357 mag (and max) primer "issue"? On sb1 frame.

[Whiterabbitttttt]

hi guys,
 
 I'm getting strange primer performance on a 357 handi with the fat firing pin on the sb1 frame. The primers crater like crazy, and some rounds even have a hole punched in the primer. Wild stuff.
 
 happens on any load, mag or max, always H110 loads but doesnt matter if start load or max load it can happen.
 
 even factory ammo will crater primers like crazy, just no punch through.
 
 any thoughts?
 
 
 
 
 accuracy is not bad. The holes all touch at 25 yards, and almost touch at 25 yards off hand.

[quickdtoo]

This has been discussed many, many times, using SR primers with thicker cups is the usual solution. 

Tim

http://www.gboreloaded.com/forums/index.php/topic,260242.msg1099540627.html#msg1099540627

[cudatruck]

Welcome to my nightmare! I have been all over this problem. Using rem 71/2 bench rest primers and lower pressure starting loads has worked out ok. anything approaching higher pressures WILL result in similar problems. Most factory ammo is to hot for this gun. 357 Max barrel on a sb1 SHOTGUN frame is a low pressure gun only. light 38s or lightly handloaded 357 mags or 357 max loaded to 357 mag pressures seem to work. I have not been able to get anything near published pressures and velocities with this combination. I have resolved to either get a sb2 reciever or sell the 357 barrel and forget it. I carry a 357 or 38 handgun and thought having this barrel on the 20 ga shot gun was cool. turned out to be a huge learning experience. I did learn to shorten a barrel and re crown, and did the max rechamber. Also fitted a used 12 ga barrel. All of the reloading practice was great too. Just not happy with the result.   the last thing i will try is very heavy 215 grain lead bullet traveling very slow for back yard pest controll. Maybe this barrel will work out for that.

[petemi]

The easiest way out is simply to get a SB2 frame.  The cost difference between the SB1 and SB2 is only the price of an expensive box of ammo.  All my Handis are on SB2 frames, including the .357 and .32-20.

Pete

[Gohon]

357 Max barrel on a sb1 frame is a low pressure gun only

Not really correct............ The 357 magnums today are on a sb1 receiver and have a smaller firing pin.  My factory 357 magnum reamed to Max is loaded to the 357 Maximum data and no issues at all. 

[cudatruck]

Didn't know the sb1 sold as a 357 was different. i corrected my post to show shotgun frame. mine has the large pin and it is a problem. most likely will rectify by buying a small pin frame.

[quickdtoo]

Yup, all factory 357 and 44 mags made since 2008 have been on SB1 frames with rifle firing pins, they can be identified by the marking on the right side of the frame.

Tim

[MSP Ret]

There have been many small diameter firing pins SB1 frames made throughout the years. I have shot .357 Mag's and Max's on several of those (early small diameter firing pin SB1 frames) with great results and no problems. I do not have any centerfire calibers on SB1 large diameter firing pin frames and have luckily avoided that issue and the primer flow problems....<><....

[Whiterabbitttttt]

Another dumb question.
 
I'm still in load development but the accuracy is very promising for a hunting gun. This has included loads that punctured primers and f course the re-flow.
If I can achieve my accuracy, the dumb question is: does it really matter if the primers are behaving wonky?