I wouldn’t sweat the twist rate that much until you try some ladder testing. I was hung up on buying my first AR10 243 upper because it had a twist rate of one in eight and I wanted to shoot 55 and 60 grain bullets at 4,000 fps and over. Both my BCA uppers in a 1/8 twist shoot sub MOA with 55 grain Nosler ballistic tips loaded over max book loads with no pressure signs and 60 grain Seirra Hollow points close to 4,000 fps. Both guns will shoot groups all touching at 100 yards. From all the forum reading and opinions I got I figured they wouldn’t have been minute of barn. I was told they would only shoot heavy for caliber 100 grain and above projectiles accurate. lol. All you can do is try for yourself. Keep us posted. I have to say my 1/10 twist 243’s shoot same hole with 70 grain ballistic tips loaded .2 of grain over Nosler max book load with IMR4831. They will shoot .2” to .3” at 200 pretty consistently as well. Just some food for thought with another caliber with a slower twist shooting the exact same bullet. Brass is easier to find and the twist is slower than The CM so you can shoot light and heavy bullets with excellent accuracy. Nice part is if you can’t find 243 brass, you can always neck down a 308. Brass is easy to come by.
Here’s a good read for you. Basically what you’re wanting to do is load, shorter, lighter bullets in a Creedmoor, which is meant for long heavy for caliber bullets that stick way out of the case. A lot of those “long for caliber“ target bullets are meant for paper punching and don’t reliably expand on game. It’s my guess is you’re better off with a 243 or 6 mm for what you want to do with it.
How does the 6mm Creedmoor stack up against the renowned .243 Winchester? Contributor Philip Massaro examines the pros and cons of each.
www.americanhunter.org
Hornady just came out with an 80 grain ELD-VT .243 bullet thats meant for CM cases. I watched varmint masters shoot a coyote with one on YouTube and it blew a giant hole in it. probably a bullet you wanna try if you already bought the gun but don’t plan on saving any pelts. lol
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www.hornady.com
here is the video with the same bullet in a 22 ARK at 185 yards. It was on bone so we all know what happens …big holes.
I have shot quite a few coyotes and a bobcat with 90 grain Nosler ballistic tips. Super accurate and they do an excellent job but you’re losing the flat trajectory because you can’t pump up the speeds past about 3250 fps…and that’s with a 26 1/2 inch barrel. Closer the 3,000 fps in a shorter 20” barel or even less. Me, I want to get something shooting at least 3650 or faster so it will shoot flat out to at least 300 to 350 Yards or more. The lighter 55 and 60 grains will shoot flat almost to 400 Yards when getting them going around 4150fps or so. Imo that’s is where a .243 chambered rifle shines for predator hunting. The 85 grain bullets and above are designed for deer and paper punching at stupid long ranges to buck the wind.