04 December 2009, 03:53
Porchdog1894 Inconsistent Ignition
Just for starters I'm no gunsmith.
A buddy and I both have older (no safety) marlin 1894's in 44 magnum. He's had his for about a year and he's had some strange trouble. With either Hornady or Remington factory loads he gets occasional sicky cases and rare split cases.
I thoroughly cleaned his barrel - no indication it was tight or leaded.
We were shooting together the other day and he had the same problem with both Hornady's and my handloads (240 JHP, 19.4 2400). Primer strikes were very inconsistent, some bullets didn't fire at all. A couple times we had very light strikes that didn't fire, followed by a second try that did.
My friend detail-stripped the action and cleaned everything. This gun appears to have been shot very little. He even tried shimming the hammer spring until it's nearly solid at full cock. Hammer strikes are still inconsistent.
I checked it out last night and noticed a few things. On my gun the back firing pin is about 1/8" back from the bolt after cocking with no round in the chamber and needs a firm push to push it forward. On his the pin is about flush with the back of the bolt. Also the rear pin on his has a huge radial clearance in the bolt, it's position after cocking appears random.
2 questions -
I assume that light strikes are causing "fizzing" primers,and inconsistent powder burn is causing the over-pressure signs?
Is this inconsistant strike a know problem with these, and if so is there a known fix? We're leaning toward sending it to Marlin.
Thanks!
04 December 2009, 07:25
p dog shooterFrist thing I would do is have the head space checked. If he has a head space problem the differants in brass could be causeing the light firing pin strikes.
If no head space trouble I would try differant primers. I had some wim large pistol primers that gave several handguns I use them in troulble. Looked like light fireing pin stikes but the primers were very hard changed to cci primers all the troubles went away.
Or maybe its a combo of both. Only some checking would tell.
I have a 94 in 357 never had any trouble with it.
04 December 2009, 07:47
Hog KillerHave you tried swapping firing pins. It sounds like he has a short firing pin to me. May need to replace it.
Keith
04 December 2009, 08:35
WestpacI would examine the rear firing pin to make sure it is centered on the front pin with the lever all the way up and not forcing an off center hit. If the lever fails to lift the rear firing pin into proper alignment with the front, you can expect light or intermittent strikes. When troubleshooting this type of firing pin system, it is important to consciously make sure the lever is up all the way everytime you drop the hammer.
04 December 2009, 16:21
PorchdogI dismissed headspace/ammo as it is inconsistent with both factory and handload ammo.
There's so much clearance around the rear pin I'm thinking it's a bad bore in the bolt - the rear pin in my gun is much better controlled.
04 December 2009, 19:28
MasteriflemanMarlin's service is very good and quick. If it were mine, I'd contact their service department
http://www.marlinfirearms.com/...rsupport/repairs.asp and give them the symptoms and abide by their advice.