.20 Cal fun

[TAJ45]

Anyone have an opinion of shooting the 55 Bergers for 600 br and F class?

 

[JASmith]

You should be good to go in a 20 PPC, 20 Grendel, or 20 BR with those bullets.

You can see comparisons of drift and drop with the 20 Grendel against the .308 Win and .300 Win mag using long range target bullets going to this page: http://shootersnotes.com/articles/20-grendel/

 

[rickiesrevenge]

It'd be fun while the barrel lasted.

Aaron

 

[Phil]

That's why barrels have threads 8)

 

[MrMajestic]

That's why barrels have threads 8)

LMAO! ;D

 

[TAJ45]

Interesting link. My plans are for a bolt gun, 26" bbl and 3500 min fps so that should trim the drift even more.

Every hobby has a price. Like the speed shop sign said: "Speed is $$ son, how fast do you want to go?"

 

[abishai]

I think the rules state from 22 to 35 cal ........... Rules are made to be broken though

 

[hogpatrol]

Interesting link. My plans are for a bolt gun, 26" bbl and 3500 min fps so that should trim the drift even more.

Every hobby has a price. Like the speed shop sign said: "Speed is $$ son, how fast do you want to go?"

OR Kenny Bernstein's famous retort, "To go fast takes cubic dollars not cubic inches"
;D

 

[Phil]

gstaylorg,

The .20BR will shove the 55 Berger along at 3500-3600fps. pretty easily.

More if you use a Dasher.

Phil.

 

[TAJ45]

OK, some musings here. I've read where Berger's BC rates are on the optimistic side. Anyone?

Also, from a point of ignorance here, I see a G1 and G7 BC criteria. Whatinthedevil is the G7 and why such a difference in values from the G1 ( I like those bigger BC #'s). But I know we are talking about the same bullet - just what does one represent, or what does it mean? Measuring different aspects? Or just a diff formula and then for what purpose?

Helped a bud interpret some ladder findings he recently did. Help may not be the operant word but I had an opinion.............;-)) I NEED a .20 cal bbl twisted at least 8.5...........

I went to the Berger site and read a bit about marginal spin stability at temps and barometric pressure. I'd always wondered why some folks said their 3 groove PN bbls were doing "just fine" with the 55 Bergers @ 9tw. I may have a glimmer now. All of this is just too interesting.

I have a set of forming/necking dies coming. How about a 6BR Long or 20BR long? Around Dasher capacity but a decent length on the neck? Just moosh them down from 243 or 308 or '06. Whatever has been accumulated over the years. I have a big batch of WW virgin '06.

 

[csandfort]

OK, some musings here. I've read where Berger's BC rates are on the optimistic side. Anyone?

Also, from a point of ignorance here, I see a G1 and G7 BC criteria. Whatinthedevil is the G7 and why such a difference in values from the G1 ( I like those bigger BC #'s). But I know we are talking about the same bullet - just what does one represent, or what does it mean? Measuring different aspects? Or just a diff formula and then for what purpose?

This might answer your question: http://www.bergerbullets.com/a-better-ballistic-coefficient/

 

[TAJ45]

Thank you for the link. When I was noodling around Berger's site earlier, I didn't look far enough apparently. Good info and it looks like my big mystery is solved.

 

[rich44]

I have a set of forming/necking dies coming. How about a 6BR Long or 20BR long? Around Dasher capacity but a decent length on the neck? Just moosh them down from 243 or 308 or '06. Whatever has been accumulated over the years. I have a big batch of WW virgin '06.

How about a 20-250 55 Bergers at 3850 you can user Lapua brass and a lot less case forming. I'm running a 9 twist for both the 20br and 20-250

 

[xswanted]

I have a set of forming/necking dies coming. How about a 6BR Long or 20BR long? Around Dasher capacity but a decent length on the neck? Just moosh them down from 243 or 308 or '06. Whatever has been accumulated over the years. I have a big batch of WW virgin '06.

How about a 20-250 55 Bergers at 3850 you can user Lapua brass and a lot less case forming. I'm running a 9 twist for both the 20br and 20-250

WHat barrel length/powder are you using?

 

[desilva]

my 20x47 lapua loves the 55 bergers at 3682fps i get consistant target hits at a 1000. at 300 the moa is .133 with 35.7gr of RL17. (always start low and work up slowly)

 

[TAJ45]

What tw & whose bbl?

 

[JASmith]

...The comparison of the .20 Grendel to a .308 linked above is a bit misleading; most F-TR shooters would be pushing a 175 in the neighborhood of 2750-2850 fps, not 2530...

The comment is correct in that shooters in this category would use rather long barrels and often handloads pushed to the max.

The comparison made is to a .308 Winchester with a twenty inch barrel and factory ammunition. Further the velocities listed for the 20 Grendel are kept at or below 52,000 psi and 20-inch barrels to reflect the AR varminting application intended for the cartridge. Should one desire to build a long-barreled bolt gun with the cartridge and run to the maximum safe pressures for the cartridge , then the velocities would be intermediate between the 20 PPC and the 20 BR. That would make the cartridge even more competitive vis a vis the .308 Winchester.

Even, so we probably won't see the velocities the OP is looking for since he appears to be going with a larger parent cartridge. Should be interesting to see how it goes!

 

[kev77]

me too, 20x47L 55gr bergers 37gr RL-17 for an easy 3920fps .25 moa grouping to 500 yards.Hell on coyotes lmao BANG FLOP!!! I have not shot it in f-class yet but will proably give it a go for a few relays.Average 1200 rounds on a barrel. BANG FLOP!!!!!

 

[kev77]

Lija 3 grove 27"

 

[TAJ45]

Kev77,

Is it an 8tw?