I just assembled my first Savage rifle. It is shockingly accurate. I seriously doubt I had anything to do with it.

[AbitNutz]

Curios as to why you chose the 7 twist?


Well, there are two reasons, one required and one personal preference. The cartridge is a 300 Remington Ultra Mag and to get the most out of it you have to shoot high B/C bullets and the high B/C bullet I like the best is the Sierra #2231 .308 200 gr Matchking HPBT which has a B/C of .715. It has a warning on the box that it requires a twist rate of at least 9:1. There's also a 235 gr bullet that requires a 1:8. If I use a slower twist these bullets won't stabilize. If I choose to shoot light bullets, like 150's or 165's I've found that I usually don't have a problem. They still shoot fine.

With Retumbo, a .308 200 gr Sierra Matchking and a 26" barrel I should easily get over 3000 FPS. I'm going to try this out at some point at Thunder Valley's 1000 meter range in South Eastern Ohio.

Second reason is the 1:7 was available in 5R. I've had good results with 5R rifling before. Not so much with better accuracy but they were easier to clean and gave a little higher velocity for an identical cartridge and length barrel.

So, when X-Caliber had their 50% off sale the 1:7-5R was an no brainer from their drop down list.

[Texas10]

At 3000 fps your bullets are going to be spinning at 308,571 RPM. At 2910 fps they're going 299,314. That seems to me to be a bit fast for most jackets, what are you anticipating using?

[AbitNutz]

At 3000 fps your bullets are going to be spinning at 308,571 RPM. At 2910 fps they're going 299,314. That seems to me to be a bit fast for most jackets, what are you anticipating using?

I can only go by what the manufacturer says, Sierra #2231 200 gr HPBT. They specify nothing slower than 1:9 and their 235 gr want nothing slower than 1:8. The groups I shot with Hornady factory 220 gr confirm that these heavier bullets seem to like the faster twist. Those clocked at 2910 fps.

One of the choices in the list for .308 X-Caliber barrels was a 1:5-5R!

[yobuck]

Well, there are two reasons, one required and one personal preference. The cartridge is a 300 Remington Ultra Mag and to get the most out of it you have to shoot high B/C bullets and the high B/C bullet I like the best is the Sierra #2231 .308 200 gr Matchking HPBT which has a B/C of .715. It has a warning on the box that it requires a twist rate of at least 9:1. There's also a 235 gr bullet that requires a 1:8. If I use a slower twist these bullets won't stabilize. If I choose to shoot light bullets, like 150's or 165's I've found that I usually don't have a problem. They still shoot fine.

With Retumbo, a .308 200 gr Sierra Matchking and a 26" barrel I should easily get over 3000 FPS. I'm going to try this out at some point at Thunder Valley's 1000 meter range in South Eastern Ohio.

Second reason is the 1:7 was available in 5R. I've had good results with 5R rifling before. Not so much with better accuracy but they were easier to clean and gave a little higher velocity for an identical cartridge and length barrel.

So, when X-Caliber had their 50% off sale the 1:7-5R was an no brainer from their drop down list.

Well if you cant get well over 3000 fps with a 200 SMK you should be very disappointed.
In fact with a 30” barrel 32 to 3300 would be very likely.
For about 25 years a 36” 9 twist barrel chambered in 30x378 gave me 3500 fps using 113 gr of H570 with that same bullet.
And many others as well using that cartridge got the same type results, and some i know still are.
The 300 Rum is fairly close to the 30x378 as for performance.
Fact is that much of the data we see are as a result of computer models, not actual live round testing.
So dont rely entirely on what it says on the box of bullets.
People today insist on knowing the BC of a bullet, but to a very large degree that is controlled by the velocity.
The 230 gr for example wont really start to show any improvement over the 200 till after about 1500 yds in your gun.
And that is due to the increased velocity the 200 has over the 230 or 240.
Same goes for the 338s. Many guys think having a 338 and using 300 gr bullets puts them in a different league, but actually it dosent, at least not with all of them.
Velocity rules regardless of the cartridge, and that requires powder, and enough barrel length to burn it before the bullet exits the muzzel.
For what its worth to you, i can run a 190 SMK from my 30” barreled 300 Norma at 3350 using 97 gr of Retumbo.