What's the right gap?

[Billnpatti]

As I stated in a previous post, I have a replica Navy Colt by Armi San Marco. I am not the original owner and it is the only revolver that I have in my collection of black powder guns. I have had it for a good while and am still learning about it. When I drive in the barrel wedge, if I am over zelous, it will move the barrel back far enough to jam the cylindar. I have learned to simply not drive the wedge in that far.....well, duh! Anyway, I tap the wedge and hold the gun up to the light watching the gap until there is just a hair of light showing between the barrel and the cylindar. How thick a hair I am not sure. So, my question is just how close should the barrrel be to the cylindar? Should I use a feeler guage to set it or just eyeball it as I have been doing. Is it normal for the wedge to be able to drive the barrel all the way back against the cylindar or do I need to make some adjustments to the wedge. Oh, ye founts of great wisdom, what say ye? :bow:

 

[necchi]

Yeah it's normal for those wedges to be big enough to force the barrel back too far.
Zonie is a trusted Revolver Guru, and if I remember right he said the gap should be around .020.

My Revovlvers are still new enough that the wedge is tight in it's groove, so I do much like you do and just push it in far enough to keep the barrel gap small but not too far to jam the cylinder.

I can imagine that the easiest set-up would be to file the wedge enough to be fully inserted and leave the .020 gap,, but that would leave no room for wear as the years go by and require a new wedge to compensate.

I really do need to go after my Uberti `51, that wedge is so tight it needs a tool to drive in as well as push out.

I will defer to others with more experiance here,,

 

[CoyoteJoe]

If a revolver is perfectly set up it is not possible to draw the barrel back too far since the cylinder base pin should bottom out in its hole. I've never owned a revolver which was perfectly set up and I really think that is too much to expect of revolvers which sell for the prices of the Italian imports. I have read where some folks have inserted a thin washer into the hole under the barrel to bottom out the base pin. Others have drilled and tapped the nose of the pin to take a set screw and others have put a dollop of JB weld on the nose of the base pin, all ways to give the pin something to bottom out on. I just set my cylinder clearance with a .006" feeler gauge. However you go about it, it is important to be consistent since that effects the elevation of the shot, drawing the barrel back farther will tilt it upward more and cause it to shoot higher.

 

[Billnpatti]

Thanks for the great info. I think I would rather do something temporary to keep it from bottoming against the cylindar rather than making any perminant change. I have to allow for wear. I think I'll give the washer trick a try. I have some various thicknesses of brass shim stock and some hollow punches. I am going to try making some washers and shimming up the pin so the barrel will not bottom against the cylindar. That way, as the gun wears, I can either add or remove washers. Easy peasy. I think I will try a gap of .020 to start with. .007 sounds a bit tight but I may end up there after some experimentation. Thanks again.

 

[M. De Land]

I would say set the gap as close as can be without cylinder impediment when fouled.I would initially use a feeler gauge but after that would simply mark the wedge with a depth line
My guess with black powder fouling is the gap should be at least .008-.010. That is getting on the large side for a smokeless revolver so should be about right for black powder guns. MD

 

[Zonie]

I don't recall saying that .020 clearance was a good number for a C&B but I might have.

If I were to guess what a good gap would be it would be somewhere between .010 and .020 but I'd try to keep it towards the .010.

That's a big enough gap to keep the fouling on the face of the cylinder from binding things up but not so large that there is a excessive blast of flame out the sides.

As for putting a spacer down into the arbor hole in the barrel, after the right thickness is installed, it should never wear out.
The spacer is just getting squeezed between the barrel (that doesn't move) and the end of the arbor (that also doesn't move) with the tapered wedge locking up the assembly.

As for the little screw that's on the side of the barrel, I have been known to adjust the wedge to get the right cylinder gap and then to unscrew that little screw until it bottoms out on the wedge.
As long as you don't mess with the screws position, it does work as a wedge stop so the next time you install the wedge you won't drive it in too far.
Maybe not the best method but it does seem to work.

 

[necchi]

Thanks for the correction Zonie, I wasn't sure.
CoyoteJoe said it shoot's higher the wider it get's,
That makes alot of sence to me cause my revolvers shoot pretty darn high!
I like the idea he has with the shim, gonna hafta experiment with that one.

 

[CoyoteJoe]

Well that is not exactly what I said. :haha:
I said drawing the barrel back more will tilt the muzzle more upward and cause shots to go higher on target. But most replica revolvers come out of the box with front sights which are too short and will shoot high no matter how you adjust the barrel gap. The only solution to that is to replace the front sight with a taller one, or just remember to aim a foot low. :haha:

 

[necchi]

just remember to aim a foot low. :haha:

And that is how much I have to aim even at 10-15yrds!
Thanks again CoyoteJoe,

 

[CoyoteJoe]

Yeah, that's pretty common. Some conjecture is that they were intended for shooting men with a hold on the belt buckle to hit somewhere on the torso from the muzzle out to better than 100 yards. I'm not much interested in shooting men so I've installed taller front sights on mine.

 

[Zonie]

Rather than messing with the front sight, wouldn't it have been easier to just hang a belt buckle 12 inches below the targets bulls eye?

:rotf:

 

[CoyoteJoe]

That's a good little bunny, you just sit very still while I place this belt buckle one foot below your head. :haha: