rifling twist rate

[bongfoo]

hello again all,

welp i'm trying to figure out what is the easiest way to firgure out your rifling twist rate. any suggestions?

i have a old ruger m77 (serial dates it to 1977) in 7mm rem mag.

 

[cbrgator]

If it's factory, you can probably look it up. What kind of gun is it? Determining the twist rate yourself... well, I'll leave that to the resident 'smiths to explain.

 

[TimRB]

Why not just put a cleaning rod in the barrel, count the turns, and measure the distance?

Tim

 

[Sunray]

The current M77 in 7mm Mag uses a 1 in 9.5 twist. Savage and Browning use 1 in 9.5 too. Remington uses 1 in 9.25.
To find out if your's is different, not likely, put a solvent soaked(for lubing) patch on your cleaning rod and stick it into the chamber. Mark the rod at the chamber and near the handle on top of the rod. Push the patch through the barrel until the handle end mark makes one complete turn. Mark near the chamber again. Measure the distance between the chamber marks. That'll give you one turn in whatever distance is between the marks.