260AI versus 260?

J

jimfinn

Guest
I have just ordered an 6.5 barrel and am leaning towards having it chambered in 260 or 260AI. This will be a hunting rifle, probably on a Model Seven or 700 action. Max barrel length will be 26".
I'd appreciate any thought or experience on the gain going to a 260AI comapred to the standard 260.
Thanks
Jim
 
I see no gain to be had.

Like the .243AI people CLAIM great gains but in fact they just run the pressure higher on the AI'd cases.

My vote is for the plain-jane version except that the AI looks cooler.

The real downside of the AI'd rounds is that they always produce excess gapspace which can be a real pita. The only way to avoid this is to have two reamers and a dedicated FF barrel, a REAL pita.

Were it me, I'd order my reamer to be .005 over the virginal brass at the rear and leave the rest of the case alone. I'd also order my go-gauge .003 or more UNDER-sized so that the gunsmith can't screw up your chamber. Re-set every shoulder on your brass for crush-fit and have at it.


opinionsby

al
 
Thanks Al,
I'll file that away and use it for my decision process. Actaully I'm copying it to a Word file where I'll save all the info and opinions I get.
I am just getting started and as the barrel is 4 to 6 monthss out there, I have time ruminate on it!
Jim
 
I like Mine

142 smk @ 2980 with a bartlain 1-8.5 with 3100 5-8 reloads per piece of ww 7-08 brass also really like the 139 scenars
 
I can not comment on the 260 - never owned or shot one, but I do own a 260AI barrel for my Encore. If you have any 260 data to compare my numbers to that will help in your decision process.
The barrel is 27" 1/8 twist. H2O capacity is 57.5 gr. Here are some of the loads I tested. 142 gr Sierra Match Kings, Varget 42.0 gr mv = 2980. Lapua 123 gr Varget 41.2 = 2872. H4350 46.6gr got them going 3140. I never ran into any pressure problems, so probably could run them hotter.
Is that much better than a 260? Don't know.
There are other advantages than just speed to the AI. Others can comment on those.
There are also disadvantages. Dies cost a little more. Process of fireforming - which really isn't a disadvantage if you like shooting. If you go on a hunting trip and forget your rounds- chances are you won't find any "box" cartridges at the local hunting store.
Deer sized game are not going to know the difference if they got shot by a 260 or a 260AI. In the end, it will be your choice - get as much info as you can - make the decision - and don't look back, it will be a sweet medium sized game rifle no matter which way you choose.

Stanley

Stanley
 
Last edited:
Apollo said:
I can not comment on the 260 - never owned or shot one, but I do own a 260AI barrel for my Encore. If you have any 260 data to compare my numbers to that will help in your decision process.
The barrel is 27" 1/8 twist. H2O capacity is 57.5 gr. Here are some of the loads I tested. 142 gr Sierra Match Kings, Varget 42.0 gr mv = 2980. Lapua 123 gr Varget 41.2 = 2872. H4350 46.6gr got them going 3140. I never ran into any pressure problems, so probably could run them hotter.
Is that much better than a 260? Don't know.
There are other advantages than just speed to the AI. Others can comment on those.
There are also disadvantages. Dies cost a little more. Process of fireforming - which really isn't a disadvantage if you like shooting. If you go on a hunting trip and forget your rounds- chances are you won't find any "box" cartridges at the local hunting store.
Deer sized game are not going to know the difference if they got shot by a 260 or a 260AI. In the end, it will be your choice - get as much info as you can - make the decision - and don't look back, it will be a sweet medium sized game rifle no matter which way you choose.

Stanley

Stanley
Click to expand...



A few things here, re this statement... "There are other advantages than just speed to the AI. Others can comment on those." I will comment on this, IMO there are no advantage. If there are, NAME THEM..... (And please, if you're going to contend that brass "flows less" then support the claim)


And this.... "chances are you won't find any "box" cartridges at the local hunting store."...... what exactly does THIS mean?? AI'd rounds BY DESIGN will shoot factory rounds. If you can't find off the shelf stuff then your gun is set up whack.

al
 
Al, does any Ackley Improved make sense?

alinwa said:
A few things here, re this statement... "There are other advantages than just speed to the AI. Others can comment on those." I will comment on this, IMO there are no advantage. If there are, NAME THEM..... (And please, if you're going to contend that brass "flows less" then support the claim)


And this.... "chances are you won't find any "box" cartridges at the local hunting store."...... what exactly does THIS mean?? AI'd rounds BY DESIGN will shoot factory rounds. If you can't find off the shelf stuff then your gun is set up whack.

al
Click to expand...

I'm contemplating a .30-06 AI, and wondering if you (or others) have any comments as to whether that's worthwhile over a standard .30-06. One of the things I like about the AI concept is that I could (and would, for fire-forming at least) shoot factory ammo through it. And per Jerry Tierney, sometimes SAAMI loads shoot very well indeed through an AI chamber, but that's another topic.

I prefer to KISS, so I'm contemplating the real advantage of an Ackley Improved. Intended application would be shooting to 1,000y, and perhaps to 1,200y (just because I never have before), mostly at paper targets, but who knows someday... :cool:
 
I've heard that you don't have to trim your cases as much - but, like you said, I don't have any proof of this - that is why I didn't post that the first time. Other advantages would be; the uniqueness of having an Ackley, the time spent on a project that not many others have. Are those advantages that will show up on paper or terminal effects? Nope, but they are still advantages of owning an Ackley.

If you go to Scheels - you probably won't find any 260 AI rounds. Will you find some 260? Maybe and yes - they will still fire in a 260AI chamber. But if you plan on forgetting your hunting rounds - why do the Ackley? That is why I listed it as a disadvantage.

Al, If you want to argue - why not just come visit with my wife?
 
Last edited:
Bill Ohio said:
I'm contemplating a .30-06 AI, and wondering if you (or others) have any comments as to whether that's worthwhile over a standard .30-06. One of the things I like about the AI concept is that I could (and would, for fire-forming at least) shoot factory ammo through it. And per Jerry Tierney, sometimes SAAMI loads shoot very well indeed through an AI chamber, but that's another topic.

I prefer to KISS, so I'm contemplating the real advantage of an Ackley Improved. Intended application would be shooting to 1,000y, and perhaps to 1,200y (just because I never have before), mostly at paper targets, but who knows someday... :cool:
Click to expand...


Bill, I've shot a herd of Ackleys..... when I was in gunsmithing school they were de rigeur. One of the few that I currently advocate is the 30-06AI, a definite improvement over the venerable 30-06. Many folks don't realize that 30-06 rounds will actually collapse at the shoulder from firing pin impact. The firing pin CAN and WILL change the headspace on unfired 30-06 brass. Fired and hardened brass will withstand the force but Ackleyfying will hold 100%. Also the problem of pullback of the neck is minimized by the short shoulder. IMO a properly headspace 30-06 Ackley will be .006-.012 SHORT of a "go-gauge." A monstrous jamfit is wicked hoovis. When I set up an -06AI I set the chamber to be a solid jam on several brands of factory loads. TIGHTER is better, you can quite easily gain jam on a 30-06 case due to the minimal and shallow shoulder.




Apollo.....

Whatever man. This is BRC not "Unfounded Guesses I Got From A Magazine," Central. It's not an argument until you present some sort of rational reasoning/discussion, preferably based on experience. :rolleyes:

al
 
Hey Guys,
Please don't turn this thread into an argument. :eek: I was just asking for opinions and experiences. I'll just take what gets posted and think about as I make my decision.:confused:
I kind of like what Appolo wrote:
"In the end, it will be your choice - get as much info as you can - make the decision - and don't look back, it will be a sweet medium sized game rifle no matter which way you choose."

It will in the end it usually comes down to personal preference. There sure isn't a lot of balck and white choices in these matters. I am still curious about possible velocity and case capcity gains with the 260AI.

I do appreciate Al's insights for sure. I wish I knew a quater of what you seem to know about gunsmithing!

Redrock,
Is that a 260AI that you are getting 2900+'/sec with a 142 gr bullets? And what length barrel?

Appolo,
Is the 57.5 gr. water capacity measured to the base of the neck or a full case.
Thanks to all.
Jim
 
Barrel Length

Mine is a 260 AI and the barrel length is 26"

Reason for owning, cause thats what I wanted.
 
Jim,

That number was a full case. Might be off a little based on the meniscus of the water, but was just an average of 5 trials done about 2 years ago when I went through that ackley project. Hope you find your needed information, let us know what you decide.

Stanley
 
Thanks Redrock,
The barrel I am ordering is a light sporter contour that is tweaked so that I can have a length of 26" and have the same muzzle diameter as the contour would normally have at 22". I had one done like this for my 7-08 and it worked out really well, fairly light for carrying purposed but not whippy like a featherweight. I had the 7-08 cut at about 23", but the 6.5 will probably start out at 26". That 2900'/sec velocity would be a good reason to stick to 26"!
Getting it because you wanted it sound like a good reason.
I am in the middle of having a 6mmBR rifle put together. It started out with an inquiry about a stock a guy was selling. As we e-mails back and further I got to buying a barrel and barrel block along with the stock. My buddies have asked me what the heck do I want with a 6mmBR as there isn't any competion for something like that up here? The reason, I have been wanting to try a super accurate cartridge like that for some time, the price was right, and it sounds like fun!

Stanely,
Do you remember what brand of brass it was that you measured the H20 in?

Have either of you tried Hornady 140 A-Max's? Hornady recommends a minimum twist of 1:7.5" I e-mailed them and they said that 1:8" would be border-line and whether it would stabilize the 140 A-Max would depend a lot on the velocity. I assume faster is better within reason.

It is going to be months before I get the barrel and I can't say that any decision will be 100% final until the barrel is here and I hand it to the gunsmith!
Take Care
Jim
 
Here is some good reading

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



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

These two guys have done alot of the leg work your looking for, is it worth it? Doesn't sound like it is to Alinwa, but it was for these two guys, myself and Apollo, you'll have to make up your own decision.

I'm a tinkerer and like messing with things, if you just want to load and shoot, go with the 123 Sierra Match Kings with a .260 rem and have a blast.

Your in the fun stages of your rifle build, keep it that way.:)
 
Jim,

The cases I choose to use were Remington.
Yes, I shot some 140 A-max's, but they didn't group near as good (in my barrel) as the Sierra's and Lapua's so I focused my efforts on the 123 Sierra and Lapua and the 143 Sierra's. I have the load data at my work. I can get that for you, if you like, tomorrow.
 
The barrel is 27" 1/8 twist. H2O capacity is 57.5 gr. Here are some of the loads I tested. 142 gr Sierra Match Kings, Varget 42.0 gr mv = 2980. Lapua 123 gr Varget 41.2 = 2872. H4350 46.6gr got them going 3140. I never ran into any pressure problems, so probably could run them hotter.
Is that much better than a 260? Don't know.
Click to expand...

I measured the H2O capasity of both the 260 Rem and 6.5x55 for a thread on another forum a little while ago and came up with 55.0gr for the 260 and 58.4gr for the Swede. Both were the average of 2 new cases with spent primers seated primers and filled to the case mouths. ~2.5 gr water isn`t going to make much if any difference in velocity at equal pressure. My Swede with 3.4 gr more capacity only runs a few over the 260 with 140s, at psi about equal to factory 260 according to my chronograph and pressure trace.

Edited to correct brass as new not fired. http://www.thehighroad.org/showthread.php?t=434629
 
Last edited:
.260

Jim-My own experience is that the improved probably isn't worth it. I had one built as a 6.5-.308 improved before the .260 came about and it was done by a reputable smith. Mine was tempermental. The same gun has gone to another very reputable smith in Iowa to make a .260, 26" Krieger. It is a walk around hunting rifle. I have a .280 AI which is above anything I've owned and shot. I also have a 6 Dasher which is a 6 BR improved more or less. I've read P.O. from cover to cover but can't sign up to Ackleyizing everything that comes along. Sometimes it is more prudent to buy a diff caliber that meets expectations of what you want. When I did mine I upsized .243 vice downsizing .308. Some say that is wrong; the reasoning I don't know. I had no brass probs(Lapua) and would add that expanding or compressing metal is stress-period. Do what you will but I don't think you'll realize the benefit of the $ you spend on the AI. At any rate, best of luck. Joy in life comes from having choices; disappointment comes from making the wrong one. V/R Greg
 
Looks of good info and reading!!!! That is what a forum like this is all about in my opinion. It is especially a boon up here in Alaska. There are lots of great thing about living here, I've been here since 1979 and don't think I'll be leaving anytime soon. But there is a limited pool of folks using some of these more, maybe esoteric is too strong, let's say not so common big game cartridges to get opinions from.
Joe, that seems like a good forum and I'm going to spend some time over there.
I am a tinkerer and like trying different things. I picked up a Model 70 chambered in a 30 WSSM wildcat that I'll be working loads up for this summer. Will it do anything a 308 can't, probably not, but it will be fun. Heck I already switched out the tupperware stock it came in for a varmint style walnut one. I'm still working on the finish shaping of that stock.
Darn right this is part of the fun of getting a rifle project going. I figured I'd ge the barrel ordered and fine tune fr0om there.
You all have a good one.
Jim
 
260 rem

Jim
i am in the process of building a 260 also. kreiger 6.5 1 in 8 twist in the number1 contour. im coupling this up with a 1999 montana rifleman short action i had engraved by ron nott of summerville pa. all wrapped in black walnut stock with a blank from www.familygrade.com i am hoping to get the 120 or 130 gr barnes triple shock to work accurately for whitetail and the occasional woodchuck.
personally if i wanted more power than a 260 rem i would go to the 6.5-284 or 6.5-06. i have a 223 AI and a 22-250AI which at times are a pain. my 223AI is finicky and only likes the 40gr sierra blitzking. the 22-250AI seems just too much of a good thing, really i can hit anything at 3400fps as i can at 3600fps. if i rebarrel these rifles again i will not use AI cartridges because i like shooting not tinkering with brass. like i said before if i want more speed i will use a larger capacity case but not an ackley one.
for what its worth, Fred
 
FIRST of all....... I apologize if I sounded argumentative to some. I just can't "feel" this stuff sometimes. I just say what I think.

I do think that Ackley's are cool enough that everyone should own at least one.

al
 
You must log in or register to reply here.
Back
Top