20 BR with 40gr bullets
 

I'd like to try a 20 cal for harvesting fur. I want something that is at least going to be the ballistic equal to my 17 shooting 30gr bullets at 4000 fps plus and some additional downrange energy while still giving me no sew pelt damage. I want to have good Lapua quality brass. I shot a 22br in the past but had feeding issues occasionally. With mag kits available and new MDT mags for the BR case the feeding may be a non issue.

No point in crying foul with Berger dropping the 55gr 204 bullet as that would be the reason to run a fast twist 20BR.

Can the 20BR reach 4100fps-4200fps with 40gr bullets and not toast a barrel in under 750 rounds? I also thought about building a 20 Practical or a 20 Predator.

What twist for 40s, 1/11 to be safe? I never get below 2200ft above sea level and it will be winter shooting.

As far as 4100 out of a straight BR with 40's maybe a stretch. I can get 4050 with a 20 Nitro ( 20BRAI) and Badger Bob's 46.5's. 1-11 3G would be all you need for 40's if you never plan on going higher.
A 1-10 with Badger Bob's 46.5 would be a great combo in a 20BR and I think you would be still fine with 40's

My 20 BR is a 12 twist
 

The 40 grain Berger is an awesome bullet for what you want and it is also what I use to wring out what a gun is capable of accuracy wise.If it was me I would choose an 11 twist just to make sure if you ever wanted to try 40 V-Max’s on pd’s you would be fine.Probably not needed but at your altitude it might be prudent.As far as velocity 4000fps is a walk in the park for the BR and a 40.The best group I Shot in competition was 5 at 100yards of .212”with the Berger,glad it is still available.
Matt

As L.Sherm mentioned, getting 4100 w/40's from a 20BR will be a bit of a stretch unless you run it really hard at some pretty high pressures. If you want to drive a 40 grainer that fast, you'll be better off stepping up to the 20-250 which is another very easy 20 Cal to make.

I've got a couple 20's, 20-222 w/11 twist that shoots the 40gr Bergers, and a 20-250 w/8 twist that shoots the 55gr Bergers. Both are a lot of fun and very accurate, but they definitely have their trade offs.

I'm up in Canada so I should be able to get Hornady, Sierra, and Berger bullets in the 39 and 40gr flavors. The cost to import other heavier bullets is really not an option.

Of the three bullets I can get, my research suggests the Berger would be the best fur bullet followed by the Sierra a distant second.

I was thinking that if could not get to 4100fps with a 20BR I would consider going to the BRAI but that is as big as I would go as I thought the 20BR would already be beyond the practical limit of performance versus barrel life.

The problem I ran into with the 40gr bullets was that I couldn't find a factory bullet that would do a good job on coyotes, with the 40gr Hornady and Berger I had a lot of sewing to do. the Sierra 39gr didn't do a good job of killing them on the spot. That was one of the reasons I started making my own 40 and 46.5gr bullets. So far all of the dogs shot with my bullets have been DRT and I haven't had to sew any of them. On a side note, the 35gr Berger did a pretty good job.

Bob

I was just getting ready to mention, if 4100 from a 20 BR is what the OP was after and with a good coyote bullet, he should take a look at shooting the 35gr Berger instead. Everything I've heard about the 35gr Berger has been what a great coyote bullet they are.

Well that's a pickle. If I have to shoot a 35gr 204 to have good performance on coyotes I'll stick with a big 17 that has the capability of shooting the 30gr bullet at 4100fps.
I am stuck shooting the factory bullets I mentioned. It is very cost restrictive getting bullets exported from the US given the difference in the dollar. Don't really have the money to invest to make my own bullets although I have thought about often.

I don't want to have wounded coyotes or torn up hides. I played with 22 cal stuff and never found what I was looking. Switched to a big 17 and have been extremely happy. Thought maybe a bigger 20 would give me a little more of a good thing.

I like the 39SMK better then the either the B 40 or 35
It is very accurate and very fur friendly.
This is with a BAT 20BR 1:11 @ 3850 fps

I'm also shooting B 50's in a BAT 20BR IMPROVED @ 3740 fps

I have a buddy that used the 40 grain Berger out of a 20 Extreme on coyotes and said they did a great job - very little sewing. Last year they shot 75 dogs and got top dollar from his fur buyer, this year .... it seems they cleaned them out last year as they only got a dozen this year.

The gun was built for the 55's so has an eight twist. The 40's work fantastic in it though anything lighter they just don't work. Not sure on the velocity but don't think it quite gets to 4000. 37-39000 is what I am thinking but haven't tested.

I'm with you on trouble finding bullets. If I could figure out the how to's and costs I'd look at trying to bring some of these other bullets up. But, of course, it has to be cost effective. A guy can put up with a little extra but $25 a box or more is getting too much. The last box of Berger 55's I believe I paid around $40. I inquired about bringing in some Black Hole bullets and was quoted $75 a box. He doesn't ship them to Canada himself, that was having a Canadian outfit bring them up. For that cost I guess I'll stick with 40 grain.....