260AI VS 6.5x284

[skeetlee]

Is there any reason not to go with the 260AI over the 6.5x284? Will the 260AI run with the 6.5x284? I am wanting to do another long range build this winter, and i cant quit thinking about another 6.5mm. I have a creedmoor that is so unbelievably accurate, that i wont even talk about, because most wouldnt believe me if i told you how well this horse will shoot. Unreal!! Anyway F-class is going to be the game for me next season so i want to have a couple rifles ready to go. I have a dasher thats shooting really well so far, but i feel like i need something a tad bit bigger for the longer events. The creedmoor i have is on a shehane st-1000 and it doesnt feel all that well shooting prone. I thought i would go with an Mcmillan MBR or another f-class McMillan.
Back to the 260AI. I have some 243AI brass from a previous rifle. the brass is Lapua and i have a 6.5mm neck sizing mandrel. I ran a piece of the 243Ai brass through the mandrel and necked it up to a 6.5mm improved case. I assume this would be the same as a 260AI case?? I will do the same with the Lapua 243 brass i have, and fire-form them. It seems pretty simple, unless i am missing something here? Anyway I like to be a bit different and i think a 260AI would make an excellent long range chambering with 140gr class of bullets.
Will the 6.5x284 out do the AI? Also i was wondering about accuracy. Some case designs are inherently more accurate than others. Will i find that the 6.5x284 is inherently more accurate than a 260AI?? Just looking for some experienced opinions.

Or should i scratch the hole 6.5mm and go to a 7mm? Oh Boy!! LOL!! thanks Fellas!! Lee

 

[savageboy]

I went thru the same thing, and yes my 260AI does everything a 6.5x284 will and with 4-5 less grains of powder. The only reason NOT to do it is the brass is a pain in the Brass! lol. Really, first your choices are limited- use Rem 260, neck up Win 7-08, Neck Down Lapua 308, Neck up Lapua 243 and risk donuts, Horn or Nosler makes brass too. I did the Rem. 260 1st now use Lapua. Either way, its a lot of work- I ended up neck turning a bit the Lapua 308 after necking, fireforming, etc. It is a great round once you get the brass done. I won the 600yd F class match last weekend at Camp Butner w/ a Savage in 260AI in my class ( F open).

 

[Dans40X]

OR,
Run away from both chamberings listed & chamber a 6.5 SAUM.
.532" bolt face required.
264 WM performance w/57-60gr of powder.

 

[Rust]

I like a 6.5 X 284. With the success I've had with mine I wouldn't consider anything else.

When the opportunity came along where I could afford to build a full on custom match rifle, I spent about a year thinking what to do and settled on the 6.5, and proceeded to build one not quite like what anyone else was doing. Ended up going with a slightly different chamber the secong barrel and haven't changed a thing since.

It takes 48.5 gr of H4350 to push a 139 gr Scenar to 2950 fps with single digit ES and SD. This compares favorably with any other 6.5 chambering as far as charge weight goes. But being as I shoot 20 round strings barrel life still isn't all that good. About 1200 rounds or so when I worry about the fire cracking that the bore scope shows, and the cleaning gets to be tedious. Accuracy is still excellent at that point but the barrel gets changed out anyhow at that point.

It is very accurate, more accurate than I can shoot. This is not simply because it's a 6.5 X 284, or has a good barrel. It's because I have an excellent smith who does excellent work, Doen't matter how good the components are if the smithing isn't at least as good. NEVER skimp on smithing.

One thing I don't have to do with the 6.5 X 284 is fire form. Been there, done that, don't feel like doing it anymore.

You could also consider the 6.5 Swede, 6.5 X 57, and 6.5 X 57 AI as chamberings. Lapua brass can be had in th Swede.