.36 caliber Navy model accuracy

[rickk]

Swampmouse, if you haven't found felt yet, looky here:

http://www.durofelt.com/image_26.html

can I suggest the "FM1836M" ?  9 square feet for 20 bucks plus shipping will get you a lot of wads.

Rick

[SwampMouse]

Mako,

I got the measurements today. The chambers are tapered, a .373 pin started on both cylinders. It goes deeper into the new one than the old one.

Pistol #1 with London grips.
1. .373 at top of chamber to .150 deep
2. .372 to .248 deep
3. .370 to .470 deep
Then a step, it stops hard. We tried the next size smaller pin like you suggested and it stopped at the same step.
4. .363 to 1.098 deep

Pistol #2 with Civilian grips.
1. .373 at top of chamber to .500 deep
2. .372 to .594 deep
It has the same kind of step the first one does.
3. .362 to 1.107 deep

Your picture looks more like my #2 new cylinder. I read some posts on High Road and they suggest reaming all the chambers to make them uniform. I'm not sure if I want to do that, I can use the .375 balls now, and I don't have a good source for the bigger balls unless I order them. Do you have a suggestion?
SM

[Montana Slim]

Simple solution for best accuracy is to use a filler on top of a light charge of powder. This sets the ball height consistently near the mouth AND close to the forcing cone....I may have mentioned this already. Ask anyone in the revolver competition at Friendship.

Slim

[Mako]

Swampmouse,
That's actually not very much for a drilled hole.  For a reamed one you would expect less taper on the first one.  The .001" difference between the final diameter and where it hits the smaller drilled bore may just be the lead they have on their production tool.

I think you can chase the Ø.373 final dimension with a Ø.373 reamer.  You can just use a standard hand reamer with a lot (and I mean a lot) of cutting fluid.  Some people use tap magic for light cuts.  If I use it I mix it with sulfurized cutting oil to keep it on the walls.  Ream them at least .70" deep and you will be able to load very light loads and not have to worry about hitting a shoulder.  If your machinist friend doesn't have one I can loan you one and and a handle.

When you're finished you should have less than .0005" taper.  I think it's interesting the diameters are in line with what I have measured on other Uberti revolvers.  It seems they have relatively decent quality control. What are the date codes on your pair?

It's obviously not the cylinders that make your accuracy different between the two.  I think you've figured out that the new cylinder is theoretically better than the first.  You never said what kind of accuracy you were getting with the second revolver, what was it doing?

~Mako

[SwampMouse]

Slim,

Is there a ratio of powder to a filler to use? Which is better, cornmeal or cream of wheat?
SM

[Montana Slim]

Slim,

Is there a ratio of powder to a filler to use? Which is better, cornmeal or cream of wheat?
SM

No hard/fast rules on these two factors. Shooters experiment to see which combo works best in their gun.
That said, a 10 grain charge (max) + cornmeal would be my starting point. I put the filler into a plastic conact lense solution bottle with an enlarged opening to "puff" it through. an exact thrown volume  of filler isn't necessary...just "puff" it over the powder until it is nearly full & still allows seating the ball fully. Load-up 50 times & you'll have it down. I use a small dab of lube on top of the ball.

This process is not beneficial for use with belt revolvers for CAS/WAS, as the enhanced accuracy is not needed & is more time consuming to load.

Slim

[boilerplatejackson]

I get very good accuracy from my 36 cal colt clones ( Army San Marcos and Piettas) by having my gunsmith ream
my cylinder holes out to a true .375 to match the barrels. We have measured cylinders to as small as .370. I quit
using fillers years ago, and just use a wander wad. I have had to go to .380 round balls, but I dont miss the .375
balls and the bump up fit in the barrel.