Quote:
Originally Posted by duceman
here's the follow up question:
what the hell is the draw toward dink bullets with high powder capacity cases; for example 50 gr bullet in a 40 gr powder capacity 22-250.
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The vast majority of people have no idea about ballistics or why your 222 is much more fur friendly at close range yet gets the job done at 400 yards. I have talked to many people who rave about their pet 22-250 coyote load only to qualify by saying "I can't shoot more than 2 or three rounds without blowing primers though". Hornady show a max of 3800 fps with the 50 V-Max and my Ballistics program shows 3680 for a Factory 55 HP bullet yet many of these same people believe that pushing these bullets 200 fps faster is Ok as they shoot so flat.
However if you go to a 39/40 grain bullet in a 20 caliber at 3650, which can be done with 22.2-22.4 grains of powder in a properly designed cartridge with an 11"twist barrel, the PBR is very close and the 20 will do better in the wind. The problem with going to a 20 caliber is that no manufacturer makes anything but the standard 12" twist barrel, which do not work very well with the 39/40 grain bullets, unless they are pushed to over 2700 fps. Most 20 cartridge designs require pressures of 63,000 PSI to get there accurately and then some think it OK to find an accuracy node at 3900 fps.
The main reason that manufacturers have not been in a hurry to go to faster twist barrels is marketing but Cartridges like the 20 Var-Targ and 20 Tactical do not lend themselves to running 39/40 grain bullets, with in Saami standard pressures as they are either too small or too large, in capacity, and they will not fit in standard magazines without running well off the lands.
I realized this early on and decided to design my own 20 caliber that had none of these problems. I also realized that a 40 V-Max would stabilize nicely at 3470 fps and run the same trajectory as a 22-250 with a Factory 55 HP
bullet which the Leupold VH Reticle was calibrated. I was elated to find that this low pressure load was better in the wind as well. The 22-250 trajectory is in yellow and is virtually covered by the 40 V-Max trajectory to 500 yards.
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When IMR 8208 I was able to get the 39/40 grain bullets to 3650 fps which does make the 22-250 look a bit anemic, with 50-55 grain bullets, even when pushed to the max. Going to a 9" twist with the 55 Berger and Varget really make the 22-250, or any of the other 20 Calibers with 12" twist look rather sick. Duceman, you will be really pleased when you get to try this load out on a few coyotes, when you get the time, and I look forward to a complete review.
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The 11" and 9" twist barrels have no problem stabilizing, or shooting accurately, good loads in 32 (3850 - 4000 fps) and 39/40 ( 3500 -3650 fps) grain loads in all rifles.
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