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Shooting 140 grain projectiles?
Has anyone had experience with barrels from Lawton Machine in Dillon, MT?
Love your neighbor as yourself. Do not take into account a wrong suffered. Never return evil for evil. Resist not the violent man. Turn the other cheek, go the second mile, give to him that asks.
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Also, I have no experience with Lawton Machine.
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Thanks for the link, I had gone to their website but I had failed to scroll down to the bottom chart! Thanks... 10 seems to be the answer.
Love your neighbor as yourself. Do not take into account a wrong suffered. Never return evil for evil. Resist not the violent man. Turn the other cheek, go the second mile, give to him that asks.
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I've noted that some 7mm cartriages have 9 inch twists for the best stability w/ the longer 175 gr. bullets. I'm told that a 10 inch twist may stabilize those bullets in a .280, or it may not. E
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Have had a number of 280's and shot out two. Go with the 9 twist for the 140's.
“Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away”. Antoine de Saint-Exupery. Posted by Brad.
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I have a 7-MM Rem. mag. it has a Shilen #2 contour and a 9 twist. This gun will shoot 140s just fine.
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Ive got a 7mm-08 that tack drives 140 grainers and is a 1:10 twist rate.............
broken bones broken heart stripped down an torn apart a lil rust but Im still runnin countin miles countin tears twisted roads and shiftin gears year after year its all or nothin Im not home and Im not lost just holdin on 2 what I got...God and Guns
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A 9 or 10 twist is probably the best bet, but on the campfire, it won't shoot unless it's an 8 twist My only 7mm is a 7-08 and it has a Shilen 10 twist and it shot everything up to and including 168 Sierras just fine.
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The 7mm-08 is normally about 1:9 ( 1 revolution in 9 inches)
The .280 Remington normally is 1:9.25, but the range is from 9 to 12. 1:10, just like a .270 Win or .30-06, works fine with a wide range of bullets.
The 7x64mm, which is about the same as a .280 Remington is 1:8.66, but it originally was designed for the 175-gr spitzer bullets.
The 7x57 originally was 1:8 for 175-gr bullets, because its forward speed was slower, and needed more rotational velocity to stabilize the bullets of its day. You cannot just extrapolate any 7mm cartridge to another one. A 7mm STW might do better with a 1:12 rate.
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A 1 in 10 should work fine for most 140s. But longer ones like the berger just might be better off with a 1-9.5. On hunting rifles it is always better to err on the fast side so 1-9 would be my choice, and then your good for everything up to the 180s. People trying to get the last fps might go the other way like a 1-11 or even 12 but I wouldn't recommend it.
Some people theorize that a faster twist increases terminal performance-straight line penetration, more destructive, faster expansion etc. etc. all of which is almost impossible to verify.
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A 1-10 will work easily. I have had a 7mm-08 and a 284, both with 10 twists. They were both very accurate with 162 Hornady BTSP's, so 140's are easy.
That said, a 9 twist may be even more of a good thing. My present 280AI and 7Rem Mag are both 9 twists, and both are very accurate with 120-162 grain bullets. The 280AI in particular will positively stack 140 accubonds at 3150 fps.
9 or 10, either is fine.
Anybody who seriously concerns themselves with the adequacy of a Big 7mm for anything we hunt here short of brown bear, is a dufus. They are mostly making shidt up. Crunch! Nite-nite!
Stolen from an erudite CF member.
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Will a 1-10 be OK for a 7x57AI w/160gr Partitions.Thinking about taking mine on an elk trip. powdr
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powdr..if you have barrel twisted as such 1 in 10..just take it to the range w/160gr partions and see for yourself..it could be just fine
I don't always venture out into the sub-freezing darkness, but when I do, it is deer hunting season, and I carry a Remington. Stay hungry my friends.
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1:9 twist is great in the 280 Rem...
randy..
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Just ordered a Hart in 280AI two days ago. Hart recommended 9" twist for bullets above 140 grain. If velocity of the 7x57 AI is lower than the 280 AI 10" twist may work. There seem to be no rules for what will work every time.
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1:10 will easily stabilize the 140 gr .284 bullet. If you ever plan on shooting 160-175 grs, you may wish to look at a 1:9 rate of twist. Of couse, it does matter which bullets you shoot. For instance, a Barnes TSX 150-gr bullet is as long as a Hdy 175-gr bullet. Obviously, 160 & 175-gr Barnes TSX bullets are longer yet. The additional length, depending on velocity, may or may not stabilize w/1:10 rate of twist. Frankly, I've not experienced any problems with the 160-gr TSX or the 168 VLD bullets in my 7x57 that has a 1:10 twist. OTOH, my 280 Rem has a 1:9 twist. Both rifles are tack drivers and produce sub-MOA.
If you're shooting Berger 180-gr VLD bullets, you might want to consider a 1:9 twist.
As a side note, both my 7mm barrels (7mmTCU & 7-30) for my T/C contender have a 1:9 rate of twist probably due to the lower velocity.
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