Forcing cone erosion

[Humbo]

Hi,
I'm starting to see a little erosion of the forcing cone, it looks like the inner edge of the barrel/forcing cone is becoming a little jagged. Should I be worried? I've had less than 5000 rounds through it I believe, most of them 300 grs LFNGC at 1600-1700 fps. I don't have a picture yet, but it's starting to look a little like the picture below, but not as severe. Is there anything I could do to slow it down, other than shooting milder loads? I'm using Vihtavuori extruded powders only.

[SM]

I was (am) in the same situation as you are; my "older" .454 has a round count of just over 4000 and over 95% of my loads have been made using VV powders. Not many max loads with N110, my most used powder for "full power loads", and I've used 3N37 quite a bit as well.

I noticed similar type of wear on the forcing cone that you mentioned and I asked the same question last year directly from FA. They told me that the wear is normal. It occurs when the revolver is new and then after a few thousand rounds. Usually after that it either stops or slows down considerably. They've witnessed this with many, many revolvers and told me that it doesn't affect function for a long time. This gave me some peace of mind..

Of course they added that the rate of erosion depends what powders you're using and the softer the bullets the faster it happens. No mention of VV powders being bad for the gun. Basically, as long as your bullets aren't too soft for the velocities, just keep on shooting. 

[benny123]

Accuracy suffered?

[Humbo]

SM, thank you for your reply, that was what I needed to hear. I always thought extruded powders are better for the gun, they usually burn not quite as hot as the American ballpowders. I'll keep an eye on it and see if it gets worse, if so I'll have to consider changing my loads and possibly my bullet alloy. I always use a gas check in the 454, and alloy is right at 15 BHN. On the bright side, if I shoot out my forcing cone, I have an excuse to ship my 83 back to FA and get a new barrel, and an auxiliary cylinder in either 45 Colt, 45 ACP, or possibly both.


I haven't experienced any changes in accuracy.

[SM]

I'm thinking that this erosion happens even if you load using jacketed bullets designed for higher velocities, since I have only been shooting jacketed bullets myself. The softer bullets must make it worse or make it happen sooner, of course.

I remember reading somewhere on this forum (?) that there is/was a certain powder that burns the forcing cone into very bad shape in just a hundred rounds or so when using it in hotter loads (.454). I think it was an American powder, but I don't recall the brand. Maybe someone knows more about this and can point out the thread in question.

By the way, the accuracy hasn't changed in my gun either, from what I can tell..

[benny123]

"...remember reading somewhere on this forum (?) that there is/was a certain powder that burns the forcing cone into very bad shape in just a hundred rounds or so when using it in hotter loads (.454). I think it was an American powder, but I don't recall the brand. Maybe someone knows more about this and can point out the thread in question"
 
 
Pretty certain the person who reprted the issue was an active GBO member.  Loosely, FA did their own tests and determined Lil Gun was the culprit.
 
Think it was an unsual situation where the the pressure was in an expected range, but temperature was not. The volatility, and/or heat generated seemed associated with double-based powders if I remember correctly.
 
Pretty sure VV classifies their double base powders differently than the N series but may want to review with them

[paul105]

Here's the Lil'Gun thread.  Bob Baker's (FA Owner) Reply (number 12) outlines the problem.

http://www.gboreloaded.com/forums/index.php/topic,180437.msg1098874919.html#msg1098874919