And..... Oddly the 243 55gr NBT has a higher BC than the 223 55gr NBT. The 243 won't get you to 4500 but it does have greater capacity and will outdo the Swift. Put 85s or 100s in a 243 and you have a whitetail/pronghorn gun......a 22, not so much. My 2!
- Thread starter GSPKurt
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If you've got some details on your 243 doing 4,050 ft/sec with 55ger's why not share your results ? I know this thread seems to have got side tracked but i would be interested in your 6x284mm that you use the 55ger's in as i'm sure the other guys would , not sure about a 243 with the 55ger's & 100ger's both shooting well from the same twist 
It's been years since I messed with them but H414, N550, 3031, RL15 and 4895 all got me over 4k while staying under 62k psi. (Lapua brass and 55NBT). I'll bet the comparatively new RL17 will do better than 4100 in a standard 26" 243.
You have to have twist to stabilize bullets but "over stabilizing" is somewhat a myth. The 6/284 wore a 27" Krieger 9.0 twist and easily shot 1/4MOA 3 shot groups at 100 on calm days with the 55s. I didn't expect such speed when I first started experimenting w light bullets but it sure turned heads including my own at the range. I used an old school Oehler so I'm confident in the numbers.
You have to have twist to stabilize bullets but "over stabilizing" is somewhat a myth. The 6/284 wore a 27" Krieger 9.0 twist and easily shot 1/4MOA 3 shot groups at 100 on calm days with the 55s. I didn't expect such speed when I first started experimenting w light bullets but it sure turned heads including my own at the range. I used an old school Oehler so I'm confident in the numbers.
I agree about 'overstabilizing' being a myth. However, when combined with extreme velocity, too much twist rate will flat out destroy a bullet. As it goes, exteme velocity can actually help to make up for an otherwise insufficient twist rate. IE, you can use a slower than recommended twist tube for a given bullet, IF there is sufficient velocity to generate the RPM needed to stabilize it...
I changed the scope at the weekend on the Middlestead instead of cutting the grass for the last time .
I shot the left group on 3.50 & 1.75 moa and then corrected to 3.75 & 1.50 . Works well , 679 rounds ( How sad is that , i should have said about 600 to 700 rounds ) I keep meaning to get that OCD fixed !
Groups shot at 349 yards
I shot the left group on 3.50 & 1.75 moa and then corrected to 3.75 & 1.50 . Works well , 679 rounds ( How sad is that , i should have said about 600 to 700 rounds ) I keep meaning to get that OCD fixed !
Groups shot at 349 yards
Got one this morning.
Just a little guy... might have still had milk on his lips. I'm skilled with a camera, but I must confess, this is the smallest coyote I've ever shot. I'm helping local farmers with a coyote problem, and I swore to them I'd kill all I could, so he had to die. He came in to some coyote sounds, and when I tried some distress, he acted like he didn't even know what it was. I caught him broadside at 190yds and sent it. I had a gusty 10-15mph wind going at 9 O'clock. Held for .5 mils but needed about .6-.7mils, which caught him right in the diaphragm. He was quartering toward me a bit and the bullet exited a bit behind the diaphragm. Couldn't find the entrance, with a teeny tiny exit. However, the impact literally "popped" him. There was about 5" of fur/hide ripped open on his back, yet the membrane underneath was completely intact. I'd post a picture of it, but I don't want to offend anyone's sensibilities if they don't like seeing exposed flesh. Strangest thing I've ever seen. He was borderline about ready to explode like a prairie dog. lol
Anyway, the new puppy slayer is doing well. Now I just need a normal sized dog to get some real testing done!
Just a little guy... might have still had milk on his lips. I'm skilled with a camera, but I must confess, this is the smallest coyote I've ever shot. I'm helping local farmers with a coyote problem, and I swore to them I'd kill all I could, so he had to die. He came in to some coyote sounds, and when I tried some distress, he acted like he didn't even know what it was. I caught him broadside at 190yds and sent it. I had a gusty 10-15mph wind going at 9 O'clock. Held for .5 mils but needed about .6-.7mils, which caught him right in the diaphragm. He was quartering toward me a bit and the bullet exited a bit behind the diaphragm. Couldn't find the entrance, with a teeny tiny exit. However, the impact literally "popped" him. There was about 5" of fur/hide ripped open on his back, yet the membrane underneath was completely intact. I'd post a picture of it, but I don't want to offend anyone's sensibilities if they don't like seeing exposed flesh. Strangest thing I've ever seen. He was borderline about ready to explode like a prairie dog. lol
Anyway, the new puppy slayer is doing well. Now I just need a normal sized dog to get some real testing done!
Just found a plot from the Middlestead when i switched from 80g to 90g'ers . This was the first test i did at distance , 1004 yards on Stickledown Bisley UK . The target was an F Class 5 inch 'V' & 10 inch 5 ring .
I use 45.0g Retumbo , BR2 and 90g Berger VLD's which averaged 3,193 ft/sec last time it was chrono'd . It will run past 3,300 ft/sec with the 90 and 3,500 ft/sec using the 80's but there seems to be a sweet spot around the 3,200 .
Evidently I have a thing for hotrod 22's. I've got a 220SwiftAI, a 22-250AI, and a 22-243AI. I don't have my load book with me right now, but IIRC the 22-250AI is running 80's at 3400 fps and the 22-243AI is running 90's at 3500 fps. There definitely is a velocity gain with the added case capacity.
That's a lot of barrel wear in the AI process , I'm curious to know why you went with all those calibers that do the same within a few hundred feet of each other ?
Opinions on 22-243 caliber
If the fire forming process isn't your thing don't go for it. For me, it's not enough wear to even matter. Not to mention that they're surprisingly accurate while forming. The swift was set up to run 55-60gr pills. The other two are setup differently as far as weights and barrel lengths. Not to mention the 22-243AI is a single shot. I built the 22-243AI then decided to rebarrel the factory 22-250. Figured why not bump it up while I was at it. I run a 6br and a 6x47 also. Similarities don't bother me.
If the fire forming process isn't your thing don't go for it. For me, it's not enough wear to even matter. Not to mention that they're surprisingly accurate while forming. The swift was set up to run 55-60gr pills. The other two are setup differently as far as weights and barrel lengths. Not to mention the 22-243AI is a single shot. I built the 22-243AI then decided to rebarrel the factory 22-250. Figured why not bump it up while I was at it. I run a 6br and a 6x47 also. Similarities don't bother me.
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I wasn't knocking it , just found it unusual . A 90g bullet at 3,500 ft/sec is going some in the 22-243 AI , can't see how that's possible without excessive PSI . We've found these velocities only safely obtainable by going to the 22-284mm .