My dad has an older Mini-14 that was produced sometime in the late seventies to mind eighties. I'm trying to figure out what the barrel twist rate is, and I am coming up with vague answers. I do not know if it is marked as a Ranch Rifle, but I do know it was sold in NJ with a folding stock and flash hider.

 

I am hoping it is a 1/10. My AR has a 16A1 barrel on it, so I can't shoot M855. I don't like M855, but I would like to be able to shoot it if I find it somewhere cheap.

I believe it was 1:10 originally then 1:7 in 1986 and finally 1:9 in 1997

 

Perfect union tends to be the keepers of good mini info but also of way more bs and bickering then I've ever seen on any other forum

You may find your answer here.

http://sunflowerammo.blogspot.com/2012/11/ruger-mini-1430-barrel-twist-rates.html

Thank you guys. Can't believe I missed that. The little bits of M855 will get fed to the Mini.

Don't believe anything even what's stamped on the barrel...

 

Measure it, it's super easy...You may be surprised.

Don't believe anything even what's stamped on the barrel...

 

Measure it, it's super easy...You may be surprised.

I always check my guns, and it is very easy.  I use a brass wire cleaning brush and put a small black mark on the and of cleaning rod (the end near the handle) and when I run the brush down the barrel I count the number of rotations.  As long as you know or can measure barrel length you then have the number of inches per rotation (or rotations per inch) , which you can convert to number of rotations per foot.

I always check my guns, and it is very easy.  I use a brass wire cleaning brush and put a small black mark on the and of cleaning rod (the end near the handle) and when I run the brush down the barrel I count the number of rotations.  As long as you know or can measure barrel length you then have the number of inches per rotation (or rotations per inch) , which you can convert to number of rotations per foot.

 

Easier way:  Cleaning rod, jag, patch.

Mark the rod with jag and patch.  Push the rod through one revolution mark again.

Measure distance between marks.

One of my 1:9.25" turned out to be 1:8.75".  That .5" allowed me to try heavier bullets.