What weights of bullets should I be able to shoot through this 1/12 twist barrel?
What range will it shoot out to with good killing power?
May better not ask about killing power, just state this barrel is 22" long.

Thanks again

I put together a 6X47 Lapua which is about half way between a 6MM BR and a .243. I used a 1 in 12 twist Kreiger specifically for an intended bullet weight of 60 to 80 grain bullets with varmints as the intended quarry. I figure for taking my grandsons out for their first deer at up to 200ish yards or so an 80 grain Speer HotCor will do nicely if the rifle likes that bullet. I think due to the extra juice a .243 has 90 grainers might do ok also in a 1 in 12.
I am currently shooting 65 grain Hornady V-Max's out of it at 3,700ish FPS and shooting bug holes. 70 grain Hornady SXSP's are outstanding as well but then my primary use is varmints.
As to range and killing power? The weight of projectile and velocity, size of the animal and personal ability will make all the difference in the world and you really haven't got the data needed for a good guess here.
Not much help but that's my experience with a 6MM in 1 in 12 for what it's worth.

I shoot a 6-284 with a 12" twist, and it is extremely accurate with 85 gr and under bullets, which is what I built it for. The original 6 mm Remington came out with a 12" twist barrel, due to the mistaken logic that it would be primarily used for varmints. The original heaviest loads were 90 gr bullets. Wincester went with a 100 gr load and 10" twist for the 243 and aced Remington. The press from the period pretty much proclaimed this one of the biggest screwups of history, since the 6mm is likely the better design. Anyway, I think based on this and my experience, the 90 gr load would be the limit with conventional bullets. With VLD or monometal designs, 80-85 will likely be the limit.

I was around for that Art, as a mere child of course . Released it as the .244 with the 1 in 12 and then re-released it as the 6MM after they rectified the twist screw-up. Like ya said, to little to late, the .243 was already off to the races.

I just picked up a Win 70 in 243 with 1 in 10 twist from a friend that said he couldn't get it to group consistently with anything he has tried. I told him I would take it for week or two and see what I could do with it. I think he was primarily trying IMR4350 with 100gr partitions. I plan to take the 2x8 Leupold off and put on a 4x16 Burris signature scope that I know will hold zero. I have a box or two of 100gr Sierra's and thought I would try a few loads with h414, h380, h4831 and IMR4320. Any pet loads or other powder recommendations?

Mine loves 87 Hornadys and near-max charges of IMR4350. Sub-moa.



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You may find there are plenty of bullets out there you can shoot in a .243 with a 1 in 12 twist.

My first deer rifle was a .244 Remington that had a 1 in 12 twist. I shot my first deer with an 85 grain Sierra spitzer. It worked just fine. I shot a number of deer with that Sierra along with about a cajillion ground squirrels and jack rabbits. We used to go down to the Sierra factory and buy seconds by the pound.

Later on, I switched to the 90 grain Speer spitzer for deer, it also worked well.

A number of years ago I had a custom 6mm Remington made up and went with the 1 in 12 twist again just because that is what my old .244 had. This rile shoots great with any bullet weight less than 100 grains. In fact, I load a few 100 grain Hornady round nose bullets some times to keep in my pocket when shooting ground squirrels in case we see a wild hog. The round nose bullets are shorter and stabilize just fine.

My favorite long range varmint load uses an 80 grain Sierra Blitz bullet. I have killed prairie dogs better than 750 yards with that load.

So, there are lots of options out there. My suggestions would be a 70 Ballistic Tip or the 80 Sierra for varmints and most likely the 85 grain TSX for deer, etc.

The 75 grain Hornady V-Max is also a fantastic varmint bullet! I don't know if they still make em but I have several boxes of Nosler Partitions in 90 grainers as well.