The real size of the ball.

[rogervan]

Hello, All,

I'm the guy who just received the custom 62 caliber sniper's rifle with a period scope. I'm searching for the right ball size.

I wanted to optimize the size of the balls I cast for it. So I went to a machinist/inventor I know, and he measured the bbl. It's 0.610-0.614 between the flats. It's 0.650 groove-to-groove.

What size ball will be the best for this rifle? I'll have a custom ball mold made for it. (I feel lucky to have access to you-all's expertise.)

Roger

 

[roundball]

Hello, All,

I'm the guy who just received the custom 62 caliber sniper's rifle with a period scope. I'm searching for the right ball size.

I wanted to optimize the size of the balls I cast for it. So I went to a machinist/inventor I know, and he measured the bbl. It's 0.610-0.614 between the flats. It's 0.650 groove-to-groove.

What size ball will be the best for this rifle? I'll have a custom ball mold made for it. (I feel lucky to have access to you-all's expertise.)

Roger

FYI...GM .62cal bores are .610" diameter too.
I had Ed Rayl rifle one of them for me and it's a so called tack driver with a .600" ball and .018" lubed pillow ticking patch.

But you can order "20" packs of different size balls from TOW and do your own testing, then decide.

 

[Zonie]

The general rule is the ball should be .005-.010 under the bore size. That would suggest that you should use balls that are .600-.609 (or .610) in diameter.

The rifleing grooves are about .019 deep (which is deeper than most round ball barrels) and the patch should be thick enough that they compress into the grooves somewhat. If the patch doesn't seal the grooves, the flame from the powder will blow past the patch/ball and burn the patch resulting in poor accuracy.

Putting all of this together, I would suggest that you try a .605 diameter ball with .020-.025 thick patching. This combination of patch and ball will need to be loaded using a starting ball (or short starter).

Most of the blue/white or red/white pillow ticking folks here have found to work well is about .018 thick which may be too thin for your barrel.
If you have access to a Cloth Store and a verner caliper or micrometer see if you can find some 100 percent pure cotton denum (like blue jeans are made from). As I recall, it is about .023 thick but it is a good idea to measure its thickness before buying it.
Buy one yard of it, take it home and wash the sizing (starch) out of it and cut it into squares measuring about 1 9/16 X 1 9/16. You can try to make the patches 1 9/16 diameter but the square ones will work just as well.

Lube the patch with any good patch lube or spit and load over a 70-75 grain powder charge to start sighting in your rifle.

Have fun. :grin:
zonie

 

[longcruise]

I don't understand why the land to land measurement varies by .004?

 

[trent/OH]

.


Buy one yard of it, take it home and wash the sizing (starch) out of it and cut it into squares measuring about 1 9/16 X 1 9/16. You can try to make the patches 1 9/16 diameter but the square ones will work just as well.

Lube the patch with any good patch lube or spit...

zonie

I can only imagine a prolonged shooting session trying to spit lube 1 9/16" patches. You'd be so dry you'd have to re-hydrate for a week!!!

 

[Zonie]

I can only imagine a prolonged shooting session trying to spit lube 1 9/16" patches. You'd be so dry you'd have to re-hydrate for a week!!!
__________________________________________
:rotf:
Nobody said this muzzleloading was easy! :rotf:
zonie

Oh! For the mathematicians out there the formula for figuring a patch size is ((Ball Diameter X Pi/2))+ Ball Diameter.
To make things simpler, Pi/2 is about 1.6.
In the case of the .60 diameter ball that roughly equals (.60 X 1.6)+ .60 = 1.560

For a .50 cal ball it is (.50 X 1.6) + .5 = 1.300
zonie

 

[redwing]

Wally World has 100% cotton duck that runs .023 in the dark blue stuff. The denim for jeans runs more like .038 a little tight, maybe. Try your mike on a pair of Levis just below the knee where there is little wear.
I never wash the stuff as it cuts better in the drill press if it is stiff. The patch lube I use will soften it up. I use a wet lube like Hoppes Black Powder Plus. :thumbsup: