Failure to Fire Issue

blue68f100 · Post by **blue68f100** » Thu Aug 25, 2011 8:57 am

Bullseye, Do you have a picture showing how and where this screw goes. I have never worked on any revolver (only autos) and would like to expand my knowledge base.

Post by **Bullseye** » Thu Aug 25, 2011 10:12 am

I don't have any of my own right now but here's a pretty good diagram of one I found on the net. The strain screw is on the lower front grip.

Hope this helps.

R,
Bullseye

blue68f100 · Post by **blue68f100** » Thu Aug 25, 2011 3:11 pm

Thanks Bullseye.

There are a lot of small parts in the trigger and cylinder group. I was told to never open one up, and I never had a need too. Now I know why.

Hakaman · Post by **Hakaman** » Fri Aug 26, 2011 1:15 pm

I have range results for my S&W 686-6-6" revolver, after I installed the new strain screw.
I have included the photos below to show the results. I shot 50 rounds of 38sp, and 30 rounds of .357 mags.
I didn't have any FTF's, and all primer strikes appear to be solid. That's a good thing. I did have about 5 weak
fires in the 38sp group, with one being so light I had to check the barrel with a rod to see if the round made it out.
Throughout both lots of brass you will notice some differences in primer appearance. Some primers have
been flattened against the firing pin bushing due to high pressure, both in the 38sp & the .357 (noticeable by the
gap space between the outside of the primer and the pocket hole). There seemed to be more inconsistent
power levels within the 38sp lot, but not much in the .357 lot. From these pictures is there anything noticeable to experienced eyes?
Thanks, Haka

blue68f100 · Post by **blue68f100** » Fri Aug 26, 2011 2:01 pm

The flattening of the primers on 357mag loads is quite common. I do not get concern unless it's all the way around. I also rotate the brass after 3 mag loads it goes into the lighter plinking box. I have been using CCI primers and have far less flattening when compared to Federal.

I've had problems with some GFL brass slitting the cases after 3 reloads.

Looks like your finally have a reliable gun and what an adventure it was.

Post by **Bullseye** » Fri Aug 26, 2011 4:09 pm

Looks to me that the reliability problem is solved. Those primer firing pin hits all seem to be very prominent dimples. Make sure you put some Loctite on that strain screw so it doesn't back out when firing the magnum rounds.

R,
Bullseye

Hakaman · Post by **Hakaman** » Fri Aug 26, 2011 11:21 pm

Looks to me that the reliability problem is solved. Those primer firing pin hits all seem to be very prominent dimples. Make sure you put some Loctite on that strain screw so it doesn't back out when firing the magnum rounds

I will be putting some blue locktite on it. It has been interesting working this issue out. Thanks for you help,
Haka