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twist rate

Posted: Fri Feb 19, 2010 6:45 pm
by nobade
Today I noticed Kreiger makes rimfire barrels with 1:14 twist. Now, we know from BPCR shooters that a faster than normal twist rate helps accuracy at really long range, such as 1:18 even though the same bullet shoots fine from a 1:22 at shorter range. I frequently shoot a 200M benchrest match with my silhouette rifles, and have been wondering if the faster twist would be beneficial at that long range? Has anyone ever tried a barrel like this? Did it work?

Re: twist rate

Posted: Fri Feb 19, 2010 9:11 pm
by lone ringer
I have been shooting one for over 15 years, its a Gary Schneider's barrel 14" twist had it mounted on an Anschutz 54 repeater and then about 5 or 6 years ago I had Mark Pharr made it into a Hunting rifle. My friend Agustin Sanchez set the 120 round National record of 115X120 in 2008 with it .
Shoots really well in the wind and at long ranges I have used it to practice HP shooting gongs at 200 meters and with Lapua Scoremax 48 gr bullets I sometimes are able to knock HP chickens over. Get it you will not regret it.

Re: twist rate

Posted: Sat Feb 20, 2010 3:21 am
by rbrandes
I make barrels for the S&W model 41 using 1:8 twist blank that is intended for .223 Rem.
Out to 50 yards, there seems to be little difference between the 1:8 and 1:16 rimfire tubes.
Image
The above is from a 1:8 twist 6" barrel from a machine rest at 50 yards. The circle is the standard bullseye pistol target X ring, 1-11/16" diameter.
Regards, Ray

Re: twist rate

Posted: Sat Feb 20, 2010 5:45 am
by AZRifle
I am far from an expert but.... I am opinionated haha! I know that the optimum twist rate is based on a proportion of the length of the bullet relative to its diameter. Somewhere on the internet I found a calculator to help figure it out. Most likely the standardized 1:16 twist for the 22 caliber was established because of past use of .22 shorts along with the .22 longs and .22 long-rifles. The shorter bullets would need a longer twist rate to remain accurate and, the 1:16 fit the average for the optimum. If they were all designed for the .22 shorts, a 1:18 would most-likely be the optimum twist rate. If they were all designed for strictly .22 long-rifle, the 1:14 is most-likely the better twist rate.

Re: twist rate

Posted: Sat Feb 20, 2010 8:04 am
by BCloninger
Interesting - a lot of the accuracy problems in the 504 were blamed on the 1:14 twist rate. That wasn't the problem, but the reflex answer was to blame the twist rate.