ssv1761982
Silver $$ Contributor
Thinking about getting a barrel for my Savage in 22-250 Ackley. I think I want to stick with 55gr bullets. Would 8 or 9 twist be too much?
What twist for a 22-250 Ackley?
- Thread starter ssv1761982
- Start date
I had an 8, 12 and 14. Still have a 12 twist and always will. It has one purpose and one purpose only, to blast yotes with 55 grain ballistic tips at 4150 FPS....and boy does it ever. I have other fast twist rifles so I don't have a need for a fast twist 22-250 AI. If you have a need or desire to launch the 75-80 grain bullets out past 600, then build it in a 8 twist. It would probably help us if we knew the intended purpose of the rifle?....
SBS
Gold $$ Contributor
For these hotrod calibers, I like to use only enough twist to stabilize the bullets I'm going to use. As the barrel gets a little rough (as all these do if you want to get all the life out of them), the extra RPM does bad things to the jackets. Currently I have a 6 Rem. AI that has a 8 twist that I use 87 V-Max's in and the rifling is a little rough after considerable rounds -- if it gets somewhat dirty, the bullets become multiple projectiles. I did have one with a 10 twist and shot it until there was no good rifling for about 6 inches and never had this problem. I have had similar results with the .22 cal. bullets and twists considerably faster than needed for stability.
ssv1761982 said:
If you intend to stay in the 55 grain weight range, a 12 twist is the way to go. Though a 9 twist would likely work, it doesn't make much sense to use that twist if you don't also intend to shoot heavier bullets.
As mentioned, a 12 twist will stabilize the 69 SMK. My 12 twist standard 22-250 shoots the 69 SMK in the .3's and .4's @ 3600ish, with both Superformance and RL-17, from a 26" barrel. Even though the SMK shoots accurately in my rifle, the slow twist degrades bc to the point where there is no ballistic advantage to using it.
Bryan Litz has established a tested G1 bc of .338 for the 69 SMK. If you plug that number, along with a bullet length of .900, into the twist calculator on the Berger website, the corrected bc falls into a range at or below the bc for a 53 VMAX. With RL-17, my accuracy load launches the 53 VMAX @ 3900ish. Plug the numbers for both bullets into a ballistic calculator and you will see that drift numbers are virtually identical, while the VMAX shoots considerably flatter.
In a 12 twist, I might consider using the 69 SMK over the 53 VMAX if I needed less explosive terminal performance. For instance, if I were going to use it for deer or pronghorn (in a state where .22 centerfires are legal for this), I would opt for the SMK. Otherwise, the 53 VMAX would be my bullet of choice.
A 9 twist will allow you to shoot bullets such as the 69 SMK, 69 TMK (Tipped Matchking), 70 Berger VLD, and Hornady 75 BTHP to their full potential (without degrading bc), while still affording you the flexibility to use lighter bullets. While it will stabilize bullets like the 75 AMAX, the bc will be degraded to the point where it has no advantage over the 75 BTHP.
If you were to decide that you want to shoot bullets such as the 75 AMAX, 80 AMAX, and 90 Berger VLD, you would be best served to skip over the 8 twist in favor of a 7 twist, which will allow you to shoot these bullets to their potential. It seems that many people using a 7 twist run into trouble when trying to shoot bullets on the light end of the scale. From what I can tell, 9 twist seems to be the cutoff for versatility. My sense is that a faster twist than this turns a 22-250 into a specialized rig.
I really like the performance I am getting from the 12 twist barrel in my 22-250. If I never planned to shoot anything heavier than the 55-60 grain class of bullet, I would stay with the 12 twist.
As it is, I would like to have the added versatility of shooting bullets up to the Hornady 75 BTHP, without degrading performance with lighter bullets like the 53 VMAX. My next 22-250 barrel will be a 9 twist.
ssv1761982
Silver $$ Contributor
We are going with a 9 twist. Thanks for all the info.
benchracer, how has RL-17 been for barrel life for you and ease of cleaning (i.e. powder residue/build up)? have a few pounds left over from a 308 that I was thinking about using up in my ackley.
I went with a 26" cbi varming contour 1-9 twist and shoot the 53 vmax at 3930 with a fireforming load of cfe 223 and moly. Haven't had the formed cases over a chrono yet. Also have played with the 75 A-Max and they shoot really well but also have no chrono data yet for them, but they do stabilize with the 9 twist
I went with a 26" cbi varming contour 1-9 twist and shoot the 53 vmax at 3930 with a fireforming load of cfe 223 and moly. Haven't had the formed cases over a chrono yet. Also have played with the 75 A-Max and they shoot really well but also have no chrono data yet for them, but they do stabilize with the 9 twist
I have a 1-9 on mine right now and it will shoot 75hpbt well but not the amax. It's more of a shotgun pattern with them. They are still making round holes but hard to keep them on paper at 100 in my gun. I have a 1-7.7 for my next barrel and 1200 of the 80 amax which should be just about perfect. I know the 1-9 will shoot down to 50 vmax well also.
Ackman
Gold $$ Contributor
My 22-250AI's are 14 twist. They shoot 50's at 4150-4250 very flat and blow the crap out of stuff. A 55 is also very accurate doing around 4000-4050. The 12 twist is fine too and I wouldn't go any tighter than that. The "versatility" of a fast twist is of no importance to me, I've no desire to use anything heavier than 55gr bullets in these guns. The slower twist has it's pro's......it's not so fussy about load and accurate over a wide range of powder charge/velocity, also not real fussy about which bullets shoot well.
The statement that a 12 twist won't shoot 55's - especially in this chambering - is complete nonsense. The longest 55gr plastic tipped bullet shoots extremely well through my 14 twist standard .223's, much slower velocity than the 22-250AI.
The statement that a 12 twist won't shoot 55's - especially in this chambering - is complete nonsense. The longest 55gr plastic tipped bullet shoots extremely well through my 14 twist standard .223's, much slower velocity than the 22-250AI.
CatShooter
benchracer said:
That is an unproven "theory" of Bryan's.
There are thousands of people over the years that have tested bullets at long range for the military and bullet companies. These guys have more equipment that you can tote in a truck... and no one has ever reported differences in drop in BC because of twist.
AckleymanII
Gold $$ Contributor
in my 12 twists, using win 760, the 53g V max is over 4000-4100 easy, tiny groups in 26" barrel.
twist the barrel for the bullets you want to shoot, many reasons, especially the length of the throat. If you want a fast twist, then put a short throat in the chamber you may be screwed with long bullets like the 75g. If you throat it long, then want to shoot the 55g you are screwed because these bullets DO NOT LIKE TO JUMP!
twist the barrel for the bullets you want to shoot, many reasons, especially the length of the throat. If you want a fast twist, then put a short throat in the chamber you may be screwed with long bullets like the 75g. If you throat it long, then want to shoot the 55g you are screwed because these bullets DO NOT LIKE TO JUMP!
CatShooter
ackleyman II said:
Man, ain't that the trut'...
About 10 years ago, I saw a beautiful 223 custom rifle in the LGS, It had a famous makers barrel, A2 McMillen stock, Jewell trigger, and workmanship was first class... so I snapped it up.
When I got it home, I checked the throat, and it was throated for 75 A-Maxs, seated to the base of the neck, and the magazine was long enough to take the long rounds
But the fly in the ointment was... it had a 14" twist
It patterned like a full choke. I don't know why it was built that way, but Poo-Poo happens. It was gone in a week to someone who wanted to re-do it.
JAnderson94 said:
I have fewer than 300 rounds on a new barrel, with various powders, mostly doing load development, so I don't really know what effect RL-17 will have on barrel life. I am also pretty careful to keep my barrel cool, so it may be awhile before any throat erosion becomes apparent.
I use RL-17 in several different rifles, in different chamberings and calibers. RL-17 seems to leave some powder fouling, but not excessive. I haven't noted any carbon buildup. Accuracy seems to hold up well. Every rifle I have used RL-17 in cleaned up easily with Wipeout, usually taking fewer than a dozen patches.
CatShooter said:
You have a strange definition of both "unproven" and "theory". Mr. Litz isn't given to throwing around opinions. He performs tests and lets the data tell the tale. His "theory" is based on hard data generated while testing the effects of twist on bc. Testing done by others, such as Michael Courtney, have mirrored Mr. Litz's results.
Of the supposed "thousands" of others who have never noticed this phenomenon, how many were specifically testing twist effects on bc, and how were they modeling bc?
You obviously have an opinion. Mr. Litz's "theory" is backed by hard data and corroborated by other testing. I will take hard data over an opinion any day of the week.
CatShooter
benchracer said:
Not at all strange... all it takes are simple drop tests.
How about his "theory" that bullets from light weight barrels have significantly lower BC's than the same bullet from heavy bullets (same twist)????
No one has ever witnessed that one either...
Nor the one where he claims that bullets that leave light weight barrels, leave at a 10° off axis angle and wobble to the target...
No one has seen that one either...
I've been looking at a 22-250 as well, a Cooper model 21. I'm told the factory twist is 1-14, just wondering why Cooper would choose a 14 twist if it can't stabilize even mid-weight bullets? I don't want to make a $2,000 mistake.
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