• This community needs YOUR help today. We rely 100% on Supporting Memberships to fund our efforts. With the ever increasing fees of everything, we need help. We need more Supporting Members, today. Please invest back into this community. I will ship a few decals too in addition to all the account perks you get.



    Sign up here: https://www.muzzleloadingforum.com/account/upgrades

Proper way to measure cylinder gap

Muzzleloading Forum

Help Support Muzzleloading Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Mar 14, 2020
Messages
323
Reaction score
282
Location
Wantage, NJ
Good morning all.
I’m sure this has been talked about a million times, but I’m having a hard time finding the actual method to measure barrel to cyl. gap on a Colt revolver. I know where to measure, but I’d like to know if the hammer should be down on a cone, Half cock with rearward pressure on the cylinder, or Full cock?
 
Ok, and that’s exactly what I did. My gap then measures .008”. However, I have an equal gap where the barrel lugs meet the frame. Is that acceptable, or does that need to be closed up, and fit the cylinder gap by removing material at the forcing cone?
 
Ok, and that’s exactly what I did. My gap then measures .008”. However, I have an equal gap where the barrel lugs meet the frame. Is that acceptable, or does that need to be closed up, and fit the cylinder gap by removing material at the forcing cone?
If you have a gap where the barrel lug meets the frame you need to tap on the muzzle with a rubber or wood mallet to close that gap then measure the b/c gap in the manner stated ie:half cock cylinder held back.
 
If you have a gap where the barrel lug meets the frame you need to tap on the muzzle with a rubber or wood mallet to close that gap then measure the b/c gap in the manner stated ie:half cock cylinder held back.
No, this gap was created when I extended the arbor. Barrel locks up solid when the wedge is in
 
Was this gap there before fitting shim?
Just out of curiosity are you sure the frame pins are not bottoming out?
If you used epox to glue in shim could there be some on top of shim?
Spin some steel wool in the hole to insure there is no glue build up.
If the gap persists pick the shim out and try again.
 
All I need to do it take down the brass button I installed on the arbor until the barrel lug meets the frame. So then my other question is once I do that, if I need to open up my barrel to cylinder gap, do I set that gap by filing material off of the forcing cone? Correct?
 
All I need to do it take down the brass button I installed on the arbor until the barrel lug meets the frame. So then my other question is once I do that, if I need to open up my barrel to cylinder gap, do I set that gap by filing material off of the forcing cone? Correct?
To open it yes you would remove material from the rear of the barrel at the forcing cone. Before you get carried away though know that a .002 to .003 b/c gap is best for keeping fouling to a minimum.
 
To open it yes you would remove material from the rear of the barrel at the forcing cone. Before you get carried away though know that a .002 to .003 b/c gap is best for keeping fouling to a minimum.
The trick at breech end barrel shortening is to keep it sqare and plumb, no easy task with a hand file. Its best done in a lathe or with down barrel rod and bushing tool made for the task and hand turned from the muzzle. The forcing cones are usually about half a ball diameter deep so that may need to be extended as well depending on how much barrel breech is removed. That also is best accomplished with the hand tool mentioned earlier.
 
The trick at breech end barrel shortening is to keep it sqare and plumb, no easy task with a hand file. Its best done in a lathe or with down barrel rod and bushing tool made for the task and hand turned from the muzzle. The forcing cones are usually about half a ball diameter deep so that may need to be extended as well depending on how much barrel breech is removed. That also is best accomplished with the hand tool mentioned earlier.
4D Reamer Rentals can help with the tools M. De Land is speaking of. Depending upon how much you remove from the button you may arrive accidentally at the perfect cylinder gap. That would be nice...
 
4D Reamer Rentals can help with the tools M. De Land is speaking of. Depending upon how much you remove from the button you may arrive accidentally at the perfect cylinder gap. That would be nice...
After adjusting the button so the barrel just kisses the frame, I wound up with .005” with the cylinder held back. I’m content with that. It is slightly tighter (maybe .0005) on the bottom side of the barrel. It’s not perfect, but I’ll see how it shoots
 
After adjusting the button so the barrel just kisses the frame, I wound up with .005” with the cylinder held back. I’m content with that. It is slightly tighter (maybe .0005) on the bottom side of the barrel. It’s not perfect, but I’ll see how it shoots
That all changes any way when the ball slams into the forcing cone and the revolver flexes !
 
Back
Top