Fire forming 260AI

[Fast14riot]

This is the cold bore group out of my recently completed 260AI. I think it'll work



Nosler 140 RDF
Lapua 260 brass
44gr H4831
Fed 210
-0.020 from lands
2850fps
100 yards

Rem 700, CBI RemAge in 260AI Match chamber 26", Jewell trigger, 40xb stock, Sightron SIII 8-32x56. Built from lightly used parts bought from here and eBay.

Next I hope too keep it just as good in fully formed brass!

 

[ShootDots]

Tell me when you have ever seen a .260A.I., fireforming or not, ever not shoot excellently? I think you have a winner!

 

[Fast14riot]

Btw, I wrote 0.146" on the target, it should be 0.156".

 

[JLT]

Very, very nice! Enjoy your new rig. How about a photo of the rifle?

I'm a big fan of the .260 AI - as ShootDots said, it's a breeze to get them to shoot.

 

[Fast14riot]

 

[JLT]

View attachment 1028585

Nice looking rifle you got there. I'll bet you have some elbow grease into that 40X stock. It looks great - classic!

 

[Fast14riot]

Lol, this is my "rat rod" rifle, I left every dent, ding, chip, scratch, etc in the stock, action and barrel. I just washed and oiled the stock! Wanted it to be a sleeper, if you will.

Thanks!

 

[swd]

Wanted it to be a sleeper, if you will.

Except you aready showed us what's under the hood, lol.

 

[JLT]

Except you aready showed us what's under the hood, lol.

Indeed he did. I was going to suggest he try RL-23, but then I looked at the group again. Never mind . . . .

Accurate rifles are beautiful.

 

[Fast14riot]

Except you aready showed us what's under the hood, lol.

Lol, numbers on the dyno doesn't mean the owner knows how to drive! We'll see how well I do from a bipod or sling, but at least I know it' not the rifles fault

 

[earlcurtis67]

What does Criterion mean by “match” chamber? just wondering. E

 

[Fast14riot]

It's a little tighter than an ackley'd sammi chamber, I believe. I haven't compared the prints, but they list two. Mine has a .298 neck.

 

[JLT]

It's a little tighter than an ackley'd sammi chamber, I believe. I haven't compared the prints, but they list two. Mine has a .298 neck.

The Criterion Match chamber has a .160 freebore. The standard chamber has a .098 freebore. I believe that is the difference between the two.

 

[Fast14riot]

The Criterion Match chamber has a .160 freebore. The standard chamber has a .098 freebore. I believe that is the difference between the two.

Good to know. I have the match chamber print on hand, but not the standard.

 

[JLT]

Good to know. I have the match chamber print on hand, but not the standard.

That one's the ticket for the 140+ bullets. . .

 

[NickB1075]

Nice shooting, I have a 260ai in the lathe as we speak and I am curious how did the brass form with that load?

Thanks
Nick

 

[fyrewall]

I would guess a 1-8 twist. That group is much better than I could get with my COW FF loads.

 

[mikeinct]

I to have a C brand barrel in 260 Rem AI w 1-8 twist...My fire-forming load using blem midway 140 grain bullets & H 4831sc was a great performer...mike in ct

 

[VaRandy]

Tell me when you have ever seen a .260A.I., fireforming or not, ever not shoot excellently? I think you have a winner!

Amen to that!

 

[Fast14riot]

Nice shooting, I have a 260ai in the lathe as we speak and I am curious how did the brass form with that load?

Thanks
Nick

It could use another firing to be fully formed, but I can likely find a velocity node as is, then just adjust charge weight a couple tenths to bring it back up. Will test this out soon.