth concave divot void of any small convex anomallies (poc marks from flame cutting on the firing pin). With all those busted primers, it wouldn't surprise me if the face of the firing pin looked like the backside of the moon by now.

I would highly recommend replacing the firing pin and sticking with the tougher primers for your sub magnum loads and whatever is recommended for the 327. Top loads in 327 are in the 42k + area.

[onelight]

The firing pin is ok it has been checked it is not flame cut. Have checked it you can still see the machine marks on the face . The 327 factory load primers have a smooth ball shaped indent from the firing pin.
I am trying to deal with it before there is damage . The stock hammer spring pierced 48 out of 50
The light hammer spring pierced 5 out of 50 . So if it shoots small rifle primers with the light spring that looks like the way to go. But I am going to look into the FP protrusion .

[onelight]

Well looked around today tying to find what spec is for firing pin protrusion from Ruger and found a post on a Ruger forum where a gunsmith posted that excluding rimfire Rugers should all be .035 to .045
I checked the single 7 it was .070 so I checked my sp101 357 it was .064 my 2 Black Hawks were .060 and .065
I measured with the FP pressed forward with a stack feeler gauges not the most precise but gives me and idea.
I will make me a better way to measure and meanwhile switch to rifle primers.
If the piercing stops I am not worried about it. It is close to the same as the rest of my Rugers

[megasupermagnum]

So after trying it myself, I beive there must be a problem with the test as described. I tried both my GP100's one in 327 federal and one in 357 magnum. Doing the test as described and pushing the firing pin as far as it will go, effectively bottoming it out on its shoulder, I get about .060" for one and .065" for the other. Neither of which have shown any pierced primers that I've ever seen.

So here is what I did instead. I again cocked the hammer with the cylinder open, and latch pushed forward. I then used an allen wrench between the hammer and transfer bar, and lowered the hammer on it. The reason for this is that the hammer has a stop on it, so that it will not fully compress the transfer bar. And the reason it does not is so the transfer bar can then retract when you release the hammer.

Anyway, so with some kind of thing between the hammer and transfer bar, and keeping the trigger pulled, both of my GP100's firing pins then protrude .040" right on the money.

Either way, I don't think this is your problem. Rifle primers may or may not help. They can't hurt the piercing, but they can hurt the accuracy.

[M-Tecs]

onelight. If you go the rifle primer route Federal priming compound is the most sensitive. Remington 6 1/2's and CCI400 have the softest cups. Remington 7 1/2 and CCI 41's are some of the hardest and seem to withstand pressure the best. If you go too hard of a cup you may start getting misfires.

Post #2 gives you you the spec of each primer http://sksboards.com/smf/index.php?topic=56422.0

[Hickory]

I would suspect that you may have a headspace problem.
With excessive headspace, when the firing pin strikes the cartridge it drives the cartridge forward when it fires. The primer can, at this point back out of the primer pocket enough to pierce the primer as the cartridge under pressure recoils to the guns recoil shield. Driving the primer back into the primer pocket.

[onelight]

Thanks guys , when I measured my FP I put a pin between the hammer and FP so it protruded the maximum and measured that , as you know the transfer bar drops out of the way as the trigger is released so it is not in the way.
Since I don't have any specs. I can use my other Rugers that don't pierce for comparison I will measure endplay on the cylinders and the gap between the recoil shield at the FP and a case head to see what that is. I have checked end shake on the 327 Sp101 before and it was good but will check it again. The SP101 only pierces 1 or 2 out of 100 with small pistol primers. The piercings with both are a tiny pin hole .
Where I buy primers has a good price on WW and usually has them in stock in normal times , availability and price are the reasons I use WW primers and I have never had any reason up to this point to not use them.
I have 800 to 1000 32s loaded at this time with WW primers so would sure be nice to make my 2 32s quit doing this. I really appreciate all the suggestions .
Thanks again.

[243winxb]

327 Federal Magnum , 45,000 PSI max = Mag primer. Thicker cup.

Lite loads- uniform primer pockets. Primers can be flush to .008" below the case head. (SAAMI)

[onelight]

I am not sure what the the differences are between small rifle primers and small pistol mag. Primers .
My Hornady manuals .327 data uses Federal 205 primers for all loads and at least one of my other manuals uses small rifle primers .
The Federal .327 factory loads don't pierce and they shoot great in my guns sub 2" 25 yard groups when I am doing my part , for me that is as good as I am going to do with 4" revolvers with iron sights.
What has me baffled is those high pressure factory Federal loads don't pierce . My 32 S&W pressure loads do.
Never had this happen before. My single seven FP does protrude more than my other Rugers but I am not sure if that is by design or a defect :veryconfu

[megasupermagnum]

Small size primers a not standardized like large pistol and large rifle. For example, The Federal 200 was at one time considered a small rifle primer, and the 205 was the small rifle magnum. That has since changed, and the 200 is now called a small pistol magnum. The Federal 205 is a very thick primer, and I believe that is what is used in Federal AE factory loads.

On another note, if you send those guns back to Ruger, they will fix it at no cost to you.

[megasupermagnum]

As for headspace, I measured both of mine. Using Federal brass, I get a rim thickness of .053" for the 357 magnum and .054" for the 327 federal. Put into the cylinder, and using a feeler gauge between the brass and frame face, I hold an .011" and pass a .010" gauge in the 327 federal. In the 357 magnum, .011" is too tight, and .010" is a slip fit. So both are at about .063"-.064" headspace. I have no idea what the normal range is.

[megasupermagnum]

Ok, a quick search shows a go gauge is about .0605", and a no-go gauge is about .0660". So I'm in spec.

[onelight]

I wish I had caught this earlier I would have returned it then.
My single seven has been a problem child from the beginning although I have no doubt that Ruger would have fixed all the issues I had with it . It was one that the cylinder had to be in in the perfect position to load or unload the long 327s or it would jam tight I relived the frame under the loading gate to get it to work reasonably , the cylinder base pin started jumping under recoil Ruger sent me a new base pin and spring it also jumped I added a heavy spring and it still jumped so I went to an after market pin with a set screw to keep it in.
I have also de-burred the insides and added trigger hammer shims and a spring set. To smooth it up and lighten the trigger a bit , trigger is ok but not great but the gun shoots really well with ammo it likes. I could put it all back stock except where I relieved the frame for loading and return it for Ruger to fix but the kicker is it works perfect with the ammunition "327" it was designed for " except for the stock base pin" so I don't know if Ruger would do anything but test fire and send it back. But I may try that if I don't find a solution I can live with.
I don't normally do modifications I can't buy parts to fix if I screw it up and I have seen firing pins for sale so I could try shortening the pin to match my other Rugers I have if I don't find another solution .

[megasupermagnum]

I promise that if you send a note with that says something to the order of "primers keep piercing with 32 s&w long and 32 h&r ammo" That Ruger will diagnose and fix the problem. Their customer service is the best in the business. Include everything you can think of, including the base pin problem.

[onelight]

As for headspace, I measured both of mine. Using Federal brass, I get a rim thickness of .053" for the 357 magnum and .054" for the 327 federal. Put into the cylinder, and using a feeler gauge between the brass and frame face, I hold an .011" and pass a .010" gauge in the 327 federal. In the 357 magnum, .011" is too tight, and .010" is a slip fit. So both are at about .063"-.064" headspace. I have no idea what the normal range is.

Thanks ,
mine measured the same way on Federal 327 brass .009 will go in 010 will not go in.
Gauge is to wide to push through but I can get a corner of it in from each side.

[onelight]

The only numbers I am seeing different on my single seven compared to the others that we have measured is FP protrusion mine being .005 to.010 more than the others we have sampled .