Is forcing cone erosion bad?

[Whiterabbit]

Obvious answer is of course it is. The metal was there for a reason.

The REAL question, is why is forcing cone erosion bad? I men very specifically. What happens? eventual barrel split? loss of accuracy over time? What's the mechanism of bad-ness, and what are the symptoms seen of such?

(I ask because I may just have it all over my BFR and noticed it for the first time tonight)

[44man]

Most is sandblasting from the powder grains. My old SBH has a great deal of it and some erosion at the edge of the cone. It has not harmed accuracy. There is a different wear pattern from too tight of a cylinder where the boolit will actually wear the cone off center if it isn't in perfect alignment. That condition can wear the throats oblong.
Had a .454 here with enough wear in 300 rounds of factory ammo that it was cutting away the rifling on one side.
Even installing a very tight belt Mountain pin can cause uneven wear.
I do not worry about the cone unless it is wearing from the bullets.

[cbrick]

It can cause a loss of accuracy, it depends on what causes it and how it's wearing. If like 44man says, if it's uneven accuracy could go south. Shooting too high velocity with too soft of a boolit can cause premature forcing cone wear.

Rick

[osteodoc08]

Forcing cone erosion is GONNA HAPPEN. You just dont want to accelerate it past normal. Examples of how to do that is to use low weight projectiles at hyper velocity. Example: 357Mag with a 110gr Jwerd driven to max by a slow burning powder. Causes excessive wear and cracking in some models....and rather unnecessary unless your goal is to produce a huge fireball.

[reed1911]

You can re-face/re-chamfer it if you see signs of decreased accuracy. If that does not correct it you can have it replaced.

[Outpost75]

Forcing cone erosion also causes heat checking on the exposed face of the barrel extension which protrudes through the frame, and metal abalated off the surfaces can cause increase in cylinder gap when extreme.

Best is to have the forcing cone erosion plug gage from Brownell's for the appropriate caliber and use it.

http://www.brownells.com/gunsmith-tools-supplies/handgun-tools/barrel-tools/chamfering-tools/barrel-chamfering-plug-gauges-prod626.aspx

[dtknowles]

Dan Wesson had a cure

Tim

[reed1911]

Dan Wesson had a cure

:D Indeed!

[Whiterabbit]

on my gun, there's no loss in accuracy (3 rounds one hole at 25 yards last week with iron sights, only shot those three rounds too cause I was using expensive bullets), and the erosion is actually really uniform. All the way around the cone, and pretty even.

Thanks guys, I'll just watch it but do nothing for now.

[reed1911]

I just noticed your user name, instantly Jefferson Airplane began going through my head.