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260 AI problems with Green Mountain barrel

I have a hard time believing Forster has changed their dies. In 2003 at the shot show I had them make my dies for a 260 AI . Dave kiff sent the a reamer for making 260AI dies . it was for the chamber of my 260AI dies . I gave them permission to use my reamer specifications. The dies I got a few months ago Sill had the same measurements as my first. the Base size .264 and the brass ends up .2645. at the base Larry
 
Maybe I purchased a bad set, this is the first time using them and I think I bought them from Midway. I have a couple of other sets for other calibers that work flawless, I really like their dies and Hornady.
 
Maybe I purchased a bad set, this is the first time using them and I think I bought them from Midway. I have a couple of other sets for other calibers that work flawless, I really like their dies and Hornady.

I don't know if it might help but at one time I had a similar problem and found out the shell holder was too thick. I took the shell holder out to the garage and faced off several thou on the bench grinder and it worked by sizing the case farther down
Best Wishes
 
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.
I told you back in reply 3 that I thought the die wasn't sizing the base enough. Matt
 
I told you back in reply 3 that I thought the die wasn't sizing the base enough. Matt

Yes Sir you did, I had a hard time believing that a Forster die was doing that, I'm think about getting one of my 6.5-06AI brass and run in into the 260AI till its topped out and make a mark and since what it's lengthed at. Not sure if Forster would take back.
 
Ok, another update. painted up a brand new brass after running through full length die, definitely have resistance when trying to chamber into barrel, cannot close bolt. Tried chambering regular 260 with bullet, resistance in same spot on brass, managed to close bolt with some effort but had to beat it out with rubber mallet.

I have also removed action again, started over, inspected throat on barrel, seems fine, however, I am not a professional and do not have a borescope, however, I have access to a digital borescope at work that I can run in there to inspect and take pictures and video.

anyways, I removed recoil lug, it measures .25" thickness, and used a slightly thinner one .18" just to experiment, (my version of thinking outside the box), and same results.

Is there any possibility that maybe the Forster die is not full lengthening correctly?? It seems after I run it through, it leaves back 3/8 of it is not touched or marked up, I have press setup where bottom of die and shell holder are already touching, never usually run this tight, usually keep a gap about the thickness of a nickel in between, but since I was second guessing the die, I ran flush, and have resistance when full lengthening.

I would get with Redding and order a small base body die.

John
 
I 2ND 22DASHER I HAD A SHELL HOLDER DO THE EXACT SAME THING IN A 243 ACKLEY WITH A REDDING BUSHING DIE TO THICK OR NOT SQUARE WITH THE DIE !!!!!!!!!!!!
 
I 2ND 22DASHER I HAD A SHELL HOLDER DO THE EXACT SAME THING IN A 243 ACKLEY WITH A REDDING BUSHING DIE TO THICK OR NOT SQUARE WITH THE DIE !!!!!!!!!!!!
That will work if you need more bump. The problem the OP had was not enough sizing at base. Can be caused by too tight of reamer at back end or sizing die is not sizing enough at base. Matt
 
That will work if you need more bump. The problem the OP had was not enough sizing at base. Can be caused by too tight of reamer at back end or sizing die is not sizing enough at base. Matt

Point well taken. I thought possibly it might need both but realize if it's just the base only, this idea could bump too much. Thanks
 



Anyone who is going to be handloading and especially if their interested in doing it rite should own or at the very least borrow one of these... It can help you deduce problems such as what you've experienced. I realize you've now solved your problem and that is great. Go out and get a 0-1" micrometer and use it in conjunction with your calipers.
 
Tools are needed to measure things. That is how most times problems can be worked out. You also need a headspace gauge like Hornady to see how much you are bumping brass. Matt
 



Anyone who is going to be handloading and especially if their interested in doing it rite should own or at the very least borrow one of these... It can help you deduce problems such as what you've experienced. I realize you've now solved your problem and that is great. Go out and get a 0-1" micrometer and use it in conjunction with your calipers.


Ok, here is a problem that reloaders deal with:

Winchester brass & Rem brass dia

Hornady brass dia

Lapua brass dia

Norma brass dia

All of these vary....

Basic SAAMI spec vs CIP spec(Europe)

Now, choose your dies accordingly!!
 
Usually the problem occurs when they use too tight of reamer on the .200 line. Some guys and gunsmiths have tightened up reamers because they think it will save primer pockets and give better accuracy. Then you have the problem like AckleymanII says. Usually WIN brass runs small and when they make a cartridge that Lapua does (like 284) and you chamber for WIN brass and use Lapua you will have trouble. You get the famous CLICK. Matt
 
Larry, the regular 260 does have marks on the bottom of the case, however with some effort it will chamber but extremely tight and has to be beaten out with rubber mallet, I can try a untouched 260ai brass but get same results. I know it sounds odd that I'm saying its untouched 260ai brass, but some time ago, I received a bunch of 260 brass that is branded 260 but has improved shoulder already, however, it's flawless, primer holes, entire round seems brand new, does not look like once fired brass. I only have one 260 with a bullet on it, but it's a dummy round from another 260 barrel that I have and guy sent me a sample, but the barrel I'm dealing with right now is stamped on barrel from GM 260AI. So, I'm a bit baffled, as parent case which is 308, I do have some of those, and I have 7mm-08 which is still within same parent case, and I have alot of 260 brass but all of it has improved shoulder, which is crazy because most of it seems brand new and never fired but it definitely has improved shoulder compared to regular 260 remington.

thanks again for all the input..................

JD

Is it possible that this brass may have been hydro Ackley Improved?
 
I'm having a similar issue as the original poster. Brand new X-Caliber 260AI and my Redding dies won't size the base enough to chamber brass. My brass is scuffing in the same spot near the base. I mic'ed some brass and got .4690" for new Lapua that chambers fine in the new barrel.
Brass from my 2 other 260AI rifles comes out to .4710" +/-.0001 fired and resizes to .4705-.4706". One Criterion and another Green Mountain blank done with what appears to be the same speced reamer, all the brass measures very close between the my 2 older barrels. I'm at a loss on how to use the new barrel without buying another expensive sizing die. Even though I could fire form brass to the new barrel I won't be able to full length resize it and don't want to use a Lee collet when I already have an ezpensive set of Redding dies that I like.
 
Every reamer for a .308 based case needs to measure .471-.472 at the base or your gonna have problems. I'm dealing with it right now in a 243, but never again.
 
You stated the die is screwed down to the shell holder but didn't say if it was bumping the shoulder?
Before anything I would take a fired case and set the die to the appropriate shoulder bump if your shell holder is too thick on top and not allowing the shoulder to set back it also might not be allowing the base to size. I have trimmed the base of several dies in the past that were bottomed out and still not touching the shoulder or base.
 

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