617 No Go Bang

[ede]

617-2 very high milage, I'd guess 100,000+ rounds. It was Carmonized maybe 6-8 years ago. Started out maybe a year ago I'd get the occasional round not fire. I have the habit of running all my ammo I don't trust in the bottom feeders in the revolver so ammo quality had been a question. It seem to get worse when I started shooting a brick of Aqueila I got last year in it. At match yesterday I was having a miss fire or two on the first two stages. I switched to some Winchester I had with me I had never tried before. Two stages ran fine and I thought it was ammo related. On the last stage I had 6 or so rounds not fire. I had took the gun apart and ran it trrough my ultrasonic cleaner last weekend for it's every five year cleaning so there isn't much question about dirt being a problem. The firing pin marks looked a little on the light side and I'm running a factory firing pin. I'm guessing it's time for a new main spring in my limited knowledge of all thing revolver related. Any help or direction would be appriciated.

[alecmc]

The 617s require a decent amount of mainspring tension to light off 22 ammo. Make sure your strain screw is tightened up all the way, maybe try a bang inc spring , or modify a stock.

Also, not all 22 ammo is created equally. Like primers in center fire, some work better than others. I stick with federal 22, but I also hear cci minimags work pretty well too.

[okshootist]

Check for endshake. If that's not it and it has a modified mainspring, you may need to straighten it slightly.

[Misterbrooks]

With that many rounds through it I am going to assume all internal parts have worn themselves smooth and the cause has more to do with the main spring. A simple fix, however best to take to a reputable Gunsmith who will properly diagnose / repair. Had a 617 and did get the trigger poundage down to 9 via Bobbing Hammer, Custom forming Springs and smoothing internals. Not really worth the effort effort I put into it as there are no known competitions for a 22 Revo.

[alecmc]

via Bobbing Hammer

everything i've read, and experienced - says bobbing a hammer on a 22 actually promotes even poorer results. Unlike it's center fire brother, heavier hammers actually work better on 617s. Either leave it stock, or go with somehting like the Apex 617 hammer, which is heavier and bulkier then stock.

[Mover480]

I have the same gun with as many rounds through it. It started doing the same thing as yours.

Check the cylinder end shake! 0.004" shim solved my problem.

[ede]

Thanks to all who replied. Looks like I need a shim or two in it to correct the end shake. I got a .016 feeler gauge to go.