Bought a M29 revolver recently that was made in the Early days with the recessed cylinder and pinned barrel. Went to the range this morning and I was firing 8 grn. of Unique over a 240grn SWC for some light target loads. After firing 4 times the cylinder started to bind up and upon getting the cylinder open I found that the primers had all back out of the fired shells a couple of thou. I don't remember this happeneing a couple of weeks ago with full house reloads but I can be sure becasue I only had 10 rounds but I think I would have notinced this if it was doing the same thing to the hot loads. Any idea's?
Primer backing out on M29 revolver
- Thread starter hunter64
- Start date
It sounds like your loads are TOO light; in a revolver, the primers will normally back out when the round is fired, but then they're slammed back in when the entire case is thrust back against the recoil shield. Since your light loads aren't developing enough back-thrust to do this, the primers are staying pushed out, and the primers end up locking up your cylinder.
Perhaps the Load you're using is "too light" to set the cases back against the frame when firing, at least this happened to me with some really light Schoffield loads I was trying. Sometimes firming up the crimp will "help" this or just increase the charge abit.hunter64 said:
My thoughts
It would seem SDC types faster then me
I have done some reading and I think both of you are correct, always thought that it was excessive pressure that would back primers out but I have never seen this before. I can run 8grn of Unique in my 629 but it doesn't have a recessed cylinder so I don't know it that just adds more space to the overall condition. As I was typing this I thought of something else that I changed. I was loading some Herco to try and at 11 grn the case was bulging from the amount of powder so I crimped the bullet on a lower groove thus extending the over all length. When I switched powders to unique I didn't change the die setting so this added another 10th of an inch or so and thus less pressure.
- Location
- Calgary, AB
SDC is quite correct, this is a common light load syndrome; there is sufficient pressure for the case body to expand and grip to the chamber wall, but insufficient pressure to generate enough back thrust to overcome the case friction to the chamber wall.
