Odd occurance up for discussion

[chet]

So this M70 featherwieght 223 of mine...... I was curious as to what the twist is...... so I put some tape on the cleanin rod and fitted a tight patch....... well......
it turned nicely for the first few inches, the stopped turning throughout the middle of the barrel, then started turning again towards the end.
So I tried pulling it back through the bore, with the same results.
Then I tried a brush.... It seemed to follow the lands and grooves better, but I still got readings between 10" and 14".
So for now I'm going with a 1 in 14" twist simply because it cant possibly cause an overreading.
But why was the patch so innacurate? It fit alot tighter than the brush, any tighter and I would not have been able to push it through at all.
I've never seen rifling wear in the middle....just at the ends..... odd.
thoughts?

 

[Antelope_Sniper]

Sounds like our hammer forged barrel had a mandrel that was a little fat in the middle.

 

[Richracer1]

How old is the rifle? My guess would be 1 in 10 twist.

 

[chet]

rich, i'm thinkin early 80's..... and you're right, my thought process was off, one in 10 makes more sense,

 

[old #7]

Your cleaning rod stopped spinning.

 

[buckfever]

I'm thinking 1/12.

 

[Ol` Joe]

Your cleaning rod stopped spinning.

My thought too. 1/10" sounds right to me too unless it`s quite old...

 

[chet]

yes, of course the rod stopped spinning..... but why? It seemed to do it in the same spot every time????
1 in 10 is a good thing cuz I wanna try something a little on the heavy side before I junk this barrel.

 

[Antelope_Sniper]

Best way to find out is to try it. Shoot some 60 partitions, or 68gr ncc at 25 yards. If they keyhole, you know it's not a 1/10 twist.