Author Topic: Rate of twist and load data  (Read 1034 times)

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Offline OLDMAN

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Rate of twist and load data
« on: December 10, 2002, 09:07:14 AM »
My question is about how rate of twist effects load data.  My BillyMarr/Oldman 6mm TCU barrel has a rate of twist of 1:8.  Does not this fast rate of twist have some effect on the choice of loads.  Would a 1:12 rate of twist use a different load than a 1:8.  If so shouldn't the manuals state the twist rate used in developing the given load, or does it even matter at all.  You tell me.

Offline Bullseye

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Rate of twist and load data
« Reply #1 on: December 10, 2002, 12:20:12 PM »
Heck Oldman, all I know is if a load does not work I try another.  I do know the rate of twist matters when related to bullet weight but I guess I will learn more along with you here.

Offline Rol Page

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Rate of twist and load data
« Reply #2 on: December 10, 2002, 02:08:16 PM »
Hi guys, I have learned a little from reading posts here and looking at RealGuns.com.. The basic premise is think of rate of twist = spin, and think how much faster you would have to spin a long salami (long heavy bullet) than a football (short lighter bullet) to stabilize it at a given velocity.

My personal experience was a TC factory 15" .243 Encore barrel would not stabilize 100 gr bullets cause the twist is 1 in 10".  I tried factory and hand loads, but with not much success.  The 85Gr are great, because they are shorter and require less spin to stabilize.

Playing with the RealGuns.com program I found out a 1 in 8 twist was needed for the velocities that I was getting for the 100gr.

I switched from the .243 to the .260 Remington (TC Factory 15") which has a 1 in 8 twist and now get groups around 1 - 1.5" routinely with 120gr bullets and the best groups run about .075" @ 100yds.

I have not tried lighter shorter bullets with the faster twist, but hope that I can develop a good chuck hunting load for the .260 without loosing accuracy.

I hope this helps.

Sieze the moment.   Rol
NRA and NYS Rifle & Pistol Association Life Member