20-250

AlbertaAl · #1 01-03-2021, 07:58 AM

Anyone built a 20-250 ?
My objective is to neck down the LAPUA 22-250 parent case and load my special order of Berger 55 grain twenty cal. bullets.
No neck turning needed and loaded ammo will feed flawlessly from any 22-250 factory magazine.
This wouldn't be a high volume shooting stick but instead a long range flat shooting low recoil precision rig.
Won't be a bench rest rifle but rather a tactical/hunter
Barrel life isn't a factor.

tikka250 · #2 01-03-2021, 08:24 AM

I kind of toyed with the idea for a while and in my research found this. http://coyotestuff.com/articles/the-...tor-cartridge/
Sounds like it's great in concept and great to shoot but if your pushing speeds to the max you will get blue streaks.

Dick284 · #3 01-03-2021, 08:48 AM

A .20-250 could see some hefty pressure spikes with it being so over bore.

I’d sooner build a .20PPC.

Dean2 · #4 01-03-2021, 09:25 AM

Interesting idea, but man that is severely over bore. That even surpasses the 7 RUM for over bore. You will have to post up the results once you get it built and shoot it. Be interesting to see if you manage to hit 5000 FPS with the 55 grain bullets.

rembo · #5 01-03-2021, 09:40 AM

Quote:

Originally Posted by Dick284

A .20-250 could see some hefty pressure spikes with it being so over bore.

I’d sooner build a .20PPC.

I'm sure Al could tell us a bit about the 20 PPC.

Go for it Al.

AlbertaAl · #6 01-03-2021, 12:14 PM

Appreciate everyone chiming in...
My interest in the 20-250 is because of the custom 55gr bullets that I'd like to use. These require a 1:9 barrel producing 38-3900 fps (not 5000)
This will be an overbore calibre but not considered extreme in my thoughts.
This calibre will repeater feed not like the very short 20BR or 20PPC

I have shot a single shot 20BR x 1:11bbl for the last few years and loved it. The pet load was 39SBK @ 4000 fps and shot multiple coyotes under 500 yards. Very accurate, mild and low noise level. Brass is made from the parent cartridge Lapua 6BR with no outside neck turning.

I also own and shoot a single shot 20PPC x 1:11bbl in a SAKO AI target rifle. It really liked the discontinued Hdy 33gr. and later shot Berger 35 and 40 gr., both very accurate. This calibre requires outside neck turning when using Lapua 220Russian brass necked down to 20Cal.

brewster29 · #7 01-03-2021, 12:20 PM

http://coyotestuff.com/articles/the-...tor-cartridge/

I would expect you have read this...it's interesting stuff. Sounds like expected barrel life is very short. The 20 BR sounds like a winner as it is...

AlbertaAl · #8 01-03-2021, 12:28 PM

Quote:

Originally Posted by brewster29

http://coyotestuff.com/articles/the-...tor-cartridge/

I would expect you have read this...it's interesting stuff. Sounds like expected barrel life is very short.

I've seen that article in the past. The writer pushed his 20-250 reloading practice to its max. with the components and rifle design that he had and then backed off, as anyone would do. Same goes for any caliber.
.

Dean2 · #9 01-03-2021, 12:38 PM

Even hitting 5000 with a 35 or 40 grain bullet would be something interesting to try. Still sounds like a fun gun project either way.

fps plus · #10 01-03-2021, 01:09 PM

I have built a few 17-250 . Kinda similar idea as you . I did this years before there were 20 cal bullets and barrels . Definitely fast. Down side is barrel life and the need to keep clean . The 20 - 250 would be a fun project . If using for coyotes barrel life was not a factor for me . The 17/250 maybe worth revisiting with more 30 gr bullets and newer powders

tikka250 · #11 01-03-2021, 02:44 PM

If you already load and shoot 20br and are looking for a repeater I would talk with these guys https://m.facebook.com/predatorworldhunting/
They are both shooting custom 20br repeaters and from my understanding have very little issues with feeding. Might be worth finding out what they did to make the BR reliable to feed.

kujoseto · #12 01-03-2021, 02:54 PM

Would be interesting to see those 55gr Berger bullets on yoties and how far you can stretch it out.

What about necking that 22-250 up to .257? Wonder what that would be like
(sorry, not even funny but I couldn’t resist and it amused myself)

eric2381 · #13 01-03-2021, 02:58 PM

I was wanting to build a 20-250 AI for a while. With a twist rate optimal for 40gr vmax, seems as a normal 204 just barely stabilizes that bullet. But the idea kind of fizzled out for me and I lost interest.

I would like to try the 22 nosler necked to 20 cal and barrel twist optimized for 32gr Vmax. For the fun of it. But my 204s and 220 swifts and 22-250 AI are working just fine. It would only be for the fun of it and to have something different. 22 Nosler brass is the holdback on that one for me.

fps plus · #14 01-03-2021, 04:04 PM

One of the 17-250 I built was a project to shoot the Berger 37 gr VLD ,it had a Douglas 1-6 twist barrel. I could only push the bullets to 3100 FPS anymore and they came apart . That being the situation having the capacity of the 22-250 case was a waste. I do have a 17 Br with a 1-10 twist and it is extremely accurate but used as a single shot

colroggal · #15 01-03-2021, 05:14 PM

Quote:

Originally Posted by kujoseto

Would be interesting to see those 55gr Berger bullets on yoties and how far you can stretch it out.

What about necking that 22-250 up to .257? Wonder what that would be like
(sorry, not even funny but I couldn’t resist and it amused myself)

Well that would be Souper.

Colin

fps plus · #16 01-03-2021, 05:36 PM

There are 3000 reasons it would not be Souper!!

Hardway · #17 01-05-2021, 05:59 AM

Unless something has changed in the recent past. Berger discontinued their 55gr 20s 2 years ago.

kujoseto · #18 01-05-2021, 09:01 AM

Quote:

Originally Posted by fps plus

There are 3000 reasons it would not be Souper!!

Haha
If we could get it to shoot 3000 fps we could call it a 257-3000

fps plus · #19 01-05-2021, 10:24 AM

Quote:

Originally Posted by kujoseto

Haha
If we could get it to shoot 3000 fps we could call it a 257-3000

25 souper is a 243 necked to 25cal

I feel 250 -3000 is a fine cartridge ,I built a Ruger #1 and with 100 gr bullets and 760 powder I was getting 3150 .

AlbertaAl · #20 01-05-2021, 11:12 AM

Quote:

Originally Posted by Hardway

Unless something has changed in the recent past. Berger discontinued their 55gr 20s 2 years ago.

Yes, Berger discontinued the 20Cal x 55gr bullet maybe 3 years ago but they did a SPECIAL RUN about 1-1/2 years ago and I special ordered a very large quantity at that time.

ljc · #21 01-05-2021, 08:36 PM

Heard Ted Gaillard built & was shooting one couple years ago.

kujoseto · #22 01-06-2021, 12:21 AM

Quote:

Originally Posted by fps plus

25 souper is a 243 necked to 25cal

I feel 250 -3000 is a fine cartridge ,I built a Ruger #1 and with 100 gr bullets and 760 powder I was getting 3150 .

I have wanted a 250 for a long time.
I just get a kick out of all these new and improved cases... yet the 8x57, 6.5x55, 7x57, 30-06, 250-3000 had a lot going for them. And with modern powder and bullet selection, they are as good as ever. But creedmoor case is (sarcasm warning) such an improvement... yet, compare 6 cm to 6xc ...

I’m just being silly about it all and don’t know if it’s as obvious in written word.
(Ex: is that a 243 necked up to .257 or a 308 necked down???)

Not to derail completely...
55 gr 20cal could be really impressive on that case. Wouldn’t do it myself but would make for some interesting results to read on this great forum