Coyote calling rifle 20-240 or 22-243?

[toddcdozer]

A big 20 cal would be great with the 55 Berger IF IT LIKES them. The twist required to shoot them will mean its a 1 bullet gun.
I played with a 204 a lot and the 55gr wont even begin to think about stabilizing in a 10 twist. Mine shot PATTERNS with the 55.
For PBR style setups the 20 cal and 55gr would be tough to beat. As to killing power.....A guy I know shot a bunch of deer with the 32 and 40gr and a 204....and they all died and quite quickly.
I still want to build a big 20 for that Berger, just have too many other projects for now.

[justinp61]

I reload so ammo not even a consideration I know this round is a barrel burner that's why I'm planning on a savage build it going to be for calling coyotes and that's it. It will shoot flatter have less wind drift and have more energy then a 22-250. All about bullet bc. If you google search there is some information on this round quit a few stuff on predator masters too. Was just trying to get some more advice from some of the savage pros around here that have built off these rifles before.

Pardon me. Good luck on your build.

[handirifle]

MUZZLE Velocity of a bullet WITH PRESSURES BEING EQUAL will ALWAYS favor the larger diameter bullet. It is based on a formula that gets velocity from the square of the base dia of the bullet. In the example above 260 vs 7-08, the larger dia 7mm bullet will exit the muzzle faster, but possibly, due to BC's, the smaller diameter bullet MIGHT retain more velocity down range.

A 20 cal, exerting the SAME pressure on a 55gr bullet will have a LOWER MV than a 22 cal exerting the SAME pressure on a 55gr bullet. What happens after than depends on bullet design.

[zr600]

Ok after talking to my barrel suplier he thinks I would be better off with a 22-243 shooting a 80 a max or 90 Berger. So I think this might be the route I go because I have more bullet options with the 20 I only have 2 bullets to pick from and if both them didn't work then the gun wouldn't do what's i want it to. There is hornady bullets sierras bullets and bergers to choose from. We're the heavy 20 cal there's the Berger 55 and the black hole 55 and that's it.

[handirifle]

Bearing surface between 2 bullets of the same weight and caliber will be the only thing you changed, so a longer bearing surface may increase resistance enough to lower the speed. We aren't talking about the same caliber, it's a smaller hole, using similar powder charges, pushing the same weight bullet. The change in diameter outweighs the change in bearing surface, increasing the pressure.

The 7-08 and .260 were bad examples because a 140 7mm bullet is nothing like (shape, construction, use) a 140 6.5 bullet. I also Wouldnt rely on that book data. I regularly see .260's well above 2700 using h4350. I have not seen a 7-08 that pushes a 140 more than 2750, but I only have experience with one and we shot facory ammo out of it.

On ANY caliber comparison, when comparing the SAME WEIGHT BULLET with the SAME PRESSURES from 2 different calibers, and same barrel length, the larger diameter bullet will ALWAYS go faster. It's physics. Velocity is a result of the pressure squared by the base (diameter) of the bullet. So a larger diameter bullet of the same weight, fired with the same pressures, will be faster.

Hydraulics works the same way, a 2" piston pushed by 3,000 psi of pressure will NOT produce as much force as a 3" piston pushed by 3,000 psi.

The only difference in cartridges, is usually the smaller diameter bullet will produce the same pressure with slightly less powder. But a 20-250 with a 55gr load, will NOT be faster then a 22-250 with a 55gr load, AT THE SAME PRESSURE.

[handirifle]

I say forget the 2 calibers you mention and go with a 243 with long barrel, 8 twist In case you want to go to a 105gr bullet later, otherwise a 9twist), and a 80-90gr high BC bullet. You will have a 600yd coyote slammin machine.