.260 Rem AI for F Class???

[1000yardstare]

Am thinking of making up a couple of new F Class rifles over the coming Winter. Will replace my 6AI which should be toast by the end of this season.

One candidate is the .260 Rem AI. Asked Pacific T&G for their reamer print this morning and got Kiff print # 417 back in 2 hours. Great service from those folks in Oregon!!!

Redding tells me that their sizing dies for the .260 AI are based on Kiff print # 417. Great service from those folks!!!

Chamber has the classic 40 degree shoulder. The case body measures .459 at the bottom of the shoulder which is .005 larger in diameter than the standard case. So it is blown out a bit. Freebore appears to be .035.

After 2 or 3 years of intensive use, 6.5/284 users are realizing that this overbore cartridge is hard on barrels. The .260 AI should give longer barrel life.

I can get 6.5mm 139 gr Lapua Scenars at a reasonable price from a Toronto area supplier. Will have to buy some Scenars and .260 cases to figure out the freebore I want. Also will have to calculate reamer neck diameter for a no-turn neck. The Kiff print shows a fired neck diameter of 0.298 and a sized diameter of 0.292.

The .260 AI should be able to launch the 139 Scenars at 3000 fps which according to my ballistic program would give a wind drift of 60 inches at 1000 yards in a 10 mph cross wind. That ain`t too shabby.

Has anyone out there used the .260 AI in F Class competition? Would be interested in their opinion of this cartridge for F Class and any loads that they deem to be successful in 1000 yard competition.

Thanks
Bill

 

[wwbrown]

I like the 6.5's for and I have shot a bunch of them. This year I built up a 6.5 x 55AI for 1,000 yard F-class and that shot great until about 600 shots and then the accuracy went south. I shot a 6.5 x 47 L all last year and have just had another one installed on my F-class rig, the first one got about 1,700 rounds before setting the shoulder back and then about another 600 rounds before the accuracy went south again. The 260 and its variants are about the only 6.5's I have not played with but I would not expect more life than the 6.5 x 47L. The 6.5 x 47L is a very accurate and easy to load for cartridge, although I think the case capacity may be small for 139g Scenars unless you can get RL-17 to shoot accurately. With Varget, RL-15 130's are great for the 47.

The rate and amount of fire in F-class makes barrels a consumable item if you want to maintain X- or 10-ring accuracy. When the conditions are right you can fire the 20 shots for record very fast with good pullers.

Just my 2 cents,

wade

 

[memilanuk]

After 2 or 3 years of intensive use, 6.5/284 users are realizing that this overbore cartridge is hard on barrels. The .260 AI should give longer barrel life.

People had realized that the 6.5-284 was hard on barrels a long time ago. And you intend on pushing the same weight bullet at basically the same velocity, and expect markedly better barrel life... good luck. Somewhat better... probably. Different neck lengths, etc. may help some.

The rate and amount of fire in F-class makes barrels a consumable item if you want to maintain X- or 10-ring accuracy. When the conditions are right you can fire the 20 shots for record very fast with good pullers.

If you noticed, the original poster is in Canada - i.e. Fullbore/pair-fire rules. Lower round count per yardline typically (10-15rds vs. 20) plus having to alternate shooters and wait on scoring, etc. gives a bit longer between shots than with U.S. style 'string fire' - so the barrel should have a little more time to cool between firings. I've *heard* from some people 'up North' that they enjoy upwards of 20% more barrel life than we do as a result.

 

[1000yardstare]

Great feedback guys. This is what I am after. Will my expectations meet reality?

memilanuk, nice observation on Canadian shooting. Shot a 2 day match in Kingston last weekend. With 2 relays takes half a day to shoot 2 targets, 2 sighters on each, first target 10 on score, second target 15 on score. Shot in threesomes alternating shots, the Canadian, Brit, Aussie way. Much easier on barrels.

My expectation of longer barrel life with the .260 AI compared to the 6.5/284 is based on less powder being burnt for similar velocity. But if someone has experience that makes that assumption invalid, I would appreciate that feedback.

 

[Laurie]

Hi Bill,

I assume you've looked at Terry Cross's .260AI tactical / sniper 6.5-08AI (Gunweek 46) on the main site? He's running 139/140s at around 2,935 fps from what looks like a 26" barrel.

I think the biggest plus about running .260AI is the near 100% fill-ratio you'll get. The 6.5-284 has a larger capacity case than really needed, so you should get a more consistent result.

I suspect that 3,000 fps is pushing it, MV wise. But why bother - as Terry Cross says, you want a bit above 2,900 fps to get this weight of 6.5mm bullet into its comfort zone and perform really well. If you're there with less powder and heat than an equivalently accurate 6.5-284N, you get most of the wind-bucking performance but with less recoil (less powder charge weight as well as a bit less MV) and longer barrel life.

Personally, I think it makes more sense than 6.5-284, getting the right quality of brass the only slight downside (reformed Lapua?) although allegedly 7mm-08 Rem by Winchester is good and is easily reformed to .260. (We haven't seen the Winchester version of this brass here in the UK yet.)

Regards,

Laurie,
York, England

 

[Erik Cortina]

I can get 2930 fps. with my 6.5x47 Lapua with 139 Lapua Scenars out of a 28" bbl. I have a new 30" Krieger sitting at my gunsmith's, I should be able to get 2950+ with that barrel.

So my vote goes to the 6.5x47 Lapua... 2930+ fps. and no fireforming needed!

 

[1000yardstare]

Laurie, thanks for the thoughts. I plan to use a 30 inch MacLennon barrel on a Savage action for the .260AI. So this should give me the 3000 fps with the 139 Scenars without too much strain. (Haven`t forgot the Plotamatic).

I have been swimming upstream all my life and this applies to brass as well. All my F Class brass is Winchester - .223, 6mm Super LR, .243, 6AI, .308, .300 WSM. And might have to add to the heresy and go with Rem brass for the .260 AI. Yes I admit it. Never have bought expensive Euro brass. I guess this makes me some sort of hermit but I have won a lot of matches with Win brass.

Thanks for the input guys. Keep it coming. Even if I don`t mention your name, it is all appreciated.

 

[ktoney]

I drank da 6.5x47 Koolaid

31" broughton 5C 7.9 contour

h4350 or RL17 2950fps+ is goal, 140 berger

Still tempted by 6.5GAP, variation on 6.5x257AI

 

[Laurie]

I can get 2930 fps. with my 6.5x47 Lapua with 139 Lapua Scenars out of a 28" bbl. I have a new 30" Krieger sitting at my gunsmith's, I should be able to get 2950+ with that barrel.

So my vote goes to the 6.5x47 Lapua... 2930+ fps. and no fireforming needed!

Erik,

great little cartridge though the 6.5X47L is, it does have one potential drawback when it comes to squeezing max MVs out of it - the small primer. Unless you're running an action with a small dia firing pin, also a good close fit in the bolt-face, you crater then pierce primers well before reaching the pressures and MVs you're running at.

With .260 Rem, 6.5 Creemoor Match and 6.5X47 producing similar performance, I'd go for one of the first two now when running a factory action with large pin to use their LR size primers. I currently have an FN SPR rebarrelled to 6.5X47 which I've hardly used for this reason - it'll be rechambered to .260 Rem later this year for this reason.

The Savage 12 action may be OK since it has a smaller firing pin than most non-custom actions. I'm hoping so as I plan to shift my 6.5X47 F-Open rig to one such using a custom trued and timed version of the action. Even so, when it comes to reaching out for 3,000 fps with 140s that Bill is aiming for, I'm pretty sure the .260AI will achieve this with less stress, and also manage better with its large size primers.

Yes, I know that Gre-Tan bushes Remy 700 bolts for a really good value fee, but that's not an option for us on this side of the Atlantic, and I don't know how Canadians would be fixed either for local gunsmiths or for sending a bolt south of the border.

Laurie,
York, England

 

[Babin708]

I'd second Laurie comments. A friend of mine tried a 6.5x 47
on his savage and could'nt do it. He pierced primers al the time.
From some reading i've done, its very difficult bush the firing
pin on a savage bolt.

If you're going to make .260ai from Win. brass try 7-08. There should be no issues with donuts.

 

[DJ111]

Gre-Tan has no problem with a Savage firing pin and bolt face.

If you run the 6.5x47 Lapua you will need to have this done to get the most out of it.

Dallas

 

[ktoney]

Not seeing this as an issue
6.5x47 requires a bushed firing pin

My pig gun runs a trued bushed rem action

My Match rig being built will be custom
Defiance Action LBRP, small firing pin
Shehane MBR tracker
31" broughton barrel

If your having primers problems then get pin bushed, running Hot loads i would do it anyway

 

[Erik Cortina]

My Match rig being built will be custom
Defiance Action LBRP, small firing pin
Shehane MBR tracker
31" broughton barrel

I was over at Mark Pharr's shop earlier today, that is one nice Defiance action that your rifle will be built on, congrats!

 

[savageboy]

I use a 260AI (Shilen 28" 1:8", etc.) for F class and other than the fireforming have been very happy w/ it. I have won a match and several relay's w. it at 600 and 1000yds at Camp Butner. I decided on this caliber for the exact reasons you are looking at it- near 6.5x284 ballistics w/ 4-5 grains less powder and hopefully longer barrel life. Several observations after living w/ it for 3 years and on my 2nd season of F class: I would get the barrel long throated, that didn't happen on my last barrel, however the longer High BC bullets that you will want to shoot really take up case capacity if not. About the max vel. I can get shooting Lapua 139's (both my barrels liked them best) was about 2940fps and 2920 is better accuracy and pressure signs. I have not shot out a barrel- I sold my 1st one w/ about 800 rounds on it and it was fine. It was a varm contour and only 26" long. Great shooter though. Also, brass has been a bit of an issue.

 

[savageboy]

Pg.2. The Rem.260 brass is easier to get to the shooting point, however the primer pockets seemed to loosen up faster and required more sorting than the Lapua 308 brass I now use. The Rem. does have more case capacity. Some have necked down Win. 7-08 brass as well. I never have.
I think you'll have a difficult time getting 3000fps. I use H4831SC. Tried Rel17 and it shot ok and maybe got me 25fps or so more, just much greater ES/SD and unexplained flyers. Thats my barrel though.
In all, I love the round, its sexy, short fat, efficient and accurate. I am sticking w/ it.

 

[1000yardstare]

Savageboy, great stuff. One of the best answers I have had to a question. To the point and no BS.

Very useful comment on the .260 Rem brass. After 60 years of reloading centerfire rifle, I have never been happy with Rem brass. Split necks have been the main issue.

I am seriously looking at the several times suggestion of Win 7mm-08 necked down. I have always been happy with Win brass and see no need to go to expensive Lapua .308.

 

[Gadget]

Hi,
I use and love the 260 AI in fact it's so good we now have three of them on my range.
My load is 48.3 g vv165 BR2 primers 139g scenars @ 2920 fps
I use Lapua .243 brass and neck up, I also have a .243 AI that's why the .243 brass.

From all the load testing we have done I don't think you will get to 3000 fps we have tryed, believe me, 2920fps seems to be the sweet spot ( in my opinion and my gear )

All three on the range are good shooter's and our loads are similar, we have three odd barels 27" 28" re chamber's from Rem .260's and my 30".
I like it so much I have a new Broughton barrel coming from the states and will have this made at 32".

Gadget

 

[wolfman]

Shouldn't be too hard to get .260 AI info in Ontario. Gord Ogg shoots one, and so does Leo D'Amour...

 

[1000yardstare]

Wolfman, I shot with Leo two weeks ago at the Kingston June Match. Gord wasn`t there. Was in a squad with Leo and Dr. Thompson. Jim and I were shooting .223s. Never asked Leo what he was shooting. What`s that old saying about ships passing in the night?

Gord and Leo will probably be at the Ottawa Long Range Match this weekend. I`m not going so will probably see them at the Ontario Championships in August.

Gadget, Very nice info. I am getting honest vibes that my goal of 3000 fps with 139 Scenars in the .260 AI may be too optimistic.

That is why I started this thread. To get realistic advice before I start spending money.

To be honest, I am starting to lean towards the 6.5x57 AI to get the desired 3000 fps at reasonable pressures. Next Spring I will have a whack of 6AI brass when I rechamber that barrel to 6mm Super LR. I have already necked up a 6AI to 6.5AI and seated a 139 Scenar to get an idea of COAL. That idea will be in a new thread sometime down the road.

So thanks to all who have given me their advice on the .260AI. Much appreciated.

 

[kdog70]

I run a 260 AI but I run the 123 class bullet, I am not a competition shooter I just like shooting a long ways at steel and its been working great for me out to 1100-1150yards. I don't know if it will hold comp. accuracy but it holds 1.5-2 MOA for me which, with my skill is a miracle.

I ran the 140 VLD hunting bullet and 140 Amax which works too but never could get the speed out of my 1 in 8 28 inch Shilen I thought I was going to get. I was too hoping for 3000fps but was getting 2850-2890 at sea level. Maybe if I switched powders it would have been better. Who knows. good luck
kdog