Fireforming .260AI brass

[WinnieTheBoom]

I'm considering building a budget .260AI on an Axis action and just wanted to see how those of you with AIs go about fireforming your brass. I know a lot of guys recommend having a dedicated fireforming barrel, but that's out of the question at the moment. I know that you can shoot regular .260 rem in AI chambers, so I'm thinking that it would be easy enough to take unfired .260 brass w/ AI loads and do it during break-in or as foulers after cleaning.

Just wanted to see what everyone's experience was, but 2,900+ fps with 140 grain pills sounds like a recipe for a laser beam.

Thanks.

[LongRange]

two ways...create a false shoulder with a bushing die or just jam the bullet .010 into the lands...im not shooting a 260AI yet but will be soon...im going to jam the bullets and run a stout load of H4831sc and a mag primer.

if the case isnt held in place some how you can have FTFs and the cases wont fire form well...or so ive read.

[WinnieTheBoom]

two ways...create a false shoulder with a bushing die or just jam the bullet .010 into the lands...im not shooting a 260AI yet but will be soon...im going to jam the bullets and run a stout load of H4831sc and a mag primer.

if the case isnt held in place some how you can have FTFs and the cases wont fire form well...or so ive read.

I'm thinking that's what I probably do as well. I think Hornady also has a hydraulic die made specifically for case forming, but I haven't looked into it yet. Just wondering if there are easier/more cost-effective ways to do it. 50-100 break-in/fouler rounds should do the trick as far as forming goes, and we'll just have to hope that the brass holds up for a while such as to preserve barrel life.

[LongRange]

im going to start with winchester brass...if i ever get my barrel...and then go from there...ive read several guys using remington brass without issues so if remington will hold up the win brass should..if not ill switch over to lapua...i guess the problem with lapua is doughnuts after fire forming but id turn the necks on the lapua so i doubt it would be a problem.

[WinnieTheBoom]

im going to start with winchester brass...if i ever get my barrel...and then go from there...ive read several guys using remington brass without issues so if remington will hold up the win brass should..if not ill switch over to lapua...i guess the problem with lapua is doughnuts after fire forming but id turn the necks on the lapua so i doubt it would be a problem.

Well keep me posted once you're up and running. I love the 6.5mm bullets and the .260AI, from all accounts, is a laser - so naturally, it's peaked my interest. If you could form the Lapua brass without having neck issues, that would be ideal, but the Winchester brass might work alright. I believe that Norma and Nosler also make .260 brass, so at least there are options if one doesn't work out the way you'd expect.

Any idea what life expectancy on the barrel is going to be with mid-heavy loads?

[LongRange]

nosler and norma would most likely develop doughnuts as well because they are both thick-er than remington and winchester.

no idea on barrel life but im thinking somewhere around 2000 to 2500 rounds as im looking for a little more than 2900fps.

[WinnieTheBoom]

I've been reading that guys have had good luck with 243 Lapua cases, but I'm not sure if that involves neck turning or not. Might be a little more work than I'm looking for when a regular .260 rem would give me a little less performance but a lot more convenience. Going to think on it. I could also go 6.5x47 Lapua.

Gotta do a bit more reading.

[LongRange]

here are two good reads and info if you havent seen them yet...

http://www.the-long-family.com/260AI.htm

http://www.6mmbr.com/gunweek046.html

[Dewey7271]

I load cheap bullets to seat in the lands and shoot. Nosler brass just because I bought a bunch, but it also works real well. One batch has four loads fairly warm with no issues as yet. Annealed after third firing. No doughnuts I could see or feel.
Fireform load is 47 H4831SC, CCI primer. That's mine but may be warm in your rifle. Seems to have the right pressure to really form it well with no further work.

[WinnieTheBoom]

If I were to do this, that'd be the method that I would use. Basically you load your AI charge into a virgin .260 rem case, seat the bullet to the lands and fire. If I'm understanding correctly, that will produce the higher velocities of the AI, and the AI shoulder will be the result of the increased pressures. Many have reported that it's actually pretty easy to find loads that shoot well in your rifle while fireforming, so it sounds like it could be a little easier than I originally thought.

Has anyone done this in an Axis action..?

[LongRange]

Dewey...thats exactly how i will fire form but with a CCI250...then ill run the 4831sc up to 48.5g in the formed brass and see where i end up.

Winnie...from what i understand you may see 2850 but not AI speeds because the loss of pressure as the shoulders blow forward...i weighed the win brass with H2o and they have an internal case capacity of 54.2g or so...thats a full grain more in virgin win brass than lapua or nosler brass thats be fired in a standard 260 so we will see what happens.

Stomp shoots a 260AI maybe he will chime in here soon.

[WinnieTheBoom]

Dewey...thats exactly how i will fire form but with a CCI250...then ill run the 4831sc up to 48.5g in the formed brass and see where i end up.

Winnie...from what i understand you may see 2850 but not AI speeds because the loss of pressure as the shoulders blow forward...i weighed the win brass with H2o and they have an internal case capacity of 54.2g or so...thats a full grain more in virgin win brass than lapua or nosler brass thats be fired in a standard 260 so we will see what happens.

Stomp shoots a 260AI maybe he will chime in here soon.

Are you going to be doing your load development with mag primers or just the fireforming? I think Dewey's method is probably the easiest way to do it. Fire once and be done, then start load dworkup. If reasonable barrel life expectancy is 2k+ rounds, taking 100 or so to form is nothing.

[Dewey7271]

then ill run the 4831sc up to 48.5g in the formed brass and see where i end up.
Funny you mention that. That's my load in the AI. With Nosler FF brass and a 140 AB clocks right at 2960. SD is tight on that one also.

Winnie,
You are correct on the accuracy of the FF loads. Sometimes I just want to quit forming and load virgin brass.:p Fireform loads spoil you sometimes.
Lets you get the scope set and practice a little, work on mechanics before things get serious

[LongRange]

yes ill start load development with the CCI250s since 4831 is slow and with the extra powder i figure it should workout well.

[WinnieTheBoom]

Good stuff, gents. Thanks for the info. Still a little ways off from getting the ball rolling on this project, but these are the rumblings of a potential project to kick off the new year :thumb: