In the very near future I'm buying a 260 Rem. Likely a Rem 700 or the Kimber 84M.

Can I have the 260 Rem chamber reamed out to 6.5x57? I've taken some measurements on my daughter's Rem 700 in 260 Rem. Their's 1" of extra bolt travel after the 260 Rem case clears the action opening. The Mauser case is .195" longer leaving .805" extra room.

The mag length seems to be 2.830". OAL length for the Mauser round is 3.160" or .360" too long.

I realize the long 140 gr bullets will invade into the powder space but I'll probably still get more velocity. Mostly, I'd like to know if it will still operate as a repeater or I'm effectively creating a single shot.

6.5x57 or 6.5x55? I doubt you'd gain anything by going with the x57 case, especially on a .308 length magazine made for the .260

The extreme minimal gain likely to be enountered, could also be reached by having a 260AI reamer ran through it, it would be cheaper and you could still use the 260 Rem ammo to make fireformed brass.

quote:

Originally posted by MileHighShooter:
6.5x57 or 6.5x55? I doubt you'd gain anything by going with the x57 case, especially on a .308 length magazine made for the .260

The extreme minimal gain likely to be enountered, could also be reached by having a 260AI reamer ran through it, it would be cheaper and you could still use the 260 Rem ammo to make fireformed brass.

I agree, unless you are happy to single load or shoot 100gr bullets, your mag isn't going to be long enough. I went w/ a 260ai on my M700SA. It's a great cart. but will only give you another 50fps maybe over the std. 260. I was going new bbl. anyway so why not?

As a guy who owns both 260s and also a 6.5 x 57 ( which is my personal favorite cartridge), I'd call it ia waste of time...

I have a long action 6.5 x 57 and I gain exactly 50 fps with a 140 grain bullet, compared to a 260 in a short action...

Plus the velocity is pretty much the same with the 100 grain bullets and down.. and with the 129 and up...

the only difference comes with the 120s, and 125s...

plus the 260s I have, have 22 inch barrels and the 6.5 x 57 has a 28 inch barrel...

you gain nothing but a batch of feeding problems....

As I understand it, unless you have a good supply of 6.5x57 cases then don't do it. 6.5x57 cases can be formed from 7x57 cases but the 6.5 is longer in the body, and has to be fireformed.
The 260 is a grand wee cartridge as is.

No doubt I should have hoped on the 260 Wagon when it first came out but thats the way things go ..... I,m going to build one on a Mauser action , Shilen barrel , Houge stock , Bold trigger and I,m not sure what scope , Probably a 4-16 X Burris , make it an 11or 12 pound rifle that will drive tacks and dump wolves @ 500 yards ..., Least , thats my hope ....

I don't want to get off topic, but what is the practical difference over the 6.5X57 vs 6.5x55? Does the x57 give you enough of a velocity gain to make it worthwhile over the greater availability of x55 brass? How much are we looking at?

Everybody...

First off, thank you very much for your well thought out replies. The info you have shared with me has enlightened me and has helped me keep from making a mistake fraught with frustration and extra cost.

For now......I'll stay with the 260 Rem.

Have a good day!

Alan

The biggest obstacle to this conversion has not yet been addressed. The 6.5x57mm chamber reamer will not clean up the existing 260 chamber. The 6.5x57 case has more taper, hence the shoulder is smaller in diameter and further forward than the shoulder of the 260. Your barrel will need to be set back and the 6.5x57 reamer ran deeper to obtain a clean chamber. By my calculations the amount of setback needed is .796†inches. This will almost certainly be impossible or impractical. The shifting back of a barrel that much will cause unsightly gaps in the barrel channel inletting and depending on the contour of the barrel may not even be possible. Switching to the 6.5x57 Ackley Improved will solve these problems.

quote:

Originally posted by Joshua W. Rich:
I don't want to get off topic, but what is the practical difference over the 6.5X57 vs 6.5x55? Does the x57 give you enough of a velocity gain to make it worthwhile over the greater availability of x55 brass? How much are we looking at?

The two cases are actually a bit different, don't let the names fool you. The x55 case is actually a bit bigger IIRC, but is loaded to lower pressures.

The x57 is so simliar to its forefather the 7x57 (as is the same case with the 260 vs 7-08) that the performance is nearly indistinguishable, and really, it comes down to what weight bullets you want to fire predominantly. As with all small bores (and really, most ANY bore) it takes leaps and bounds to make tiny step-ups in velolicty. If you want a 6.5 to go faster enough to be worth talking about, you gotta shovel more powder in the fire. Factory wise, the next step is the 264 Win Mag. And after that...you've gotta go wildcat or expensive proprietary to make any other real gains (Lazzeroni, 6.5/300 RUM, etc)

As dedseven said, the barrel will have to hve the chamber section shortened and the reamer run in to completely remove any traces of the original chamber because the .260 Rem. case is bigger around than the 6.5X57mm case for about 1/3 of the forward portion. However, one really good conversion that WILL clean up the entire .260 chamber w/o having to set the barrel back is the 6.5 Gibbs. This is a blown-out .30/'06 case, and it is big enough in diameter to cut out the whole .260 chamber. And it produces ballistics very close to the .264 Win. Mag.

Remember also that we have two different 6.5x55s now ! European with guns and ammo made for the .480" head and the American guns and ammo with the .473" head !!

I investigated these very same questions a few months ago when I decided to rebarrel my Ruger 270 to 6.5...

In a nutshell:

If your action is short, stick to the 260Rem.
If long (ie 270 length) the 260 Rem is too short, so you'll need to go with the 6.5 Swede or 6.5x257... if you go 6.5x257, you're up for special dies (read expensive) and no factory ammo available if you get caught short..

Yep, there are two 6.5 Swede case dimensions - CIP (European) that has the .480 head, and SAAMI (US) with the .473 head... the advice I received from others on this forum was that SAAMI ammo could be used in CIP chambers without any impact on accuracy, although cases may not be reloaded as many times.

In terms of velocity, I did heap of analyses looking at the differences between the three options (allowing for handloading in a modern action) and realistically, there's not much to choose between them... and none of the three are far behind the 6.5/06...

I went with a PAC-NOR barrel chambered in 6.5Swede (CIP chamber) because it seemed to present the best option.

Haven't done any fine tuning yet, but using the cheapest, crappiest, dirtiest ammo I could buy (and not shooting for groups) I put 20 into about an inch at 100... can't wait to see what it'll do wihen I work up some loads...

Given what you're talking about, I'd stick with the 260..

I have a Sako Finnbear in 6.5X55, and a Steyr ProHunter in 6.5X57. The differance in velocity is about 75fps depending on the bullet weight. The 6.5X57 case if memory serves right has about a 3% greater volume. Reloading data for the 6.5X55 is generaly lower due to the many older Mausers and Krags still around. I really find very little differance between the two. I take either depending on the type of hunt, if a rough one I take the plastic stock Steyr. Both will shoot 1/2" groups with handloads.

If you are working with a short action, have you considered the 6.5-284, 6.5 SAUM, or 6.5 WSM? I have 4 rifles chambered in 6.5-284 and think that it is a nice cartridge and if you're starting with a 260, it is easy/inexpensive to rechamber to 6.5-284 without needing to set the barrel back. I'm happy shooting 120 grain BTs and 129 grain SSTs at medium game and 95 grain VMaxs at anything under 125 lbs.

Jeff

quote:

For now......I'll stay with the 260 Rem.

260remguy - no problems with the 6.5-284 on a 2.8" action? I figured you'd start having COL and capacity issues on the short magazines.

I'm shooting the 95 grain VMax, 120 grain BT, 125 grain Partition, and both styles of 129 grain Hornadys without any OAL issues. If I was using bullets over 140 grains, I might need to seat them deeper, but I'm only shooting coyotes and deer with my 6.5-284s, so the bullets that I'm using cover that spectrum of game without any trouble.

Jeff