Home Forums Hunting & Shooting Hunting Rifles Barrel twist: factory spec vs actual?

MELLO, mellow. Nothing wrong with asking questions and talking about manufacturing.

I've noticed a rather non-mellow character to MELLO's posts.

Too much Mello Yello I suspect. Or perhaps mellow yellow (quite rightly).

That's right, I haven't heard anyone posting here proclaiming they are barrel makers but just asking for info. And the part about errors when measuring rifling twist, Shinbone got results of a twist faster than the manufacturer indicated. When a patch (no matter how tight) is pushed or pulled through a rifled barrel, it's rotation can indicate less rotation from slippage , but can never rotate faster than the actual twist of the barrel. So, if you measure a twist rate slower than the manufacturers spec, the patch might have slipped a bit in the rifling or your measurement may be correct. If you measure a twist rate faster than the manufacturers spec, you are most likely correct that the twist is faster than manufacturers spec. It doesn't take a barrel maker to figure that out. RJ

My guess is that the manufacturer changed the barrel twist mid-run, and that change was too minor to make it into the marketing materials; or, they got a deal on a bunch of 1:8.5 barrels in and figured that was "close enough" to 1:9 to simply go with them.