Green Mountain Ball Size for .40 Cal Barrel

[b_haycock]

What would be the recommended RB size for a .40 caliber Green Mountain barrel - competitive shooting.

 

[spitpatch]

In my .40 cal gm I use a .395 ball. You have to try different patching to get the best results. I have a 40 cal webberstown barrel by 42" shoots best with a .389 and thicker patch. I think most guys are going to use .395. My thoughts.

 

[roundball]

A Hornady .395" & .018" pillow ticking patch is extremely accurate in my GM .40cal Flint barrel...

 

[Jarikeen]

I use a home cast (lee mould) .395 RB with .012" cottom drill patch, lightly lubed with olive oil, in my .40cal GM. I think I remember reading somewhere that .395 RB for hunting and .400 RB for target with the GM. I was pleased with the accuracy I had with what I was using, so I didnt try the later. Maybe one day.

 

[b_haycock]

Thanks for the replies - The reason I asked is because I just recently bought a flint with a GM barrel in 50 caliber - the builder of the gun told me to use a .500 with a .015 patch as GM recommends .500 for target and .495 for hunting. I use a .500 and .015 Teflon coated patch and get excellent results. Was wondering if the same would be for the .40 cal GM I am considering.

Possibly then a .400 with .015 patch for competition would be my best choice?

 

[WV-Rocklock]

My 40 GM likes a .400 and a .015 patch.

 

[roundball]

Do .400's come WITH a mallet or do you have to supply your own??

:grin:

 

[bwhoffman]

my .40 GM (percussion) likes my home cast .395's.
soft lead (sheet lead) which my lee .395 spits out ballsat .396 to .397, these and a true .015 patch is accurate. Lee does have a tolerance company wide of -.000/+.003, so my mold meets their specs. an .017 or.018 patch is a hammer affair. so I shoot .396 and .015.

do not automatically assume that a mold will throw as designed nor a box of production made balls to be as labeled!

I also have an old lee .400, that throws soft lead at .400, these wont go in my GM with a .015 patch. just wont fit.

 

[roundball]

Similar thing with me...the commercial cast .395s I bought are a couple thou over and I have to use a mallet with .018" pill-tick, so I use .015" so I can short-start them OK.

But Hornady .395s are more true and short-start OK with .018" pill-tick, which I use for hunting.

 

[Jim/OH]

I have a GM .40 cal. on one of my target rifles. I use a .400 cast ball from a Lyman double mold. Use a prelubed .17 patch and 40 grains of powder. This combination is very accurate, so much so this is my "go to" gun when I want to shoot my very best. Yes I do use a mallet to start them, but again this is target shooting, not hunting. Hope this helps, Jim