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**Mike Irwin** · June 26, 2001, 03:48 PM

I seem to recall the .22-250 rifles I've worked with having a 1 in 8 or a 1 in 9 twist.

Very easy to test, though.

Put a cleaning rod (preferably one on a swivel handle) in the bore with a tight fitting patch so that it is well engaged with the rifling.

Mark the rod at some convenient point, say where the rod enters the action body.

Also, put a mark near the handle.

Slowly but steadily push the rod into the bore -- you want to watch the mark near the handle to make sure that it starts turning immediately -- until the mark you've made on on the rod near the handle has made one complete revolution.

Mark the rod again, using the same reference point on the action.

Withdraw the rod, and measure between the start and finish marks. The distance in inches is your rifling twist rate.

As for the sizing, that's something you're going to have to figure out for your gun. You may be able to neck size only, you may have to full length size.

Given that there isn't a lot of camming force to help start the shell into the chamber, I'm betting that you'll have to full-length size.

June 26, 2001, 03:48 PM	#2
Mike Irwin Staff Join Date: April 13, 2000 Location: Northern Virginia Posts: 41,390	I seem to recall the .22-250 rifles I've worked with having a 1 in 8 or a 1 in 9 twist. Very easy to test, though. Put a cleaning rod (preferably one on a swivel handle) in the bore with a tight fitting patch so that it is well engaged with the rifling. Mark the rod at some convenient point, say where the rod enters the action body. Also, put a mark near the handle. Slowly but steadily push the rod into the bore -- you want to watch the mark near the handle to make sure that it starts turning immediately -- until the mark you've made on on the rod near the handle has made one complete revolution. Mark the rod again, using the same reference point on the action. Withdraw the rod, and measure between the start and finish marks. The distance in inches is your rifling twist rate. As for the sizing, that's something you're going to have to figure out for your gun. You may be able to neck size only, you may have to full length size. Given that there isn't a lot of camming force to help start the shell into the chamber, I'm betting that you'll have to full-length size. __________________ "The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza Baby Jesus cries when the fat redneck doesn't have military-grade firepower.