View Full Version : Rate of twist Ruger mini-14 barrel

May 9, 1999, 03:19 PM
Anybody have an idea of the twist in my 223. caliber mini-14? Serial #188-xxxxx. I tried watching a marked cleaning rod with tight jag and patch as it rotated down the barrel but got varying measurements. I have heard these little jems were a fast 1-7" twist rate. yo. Thanks for any input. Stay safe.

4V50 Gary
May 9, 1999, 04:50 PM
The answer you seek is in the archives of the rifle forum. Do a search under Ruger Mini 14 and under my username and you'll find it.

May 9, 1999, 07:31 PM
4V50 Gary: Couldn't find a post about rate of twist by searching: Ruger mini 14, under your username, in the rifle forum, any date, But then, I am an absolute neophyte with this computer stuff so this may be completely operator error. Thanks.

Mal H
May 9, 1999, 08:17 PM
I don't know if the rate has ever been different, but the mini-14 I am familiar with is 1 in 9".

George Stringer
May 10, 1999, 09:22 AM
tanstaafl, according to published info the Mini-14 is 1 in 10. George

Mal H
May 10, 1999, 01:23 PM
Are you sure? I know the Mini-30 is 1:10", but I just rechecked (Ruger catalog and Gun Digest) and the Mini-14 is 1:9".

May 10, 1999, 10:11 PM
Thanks to all for the replies. When I tried the cleaning rod in the bore with a tight patch trick I got various results from one complete revolution of the rod in 8" to one in 10.5"...obviously some slippage and some binding going on. 1 turn in 9" fits the average pretty much. I'm thinking about trying some different bullet weights and wanted some idea on what rate of twist that short little barrel might be. Thanks again.

George Stringer
May 10, 1999, 11:28 PM
MalH, I'm just going by what's listed in the Speer manual. It could very easily be 1 in 9 but they say it's 1 in 10. George

May 11, 1999, 06:04 AM
I'm pretty sure Ruger has changed the twist rate a couple of times. I had a series 180 Mini-14 that shot 1 1/2" groups with good ammo. I bought it back in the '70s. I think they went to a much faster twist for heavier bullets and have since gone to a more moderate rate. I'm not sure what the numbers are but the older ones shot 55 gr. bullets a lot better that the ones with the real fast rate.

Mal H
May 11, 1999, 11:06 AM
Cat, That explains it then. It was probably 1:10", then they changed to 1:7" as a lot of .223's were but they didn't work well with some of the newer varmint bullets, and now it's 1:9". Obviously, tanstaafl has one with a variable rate. Those are hard to find, but effective with any bullet. ;)

4V50 Gary
May 11, 1999, 11:28 AM
Grumble grumble while I unearth my notes from Ruger:

Until 1987, the Mini-14 barrel had a 1-10" twist. It was then changed to 1-7" to stabilize the new 62 grain military bullet. The old 1-10" handled the 62 grain satisfactorily, but wasn't deemed good for the new tracer round.

Law enforcement agencies primarily use the 55 grain bullet and the CA Dept. of Correction complained that their Mini-14s would hold a 8-10" group at 100 yards and a 1-2" group at 50 yards. Ruger dispatched its Chief Armorer (my instructor) who examined the guns and ruled out the ammo. CDC had a national match level shooter who demonstrated that their guns wouldn't group.

So, Ruger procured firearms from Colt and concluded that Colt enjoyed no advantage over the Mini. Ruger engineers then concluded that the twist needed to be changed and sometime in 1996, the twist was changed to 1-9".

Vigilantibus et non dormientibus jura subveniunt

May 12, 1999, 03:54 AM
I have 2 mini 14's one made in 1979 and one made in 1986 both have a 1 in 10.......

Travelin' Man
October 16, 2013, 08:08 PM
My mid '80s production Mini-14 shoots both 55 grain and 62 grain ammo with what I consider good accuracy for the 18.5" barrel, shooting 5 round 1" groups with the 55 grain bullets and opening up to about 1-1/4" with the 62 grain bullets. The only changes I've made to the rifle is to replace the wood stock with a Hogue overmolded one and installing a Leupold Vari-X II 2x7x40 scope with Ruger rings.

October 16, 2013, 08:45 PM
Mine was one of 640 shipped to Oklahoma Highway Patrol in March, 1979. 181- series. It's 1 in 10. It shoots in about 2 1/2" with good 55 gr. ammo, but I think it was "tuned" after it got here. Minis weren't known to be that accurate at the time.

October 17, 2013, 07:39 AM
Uh oh, a zombie thread.