Has anyone tried this?

[Tangent]

Has anyone tried necking down a 260 Remington to 25cal and used a 135gr Berger hybrid? Gives equivalent G7 BC to the 6.5mm 144gr hybrid with less recoil. I know 25 Souper, but it just seems easier from a 260 Remington case. A 260AI down to 25cal looks even more interesting...

 

[brxlefty]

I have not played with the 25 Cal yet but the 6.5 135 Atip are really close to the Berger 144s! I am pushing them 2920 in a 1-9 twist 6.5-47 with Varget and cci 450s. I have those bullet at 3331 ft and 189 ft in elevation and it shoots the same groups!That is 3 shots at 600 yds! The load has agg 2.09” in a match!

 

[357Mag]

Has anyone tried necking down a 260 Remington to 25cal and used a 135gr Berger hybrid? Gives equivalent G7 BC to the 6.5mm 144gr hybrid with less recoil. I know 25 Souper, but it just seems easier from a 260 Remington case. A 260AI down to 25cal looks even more interesting...

Tangent -

Howdy !

Trying to form a notional .25” cal wildcat case from .260AI parent brass would be problematic, IMHO.

The sharp Ackley Improved shoulder angle would present at least some challenge in the
mechanical case forming process; towards arriving @ the desired final .25” calibre.
I am wondering how far downward on the neck, one could truly size the OD to; because of things like die or bushing entry hole sizes…. where the sizing takes place.

Another consideration would be whether the chosen / existing “ .260AI brass “ had enough starting neck wall thickness to still provide the desired amount of final neck wall thickness…. after necking it down to .25” cal? How thick do you want the final neck walls to be ?

I say this because -
I formed some sample 6.5mm wildcat brass for a shooter in NZ, who hunted Tar on the South Island. He wanted fairly thick neck walls for his wildcat…itself a design that had some features of both the 6.5 X 47L and the 6.5Creedmoor. The first case tried was .260 Remington, but the final formed wildcat had neck walls thinner than the shooter wanted.

When trying to form same wildcat cases from 7-08 brass, the final formed cases still had too thin case neck walls; to meet the shooter’s desired spec.

The brass shortage/hording was in fulll swing @ the time, and no virgin .308 Win brass could be sourced. I was able to source .358Win brass, and the subsequent multiple calibre neck-downs resulted in wildcat cases/ thick enough neck walls to permit
neck “ turning “ the the final thickness sought.

YRMV.


With regards,
357Mag

 

[358WCF]

Has anyone tried necking down a 260 Remington to 25cal and used a 135gr Berger hybrid? Gives equivalent G7 BC to the 6.5mm 144gr hybrid with less recoil. I know 25 Souper, but it just seems easier from a 260 Remington case. A 260AI down to 25cal looks even more interesting...

During the last panic, there was no 257 Roberts brass to be had. I scored some PPU 6.5x57 & necked it down successfully for a 257 Ackley Roberts. Same neck dimensions/changes as your project. It made positive headspacing easy since I was necking down & left a small hump at neck/shoulder junction. It's only .007" O.D. change & neck turning wasn't necessary with my chamber. Unsure where you would find 260 Ackley brass.

I have a 22BR arriving any day now, the next rifle will (finally) be a 280 Ackley followed by a 25 Souper if I can find a push feed Model 70 short action. I'm staying awake tonight to grab some Lapua 260 brass on sale after midnight in anticipation of the Souper... maybe in a year or so, as SS isn't keeping up with cost of living very well.

 

[Tangent]

Tangent -

Howdy !

Trying to form a notional .25” cal wildcat case from .260AI parent brass would be problematic, IMHO.

The sharp Ackley Improved shoulder angle would present at least some challenge in the
mechanical case forming process; towards arriving @ the desired final .25” calibre.
I am wondering how far downward on the neck, one could truly size the OD to; because of things like die or bushing entry hole sizes…. where the sizing takes place.

Another consideration would be whether the chosen / existing “ .260AI brass “ had enough starting neck wall thickness to still provide the desired amount of final neck wall thickness…. after necking it down to .25” cal? How thick do you want the final neck walls to be ?

I say this because -
I formed some sample 6.5mm wildcat brass for a shooter in NZ, who hunted Tar on the South Island. He wanted fairly thick neck walls for his wildcat…itself a design that had some features of both the 6.5 X 47L and the 6.5Creedmoor. The first case tried was .260 Remington, but the final formed wildcat had neck walls thinner than the shooter wanted.

When trying to form same wildcat cases from 7-08 brass, the final formed cases still had too thin case neck walls; to meet the shooter’s desired spec.

The brass shortage/hording was in fulll swing @ the time, and no virgin .308 Win brass could be sourced. I was able to source .358Win brass, and the subsequent multiple calibre neck-downs resulted in wildcat cases/ thick enough neck walls to permit
neck “ turning “ the the final thickness sought.

YRMV.


With regards,
357Mag

Howdy 357Mag. That sounds interesting and quite a lot of work. How about making the 25-260 first then fire forming to an AI version?

As you may tell I've never tried any of this but I know there's nothing new under the sun and if anyone has it's probably someone on here! In my case, I have a perfectly good 260 load but I'm always wondering if it could be improved. As brxlefty said there is the 135gr A-Tip but at £1 each over here that's a bit steep.

 

[muleystalker]

To me the easy button is the 25-6.5 PRC, strait neck down, there are dies available or you could also use a 6.5 bushing die with the appropriate bushing. Also there are seating dies available. It will shoot as fast and faster than a 25-260. Great brass available. I know it takes a magnum bolt face but thats easier than forming a bunch of 260 brass to 260 AL then necking down to .25 cal.

 

[Tangent]

To me the easy button is the 25-6.5 PRC, strait neck down, there are dies available or you could also use a 6.5 bushing die with the appropriate bushing. Also there are seating dies available. It will shoot as fast and faster than a 25-260. Great brass available. I know it takes a magnum bolt face but thats easier than forming a bunch of 260 brass to 260 AL then necking down to .25 cal.

Yes, I suppose that makes a lot of sense if you want to step up in velocity. A slight step down to 25x47 may also be a good option too.

 

[Albany Mountain]

Or neck up a 243 Winchester who's existance is probably why the 25 never caught on.
per AI,
"25 08" is the name for a wildcat cartridge, also known as the 25 Souper, that was developed from the .308 Winchester case. It is a .25 caliber cartridge for short-action rifles, but it is not a common factory round, requiring handloading for use. It is favored by a small group of enthusiasts for its versatility in hunting varmints and medium-sized game.

 

[Kracken McGraw]

No one can mention Creedmoor. lol!

 

[SVT_Tactical]

6.5 creedmoor, 260 remington, 6.5x47 Lapua.... all so close in performance the decision is personal, same would apply to 25x47 Lapua, 25 Souper, 25 Creedmoor. Comes down to what components you might already have or bushing dies already set up.

If you AI the 260/25Souper that puts it ahead by a good bit. And you get the benefit of not having to trim brass as much with the AI versions .

I've shot 25 Creedmoor, 25x47, and 25SAUM Imp. And have all three still. 25 creed is a bean field hunting rig, 25x47 is my heavy gun for IBS long range, and 25 SAUM Imp is a lightweight walking hunting rig.

 

[JRanum]

The 257 DGR is what youre looking for. 260 Remington necked down and fireformed with slightly steeper shoulder. I had one built before we have the heavies we do now so I only shoot 100s and 115g

 

[dave7mm]

Has anyone tried necking down a 260 Remington to 25cal and used a 135gr Berger hybrid? Gives equivalent G7 BC to the 6.5mm 144gr hybrid with less recoil. I know 25 Souper, but it just seems easier from a 260 Remington case. A 260AI down to 25cal looks even more interesting...

The 25/260 SLR is your Huckleberry....
One stroke of the case in a proper die.
And you have a net shape case fitted to your chamber ready to fire and no fire forming.
Pretty much a
6.5x47 neck and shoulder on a 260 case .Necked to 25...
You will end up with a bit of the thicker shoulder material in your neck.
But a light turn job will eliminate that.
And you don't have to fire form it to get your case.........

 

[CJ6]

No one can mention Creedmoor. lol!

What's that??

 

[10XSHOOTER]

25/260AI
Chamber barrel. neck down brass and fire form!
trick will be to get dies!

 

[B23]

Nothing against the 260 or one of the many different brothers from another mother the "improved" versions but why improve the 260 when you can just do a 25-284. Even if it's run at 260 COAL in a short action you still have more usable case capacity then the 260 Improved but with less work easy to obtain dies and no FF brass.

 

[21PHX]

How about .250 Ackley?? Dues are available, brass is no problem(.22-250 necked up or .250 Savage if available or make it from others). I have one and it’s me favorite of my 4 .25 caliber rifles.

 

[Tangent]

Some great ideas. If only I had the time and money to try them all! I think if you're hunting some of the hotter options could be great but barrel life might not be too long for target work.

 

[B23]

Some great ideas. If only I had the time and money to try them all! I think if you're hunting some of the hotter options could be great but barrel life might not be too long for target work.

True true!

Hunting rifle 25-284 to me is the easy button but something more in the line of a higher mileage target work kind of setup I'd probably look at necking up Lapua 6GT to .257 or neck down Lapua 6.5x47 to .257 either a 25GT or 25x47 shooting any of those 131-135's would likely make for a pretty sweet and easy not to mention soft shooting target rifle with some pretty long legs. Depending on barrel length and powder used I'd imagine either of those could get real close or into the 2900fps range.

 

[dave7mm]

Some great ideas. If only I had the time and money to try them all! I think if you're hunting some of the hotter options could be great but barrel life might not be too long for target work.

L to R
6.5 GT
6.5x47
6.5 Manbun
6.5 SLR

Only one I haven't shot is the manbun
Any of them could be a 25.
All it takes is money

Dave

 

[muleystalker]

Yes, I suppose that makes a lot of sense if you want to step up in velocity. A slight step down to 25x47 may also be a good option too.

You can run the 6.5 PRC case at 260 AI velocity very nicely with no ill affects and certainly some positive ones.