Fred_C_Dobbs wrote:If you have long enough a barrel and tight enough a twist, you should be able to easily drive a 55-gr Berger to more than 3000 fps, which will remain supersonic to about 1000 yards. Almost 1100 with a near-max pressure load.
QuickLoad says a 20" barrel should be able to drive it to 3000 fps with not quite 51,000 psi. It predicts a 26" barrel and max SAAMI pressure will get you a shade over 3300 fps. That's with 101.5% case fill with RL-17.Varoum wrote:Fred_C_Dobbs wrote:If you have long enough a barrel and tight enough a twist, you should be able to easily drive a 55-gr Berger to more than 3000 fps, which will remain supersonic to about 1000 yards. Almost 1100 with a near-max pressure load.
How long should the barrel be?
Berger recommeded twist is 8. Who shoots 55gr Berger and what twist their barrel have?
Not sure, Varoum. You might call Todd Kindler @ The Woodchuck Den and talk to him about it. He's sort of the Oracle for all things .20 cal.Varoum wrote:...One more question is the 57gr bullet requiring a thighter twist than 8
Jim, a bigger caliber makes better sense to me, too, but there's some folks who just get a kick out of doing things the hard way. There's a poster at The Varmint's Den forum who recently scored a 1032-yard hit on a prairie dog with a .20 BR. He was pushing the 55-gr Berger @3600 fps. It should have arrived with about 1350 fps still in the tank, ~220 fpe. That was enough to zap the poor little p-dog.Jim White wrote:I'm just curious...if one wants to shoot 1000 yds (or further) with a 204, would it be for paper punching or real small critters (because it doesn't have a lot of energy out there)? For the long stuff there better cartridges with much more horsepower for either option.
Fred it's interesting you say that. I was just chattin with an old shooting buddy and one of the things he mentioned was that I earned my NRA Highpower Classification (High Master) the hard way. Thinking about it, I would agree. I did it with a M14 rifle shooting mass produced (M852) ammunition even after the AR-15 using handloads had taken over of the sport. To add...I was a sailor, a submarine sailor at that.Fred_C_Dobbs wrote:
Jim, a bigger caliber makes better sense to me, too, but there's some folks who just get a kick out of doing things the hard way.
Heck, at the time, it was all I knew and besides, all one has to do is hit the 10 ring everytime. 
Of course, the stigma of a sailor's (except SEALS) marksmanship skills is along the line; they couldn't hit a bull in the butt with a base-fiddle. Of course that goes along the ole' saying; "one should never judge a book by its cover". 
A 39-gr SBK has @1000 fps has about 90 fpe. A good stout airgun only has around 20 fpe energy at the muzzle. Ninety fpe should zap 'em pretty good.Hotshot wrote:With a stout load pushing the 39gr Sierra I have experienced consistent performance at 550 to 600 yards. I believe that bullet to be stable at that distance. Energy is doubtful even for prairie dogs, I would recommend shooting them in the head for a sure kill.
100 ft lbs of energy will kill a PD without any problems, heck that would kill a Coyote too.Fred_C_Dobbs wrote:A 39-gr SBK has @1000 fps has about 90 fpe. A good stout airgun only has around 20 fpe energy at the muzzle. Ninety fpe should zap 'em pretty good.Hotshot wrote:With a stout load pushing the 39gr Sierra I have experienced consistent performance at 550 to 600 yards. I believe that bullet to be stable at that distance. Energy is doubtful even for prairie dogs, I would recommend shooting them in the head for a sure kill.