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260 AI vs. 6.5-284

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18 August 2003, 07:02
todbartell
260 AI vs. 6.5-284
Which one of these would be the best fit in a SA 700? Would they be close in capacity? Or would the 6.5-284 still have the edge? How long of a barrel is optimum for a case this size, I was thinking 24". What kind of speeds can be expected with the different weights?, especially the 140 gr.

Thanks. TB
18 August 2003, 07:34
<BigBob>
todbartell,

To guess at the velocities you would get with any bullet in either cartridge would be a SWAG. To tell the truth , I really don't know, but think it would be around 100 fps to 150 fps in favor of the 6.5-284. The 6.5-284 is about identical to the 6.5-06 ballistically. I've played with the 6.5-06 and liked the cartridge very much. It was very effective on deer and antelope. After quite a bit of testing, I settled on the 125 grain Nosler Partition. The .284 case does however, have its problems. The feed rails must be altered to properly feed the case. I've never done this, but have been told that it is somewhat ticklish.

Something else I've never done, is to attempt to improve the .308 family of cases. My guess would be that there is not much to gain by doing so. The final result might be using more powder for the same results. Let us know what happens. Good luck. [Big Grin]
18 August 2003, 13:39
fredj338
Todd, I bounced this one around for awhile, as I wanted to rebarrel my M700VSSA. I decided on the .260ai because of the o/a length of the cart. It is @ my gunsmiths now along w/ a new PacNor 1-8 Sendero profile bbl. It will finish @ 27". Bill Davis, on this board, was kind enough to send me a couple of fired cases & after measureing, the actual increase in powder cap. is less than 2gr. So, will it perform close to a 6.5x.284 in a short action? When I get the rifle back & start putting loads together I'll post the results.
I think some of the increase in cap. w/ the 6.5x.284 is going to be negated a bit when you have to deap seat the longer match bullets. I hope to break 2800fps w/ a 139-142gr bullet & 3300fps w/ the 105-107gr bullets. This is going to be a heavy varmint/casual target rifle. Someday it may make a trip for a "speedgoat" but we'll see. Right now I'm busy w/ loads for my .338x74keith, very cool looking cartridge.

[ 08-18-2003, 04:41: Message edited by: fredj338 ]
19 August 2003, 01:47
Bo-regard
Tod,
Having worked with the 6.5x284,6.5 Phantom (Lazz) and the 260 AI,the 6.5x 284 and the 6.5 Lazz are ballistic twins and will get more velocity than the 260 AI. The down side to the first two are: 6.5x284 requires the longer action to reach full potential. The 6.5 Lazz requires their very expensive (but very strong) brass but can be used successfully in a short action. What sold me on the 260 AI was the velocity vs powder used,low recoil and its use in a short action,cheap brass and most of all its accuracy with hunting bullets over the other two. Don't misunderstand,the 6.5x284 and the 6.5 Lazz are good but I happen to hit an extremely good barrel for the 260 and its a hummer! It really boils down to what you want and what you hope to accomplish. If I were going to consistently use 140gr bullets or larger then the 6.5x284 in a long action would be my choice. Bill Davis
19 August 2003, 23:13
<JOHAN>
Well

I would go for a long actions to seat out the bullets in a 6,5-284 Norma.

I would choose a 6,5-284 since it's a commercial round CIP proved by NORMA and has three good sources of correctly headstamped brass(Norma, Lapua and Hornady).
This will also give you a better secondhand value since more shooters would be interested in it. I would go for 8,5 in twist soo that you can shoot the 140 grain + missiles [Big Grin]
Friend of mine who had two rifles in 6,5-284 NORMA had stabilisation problems with 140 grain bullets in a barrel with 1/9 twist. I would got for 25 inch barrel to get the full potentinal of the round with slow powders. Good luck [Smile]

/ JOHAN

[ 08-19-2003, 14:15: Message edited by: JOHAN ]
20 August 2003, 03:49
fredj338
I would agree Johan, but Todd wants to fit it in a M700SA. This really deap seats bullets in the 6.5x284. The availability of brass isn't really a problem as good .308 & .243 brass will be around for along time & forming isn't too difficult. If it was a M70 I might go w/ the longer 6.5, but the M700 is just too short.

[ 08-19-2003, 23:46: Message edited by: fredj338 ]
21 August 2003, 02:03
Pokerplayer
I am working on a little project 6.5 RSAUM in XP-100
23 August 2003, 13:06
leo-too
"Cartridges of the World" shows the Norma 6.5-284 to have an OAL of 3.23 inches.....too long for a short action. You'll have to handload for a short action 6.5-284.
24 August 2003, 05:15
<1_pointer>
Barsness stated that in a 7-08AI that he got the same velocity as the regular version with 2" less barrel, so I assume the same would work for the 260.
02 September 2003, 23:05
<Kimmo E>
Why not the 6,5*55ai or the 6,5*55 with max 140gr bullets it will fit in SA. So does lapua 156gr mega factory round in my Browning blr 308w.

Kimmo
03 September 2003, 19:34
fredj338
Kimmo, the 6.5x54 & the 6.5x.284 are very close in length. Neither one will fit the M700SA w/o seating bullets very deep. I think the .260AI is about all you can get into the M700SA w/o extensive mods. I'll let you know how mine performs when it's done this fall.
03 September 2003, 23:13
HondoJohn6508
todbartell,
I have just about finished my 260AI project but have aproached it from a different direction. FYI,using a Rem 788 action,PacNor SS #5 contour with a 1 in 11" twist,25" long. I don't plan to use bullets heavier than 100 grains so thats the reason for the slower twist. Lapua 243 brass necked up to 6.5 and fireformed.
I am fully aware that the velocity difference between the standard 260 and the Ackley version is minimal. My reason for going the Ackley route was not so much velocity increase but case life and bolt thrust reduction.
When we both have the rifles completed I would like to share info and loading data with you if you don't mind. Best regards, Ol' John
05 October 2003, 09:43
Trautman
where is the problem in seating bullets very deep on 700SA with 6,5-284 cartridge?
05 October 2003, 13:56
Cold Bore
quote:
Originally posted by Trautman:
where is the problem in seating bullets very deep on 700SA with 6,5-284 cartridge?

If you seat the bullets deep, they infringe on space that could be used for powder. If you have to "download" on powder to make room for the bullet, you've defeated the whole purpose of making a hotrod cartridge.
22 October 2003, 01:31
Pete E
Gents,

How does the .260Rem AI compare to the standard 6.5x55mm?

I am looking to rebarrel a L591 (short action) in .308 in to something in 6.5 caliber but did not want theperformace to fall below that of the 6.5x55...

regards,

Pete
22 October 2003, 03:50
N. Garrett
I am shooting the similar 25-284 in a Mark X Mauser, and didn't run into any of the infamous feeding problems.

I did have the feedrails polished by a 'smith who mainly works on Mausers, but outside of that, the only change was a Model 70 style safety and a new trigger.

My vote is for the 6.5-284.
One of the Radiologists I work with just took pocession of his rifle in that caliber, and took a nice mulie with it this month.

I think your resale value will be much higher.

Garrett
24 October 2003, 22:22
sscoyote
Pokerplayer-- i'm dying to hear about that XP 6.5 RSAUM you're doing. Is this going to be a pistol or rifle configuration?? I have a 6.5-284 Win. XP 16" Shilen, and i love it.
25 October 2003, 08:18
cummins cowboy
how does the 284 winchester case compare in size to the x57 family of cartridges. I don't have a x57 case with me but compaing a 8mm mauser to a 7.5 swiss that I got laying on my desk which is supposed to be almost exactly a 284 winchester all you have to do is run the 284 through a FL die and you get 7.5 swiss, it looks to me that the x57 cases is slightly bigger, what would happen if you made a 6.5x57 how would this stack up to the wildcats you guys have talked about. or would the same short action problems apply
25 October 2003, 08:48
Blackhawk44
You are back to comparing the 308 and the 30-06. The 284 could be called the father of the WSM's. It has a magnum diameter body without a belt shortened to work thru a short action. Actual capacity is within a grain or so of 270/280/06 case. It was designed to be the 270 in a short action.
26 October 2003, 17:11
<OTTO>
From what I can tell, the 6.5-284 will hold about 9 grains more capacity than the 260 imp. Brass for 6.5-284 is standardized and available. what more do you need to know?