It's not April 1st yet. Really? bullet going 4000fps form a 8 twist explodes better than a bullet going 4000 fps form a 10 twist. I thought I was starting to understand twist rate stuff i.e. stability, velocity. Does this mean when choosing a twist rate for a 30 cal big game bullet a fast twist could reduce penetration? Really?
6mm BR for P-Dogs, What twist?
- Thread starter SLB
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Alex Wheeler
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Centrifugal force. If it can cause a bullet to explode in mid air, dont you think it will make them open more violently in an animal?
I guess. Hell, I can't even spell the word form, or is that from. You learn something new everyday.
Yes for the reasons stated above. I can't speak to the big game but for pd using the exact same ammunition in a 1:8 twist and in a 1:12 the faster really does more damage to those little critters. After seeing that I only use 1:8 in my 223 uppers.
ASbobcat
Silver $$ Contributor
Exactly. Think of it as "pre-stressed".
AckleymanII
Gold $$ Contributor
in 1990, I put a leupold 3.5-20 on a 7T Colt H bar that I had re worked the trigger to make it lighter. Worked up a good load with a 55g Sierra HPBT with AA2460 that shot 1/2". I loaded the same bullet in a 22/250 Shilen 14T at 3600.
I had 17 of the 30 round clips and 12 of the twenty round clips. I Found a p. dog town around Valentine, Nb that was 13 miles long and 3.5 miles wide, no way to get to it but drive across the prairie. We started hammering the dogs, I of course was blazing away with the H bar. I noticed that the 55g Sierra BTHP at 300 yards was making the p. dogs fly in the air, and not so much with the 22/250 going 600 fps faster...learned a thing or two on that trip.
Bullet jackets seem to have a certain amount of rotational torque(and the base) before they explode. It did not take much for the H bar round to detonate a p. dog.
My next lesson was on a 223 with a 9Twist and zero freebore, I had the same reamer used on two Hart barrels, on 9T and another 14T, zero freebore. I noticed the 9T blew up dogs better. So, I had a custom Sako A1 built, as a repeater, 9T Hart barrel, in a McMillen Sako varmint stock, 22 ppc-9T, zero freebore. The 9T in the 223 and 22 PPC both blew up dogs better than their 14T counter parts, but the tune window on the load was much more narrow and susceptible to more changes in weather.
I think that if you want to shoot heavies, throat for heavies and shoot heavies. If you want to shoot light bullets, go for the proper twist and throat very short.
Maybe a .0003+ over bullet dia throat would help with longer freebore, then again, the reamer makers have a .0005 +/- on dimensions that they allow on a dimension...better trust your reamer maker....
I had 17 of the 30 round clips and 12 of the twenty round clips. I Found a p. dog town around Valentine, Nb that was 13 miles long and 3.5 miles wide, no way to get to it but drive across the prairie. We started hammering the dogs, I of course was blazing away with the H bar. I noticed that the 55g Sierra BTHP at 300 yards was making the p. dogs fly in the air, and not so much with the 22/250 going 600 fps faster...learned a thing or two on that trip.
Bullet jackets seem to have a certain amount of rotational torque(and the base) before they explode. It did not take much for the H bar round to detonate a p. dog.
My next lesson was on a 223 with a 9Twist and zero freebore, I had the same reamer used on two Hart barrels, on 9T and another 14T, zero freebore. I noticed the 9T blew up dogs better. So, I had a custom Sako A1 built, as a repeater, 9T Hart barrel, in a McMillen Sako varmint stock, 22 ppc-9T, zero freebore. The 9T in the 223 and 22 PPC both blew up dogs better than their 14T counter parts, but the tune window on the load was much more narrow and susceptible to more changes in weather.
I think that if you want to shoot heavies, throat for heavies and shoot heavies. If you want to shoot light bullets, go for the proper twist and throat very short.
Maybe a .0003+ over bullet dia throat would help with longer freebore, then again, the reamer makers have a .0005 +/- on dimensions that they allow on a dimension...better trust your reamer maker....
I got bit hard with the PD bug last summer. EVERYTHING I owned had a 1-8 twist. I tried the lighter bullets in my 6-47L with around 2000 rounds down the tube. NOTHING from Hornady smaller than the 105 would hold together ...they all blew up at about 25 yards. I switched from 105 Bergers to the 105 a-max ...more explosive fore sure!!! I did manage to get the 70 grain Balistic tip to hold together. That was pretty awesome!! I went to a 12 twist Dasher and the 65 Vmax!! Perfect combo for me since I always have the 105 class bullets loaded up in other 8 twist tubes for LR work.
Anywhere there are prarie dogs there's wind. Here's a pic of one taken @ 745 yards with my 6-6.5×47 Lapua 8 twist running the 105 AMAX's 3050 fps. Helicoptered him 2' in the air and laid him on his back.
Until the pups get out of the dens the shots are long.
Until the pups get out of the dens the shots are long.
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I would do an 8 twist (and have, for my 243AI). As stated the 105 AMAX (discontinued) does very well on prairie dogs and bucks the wind a lot better than 70-87gr bullets.
I shoot the 87 Vmax out of the same gun. Every bit as accurate. For my trip this summer I'll load 2/3 of my brass with 87s and 1/3 with the 105s for longer shots.
I shoot the 87 Vmax out of the same gun. Every bit as accurate. For my trip this summer I'll load 2/3 of my brass with 87s and 1/3 with the 105s for longer shots.
AckleymanII
Gold $$ Contributor
Alex is trying to explain kinetic energy= centrifugal force
Hotshot
Silver $$ Contributor
I've been shooting prairie dogs for 60 years. On the subject of long range prairie dog guns a 6 BR would be closer to the bottom than the top of my list.
Your best friend will be velocity to flatten the trajectory, then ballistic coefficient for the same purpose. Seems like there are many better choices to get a combination of the two.
Your best friend will be velocity to flatten the trajectory, then ballistic coefficient for the same purpose. Seems like there are many better choices to get a combination of the two.
AckleymanII
Gold $$ Contributor
perfect battery for p. dogs
6 BR,12T-14T zero freebore for 55g-70g bullets
6 BRX or Dasher, .040 FB for 87g bullets, will be seated a little deep to begin with, but leade will grow out pretty fast on dog town shooting
6 BRX or Dasher, .105 FB for 105 A max; some may choose a 6 XC or 6-6.5/47 Lapua, 6 CM, 243, 6 SLR
Done.......
6 BR,12T-14T zero freebore for 55g-70g bullets
6 BRX or Dasher, .040 FB for 87g bullets, will be seated a little deep to begin with, but leade will grow out pretty fast on dog town shooting
6 BRX or Dasher, .105 FB for 105 A max; some may choose a 6 XC or 6-6.5/47 Lapua, 6 CM, 243, 6 SLR
Done.......
I shoot 58 Vmaxes in
With a rangefinder, I can tell within a yard or three how far away they are, and can correct accordingly. With swirling winds changing in the hills and valleys, I can and have been clueless as to how far to hold or dial in the wind. This is where the heavies shine.
Definitely the 8twist factory savage. If custom I suggest even 7twist in a 6br. As pictured and stated above by others; rotational speed causes more "tissue dispersion". Will caution though that a rough or worn bore will stress bullet jackets more. 105 amax at 3000fps with rl17 (.140 free bore) works very well!
powderbrake
Gold $$ Contributor
I agree velocity is good, and ballistic coefficient is very important. I too am an oldster with lots of prairie dog years, but now with the use of the ballistics programs on an iPhone, ranging binoculars and wind meters, I start with the ballistics coefficient, and find a load that shoots a heavy bullet into small groups. I no longer worry about velocity, I let the ballistics program deal with it.
I have moved from 223 to 22-250 to 6BR, and the 6BR makes me happy.
ps it's an 8 twist, Berger 88gr varmint bullet.
If its going to be a dog gun think brass first. There are still some towns out there where the shooting is non stop. The BR is a great little round but brass isn't cheap. Don't overlook the regular old 243. Good once fired brass can be had for $0.15 per. The 87 gr V Max is an unbelievable varmint bullet that will shoot well out to 1K using a factory barrel 1-9 or 1-10 twist. The great part about the Savages is you can pick up good take off barrels and have them ready to screw on when you smoke one out or just want to try a different round. Even the bolt faces are easy to change.
6BR is one of the more economical cartridges when you factor in barrel wear cost per rd (largest per round expense in many cartridges) and brass life. Let's see somebody get 50-100 reloads out of 243, 6XC, 6 whatever.
Besides being very easy to find good loads.
Gives meaning to the phrase- pay once, cry once.
Besides being very easy to find good loads.
Gives meaning to the phrase- pay once, cry once.
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