Is a .62cal really a .620 ??

[roundball]

My GM .62cal Flint smoothbore only mics .609/.610/.608 as accurately as I can mic it.

In talking with GM because I could not start .600 balls with a .010" patch without using a piece of 2x4 on the short starter (and then accuracy was horrible of course) they said:

".62 calibers are actually not really .620...that is an unfortunate misnomer in the industry...they are really only bored to .610".

Is this true.....or is it horse hockey?

 

[Mike Brooks]

It's horse hockey. .62 is 20 ga. Getz and colerain bore theirs at .620. A .610 is a 21 ga.

 

[No Deer]

My .62 mics out to .620. No problem starting .60 ball with pillow tick patch. I do use a short starter for convienience, but probably would be able to start without it.

 

[Deadeye]

My .62 Fucil de chasse mikes exactly .620 .

 

[tg]

It is an interesting issue as these guns are supposed to be somewhat of replicas of guns from an earlier time period when the calibur/gauge sytem was not the same as it is today, bit most makers today bore out the gun to the size of the intended caliber and a smaller ball is needed though some will use a ball the same as the bore size given for the gun.

 

[roundball]

Thank you gentlemen...sort of what I thought but needed reassurance from the brain trust!
:bow:

 

[Deadeye]

The barrel that I bored out from .54 turned out to be .626. I still use a .600 ball but with a .020 patch instead of .015. With .610 barrel you might try a .005 patch with the .600 ball.

 

[Grenadier1758]

Since you know the bore size of your gun, I would use a ball about 0.020" smaller in diameter than the bore. A patch of 0.015" will slightly compress and hold the ball in place. Your gun should shoot well with a 0.590" diameter ball. That gives you a 22 gauge ball.

By the way, my 20 gauge fowler has a barrel with a 0.625" bore. I use a 0.600 ball and at times I think it might be better to use a smaller ball.

 

[Wes/Tex]

You'll find bores ranging from .595 to .625, though the majority run between .600 to .610 in most commercially available guns.

 

[roundball]

You'll find bores ranging from .595 to .625, though the majority run between .600 to .610 in most commercially available guns.

Maybe that explains it...GM is a mass production manufacturer of course...the guy didn't even hesitate when he replied...anyway, it is what it is...it's made to their specs so a .610 it shall remain.

Heck the thing shoots a long range turkey load so good out to 40yds I'd be foolish to have it opened up anymore anyway....so I guess I'll keep it like it is...I already have a .58cal which is overkill for anything I hunt in the first place...

:g

 

[paulvallandigham]

My .20 ga. fowler measures something like ,631 and I had to go to 19 ga. card wads, cushion wads, and overshot cards to get it to shoot. I do use .600 balls, but I have the opposite problem. I have to use the thickest patching I can find. My gunmaker said he called his source of barrel stock, and they were also surprised at the dimensional variation. He has bought barrel stock from them before and it always measure .620. I just figure I have a lot of " trading stock" when I meet another .20 ga. shooter.

 

[The Baron]

My Caywood is a true 0.620" according to the maker. :v

 

[rudy parnell]

Heck the thing shoots a long range turkey load so good out to 40yds I'd be foolish to have it opened up anymore anyway....so I guess I'll keep it like it is...I already have a .58cal which is overkill for anything I hunt in the first place...

:g

If you're going all out for the feathers...you may as well apply the same logic for the steak meat. :rotf: