swithing from 260 to 260ai

[foxx]

I have never switched barrels before, and just ordered a McGowen 260AI to replace my factory 260... I have looked, and cannot find a 260AI go-gauge. Also, I do not have any 260AI brass to use for seating the barrel.

I have searched the net for info on head-spacing the barrel, and am not sure I understand exactly how to do it.

My plan is to use a 308 go-gage as a 260AI no-go... initially seating the barrel to it, then remove the gage and turn the barrel into the receiver another .004 inches. Is this correct? If so, roughly how many turns (or fractions of a turn) should I expect to have to make to get it .004 inches shorter than what the no-go allows?

Any advise is greatly appreciated.

[stangfish]

See if you can size a piece of 308 brass down in the 260 AI die. Use that as a go gauge.

[calib]

if you are will get it back to me i have a 260 ai gauge that i just got from ptg for my build that i am getting ready to do

[foxx]

AWESOME, calib. Absolutely. Thanks. How much was the gauge? I'd be happy to help you pay for it.

[foxx]

See if you can size a piece of 308 brass down in the 260 AI die. Use that as a go gauge.

What dies are you using?

I'm asking cuz I was planning on using my 260's Lee Collet Neck sizing die. I know you don't like those, but I haven't seen AI's that don't use bushings, etc. Those seem complicated to me and expensive if you don't know what you're doing or what you're getting into.

[stangfish]

I don't have a 260 AI. You can ask me about a 280 AI if you want. One thing you can do is do a search for the Saami print for a 260 case and one for the AI case and you will see what the differences are.

[stangfish]

Here is something I found.
http://www.6mmbr.com/260AIforming.html

[foxx]

yep. Thanks. That's a good read. That and a few others from that same guy are why I am going to the AI (besides the fact I cannot get consistent tight groups outta the trophy hunter xp)

With the .260, I am getting solid .75 inch groups all day long no matter how many different loads of H4350 I use with Hornady Match 140's. It's weird. I find 2 "nodes" that shoot equally well within a range of about +/- 2gr of either of them, but nothing shoots better than that. All I get is different POI's. Have tried a few other bullets and powders, same results. For an inexpensive hunting rifle, I should be really pleased by how tolerant it is, so I can't complain, but I don't need another hunting rifle, I want a "target" gun. And, I want to try an aftermarket barrel.

[calib]

pm sent

[calib]

I don't know if i am late on here, but I have been using redding bushing dies and have been stepping down 308 mil brass to make my 260 brass, it is already primed so i am just going to load up some bullets seated at varying lengths with the same charge and see what i may find for seating depth, then once i have enough fir formed I will play with a powder charge to get it finished. I think with the 308 brass i have been stepping down using 4-5 steps

[BillPa]

I haven't seen AI's that don't use bushings, etc.

Really? I been using FL dies for improved cartridges for well over 30 years. They're not any different than any other FL die.

Bill

[foxx]

I am looking for your belp, Bill. What dies are you ux ing for 260AI?

[stomp442]

I use redding dies on mine. No bushing just a fl sizer and seater.

[foxx]

I use redding dies on mine. No bushing just a fl sizer and seater.

Thank you Stomp. I will look into those.

[BillPa]

I am looking for your belp, Bill. What dies are you ux ing for 260AI?

I don't shoot a 260AI, but currently the improved 22-250, 250, 270-08 and 280. My dies are a mixed bag, RCBS, Redding and CH4D.

Bill

[bootsmcguire]

What dies are you using?

I'm asking cuz I was planning on using my 260's Lee Collet Neck sizing die. I know you don't like those, but I haven't seen AI's that don't use bushings, etc. Those seem complicated to me and expensive if you don't know what you're doing or what you're getting into.

Nothing wrong with the bushing dies. I use the Reddings on my 6-WSM and use different bushing to neck down the 270WSM brass to make the cases. They work great and are not too complicated once you get the hang of it.

I am a huge fan of the Lee Collet Dies. They are simple to use, the case require no lube when run through the Collet Dies and the ammo I am making with mine shoots great in all the chamberings I load for. I use 22-250 dies to load the 22-250AI and 243 dies to load 243AI. Both the Collet Die and the Dead Length Seater work fine for the improved versions. Other people on here have reported that the 260 Collet dies work fine on the 260AI. I have no 1st hand on the 260AI as I have yet to have one.

Some people don't like the L.C.D.'s and that's fine, we all have our preferences but they have always worked great for me and that's why I keep sticking with them when I can.

[foxx]

Alright.

Good.

Thank you, guys.

Hopefully I'll have everything by early next week, put it all together and see what I can do with it. :)

Norm

[foxx]

So I rented a set of 260 AI Go and No-Go gauges and I rec'd a 308 go-gauge (serves for the no-go in .260AI, I get that), and I rec'd a .308 AI go-gauge which the rental company said is 100% interchangeable for the 260AI gauge.

Is that right?

[bootsmcguire]

According to the 49th Edition of the Lyman reloading manual, The 308 has a length of 1.560" to the base of the shoulder where it joins the sidewall of the body, and the 260 is showing a 1.5598" to the same location, so with only 2/10,000 of an inch difference I would say that they are correct since the AI versions are both nominally .004" shorter than there respective parent case.

Please do not quote me on this and do your own research as it is your face behind the rifle, and no-one is responsible for you but you, but if it were me based on what my manuals are showing I would use them.

If I am mistaken or missing something somebody please speak up.

[foxx]

Thanks, Boots.

Unless I hear from someone else, I will go with it. (excuse the pun).

Unfortunately, I am embarrassed to say I could not loosen the smooth nut from this new Trophy Hunter XP... I was using the Wheeler wrench, hammered the heck out of it with a steal hammer, and could not make it budge. Maybe a "cheater bar" would have helped, but I could not find anything that would work, so I took it to a gunsmith hoping he would loosen it for me while I waited (for a nominal fee, of course), but this place does not work that way. They took it, said it would be a few days and are charging me $40. The money isn't what bothers me, but the time. Oh well.