Great Plains Rifle rate of twist

[longcruise]

And, with that, I dragged out my old GPR barrel (circa 1980-1983) and measured the twist rate. I had always been under the impression that the twist rate was 1/66. In fact it seems as though the kit was so labeled.

But, it is 1/48!! :shocked2:

Even with that, I have shot it with elk hunting loads as high as 120 of ff and had good accuracy with a tight patch and a RB. For the past eight or so years I've been shooting it with a 1/70 GM barrel and can't say as it is any better with round balls than the original GPR 1/48 barrel.

"The muddler"

 

[fearless51]

Wow, all this information from Lyman really had me going there for a minute and I was actually beginning to wonder if I had a 1:45 barrel even though it shoots a patched round ball like a house a fire. I had just cleaned the rifle from the days shooting and pulled it out of the case, stuck a non-rotating jag on the wood ramrod and shoved a double thick patch down the barrel. On pulling the rod out I was curious as to whether it would begin to approach anything close to a half a turn before it exited the barrel and was relieved to see that it barely made the half a turn, indicating a more than likely 1:66 barrel as I was led to believe, 1:60 is just fine as well. My custom Colerain barrel is 1:66 and is a super grouper with PRB.