20-250 ?

[shoots100]

Anyone here build a 20-250 rifle recently ?
Barrel twist recommendations or any other advice would be appreciated.

Thanks,
SJC

[Fuj']

A nine twist will cover just about everything. Because of the speeds that can be generated
by the 22-250, you run the risk of blowing up bullets with faster twists and RPM's. You can
do some of your own checks using calculators like JBM. For instance, a 77 grain SMK about
one inch long at 3500 fps, a nine twist gives more then enough stability but not over spinning
it. And note if using longer bullets try to get as much throat as possible to match up with your
magazine.

[Dave Hoback]

Yup! 1:9.. Like Fuj’ said. Remember 1:9 is good for 223 up to about the 75gr range. And it doesn't have near the velocity of the 22-250 Varmint “Vaporizer”!

[jpx2rk]

Look over at Accurate Shooter dot com, somebody has probably already traveled this road.

[sharpshooter]

He's talking 20 caliber, not 22. A 1-9 will work the best for even up to 55 grain bullets,(which Berger doesn't make anymore). Some shooters have had luck with a 1-8 for smaller cases like the .20 BR, but for the higher velocities, the 1-9 will stabilize without shredding the jacket. I've got a .20X47 Lapua that will push a 55 gr Berger 3875 fps with no trouble of losing bullets.

[Dave Hoback]

Wait a second…… I could have sworn that said 22-250 when it first was posted. Because it stuck out like a sore thumb just now! Fuj’, am I right? Feel like I’m takin’ crazy pills! Anyhoo.. yeah, still rec. 1:9. The 20cal pills just aren’t long enough to really need that extra stabilization.

[Whynot]

Without a very specific purpose and need then I would stay away from it. The 204 is already a great performer and so much easier. Barrel life would not be very good- and it's just not a very practical round. I have a neighbor that loves all things unique or different (with guns) so I get to try a lot of these things without having to buy them. He found a 20-250 and had to have it- it was crazy fast but he never liked it and either sold or re-barreled it. He was using it for coyotes but he never found a good combination that wasn't destroying them (not a issue to me because I'm not going to save them anyway). It was years ago- and don't remember the brand of dies he had but there was some difference between them and his chamber that was causing problems. When you go with a wildcat there's no standard so things can get interesting.

[shoots100]

Without a very specific purpose and need then I would stay away from it. The 204 is already a great performer and so much easier. Barrel life would not be very good- and it's just not a very practical round. I have a neighbor that loves all things unique or different (with guns) so I get to try a lot of these things without having to buy them. He found a 20-250 and had to have it- it was crazy fast but he never liked it and either sold or re-barreled it. He was using it for coyotes but he never found a good combination that wasn't destroying them (not a issue to me because I'm not going to save them anyway). It was years ago- and don't remember the brand of dies he had but there was some difference between them and his chamber that was causing problems. When you go with a wildcat there's no standard so things can get interesting.
Thanks for the replies.
I built a 20 practical a few years ago and am pushing the 40 grn V max pill to 4k fps.
It's my backup rig and the rig I use for hunting coyote in restricted caliber areas in NY state.
The rifle I want to make into a 20-250 doesn't have a .378" bolt head available (Impulse) to make it a 20 practical, so I needed to find a case that has a .473 rim dia.
Just like with the 20 practical, you only need one die to size the parent case to 20 caliber and I like that simplicity.
All of the other 20 cal lasers need a lot more case prep and special magazines to feed them reliably.
I know it'll have a relatively short barrel life pushing it to high speeds, but it'll be my backup rig and if I shoot it 50 times a year, that'll be a lot.
I don't care about pelt damage either, dead is good for me.
The 20-250 checks all of the boxes.

SJC

[Fuj']

Wait a second…… I could have sworn that said 22-250 when it first was posted. Because it stuck out like a sore thumb just now! Fuj’, am I right? Feel like I’m takin’ crazy pills! Anyhoo.. yeah, still rec. 1:9. The 20cal pills just aren’t long enough to really need that extra stabilization.

Yes Sir.....It was originally posted as 22-250.

[Dave Hoback]

Thought so… :smile-new: Just making sure. These things are quite unsettling to an individual who’s had some brain damage in their lives. ;)

[bootsmcguire]

What about a 22BR necked down for a 20cal?
Maybe such a beast already exists, that I don't know, but would get you closer to case capacity of a 204 Ruger and still maintain a .473 bolt face.

Just a thought as I am not familiar with the Impulse. Assuming it utilizes standard CF type magazine (again I don't know) you could hunt up one of the old 6BR mag bodies.

[shoots100]

What about a 22BR necked down for a 20cal?
Maybe such a beast already exists, that I don't know, but would get you closer to case capacity of a 204 Ruger and still maintain a .473 bolt face.

Just a thought as I am not familiar with the Impulse. Assuming it utilizes standard CF type magazine (again I don't know) you could hunt up one of the old 6BR mag bodies.
There's a lot of feeding issues with the 20BR, parent brass is expensive and not readily available, case prep and forming is a long process, unless you buy a couple of die sets, which are expensive.
I was looking at getting the slower twist barrel for shooting the 55 grain projos, but their not readily available now a days, so I might just get the faster twist barrel and shoot the 40 grain projos.


SJC

[bootsmcguire]

There's a lot of feeding issues with the 20BR, parent brass is expensive and not readily available, case prep and forming is a long process, unless you buy a couple of die sets, which are expensive.
I was looking at getting the slower twist barrel for shooting the 55 grain projos, but their not readily available now a days, so I might just get the faster twist barrel and shoot the 40 grain projos.


SJC

Roger that, was just a thought. Often times I have come up with my best ideas that sparked from a random suggestion I saw or was made to me so figured I'd throw it out as food for thought. :tea:

[Fuj']

I have no interest in a 20 cal, but being a wild catter. I'd look at optimizing and feeding.
For a 473 bolt face, I would go with a the 6gt case. It's in between the BR cases and the
6.5x47 case. It was designed to solve the problems of feeding issues with the shorter
cases.

[jpx2rk]

There is a 20-250 set up for sale on accurate shooter website, FYI.