Anyone Got A 12.5 Barrel On There. 22 Rimy

[GEOFF.223 83]

Just picked up a 10/22 going to put on a few custom parts like the thought of the carbon fibre 12.5" barrels

 

Just wondering if there any good

[andyf 144]

There's a good reason 'most' rimfires are made or cut down later to 14" or 16", at least this 'my' engineers take on it.

The twist rate of the rifling in a rimfire is almost always 1 in 14, so it would seem to make sense (to me) to get the bullet to

turn at least 1 revolution when passing through the barrel?

My Sako Finnfire is however different (I researched this first), it's 1 in 16, so when I had it shortened from the 22" factory length,

bearing in mind my theory about twist rate, I figured that the case on a 22 rimfire is 1/2" so the rifled 'bit' should be 16" at least,

so I asked for it to be shortened from breech face to end ay 16 1/2". This works very well for me.

I think 12" is too short, but then again plenty of 22 rimfire handguns have barrels only 2" to 4" long and they do OK.

[bilbobagins 92]

been considering chopping my rimmy down to 14 inch but wondering if it will make it inaccurate

[andyf 144]

Don't worry at all, 14" is plenty of barrel, at 14" all the powder is burned off and the bullet is now starting to 'slow down' in

the barrel that's left!

I can only comment on my experience, both with a factory 16" 17hmr and my Sako Varmint.

The CZ 17 American was very accurate, the cartridge (in my opinion) was over rated and expensive to feed, the factory ammo

was really crap, with too many primer only, bullet stopped 3" up the barrel, plus runner Foxes needing a second or more shot,

reverted to a 22.250 and no complaints thereafter.

My Sako will group at 3 shots under 1/2" at 75 yards with GECO 40gr Target, off a bipod with no wind from a 16 1/2"

barrel, and about 3/4" with RWS sub's, which is no worse than when it was 22".

[walshie 2,804]

I read an interesting book about 10/22s. This american guy progressively cut 1/2" sections off his 10/22 and noted the accuracy and velocities at each successive length. His figures showed that in fact 12 1/2" is the ideal length for that model of .22 rimfire.

[shropshire dan 467]

I'd love to have my old brno mod 2 barrel cut down to around 14/15 inch

[Rimfireboy! 1,463]

So long as the crown is good it'll be fine at 12:1/2 inch in .22lr.

[shropshire dan 467]

12.5 inch would be really handy

[Born Hunter 17,638]

There's a good reason 'most' rimfires are made or cut down later to 14" or 16", at least this 'my' engineers take on it.

The twist rate of the rifling in a rimfire is almost always 1 in 14, so it would seem to make sense (to me) to get the bullet to turn at least 1 revolution when passing through the barrel?

 

 

I can't really think why getting one full rotation in the barrel would be important? Surely it's the rate of rotation that is important, which should be independent of barrel length? Interesting hypothesis if it is right, I just can't think why it should be.....

Edited October 6, 2015 by Born Hunter