70grns Goex FFFg is the magic number in this .54cal GM Flint smoothbore!
Tried 100, 90, and 80grns Goex 2F...100 & 90grn groups were worthless at several inches wide with a wide flyer even beyond that...with 80grns 2F the groups started to improve but still 5" at 50yds...AND...always had a wild flyer several inches off to the side no matter how had I tried to eliminate everything that could cause it.
Switch to 3F...90grns 3F was actually a little better but had that flyer...80grns 3F started to look very good at a few inches but still had a nagging flyer in every group.
In frustration, I decided to try 70grns 3F which is below what I normally like for deer hunting...and I was shocked at the results...like somebody had flipped a switch...some holes touching, a cloverleaf, etc, and most importantly no flyers !!
Tried a 5 shot group with 80grns again, it opened back up a little plus had that nagging flyer...back to 70grns and tight groups with no flyers.
Never had a barrel do this before...don't understand the flyer...took pains to clean, lube, and load the bore precisely the same way every time...using wonderwads every time, patches were immaculate of course...a mere 10grns difference and it's unbelieveably accurate...go back up above 70grns and the fylers start up again.
Interesting coincidence...the best shot pattern was 70grns Goex 3F...now it's clear the best PRB charge is also 70grns Goex 3F.
That's lighter than I like for deer hunting...muzzle energy falls between a full power .45cal & .50cal PRB load, but I have a stand where the maximum distance is only 40-50yds, so I might try it some there this season.
Tried 100, 90, and 80grns Goex 2F...100 & 90grn groups were worthless at several inches wide with a wide flyer even beyond that...with 80grns 2F the groups started to improve but still 5" at 50yds...AND...always had a wild flyer several inches off to the side no matter how had I tried to eliminate everything that could cause it.
Switch to 3F...90grns 3F was actually a little better but had that flyer...80grns 3F started to look very good at a few inches but still had a nagging flyer in every group.
In frustration, I decided to try 70grns 3F which is below what I normally like for deer hunting...and I was shocked at the results...like somebody had flipped a switch...some holes touching, a cloverleaf, etc, and most importantly no flyers !!
Tried a 5 shot group with 80grns again, it opened back up a little plus had that nagging flyer...back to 70grns and tight groups with no flyers.
Never had a barrel do this before...don't understand the flyer...took pains to clean, lube, and load the bore precisely the same way every time...using wonderwads every time, patches were immaculate of course...a mere 10grns difference and it's unbelieveably accurate...go back up above 70grns and the fylers start up again.
Interesting coincidence...the best shot pattern was 70grns Goex 3F...now it's clear the best PRB charge is also 70grns Goex 3F.
That's lighter than I like for deer hunting...muzzle energy falls between a full power .45cal & .50cal PRB load, but I have a stand where the maximum distance is only 40-50yds, so I might try it some there this season.
, glad your enjoying your new barrel. bb75
