7mm-08ai barrel profile for F-Class

[wadcutter]

Hi, First post but have been reading and learning for a while. ;D

I have been offered a new barrel in 7mm that I am considering buying. It is a 1.25" straight for 4" then taper to 0.9" at 29".
Would this be a suitable barrel profile for this calibre for F-Open or would I be better off getting a heavier barrel?

 

[benjamin199]

This will really depend on the stock you are using, you want to maintain a good balance with your rifle. My last 2 Fclass rifles have both been built on dedicated Fclass stocks. The first one was a strait 1.25" barrel out to 30" the rifle did shoot well, but the second barrel I ordered was 1.25 for the first 10", then tapered to 1.0" at 30". So far I feel my second barrel gives better balance and seems to ride the bags more consistently.
Good luck,
Ben

 

[XTR]

I love my 7-08 hunting rifle, but for F open I have to wonder if it can run with the big dogs. Doing the AI thing will keep the brass stretch to a minimum, but the case volume increase on an AI anything based on a 308 case is single digit %. PO got great improvements from tapered cases like the 30-40 but the 308 has very little taper, all the boost is what you get in the shoulders from the increased angle.

If it's a .284 blank consider going with a284Win, 7mm RSAUM, a 7WSM, or one of the 7-300WSM wildcats. The taper is fine, but the length is probably 2 to 3 inches shorter than "ideal" to maximize MV. In F-Open you're only limited by the 22lbs total weight with scope. Worth noting that the current F-Open champion won with a 280Rem

 

[DBailey]

What distance will you be competing at most of the time?

 

[wadcutter]

What distance will you be competing at most of the time?

I will be using it for all distances out to 700 yards. Beyond that I have a .284win that I use for matches out to 1200 yards.

The main purpose off this rifle is to take the shooting load off my .284win so that it will be in top condition for serious long range events. I see no point in wearing its barrel out on shorter competition events.

I did consider the 6.5x47 instead of the 7mm-08ai but I like the 7mm projectiles so much I just want to stick with this calibre.

 

[XTR]

You are shooting in Open (TR is only 308s and 223s) so what ever will make the 22lb weight limit with your stock and scope. With the 7-08 you'll probably want to be running the 162Amax, I really don't think you can push the 180s hard enough to beat the 162s. I'd look at something in the neighborhood of a 34" heavy palma or heavier profile. A lot will depend on your stock.

Just for the same of reference:

my F-TR rifle weighs 12.4 w/o the scope, rings or bipod, that has a 30" Kreiger heavy palma that's right at .9 at the muzzle
I have a Savage F class 6.5-284 with a 30" barrel that is .98 at the muzzle that weighs 13.3
My Night Force 8-32 weighs 2.4 lbs.

You could easily run a rifle up to 19 lbs and still make the 22lb limit with scope and rings. You could get at least 34" and have a muzzle over .9 with no problems. I'd get something like a Kreiger #10 or a Rock Creek #8 profile blank at 35", have it mouinted up and tell the smith to trim to weight, but I'd bet you'll make weight with a 34 in that profile. With that little cartridge you'll be dealing with recoil like a .223. That would be pretty sweet.


Edit: My only comment would be "Do you really want to go with the AI?"

Barrel life is not really a concern, but you're going to have to fire form all of your brass. A typical F class weekend for me is 120 rounds for record + sighters so figure close to 150 rounds per match weekend. I try to keep at least 500 cases in my rotation, but I can shoot virgin brass in matches (which I guess you can). Take a hard look at what you're really gaining in the AI and not just what is written on BB's because there is a lot of BS regarding MVs out there. I read a whole lot of reports of people getting MVs from short barreled 308s that I can barely top with a 30" kreiger, and have never been able to approach with my 24" Rock Creek. So either I have some of the slowest barrels ever made, or a lot of people are over estimating their MVs.

 

[DBailey]

I used the 7mm-08AI in F-Open for about a year before switching to a 6.5-284 in 2007 for the team tryouts.
It is a nice cartridge, very easy to make shoot even with fire forming loads. But everything it can do the 284 can do just a little better and easier without much difference in barrel life. Since you already have all the stuff for the 284 why not just build a dedicated mid range 284?
I would not be afraid to use that barrel length and contour on a mid range gun. The 280 I shot at the nationals this year has a similar contour. It is 1.250" for 5" then tapered to 1" finished at 32".
Whether or not you would be better off getting a different barrel than that one would come down to the price and twist rate.