Still getting misfires on .357 loads - Page 2

stump shooter · February 22, 2010, 04:03 PM

Like Weshoot2, I pretty much only use D/A in my GP100.
So last night I checked everything on the gun based off the data I found here: http://gunner777.wordpress.com/2008/...-of-knowledge/

Headspace, FP protrusion and travel, hammer/frame contact, etc. including all the non related (b/c gap, end play, etc.) were all to spec.
I learned that I may in fact have a lighter than stock or even 12# spring in mine as I was able to check the D/A pull with a coat hanger and some exercise plates last night (my trigger pull scale only goes up to 8lbs. 8oz.).
Turns out a (verified on a postage scale) 11# of plates will cycle the D/A all the way through, while a 10# and very minimal finger assistance on the plate will also cycle it

I am going to get a 12# spring as well as a 10# trigger spring to see if they help. Based on GP100mans focus, I believe the main spring may be too light as he pointed out after all.

As far as the primers, visually and by the best means I could with a mic and caliper, the 500s and 550s are exactly the same externally.

I'll change out the springs and be back with an answer if things improve.

Thanks for the help guys!

BigJimP · February 22, 2010, 04:29 PM

I've used CCI primers for many years on all my handgun reloads ....hard to believe you'd have that many primer problems. I can't remember the last time I had a primer fail in a handgun reload ....its been years ....and I shoot 15 - 20,000 reloads a year thru my handguns ...

You've identified a spring issue / so that is probably it .....

80viking · February 22, 2010, 07:52 PM

I had the same exact problem with my Taurus .357, also I used to have a police surplus S&W M65 .357 that did this (the S&W went back to the factory, they said it was end shake and fixed it, but it still did it). I realized that I never had a DA misfire with 38spl's, I switched to standard primers in my .357 loads and have not had a single misfire since.

I attribute this "DA misfire phenomenon" to reduced hammer energy because the hammer does not cock back as far before it is released while in DA mode. If you check your revolver, I think you will find that the hammer is further back when cocked for SA, than the point that it is released in DA.

Magnum primers are really only needed for hard to light ball powders or for very hot loads.

joneb · February 22, 2010, 09:42 PM

Quote:

Try factory loads. If they work it's not the revolver.

Was this question answered ?
I have experienced difficulty seating CCI 500 and 550 in WW .357 brass. Before overhauling the gun Change the brass or primer 1st

GP100man · February 22, 2010, 10:03 PM

I had a problem with CCI 500s & WW nickle brass , the pockets were so tite I could`nt feel the primer bottom!!!!

February 22, 2010, 10:03 PM	#30
GP100man Senior Member Join Date: August 1, 2007 Location: Tabor City , NC. Posts: 1,969	Brass Yellow or Nickle??? I had a problem with CCI 500s & WW nickle brass , the pockets were so tite I could`nt feel the primer bottom!!!! __________________ GP100man

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February 22, 2010, 04:03 PM	#26
stump shooter Member Join Date: March 23, 2008 Posts: 61	Like Weshoot2, I pretty much only use D/A in my GP100. So last night I checked everything on the gun based off the data I found here: http://gunner777.wordpress.com/2008/...-of-knowledge/ Headspace, FP protrusion and travel, hammer/frame contact, etc. including all the non related (b/c gap, end play, etc.) were all to spec. I learned that I may in fact have a lighter than stock or even 12# spring in mine as I was able to check the D/A pull with a coat hanger and some exercise plates last night (my trigger pull scale only goes up to 8lbs. 8oz.). Turns out a (verified on a postage scale) 11# of plates will cycle the D/A all the way through, while a 10# and very minimal finger assistance on the plate will also cycle it I am going to get a 12# spring as well as a 10# trigger spring to see if they help. Based on GP100mans focus, I believe the main spring may be too light as he pointed out after all. As far as the primers, visually and by the best means I could with a mic and caliper, the 500s and 550s are exactly the same externally. I'll change out the springs and be back with an answer if things improve. Thanks for the help guys!

February 22, 2010, 04:29 PM	#27
BigJimP Senior Member Join Date: February 23, 2005 Posts: 13,195	I've used CCI primers for many years on all my handgun reloads ....hard to believe you'd have that many primer problems. I can't remember the last time I had a primer fail in a handgun reload ....its been years ....and I shoot 15 - 20,000 reloads a year thru my handguns ... You've identified a spring issue / so that is probably it .....

February 22, 2010, 07:52 PM	#28
80viking Senior Member Join Date: December 8, 2009 Location: The Peoples Republic of Massac Posts: 333	I had the same exact problem with my Taurus .357, also I used to have a police surplus S&W M65 .357 that did this (the S&W went back to the factory, they said it was end shake and fixed it, but it still did it). I realized that I never had a DA misfire with 38spl's, I switched to standard primers in my .357 loads and have not had a single misfire since. I attribute this "DA misfire phenomenon" to reduced hammer energy because the hammer does not cock back as far before it is released while in DA mode. If you check your revolver, I think you will find that the hammer is further back when cocked for SA, than the point that it is released in DA. Magnum primers are really only needed for hard to light ball powders or for very hot loads.