20 br load development

[doctorh]

So I put together a 9 twist 20 br a year ago. Have been back and forth w load development. I'm using norma brass, berger 55s, 7.5 remington primers, & a2520. I've worked up to 29.8 gr of powder and not seen velocity over 3500. So my question is where do I want to be velocity wise? Barrel is 28" I think. I just got a decent chronograph this spring. Shot a .198 group today @ 29.6gr w Ave velocity of 3463. Es and SD were not great. Es was 85, and SD was 35.5. I have read on here most guys seem to want to be around 3600 or a little more. Should I keep feeding it more powder or switch to something faster? Barrel life is a concern knowing that it's a short life w this clambering. I'd like to get there soon. Thanks for any help

You may want to try reloadedr17 with the 55 Berger bullet.I getting appox.3650 fps with 450 primers. Shoot good in my 20 br barrel 26". Start at 30.0 of r17 and work up at .3 gr.

 

[Piglet]

That's a nice group Piglet. I'm curious who made that barrel. If the SD and ES is really bothering you I'd weigh your cases and try a group of five of the closest and see how they do. Or I might beg,borrow, or steal 5 Lapua pieces of gold and see what they do. I'd also try vv140 or vv150, the burn temp is low and the burn rate will be where you want to be. Also try cci450s. Are you hunting varmints or just targets?
Matt

 

[Piglet]

17vld. I'm not sure I bought it at a gun show,it was threaded and chambered for a 700. I refitted,rechambered it to fit a mack bros. single shot action.bedded it in an old 40x stock. I timed the threads so the barrel marking is in the right place. there is engraving on the bottom of the barrel, gunsmith name that fitted it originally,the date,but no maker. was bought from a local gunsmith that bought it from an estate w several other 20 caliber shilen barrels, its a 3 groove bbl. this will be a mid range varmint rifle, pdog special. would like to stretch it out to 600 or so. I always just loaded ammo to get the best group I could, never had a good Chrono. the one I had b4 would only work when mars,Venus and Pluto were all in alignment! anyway I'm trying to learn how to use this chronograph to develop the most precise loads I can. Tommie I wasn't thinking bullseye more like 4064. I guess I was thinking backwards. 450 CCIS were something I was thinking about trying. I've got some Lapua brass, but been using it in 6br. I've had sd of 1.3 in it. may try varget or sw precision. maybe rl 15,16 or 17 too thanks for all the info guys.

 

[JSH]

I did a LOT of reading and question asking when I considered the 20BR.
Powder wise I started and ended with VV N150, the only powder I tried. It was a pure pleasure to do load work with. Went like clock work. Watch your chrono and understand what it tells you.
3600 was my goal with the 55’s. Oh, I also went with 450’s over the 7 1/2’s.
I am thinking a 28-30” barrel on the next one to gain some FPS.
Once again thanks to several in this thread that gave me advice, y’all know who you are ;-).

 

[Bodhisafa]

I did a LOT of reading and question asking when I considered the 20BR.
Powder wise I started and ended with VV N150, the only powder I tried. It was a pure pleasure to do load work with. Went like clock work. Watch your chrono and understand what it tells you.
3600 was my goal with the 55’s. Oh, I also went with 450’s over the 7 1/2’s.
I am thinking a 28-30” barrel on the next one to gain some FPS.
Once again thanks to several in this thread that gave me advice, y’all know who you are ;-).

Where could you get a barrel that length? Krieger said the longest 20 cal the make is 26 “ finished length

 

[Tommie]

Where could you get a barrel that length? Krieger said the longest 20 cal the make is 26 “ finished length

Pac-Nor can do 30”

 

[Gabe22BR]

Where could you get a barrel that length? Krieger said the longest 20 cal the make is 26 “ finished length

Any length you want-up to 36”
Just a matter of $$$. For extra “

I got a 30” 20 cal 1.250” straight chambered in 20BRAI with a Harrell’s 20 cal radial brake..

 

[Gabe22BR]

I’ve done a lot of searching on here-
Terry runs RL 15 =3550fps
Another guy uses H4350 yielding 3600fps
Another using IMR 4320
List goes on & on..

Concluded BR case= 3550fps
Brai case 3650fps
Dasher case 3750fps

That’s about the difference in case capacity in all of them.. 1.5/2gr. Depending on reamer and the gunsmith

 

[Gabe22BR]

Planned on not posting, just watching..
piglet should be able to get it where ya need to be, use the 450 primers for fireforming, & use a CCI BR or Fed 205M primers for everything else..

I made a Blaine Eddy plate to size the brass down brass with a long time ago.. video link on the 22br,brai,dasher,GT thread…

RL 15 or equivalent burn rate , 203B, varget, vvN140/150, IMR 4064 ,AA2520 , CFE223, and the likes…

 

[L.Sherm]

I would add one to Gabes list RL15.5.
I'm gonna give 15.5 another go in my 20BRA last time just basically did a FPS test.

 

[Bodhisafa]

Any length you want-up to 36”
Just a matter of $$$. For extra “

I got a 30” 20 cal 1.250” straight chambered in 20BRAI with a Harrell’s 20 cal radial brake..

Is yours a Krieger?

 

[Gabe22BR]

Is yours a Krieger?

Yes

 

[Bodhisafa]

Yes

I guess they changed some of their policies regarding 20 cal

 

[B23]

I guess they changed some of their policies regarding 20 cal

And it must be a recent change because when I talked to Krieger about getting 28in tubes for my 20-250 they told me 26 was the longest they'd do in a 20 call and to be more specific they said it was because they couldn't keep the tolerances with regard to straightness to their liking drilling a hole that small that long.

This was a couple years ago so maybe something has changed at Krieger but that's what they told me at the time.

 

[Piglet]

Gonna try to get some more loads for this weekend and keep you all posted. Would like to be at not necessarily the fastest speed but the fastest that's stable and groups well. I could be wrong on barrel length, but since it was brought up I'll measure it to be sure.

 

[Piglet]

Gonna try to get some more loads for this weekend and keep you all posted. Would like to be at not necessarily the fastest speed but the fastest that's stable and groups well. I could be wrong on barrel length, but since it was brought up I'll measure it to be sure.

Thanks for all the info guys

 

[Piglet]

Ended up trying rl-16 think I'm going to tune this load for depth and if she tightens up call it good. Thanks for all the tips and info. One more question im seated about 2 thou back from touching using the stripped bolt method, w this bullet being a tangent ogive which direction do i want to go? Into lands or out? Thanks again guys

 

[Piglet]

Don't know how I managed to post same picture 2x but I did. Gonna try to edit

 

[Piglet]

 

[Gabe22BR]

Ended up trying rl-16 think I'm going to tune this load for depth and if she tightens up call it good. Thanks for all the tips and info. One more question im seated about 2 thou back from touching using the stripped bolt method, w this bullet being a tangent ogive which direction do i want to go? Into lands or out? Thanks again guys

I’m .007” into on 55gr bullets-
Use a 12” drop tube to get more powder in there-
I found you can’t get enough RL 16 into the case to get velocity to 3550fps…