260 Remington Headspace issue

[cowtownup]

Just put a 260 Remington barrel on my model 12 and on the first firing I noticed the brass grew strange around the neck area... What is causing this? Bolt closes easily on the go guage and doesn't close on the no go guage.

http://i185.photobucket.com/albums/x256/cowtownupp/C623EE46-0128-4873-B578-4B17094B0C01_zpso9oz3oec.jpg (http://s185.photobucket.com/user/cowtownupp/media/C623EE46-0128-4873-B578-4B17094B0C01_zpso9oz3oec.jpg.html)

[Robinhood]

You have a 260 AI chamber. Not the 260 you thought you purchased.

[cowtownup]

Son of a BISCUIT!!!!

[stomp442]

Don't cuss it, having a .260AI instead of the standard is a mistake I would gladly take. Excellent cartridge with just a little extra in all the right places and less in all the right places. What I mean by that is extra performance with less brass prep.

[stomp442]

The beauty of the Ackley chamber is you can still use factory .260 ammo if you wish and still achieve sub moa accuracy with it. I just fire formed 10 cases this weekend at the range and held a 1" or less group on the 200 yard gong.

[hafejd30]

Not trying to hijack thread but can you headspace a 260 AI correctly off a standard 260 Go/no go gauge?

[cowtownup]

That was my next question...

[Michadian]

I believe that to correctly headspace the 260 Improved, you use the 260 Rem "no go" gauge as the "go" gauge and a seperate "no go" for the AI. Or, use the addition of tape to the back of the 260 Rem"no go" gauge as the "no go" for the AI. AI shooters please chime in, I am building a 260 AI, but have not installed the barrel as yet, so this is my understanding. Gauges for the 260AI can be rented from 4-D that are marked in the conventional way (http://4-dproducts.com) or purchased.

[Dewey7271]

That's a great cartridge by the way.
I really like mine. Excellent accuracy and the capacity to get to that seemingly magic 2900 fps number with 140s. (48-48.5 H4831SC, work up as always)
I think once you get used to it you're going to really like it.
I use Redding dies as they make them without a special order.

[22 Mag]

Order the correct GO gauge (260 AI). A Improved go gauge is 0.004 shorter at the junction of the neck/shoulder than a standard 260 go gauge. The standard 260 case needs to "jam" into the chamber to help form the AI case shoulder correctly.

22 Mag

[scope eye]

The go gauge to a standard 260 chamber becomes the nogo gauge to an AI, so just get a go for an akley and you will have both to set your headspace with out breaking the bank.

Dean

[Michadian]

Scope Eye & Cowtownup,
My bad.
Standard 260 "go" for the "no go".
You have saved me from making a significant mistake.
Thanks!

[scope eye]

It is just one of many of my public services.LOL

Dean