Primer problem-need advice

38 Super with 4.6 Bullseye and 115gr bullet. Gun is early Springfield Trophy Master Distinguished(old race gun). 

It looks like the primer is pierced and then melted shut- is that even possible.

Thanks for any suggestions/opinions

Tom Stewart/Oregon

Image isn't real clear, but it looks like the primer is extruding around the firing pin and then being sheared off when ejecting.

Thanks. I post better photos shortly

hope this helps

Clearly a sign of overpressure.   The cup is being extruded into the firing pin hole and then sheered during ejection.   I don't know that it's been punctured as there no sign of soot, but it may have been wiped away.

I experienced similar with 9MM and a heavy bullet.   I used a load in the middle of the range in the loading book, but it still produced overpressure.    I guess that's why they show starting loads.

What primers are you using

I’d try super comp brass, might be a headspace problem where pressure is pushing material back after firing pin drives case forward

Brass is Sellier &Bellow small pistol. maybe I should use small rifle. I will field strip the gun now and check the headspace. Thanks

The gap from the case head to the hood is .011-.012
New brass

Supercomp brass is semirimmed and headspaces better than factory rimless.

Also read this thread

https://www.bullseyeforum.net/t6987-38-super-pet-loads

Brass choice aside, imo this is not over pressure, at least not alone.  The primer radiuses are still there.  It is my supposition that the firing pin spring may be too strong.  This will allow the firing pin to retract faster leaving the firing pin indent unsupported at maximum pressure. A very weak FP spring may act the same.

A new case measures .895 and the chamber measures .920 so I think I have a headspace problem 

oldtrptplyr wrote:A new case measures .895 and the chamber measures .920 so I think I have a headspace problem 

Factory chambers are very often 0.920”, so I would not fret over that dimension. The extractor will help headspace the cartridge.
Jon

Thanks very much Jon. I thought it needed to be around .010 or less. 
Tom

Any chance the firing pin diameter is too small for the diameter of the firing pin hole in the breechface?

Thanks to everyone for your comments. I am still trying to figure this out-with your help!!
Tom

BTW, with regard to my firing pin spring. It is a newer type that is shipped with recoil springs from Wolf.

How about a picture of a loaded round and the primer area on that round when new.  Suren looks like the silver portion of the primer filled the empty space between the case and breech face shown in the second photo. Pop one of the fired primers out and look for a hole from the inside

Not sure I understand. I may be one of those you mention below your signature- Thanks

4.6 BE with a 115gr bullet if loaded properly should not be a high pressure load for .38 Super. My guess 1140 -1220 fps.

You said this was an old race gun. Race guns with a comp, typically ran slow burning powder and fairly light recoil springs. BE is a fast burning powder. Is the light recoil spring still in the gun, and has the comp been removed? Removing the comp and not increasing the recoil spring will make that gun cycle much faster. Barrel mounted comps, retard barrel unlocking, since they force the muzzle down, thus the chamber up, retarding unlocking. The primer looks like the barrel may be dropping while the FP is still extended. Is the FP channel cruddy? Why is that FP able to extend that far through the breach face? Is it an extended length FP? Maybe the spring had been removed for the photo. Just some thoughts. Still too many unknowns. Last, does the brass and primer look like this when you shoot other ammo?

Try it with a STANDARD firing pin spring.  An “Extra Power” FP Spring is used to counter-act the extra inertia of the high energy recoil spring used for the 38 Super combat loads..  you’re not shooting those so you don’t need the extra power.

Allgoodhits wrote:4.6 BE with a 115gr bullet if loaded properly should not be a high pressure load for .38 Super. My guess 1140 -1220 fps.

You said this was an old race gun. Race guns with a comp, typically ran slow burning powder and fairly light recoil springs. BE is a fast burning powder. Is the light recoil spring still in the gun, and has the comp been removed? Removing the comp and not increasing the recoil spring will make that gun cycle much faster. Barrel mounted comps, retard barrel unlocking, since they force the muzzle down, thus the chamber up, retarding unlocking. The primer looks like the barrel may be dropping while the FP is still extended. Is the FP channel cruddy? Why is that FP able to extend that far through the breach face? Is it an extended length FP? Maybe the spring had been removed for the photo. Just some thoughts. Still too many unknowns. Last, does the brass and primer look like this when you shoot other ammo?

I will try to answer the questions in order. 

The lite spring is in the gun. The cases fall near me

FP channel is clean and the FP spring is newer Wolf. FP is original.

The compensator is on the gun (barrel)

I put the FP through the breach face without the spring for information only. It was asked if it was too small in diameter

Cases in the photo were fired with 8.4 of HS6, 115grain bullet and small rife primers


Thanks-Tom

Yep, use a std FP spring and be sure you're putting it on correctly. It should be twisted onto the pin. If not its backwards. Looks like a pierced primer with the anvil metal flowing back thru the hole onto the breech face. How else are we getting dissimilar looking  metal on the back of the primer? The primer anvil appears to have a hole in the middle. Are we using a std. mainspring of 22lbs. 

Hard to diagnose from a distance.

The picture of the cases using HS-6 show that this phenomenon of the “smeared” primers is from a lack of support from the FP retracting.  The high energy FP spring retracts the FP faster.  This allows the softer pistol primers to extrude into the FP hole, hence the smeared primer indent.  A standard FP spring won’t have the stored energy to retract the FP until after the pressure peak has passed.

I think the main spring is standard as that is my routine.  I will check it and find some standard, not "extra power", FP springs.

I am grateful for the opinions and ideas. I will post follow the results after testing.

Thanks again- Tom