.20 Cal Berger 55gr, any one using?

[strombeckj]

I am looking at a .20 cal build. I want to shoot the 55gr Berger's but can't seem to find a 1:8 twist barrel.

So my Q is this... What is really working? what cartridge are you using and what kind of accuracy and FPS are you getting?

Thanks for your input.

 

[65WSM]

Please note that Berger (Mr Litz) has redone the calculations and suggests a 7 twist barrel for this bullet. The only 7 I could find was Pac-Nor. I don't actually know if and what their timetable for delivery would be. I used an 8 twist McGowen 28 inch barrel. I had the barrel "nitrocarburized" so it will last a few rounds.

So far my .20 BR is very fast. The Magnetospeed shows with CCI 450 and R-17:


31.0 gr 3604 31.0 gr 3578 31.1 gr 3617 31.1 gr 3570 31.2 gr 3617 31.3 gr 3646 31.4 gr 3632 29.7 gr 3572 31.0 gr 3543

 

[65WSM]

I had actually started to build a 22 BR to shoot 80gr Nosler Berger and Sierra bullets at 550 yards (the back clay bank of my Club Range). When I ran into a supply of Berger 55 gr .204 bullets at Sinclair, I bought 2K and started to build a .20 BR. So far the 22 BR is more accurate than the 20 BR with Sierra and Nosler 80 gr bullets compared to the .20 Berger 55s. The .22 cal bullets go between 2800 and 2900 with R-17 or VV N-550. I think that a 7 twist barrel might be more accurate than the 8 twist that I own. Both rifles have Sightron 10-50X scopes and Richards Microfit stocks.

 

[65WSM]

Because there is still case room. I am going to try VV N-550 at nearly case capacity with the 55s. That is my next project. At 29.7gr of N-550 I get just 3500 fps and the SD is not as good as the R-17. It is not up to max pressure.

There are other IMR 4350 burn rate powders to try as well, the IMR 4451 interests me because it is built in that new ISO 9001 plant near Toronto that belongs to General Dynamics.

I coat all of my bullets with HBN so copper fouling is present but probably a tenth as severe as most .20s suffer. I get a trace of blue on the first patch after letting Wipe-out Patch-out sit overnight.

 

[Garycrow]

I am looking at a .20 cal build. I want to shoot the 55gr Berger's but can't seem to find a 1:8 twist barrel.

Mullerworks Barrel

 

[B23]

Defensive Edge is building me what they call a 204 Terminator that'll be shooting the 55gr Bergers in. Considering the speed those 55's will be launching at a 1-8tw will be plenty and the barrel is coming from Krieger but the longest they'll do in a .20cal bore diameter is 26 inches.

I think that 1-7tw recommendation is because they're assuming most with be shooting the 55's in things like a 204 Ruger and at those speeds you'd need more twist to stabilize them but at 4000+ FPS a 1-8tw puts you well into "stabilized" per Bergers twist rate calculator.

 

[7mmShooter]

Defensive Edge is building me what they call a 204 Terminator that'll be shooting the 55gr Bergers in. Considering the speed those 55's will be launching at a 1-8tw will be plenty and the barrel is coming from Krieger but the longest they'll do in a .20cal bore diameter is 26 inches.

I think that 1-7tw recommendation is because they're assuming most with be shooting the 55's in things like a 204 Ruger and at those speeds you'd need more twist to stabilize them but at 4000+ FPS a 1-8tw puts you well into "stabilized" per Bergers twist rate calculator.

4k+ with the 55gr? ****... Any more info you can share?

 

[B23]

4k+ with the 55gr? ****... Any more info you can share?

Just started the build about a month ago and we are still waiting for a barrel from Krieger. I talked to quite a few barrel makers and a lot of them don't make a .20 cal barrel and even some that do didn't offer one with a twist faster than 1-9. The barrel companies I talked to said since there isn't a great deal of demand for fast twist .20 Cal barrels the wait time will, likely, be longer than normal so I don't look for this build to be done nearly as fast as the others I've had built by Defensive Edge which is typically only around 3-4 months.

The 204 Terminator is kind of a new creation from them and will have their proprietary +P throat design. In preliminary testing they were getting well over 4000FPS with the 55's. It has a pretty healthy amount of overbore so I'm fully aware barrel life will definitely suffer but I am certain it'll be a hell of a lot of fun along the way. Until it's done and we're shooting it I don't know much more than that.

 

[7mmShooter]

Sweet, gonna be a fun laser while it lasts though gun)

 

[65WSM]

Update on the 55 Bergers. I was shooting the .20 BR with the 55 gr Bergers alongside two .22 BRs all with 8 twist barrels at 550 yards. The .20 BR was producing 5 shot groups 5-6 inches. I switched to Sierra 77 Tipped Match Kings (I also have evidence the tips melt like Hornady says) and got groups consistently under 3 inches.

So that got me thinking. I tried both 40gr Hornady V-Max and 39 gr Sierra Blitzkings in the .20 BR. I was surprised, better shocked, at how accurate the rifle was at 550 yards with the lighter bullets. I have repeated this now in 4 trips to the range.

I have a long way to go yet in finding the powder charge I want. .20 BR powder data is scarce. I am auditioning VV N-135, N-140 (next trip when it stops raining) and SO-62 Precision. I have shot good groups with less than a caseful H-4895 and Alliant AR Comp. So far the only powder I have wound out to above 4,000 fps is the VV N-135. Yes, I have three .204 Rugers on deck with 26 inch barrels that can do that.

 

[65WSM]

So I guess I am looking for a 7 twist .204 barrel. Any suggestions?

 

[M Jager]

So I guess I am looking for a 7 twist .204 barrel. Any suggestions?

Unless you still have a stockpile, I have read the 55 Berger is being discontinued.

 

[B23]

Unless you still have a stockpile, I have read the 55 Berger is being discontinued.

Not being discontinued, they have been discontinued and any of the old stock that was still on the shelves is pretty much all gone. Soon as I caught wind of it I snatched up enough 55gr Berger's to last me awhile.

 

[65WSM]

I was not aware that the Berger 55 was going away. Thanks for informing me.