Re-chambering one of my 700 Rem ADL 270's

[Idaho Lefty]

Keep in Mind, Slow Twist ( 1-9 to 1-9.5 say ) = Lighter Bullets, work best. 140- 160 grains, Max. usually, in 7 MM's.
My son's 1-9.25 twist, 7mm-08, Tikka, Shot up to 150 grain Bullets, Fine,. 168's,.. NOT, good, at all !
Worst case Senario, the 1-8.5 would Like, the 162 to, the 175 grain "Class" of, Bullets, best,.. Maybe.

 

[FEENIX]

What would you think for a 24" barrel in regard to twist? My gunsmith recommended 1-8 or 1-8.5 for longer range and higher BC bullets.

A faster barrel twist has nothing to do with a longer range. Heavier/longer higher BC bullets require faster barrel twist flight stability. As I previously noted, have the minimum recommended barrel twist for the bullet you will use.

 

[Muddyboots]

I have 2 Remington 700 ADL's in 270 Win. One with a 24" barrel and the other with a 22". I am going to re-chamber the shorter barreled rifle to 280 AI to match the type of deer and coyote hunting I do. I don't want to spend more than $400 to do it.

Lot of good suggestions posted up for you. The key issue I see is max cost you want to spend is $400 on switch to 280AI. I know you feel the .280AI is significantly better in performance when compared to a "standard" .270 but the difference is far less if you build the .270 with the "governor" removed.

I have not seen any discussion on the cost of another infrastructure needed to support another cartridge. This cost of a new decent dies, new cartridge brass and another layer of bullets in new caliber is probably equal and or more than just changing barrel.

You have .270 dies, brass and bullets. Easier to add longer higher BC .277 caliber bullets than adding a whole new cartridge infrastructure.

Me? Recommend another .270 barrel with fast enough twist for the higher longer BC bullets. The 700 ADL is perfect to do this since it has likely 3.67" max magazine capacity which allows longer COAL. Get barrel with sufficient freebore to marry up to this capability and now you have a rifle with similarities you are accustomed to with added significant added performance. The most overlooked benefit of the .270 is the higher operating pressure at 65K plus the longer case neck which is often criticized but now benefit for seating longer higher BC bullets.

A .270 built to this concept will most definitely out perform what you stated as need.

Good luck!

 

[Idaho Lefty]

At SecretSquirrel,..
Per, the BERGER Stability Calculator, their 175 grain Elite Hunter 7mm bullet Has, an SG of 163 ( Plenty "Stable" at,. 2,750 FPS at, 3,000 Ft elevation ! ) for, the 1-8.5 Twist Barrel. SO, yes,. the 1-8.5 TW,..Looks Good to, Me !
The 175 gr. Berger, E-H bullet, is a very Popular, Elk Bullet, in 7mm Rem Mag's, etc.
That Twist rate, will probably "Handle",.. the 180 gr. H-VLD's and, Hybrid's, just FINE, also !
There have Been some "issues" with 180 grain ELD-M's at, the Higher Velocities with, the 1-8 twist or, Faster twist in, 7mm Rem Mag's / 7mm PRC's
( Bullets Blowing Up, on the way to, the Target ) This usually ocurrs in Dirty / Hot, Barrels or when, Severely "Fire Cracked" just past Throat area.
I'd say that, the 1-8.5 Twist, is, a pretty "safe Bet" for ANY of, the Thinner Jacketed, Bullets and Up to, 180 grains.

 

[FEENIX]

Twist a barrel as fast as you can, they're only making bullets longer. I made the mistake of using a slow twist barrel in the past because I got it cheap. It really limits what I can do with the rifle.

I now just buy the fastest twist available when possible. That said I don't have anything faster than 1:7. I'm not going to build a .338 anything with a 1:3 twist barrel, unless I really get an itch for the 8.6 Blackout.

Same here! My .257 WBY and .264 WM are 1:7", and my .338 Thor is 1:8" twist.

 

[Idaho Lefty]

@ Secret Squirrel,..
I just Checked, the "Stability" Factor of, the 180 grain, H-VLD Berger ( the Hunting Version ) at, 2,700 FPS ( with a 1-8.5 Tw ) and,..
it's More than, "Stable" with, an SG of 183 !
So, your, "Good to Go" with, the 1-8.5 Twist, for your new, .280 Ai Barrel

 

[Turpentine21]

I called the other day and Jim in on vacation until next week. I will get with him then. Thanks Lefty!

I bought my Remage Criterion 6.5-06 set up and the necessary tools from Jim. He knows his stuff. When you consider triggers don't overlook Triggertech. They build a good trigger and it can be adjusted without removing the stock. I'm not brand loyal though as I have Triggertech, Timney, and Geisslee triggers in my bolt rifles.