260 AI problems with Green Mountain barrel

[jdscada]

Ok Larry, will try it. I think I already have, but does not hurt to try again, do not remember observing neck after trying. However, I did try trimming neck and had to go down to 1.93" from 1.99 for bolt to start closing. Get with you in a few minutes.

Thanks

JD

 

[savagedasher]

I feel the neck OD is where the problem is. Larry

 

[dkhunt14]

I don't know of any company making 260 AI brass. Somebody fireformed them and cleaned them. If they were done in a chamber bigger then yours they maybe will never fit. You need to try a new 260 case without a bullet. I'm also thinking the reamer that made your chamber is tight. The die you have may not size them small enough. That is another possibility. Matt

 

[L.Sherm]

I agree with savaged asher cut a neck completely off and try to chamber it. If it chambers you know it's
the neck,could be a very tight neck. Are you using bushing dies?

 

[savagedasher]

I feel the neck OD is where the problem is. Larry

If he sized a case and didn't put a bullet in this is not it. The die would just push the neck small enough. Matt

Matt it would depend on how small the neck had to be . Dashers not turn is. 2704 I have seen some with as small .2640 custom chambers you must know the neck size. With it stopping back that far is sound like the neck could be the problem . Larry

 

[savagedasher]

I agree with savaged asher cut a neck completely off and try to chamber it. If it chambers you know it's
the neck,could be a very tight neck. Are you using bushing dies?

Another way to skin the cat Cut the neck off. thanks Larry

 

[jdscada]

Time to break out the dremmel. BRB

 

[jdscada]

Ok, I have cut neck off a round, and bolt will not close, I mic'ed another brass, and trimmed down to 1.93" case length, with identical neck dimensions, only difference is at base before rim, and it will not close, I'm a sinking ship, or haunted..............please observe my pic.

 

[savagedasher]

Ever case I see still has a neck on them. Larry

 

[jdscada]

Case 3, I cut it off, or is that not enough? I only left shoulder

 

[L.Sherm]

You may be to big at the .200 line

 

[savagedasher]

All are ackley cases . Sorry I'm done. Larry

 

[Hotshot]

I had some 220Swift brass years ago that had been fired in a 220AI chamber. I resized them to standard 220Swift and they stuck in the chamber often. I had to bring my rubber hammer with me all the time. I threw it out at my gunsmiths suggestions and my problem ended. Just saying.........

If you have a bottle of good bourbon maybe you should pour one and go back to this problem another day.

 

[lawman29]

JD,

In your original post you indicated that the modified 260 case hornady lock-load would chamber with no problems, but the 260 dummy round wouldn't. Take several different measurements of these two cases and see what are the differences.

Tim

 

[savagedasher]

JD,

In your original post you indicated that the modified 260 case hornady lock-load would chamber with no problems, but the 260 dummy round wouldn't. Take several different measurements of these two cases and see what are the differences.

Tim

Tim most of the hornady cases are reamed for bullet clearance The necks are thinner the standard. When he tried one with a bullet in it stuck or a factory round.. Standard 260 case have a taper wit ackley some is gone. with the neck totally gone of a factory case it should chamber. If it was the neck that was problem it should close . Now you have a case with a known base size for a reference . Like I said I'm done. Larry

 

[Riesel]

You might try sizing that base in a .45 ACP carbide sizer die. I had a similar problem like this once and the chamber was very tight at the base. Sized down, fire formed and just bumped the shoulder in the future. No more problems.

 

[CaptainMal]

From the git-go I have been yelling into my head ... "you need a smaller base sizing die"!

That's where it scrapes. That's where it hits. That's where it's like my belly. Too fat.

I have an '06 small base die for a Remington pump. It really does squeeze it down. Yours is a 308 based case. Got to be some small base dies around for any caliber based on the '06-208 case. All you want it to do is squeeze the bottom.

 

[pdog2225]

You are describing a problem I had with my Remington 700 in 260AI.

I used a shilen Savage prefit 260 chambered barrel that had a 260 AI reamer ran into it to fireform brass. Then I would run the fireformed brass into a Redding FL die. Turns out the die was ok for the prefit but not the Remington as it had a custom chamber and was .0015" smaller in diameter at the webbing. By running the brass into a 30/06 small base die it squeezed the case dia. down and solved my problem.

Use a 1"mic and measure the case diameter at the place where the web of the base is on several.

 

[jdscada]

Thank You Thank You Thank You, I did not have 30-06 die, but I did have a 6.5-06 die which is basically the same dimension as the 260AI except longer......................BOOM.................. bolt closes on every brass I try, now I can load up some loads and let the fireforming take care of the rest, Thanks to everyone who helped in troubleshooting this problem I had, what a relief.

 

[jdscada]

I knew I could not have been the only to have run into this problem before, I was losing faith quickly, but it's regained.