Home Forums Hunting & Shooting Custom Rifles & Wildcats 260AI velocity

What is a safe estimate for 260AI velocity using 130grain boolit and firing from either 25 or 26" tube? Been racking my brain for a new project and the 260AI keeps coming up. Im not into the lightweight thing enough to want a short pencil barrel but a fluted #4 is more to my liking. Just curious to what velocity i could reasonably expect from such a loading.

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

Load data for 139's and 123's from a 26" barrel.

ty. very informative post.

Personally, I think a 260 is fine as is, 2850 is reasonable in a hunting length without AI, and no forming brass. .488 and higher BC makes for very good trajectory and impact at any sane range IMHO. A standard 7/08 will boost like bullet wts. higher, but BC/SD lower....tit for tat....

What is your range and application?

6.5 x 47 Lapua runs there with less powder but at a higher pressure level.

In all reality 2800 FPS is all thats really needed for MOST of the lower 48 big game hunting.

ML

And when did "need" ever really factor in to rifle chamberings? True 28 and some change may be all i "need" but i like fast. And some of the advantages of the AI like case life, improved accuracy, lack of trimming etc. all make the fireforming task that much more enjoyable. Been the 7-08AI route and the 280AI route. Both were lights out shooters that were more than i imagined they could be. Now its time to try somethin different. Just checking to see if this is the route i want to take or if maybe there's a 6.5/06 AI in my near future.

As Mntngoat, I admire the 6.5x47, great brass and less trimming concerns, but Lapua is outpricing themselves on brass. When I was younger, I had more time, I played with a few i.e. 6mm, 6.5 and 7mm TCU in carbine and pistol bbls. Forming brass was not bad, but time seems to be harder to come by ....as life goes by...that aside as well as bbl life, a 260AI is not a bad round by any means and a '06AI is just more a good thing but recoil will go up as you know.

I can't blame you for playing with new flavors as most of us all do it. I am thinking a 250AI would be alot of fun, when thinking of wildcats. Not that it's performance will trump a 260 or similar round....just because I want one....so I can relate.

If you really want to experiment, do a 260AI on a long action and after about 2000 rounds or so rechamber to a 6.5/06 AI and see how you like the two. Be sure to start with a 25-26" bbl at a minimum for rechambering if I were you and you go this route. 27 or 28 might be better. An efficient round is the 6.5x55 improved...great brass i.e. Lapua cheaper than 47L brass, more capacity, and better bbl life than the 284 or 06 case. Just another idea - Endless in wildcats.....

Good luck and post your results when you get there.

This thing, when it all comes together, will be a deer slayer. Thought the 260AI would be somethin me and the wife could shoot. Excellent ballistics with little recoil( or at least manageable for her). It will see action everywhere from woods to green fields. Mentioning the 6.5x55AI, a cartridge I hadnt thought of, how is the recoil there? Doesnt bother me, just the wife im concerned about. Where does it fall in the velocity category? Love to see 3000+ and not be a barrel burner with 130NAB. Maybe I should give it a look. But was hoping to stay short action on this one. the 55 is a LA caliber if im not mistaken, correct?

I think the .260 AI is a fantastic round. Will it feed from a magazine? 65BR makes a good point about the Lapua brass getting spendy probably why I only have 100 rounds each for my 2- 6.5x47's.

ML

Hate to throw ANOTHER good idea at you, but since you brought up 130s, a 270 Redding, aka 27/08 AI is a round that will get you 3000 in the 25-26", but so will the 260ai and the 7/08 (though I believe you are looking for a 1/2mm smaller 6.5).

The 270 Redding would give you MANY 130 options as well as down to 90 HPs for varmints if you wanted them. It's another option.

The recoil will not be an issue with the 6.x55 ai anymore than the 260 ai. The standard 6.5x55 has about 1 1/2 to 2 gr. more powder room than a std. 260. Ai to Ai I don't know.

Hope that helps somewhat. Not sure of your ranges, but a 6mm on the 6.5x47 is very well liked also. Info here:

http://www.6mmhot.com/

Anything from 85 TSX, 95 Ballistic Tip, various 105s like Berger and even up to 115 DTACs in a fast twist 6mm will kill most any deer well out to most sane ranges, very light recoil/blast for the wife (I shoot the 6BR and call me a sissy but I have killed deer at 400 yds with 105 amax....plenty power, accuracy w/o peer).

Choosing the right bullet, i.e. one that will penetrate from any angle like the TSX and B. tip vs match bullets will ensure not passing any reasonable shots. I'd be content to 400 yds with a good 6mm.

A good BC 6.5 bullet at decent speeds will get you to 500-650 yds if you need/want to shoot that far. Over on longrangehunting.com guys have used the 260 ai w/140 amax for OVER 600 yd deer.

That just gives you the outer limits if you want/need a real long range set up. Some of those guys think long range is closer to and beyond a 1/2 mile but I prefer to stay this side of a 1/4 and often it's 200 yds or less for most any shot opportunity. Only 3 deer that I shot were further, though my son killed his first two at 300, and 250 and with a 243/85 BTHP at that.

I would not be surprised at getting a 130 AB at 2950 in a std. 260 or 6.5x47L if you are using a 26" tube. I always want and use an 8 twist but if building and you KNOW you will never shoot over a 130 gr, a 9 twist will lower pressure some and give you a little more speed. Shot placement rules and a few fps either way can easily be made up in how a rifle is set up for POI.

Anything from the 6mm/6.5x47L and 6.5x47L, 260/260AI, even a 250AI, or a 270 Redding will likely tickle you and your wife. I'd pick the caliber you want first and then decide if you want simple no forming or a one pass forming wildcat and have a really unique round. I would be happy with any of them and not feel less gunned with one vs another. They will all shoot very well.

If you asked me to rank them above....

6.5x47L
6mm/6.5x47L
250 AI
260
260AI
270 Redding

That is just how I see it as to my preference to bullets, and time spent loading. Before the 47L was around, there were wildcatters doing the 6.5/250 Improved and the 6mm/250 Improved, both very similar, cheaper brass than the 47L. All the above will feed well. I did not mention in my list the 6mmBR which ironically gives speeds that many guys load their 6mm/6.5x47L's at for accuracy. Feeding can be iffy in some guns.

Hope I did not confuse you with more options...realistically they all will work. I am sure you know most of these things so no intention to insult your knowledge.

Im not a fan of .277 anything. Just doesnt float my boat. My only choices are the 260AI, now that it was brought up maybe the 6.5x55AI, and the 6.5-06AI. Preferrably the first two. I have heard the praises of the 6.5 for some time and figgered it is time to get my feet wet. Just looking for a viable combination of 3000+ with a 130NAB, (+ being the magic number here), barrel life, and accuracy.

I understand, the Redding is the only 277 I'd be interested in, not that the Win and even WSM are not good ctgs. The 55 will need to be in a long action, and the 6.5-284 as well to be at their best, and many do build the 6.5-284 on a long action, although it technically is a short action round.

I think if you are wanting to stuff it inside a short action a 6.5-284 and even the almost obsolete 6.5 Rem Mag would be ideal for you, and bbl life aside the 6.5 WSM is a hot number, but recoil is going up and bbl life is likely from 1k-1.5k. A 260 ai running full steam should get 3,000 but at top pressure and if you don't for some reason get a 'slow bbl'...

Good luck with your project. Hard to go wrong in any 6.5 with good bullets.

I am a dyed-in-the-wool fan of the 6.5 caliber and the 260AI(6.5/08AI) ranks right up there as a highly efficient cartridge. You might find the following thread of interest on another forum. An in-depth discussion of various 6.5 cartridges and estimated velocities.

.. http://www.thehunterslife.com/forums/showthread.php?t=1560&page=5

Best regards,

Ol' John

Mind is made up on rifle specifics....260AI, Rem 700 Action, Krieger LVSF taper @ 25", Laminated Rem Mtn Rifle stock with modified barrel chanel. Now for next thing. Thinking about going with a wyatts box to get a tad bit more OAL. Would i be better off fireforming std 260 brass or would i benefit from the tad longer neck from sizing down 7-08 cases? Speed IS an issue here and i wanna milk it for all i can. Most would say a few extra fps wont make an animal any more dead, but i like BIG numbers on the chrony. Also what smith should i get to do this thing. I know Mickey and Kampfeld are popular here and I also have experience with Jim Borden. Any other ideas or reccomendations?

If you decide on Karl theres probably an 18 month waiting list if he decides to take the project on.

no disrespect intended..but not gonna wait 18 months. Especially when it will take me about 4 more months to acquire the things i need to get this one going. This dang economy doesnt help either.

If speed is the issue, why not go with a bigger "engine"; 6.5-284, 6.5 SAUM, or 6.5 WSM?

Jeff

The sarum and wsm are out due to the wife not wanting to deal with that much recoil. Speed is an issue...but the GOAL here is to milk the 260AI for all its worth. And be satisfied with that. Thinking subtle changes can get me close to 3200. And from a std SA caliber with a 130 grain boolit...thats cookin.

I doubt that you'll be able to load a 260AI as high as 3200 fps with a 129/130 grain bullet without very high pressures, maybe 70K+ PSI.

If you could get 2900 fps from the standard 260 at reasonable pressures, what practical value would you gain by adding 300+/- fps and 12K+/- PSI? The difference in flight time would be around 97/10,000th of 1 second per 100 yards. If you need higher speed, you could probably get 3200 fps with a 100 grain bullet at safe pressure and I doubt that any medium game animal would die any more slowly/quickly if shot through the lungs with a 100 grain Partition or a 129/130 grain whatever.

Jeff

I like the idea of longer necks! and Yu would not go wrong using Jim Borden.

ML