22-250 twist rate
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A_Gamehog
Member
L= LENGTH OF BULLET IN INCHES
D- BULLET DIAMETER
T=RATE OF TWIST
sambo {QUOTE}
The orig. poster had a flawed formula in that it had no input for speed.
The 1-12 twist 22-250 will shoot the 69's if the elevation and speed are high.
But a slow speed .223 with a 1-12 won't shoot anything accurately 60 grains or higher, some 1-12's won't shoot the long 55 V-max.
in a 223 only. I own each twist and speak from experience, not formulas.
1-8 twist shoots 50-80's best is a 75 out to 600 yards.
1-9 twist shoots 34-75's best is a 69 out to 600 yards.
1-10 twist shoots 34-69's best is a 69 out to 600 yards.
1-12 twist shoots 30-55's best is a 55 out to 400 yards.
D- BULLET DIAMETER
T=RATE OF TWIST
sambo {QUOTE}
The orig. poster had a flawed formula in that it had no input for speed.
The 1-12 twist 22-250 will shoot the 69's if the elevation and speed are high.
But a slow speed .223 with a 1-12 won't shoot anything accurately 60 grains or higher, some 1-12's won't shoot the long 55 V-max.
in a 223 only. I own each twist and speak from experience, not formulas.
1-8 twist shoots 50-80's best is a 75 out to 600 yards.
1-9 twist shoots 34-75's best is a 69 out to 600 yards.
1-10 twist shoots 34-69's best is a 69 out to 600 yards.
1-12 twist shoots 30-55's best is a 55 out to 400 yards.
Joe King
Well-Known Member
What I would like to know is how am I stabilizing a 53gr vmax in my 22-250 with a 1 in 14 twist. It shouldn't work but it does. according to a twist rate calculator I would have to push it north of 4100fps. All I got is my gunsmith is really damned good, and my dies are make some very concentric loads, so everything lines up just so.
A_Gamehog
Member
Zep,
The best powder I have found to work with 34's thru 80's is IMR 8208. With my 9 twist .223 I have a 3 shot 100 yard one hole group, in the 68-69 grain groups same rifle 1/2" at 200 yards. Lapua brass, cci450's, the brass is turned and the bullets are sorted by weight. When I shoot varmints I use lake City brass (unturned) and CCI450's, with 53 V-max, and 55's and I don't sort the bullets by weight.
Best 200 yard loads:
53 V-max
CCI450
25.6 IMR-8208
Lapua brass
2.260 col
69 Nosler CC
CCI450
24.5 IMR-8208 * over max!
Lapua brass
2.260 col
Joe King has a good point, sometimes it just works.
The best powder I have found to work with 34's thru 80's is IMR 8208. With my 9 twist .223 I have a 3 shot 100 yard one hole group, in the 68-69 grain groups same rifle 1/2" at 200 yards. Lapua brass, cci450's, the brass is turned and the bullets are sorted by weight. When I shoot varmints I use lake City brass (unturned) and CCI450's, with 53 V-max, and 55's and I don't sort the bullets by weight.
Best 200 yard loads:
53 V-max
CCI450
25.6 IMR-8208
Lapua brass
2.260 col
69 Nosler CC
CCI450
24.5 IMR-8208 * over max!
Lapua brass
2.260 col
Joe King has a good point, sometimes it just works.
Trickymissfit
Well-Known Member
Lots of misinformation here, by comparing the 223 and 22-250 with their twist rates. A 223 with a 10 twist shoots 69's a 22-250 with a 12 twist shoots 69's.
For the 12 twist 22-250 you can shoot the 34 Grain dogtowns all the way up to the 69's. I know I own and shoot one.
The most accurate is the long 60 grain V-max @ 3700+ fps.
The 69's from a 22-250 must be shot at 4,000 elevation to work, as the twist is bordering stability.
a 1:12 twist rate is good for roughly .30 B/C in the real world, and even then it's getting ragged. The Hornaday 53 Vmax is rated at .29 B/C, and really a 1:11 barrel would be better. I always work with a .85 factor number when figuring the thing out for a slight bit of cushion. The Sierra 1365 bullet is dead perfect for the 12 twist barrel, and my groups from three barrels seem to show this (mid twos for five shots if I'm lucky). I don't know what the B/C is for the Noslers, but it's gotta be in the .35 or higher range, and with that you need the 1:9 barrel minimum (maybe close to a .40B/C).
a .223 bore barrel in any caliber is still a .223 bore with a certain rate of twist. The twist rate is what stablizes a bullet, and never the velocity or really even the rpm's at impact like we all thought thirty years back. A 1:14 twist 22-250 will not stabalize a bullet any better than a typical .223 in a barrel with the same rate os twist. Just the nature of the beast. It cost me a lot of hard earned money to learn this the hard way
gary
Gamedog - Many thanks. I was doing a lot of reading last night and I was wondering about Varget for .223 for a lite bullet, 34 grain Dogtown or a 40 or 50 grain Sierra. Gun is a 1-12 twist. Have you tried Varget here.
I shoot all year and I like the idea of the no real temperature sensitivity with the Varget but as I am sure you are aware some of the upper loads can go compressed. I am not sure about compressed loads, I am not smart enough to start with that just yet.
Also thinking of H322 as it appears to be less temperature sensitive than some other powders.
I shoot all year and I like the idea of the no real temperature sensitivity with the Varget but as I am sure you are aware some of the upper loads can go compressed. I am not sure about compressed loads, I am not smart enough to start with that just yet.
Also thinking of H322 as it appears to be less temperature sensitive than some other powders.
Gary - thanks as well. This is a very good thread.
Can I ask about your powder choices as well.
Anyone else who can add as well, good powders for 223 and 22-250. Shoot all year 20s up to mid 90s temperature wise. 1-12 twist on the 223 and 22-250, lite bullets 40 or 50 grain.
Can I ask about your powder choices as well.
Anyone else who can add as well, good powders for 223 and 22-250. Shoot all year 20s up to mid 90s temperature wise. 1-12 twist on the 223 and 22-250, lite bullets 40 or 50 grain.
Trickymissfit
Well-Known Member
a long (and I mean a really long time ago) ago Walt Berger told me that it took 179K rpm to stabalize his VLD's at impact. We all thought hey that's right, and it did make some sense at the time. Later we learn that some other things (the data was there already, but nobody bothered to listen). But this also answered a lot of questions as to why I couldn't get 88LD's to stablize in a 6mm that was really spinning the bullets extremely fast. I was roughly one twist in a foot too slow.
Now as to how you are doing a .29 B/C in a 1:14 twist is a mystery. Shouldn't be able to do this, and it's been proven out many times over the last 12 to 14 months. Have you actually measured your twist rate? Or simply went by what you were told. (I've seen them vary as much as an inch). In a 12 twist the .29 is right there, and with a factor of .85 it's still close. I've found that the 55 grain Vmax is about it with a 1:14 twist, and a 50 grain Vmax works better. But on the otherhand a 55 grain Nosler BT has a slightly lower B/C than the Hornaday, and may well work. I can shoot the 60 grain BT's just fine in a 12 twist due to their lower B/C number. Never had a 1:12 twist .223 to compair notes with, but have been around several 1:14 twist 22-250's and the results are always similar
Reason I use the factor number is to allow for friction and other varibles. You figure take the bullet length and divide the diameter into it, and then divide the twist rate into that number. Then I multiply it by .85.
example: .88 length divided by .223 equales 3.946. Then divide that by the twist rate of 12 for .328. That would be for perfect conditions. Now I mulitply that by .85 for .279B/C. Some guys use .80 and some use as high as .95 for a factor number. A .90 factor number gives you a near perfect match for the 53 grain Vmax with a .29B/C (note I'm only guess at the actual length). Is the formula perfect? I can't say but it works. I have noticed that the larger the diameter of the bullet the lower the factor number is needed (for me anyway), but the .85 number is just a generic number I use. I never get lower than .80 and have gotten as high as .95 in the past
gary
Joe King
Well-Known Member
Gary, yea I verified my twist, checked it 6 times just to be sure. Not complaining about results just baffled by em, maybe it's just an anomaly.
Trickymissfit
Well-Known Member
I like 3031 in the 22-250, but there are a couple from Accurate I'm getting ready to try (right now the fishing's just too good to believe!!) I think I use 35.5 grains of 3031 under the 55 grain sierra bullet. I can do better (velocity wise) with H380 and 748, but the groups seem to be bigger and we're talking less than 100fps. As I've said before, I tried to make 2015BR work as I had several pounds of it, but it just didn't come together (very similar to 3031). It seems like no matter what new powder I try, I keep comming back to 3031. In my .223's (I shoot four different ones), I still like good old BLC2 and 2015BR, but have been playing around with H335 and H322 lately Any of these four will work well. I did try an old lot of AA2230 "data" powder which is much different than the current 2230, and got some smoking velocities, but groups opened up to about .70". Maybe with another bullet; I don't know. Besides when it's gone, it's gone forever.
gary
