6.5 x 57 Mauser Improved??

[SteveLC]

I shoot a 7x57 Ackley Improved in an old Rem 722. It shoots so well I got to thinking what if that case was necked down to 6.5. Well I look in quickload and opened the 6.5x57 mauser,then made the changes to case capacity to reflect the Ackley Imp equivalent of my 7x57. Looks like it would push a 142 gr Sierra over 3000fps w/o exceeding 55K Chamber pressure, and using less powder than my 6.5-284 Shehane to get there. My interest is really in pushing a 123gr scenar hard though, and looks like it would drive the 123 at 3300fps or so. Norma makes 7x57 brass so that is not a stopper. It is expensive, but everything in this hobby is. The experience I have with the 7mm version makes me believe it would perform as well or better as a 6.5. My groups with the 7 average around .2MOA. ES has also been very good with that round. Anyone ever tried this or read about it? I'm sure it would be a bit hard on barrels, but a 123gr Scenar is as good or better in the wind, with less drop than my 6.5-284 at 2950fps where I shoot it. Opinions????

Steve

 

[2644ever]

Tried one, used a 260 Ackley Improved reamer, had the body taper altered in order to match the diameter of the 257 Roberts case head at the same length. You can use 6mm Rem, 257 Rbts, 7mm & 8mm Mauser brass, it works real good and you should get 62 grain of water capacity,quite close to the 6.5-284 and a lot cheaper). It's also an alteration I would recommend for a very tired .260 Rem barrel...

 

[SteveLC]

Thanks for the reply. 62 grain capacity is what I have input in QuickLoad to calculate the velocities. Actually, when I take a closer look, it uses only a grain or 2 less powder than the 6.5-284 but still intrigues me. Like many here, I like to try different things just for kicks, and to learn in the process.

Steve

 

[Spotcheck_Billy]

With no insult intended - what makes you think that you can get a 123 Scenar going at 3300MV with this cartridge without resorting to excessive chamber pressure loads? Having a 123 Scenar shoot flatter and take less wind from this cartridge than a 139 scenar from a 6.5-284 with both loadings at equal pressures seems to be a pipe dream! I've found,at considerable expense) that there's never something for nothing in this game!

Just my .02

 

[SteveLC]

Well, I don't think it. I only stated what QuickLoad tells me would happen. The reason for the post is exactly that, and how can this be? No offense taken. There must be a downside here, but to say that it's a "pipe dream" without facts is pointless. The 6XC does exactly the same thing to the 243. Less powder, similar performance. It does happen, and it happens when ideal cartridge dimensions match up with bore diameter and bullet weight. My question was for someone that has used the cartridge to relay their experience.

QuickLoad data:
6.5 x 57 Mauser,case capacity modified to 62 grains reflecting Ackley Improved case)
123gr Scenar
55.5gr Norma MRP
Chamber pressure 50644
Velocity w/28" barrel 3304fps

6.5-284
123gr Scenar
57.8gr Norma MRP
Chamber pressure 48788
Velocity w/28" barrel 3305fps

My point was not that it took less pressure, but less powder,2.3 grains) to achieve the same performance and uses a case that has performed very well for me. I have seen QL be wrong on some of these calculations, but it is still intriguing.

Steve

 

[2644ever]

Well, it is certainly possible to reach 3300 fps with a Scenar 123 in a 6.5X57 Imp with MRP but you'll have a very high loading density, you'll probably need a drop tube and it's definitely critical to use only Moly or WS2 coated bullets.
It could be possible to reach these velocities with H 4831 SSC or H 1000 but at the cost of excessive pressure.
MRP is the best choice for this combination of bullet and case if speed is your goal.

 

[SteveLC]

Speed is not the primary goal, and I figured on a drop tube using some of the loads being calculated. I'd be impressed with 3100-3200 fps. The wind drift and drop chart with the 123 scenar at these speeds are impressive even out to 1000 yds. My interest is out to 600 yds though.

 

[RickB]

What you have described is known as the .260 AAR,All Around Rifle). I have not shot one, but a friend had one and was pleased with it. He used heavier bullets and so I can not comment on the possible velocities with the 123 gr Scenar. It was, I believe, mentioned in the Ackley Book. You may be able to find some off the shelf dies for it somewhere.

 

[SteveLC]

I have seen dies for the non improved version, but can't find any 6.5x57 Ackley, or Improved dies. I have a 7x57 Improved die made custom by Redding. I'm thinking I could spec a reamer the same as the 7 AI, and use a different bushing to do the sizing on the 6.5. Seating could be done a number of ways, but would probably have the 'smith use a Wilson blank and chamber a seater for the arbor press. 260 AAR?? I will do some searching with that name, and see what I find. Was that rifle in an improved chamber? Thanks for the info.

Steve

 

[RickB]

I have seen dies for the non improved version, but can't find any 6.5x57 Ackley, or Improved dies. I have a 7x57 Improved die made custom by Redding. I'm thinking I could spec a reamer the same as the 7 AI, and use a different bushing to do the sizing on the 6.5. Seating could be done a number of ways, but would probably have the 'smith use a Wilson blank and chamber a seater for the arbor press. 260 AAR?? I will do some searching with that name, and see what I find. Was that rifle in an improved chamber? Thanks for the info.

Steve

The seater is the easiest part of it. Just have the 'smith who chambers the barrel run the very same reamer into a seating die for the 6.5x57 and there you are. My favorite for custom seaters is the Forster Benchrest Ultra. They are a good solid die and the aluminum inserts are easily machinable. If you don't have the right insert, just use a piece of aluminum bar stock. You can either get the correct diameter seating stem or make a free floating piece which is actually better.

 

[NeilNE]

I had a 6mm Rem. case necked up to 6.5 and improved the case. Thought no one had done it. Well the 6 Rem. is made off the 7x57. I made it for a silhouette gun about 8 or more years ago. Have not shot it much. I posted a note when someone else was asking about it. I think I was getting about 27?? with 155 Sierra's.

 

[RickB]

I had a 6mm Rem. case necked up to 6.5 and improved the case. Thought no one had done it. Well the 6 Rem. is made off the 7x57. I made it for a silhouette gun about 8 or more years ago. Have not shot it much. I posted a note when someone else was asking about it. I think I was getting about 27?? with 155 Sierra's.

Assuming that you had an 8 twist barrel I would guess that you were pretty close to 2800 fps,or above it) if the 155 gr Sierras grouped well.

 

[rhino]

6.5x57 improved your running at near 6.5x.284 case capacities maybe 3 grains less or so.

It maybe worth it if you can afford to run RWS brass. However most use Lapua and the 6.5x.284 or in my case the 6.5x55 SE. Yes I can get it up to 3k fps no sweat!

RHINOUT!

 

[SteveLC]

I agree it is near 6.5-284 capacity. I was only looking at the calculated performance and thinking, "I wonder if this would work?". Like I said the 7x57 Improved I currently shoot shoots really well, and is more accurate than any 6.5-284 rifle,3 of them) I've built. 3 grains difference may only mean a tiny bit of extended barrel life, and that wasn't my main objective, nor was saving the few cents I might save on the few grains of powder. Mostly it's just something different, hopefully more accurate, and I like to play with the more efficient cartridges, even if it's just barely.

Steve

 

[rhino]

.260 AI if you want a sharp shoulder. GIve you about same case capacity as 6.5x55SE and works in a short action.

Or 6.5x55 AI

6.5x57AI would probally shoot very well. Just more costly for good brass.

RHINOUT!

 

[SteveLC]

Yep, I have a 260AI, but can't get to the velocities that others can. Not sure why. It shoots Ok for what it is, and the velocity wasn't important to me as it is just a deer rifle for shots to 300 yds. My buddy shoots the 6.5x55 and it shoots exceptional also, with better velocity than the 260, but short of QL predictions for the 6.5x57 Imp case. The Norma brass I currently use seems high enough quality. It is expensive, but should last many loadings.

Steve

 

[RickB]

Yep, I have a 260AI, but can't get to the velocities that others can. Not sure why. It shoots Ok for what it is, and the velocity wasn't important to me as it is just a deer rifle for shots to 300 yds. My buddy shoots the 6.5x55 and it shoots exceptional also, with better velocity than the 260, but short of QL predictions for the 6.5x57 Imp case. The Norma brass I currently use seems high enough quality. It is expensive, but should last many loadings.

Steve

What sort of velocity were you able to achieve? The 6.5s normally "like" slow powders...4350 and slower with any of the heavier bullets in my experience. There is always the possiblity that you simply have a "slow" barrel, but that is somewhat rare.

 

[rhino]

my powder of choice for the 6.5x55 is VIN N560. Since your .260AI has almost identical case capacity try working up from 47.5 grains. I got a 28 inch barrel and with 49.6grains of VIN N560 I get 2950 FPS.

I will be going to a 30 inch tube soon. VIN N560 and Reloader 22 work well as well as Norma MRP...when you can find it.

PMC/Wolf/Russian primer and your good to go!

I shoot molyed 140 VLD Bergers at 2950.

RHINOUT!

 

[SteveLC]

Using 4350, and Nosler 120BT's I couldn't get over 2900 fps without serious pressure. 44.5 grains of 4350 was failing some cases on their second firing, and yes headspace was checked, and all seemed well there. I plan to start over with Lapua or RWS brass, and see what I can get it to do. I only have a 24" barrel as it is to be a carry deer rifle, and the velocity with that short barrel was pretty close to QL calculations. I am just not able to maintain brass at the high end loads. Getting it to shoot reasonable groups in a slower node required I drop to <2800fps. I did try some Varget as well because of the barrel length, and had about the same results. If it shoots well, and brass life is good at 2800fps then I guess that's what I will live with. BTW, the rifle is built on an old Mk X action, trued and Pac Nor barreled, pillar bedded on a Fajen stock. I had higher expectations than I have gotten from the chambering so far. Of course the action has limitations, but I have first hand experience with some that shoot extremely well.

Steve

 

[rhino]

AAH yes, 24 inch tube you can't get that velocity. 2800 fps is about what I get maybe 2850, I can get 2900 fps with 51.6 grains of VIN N560...this is hot though and primer pockets get toasted after maybe 3 firings.

28-30 inch tubes no probelmo with 3000fps.

RHINOUT!