20-06

[trotterlg]

I finally got my dies all set and working good. I have a reamer partly ground for it so I am moving along slowly. I want to pick up some bullets to use in it. I have a 24 inch 1 in 12 twist barrel to use, the case holds 63 gr of water to the bottom of the neck and the neck is fairly short. Anyone with a calculator that can tell me the best bullet weight to use for the case capacity and twist of the barrel I have? Also something about the powder to go with, something good for a 50 BMG? Let me know what you think may work. Larry

http://www.22-250.com/20_06.jpg

[king canis]

with extremely overbore cases like this, heavy bullets in the 70-80 gr range show the biggest velocity gains over the swift. with your twist a 60 gr would be the most i would hope for though. most of the ideal powders for this are either discontinued or hard to get. h-870 has been successfully used in that case, but i don't think it's around anymore (maybe AA 8700 is still avail., about the same thing). ditto for rvo 62/wc 860 surplus. i think vihta vouri n-170 would be good, but haven't seen it around. with 60 gr. pills try vv n-165, h-1000, reloader 25, and imr 7828. with these slow powders in the amount you will be loading, you really need a 29" or longer barrel to get a full burn and the velocity potential from the gun. since you don't have the reamer done yet, i recommend getting a long blank so you don't waste a lot of powder on muzzleblast. i would expect the velocity loss/gain on this combo to be 40 fps per inch of barrel. for comparison, i have a 243 ackley with a 29 1/2" barrel. i load 50 gr of r-22 or 7828, and recently have switched to 49gr. of vv n-165 to propel my 95 gr vld's. the longer barrel has put me at about 3500 fps. with max load. others are getting about 3200-3250 fps with max load of same powders and a 26" barrel. you will be burning more powder and possibly slower powder (aa 8700, n-170, or h1000). the ackley vol. 2 book had some data with limited powders/bullets. i don't have the vol.2, or i would quote some of it. i would also consider a 9 or 8 twist barrel to shoot 70-80gr bullets, this is where these type of cartridges really start to shine. 3900 fps with a 70gr bullet perhaps? 22-284 shooters have reported 3800fps. that with a high b.c. equals flat long range trajectory and low wind drift. rich kayser's article on the 22-284 also stated that no velocity gains were experienced with 55gr pills over the swift. just my 2 cents.

[trotterlg]

Thankyou, exactly what I am looking for. I will put some numbers in my bullet stability calculator and see what the best heavy bullet may be, I'll run it in the 24 inch barrel first because I have it and see if it is something that may work out. If things start looking good then a longer barrel would be the thing to do. I may get some load development done with this barrel, I don't imagine it will live very long. Larry

[king canis]

barrel life will be less than 500 rounds most likely. a 500 round coyote/fox rifle will give many years of enjoyment. a 500 round prairie dog gun will give you a couple real good weekends!:D with the 24" barrel, pay particular attention to the amount of muzzle flash. it will probably be pretty big. this tells you how much powder isn't being burnt in the short barrel. if velocity readings disappoint you, keep that in mind. a long tube will support the burn you need to see the big gains. if you could find a 30"ish barrel that has been shot out, you could run your reamer in it and use it just for velocity experiments (and save wear and tear on a new barrel). then you could buy a good blank to use if you like what the other delivers. also, that long chamber is like losing an inch of barrel compared to a shorter round like the 22-250. have fun and report your findings.

[zeke06]

I think you should blow the shoulder out to 40 deg. ;) I'm just joke'n but keep us informed on how it turns out.

[trotterlg]

I have found some RL25 powder, so will probably start with that. Blowing the sholder out would look good, I left it the same angle as the 25-06 because I made the dies from 30-06 dies with a neck insert. This turns out to be a very easy way of making custom dies, I step it down first in the seating die with an insert and then in the sizing die with a smaller insert in the neck. They were dead easy to make. Donor action for this science experment is a S&W I-Bolt in 25-06. If it shoots I will use it for a Coyote getter in AZ. Larry

[impalacustom]

I hope this is one of the fixed I-bolts, you got the recall information right?

[king canis]

i see that is a 20-06 now. i thought you had a 22-06. comments still apply, but bullet weights will obviously be different.

[Ackman]

That thing is ridiculous.

[sicero]

Larry, I think a 40gr Hornady is the highest BC bullet that might work in your little jewell with the twelve twist. I have heard the 39 Sierra won't hold up under the stress. I would start testing with H4895 since it is not at all sensitive as to the % of powder in the case. Think 4500 with throttle to spare. Kenny

[17varminter]

I used Butch Lambert's Case Forming dies to resize my 30-06 down to 17 cal. I am going to get serious about this project this summer. I think it would have made more sense. COL with a 30 gr bullet was 2.10" if I remember correctly. Still a large case but more manageable than your version, and far less dangerous I believe. Good luck and have fun.

[sicero]

I think you have a 17-250 or very close. Kenny

[trevort]

Larry, sorry if I;ve missed another thread somewhere but have you fired this thing yet?

Keen to hear how you went!

[trotterlg]

I thought slightly better of this and now have a 20-30 (30-30 necked down to 20 cal. I just tonight fit the barrel to the action, the barrel is chambered and I am getting close. I think the 20-06 would be fun to do also, but I think the 20-30 will probably be more practical. I have posted some pictures of the barreled action and a chamber cast. Larry

[trevort]

Dam! Blow practical, its because it was so, well, impractical that it fascinated me so much!!!!

Hope the 20/ 30 works well, I'm watching that thread too!!!

[Oleman]

Now that's funny how long you think that throat is going to last? Less than 500 rounds is my guess.

[trotterlg]

Yes, but with a good load development program that would leave about 400 dead Coyotes. Larry

[Alycidon]

With that case capacity then heavy bullets have to be the way to go, that means 1 in 9 for 50s, 1 in 8 or 8.5 for 55s.

A

[william t. oviatt]

You better hit what you aim at, or it will go around (the globe)and hit you in the back of the.... head!
Shoot & cook it for lunch on the barrel:D
I too, am interested in your 20-30, will stay tuned!
Bill