The .257 Marksman (25 western)

[sierracharlie338]

Do it! Lol
It would be really cool to have more than just my data.

From what I've seen so far it's exactly what I wanted. If the barrel speeds up 50fps and I'm sitting at 3200 I'd say mission accomplished.

But realistically this is all doable with the 25-7 prc, just not in a short action.

Or like @hereinaz said similar to the 25sst, although maybe a bit faster? But then your into the Sherman dies and brass.

Hell I’d be tickled pink to be running at 3100 in a 20 inch barrel with 134s. Depending on how the rest of this year goes and the first couple weeks of Jan I may be getting a barrel spun up.

 

[WKR]

Hell I’d be tickled pink to be running at 3100 in a 20 inch barrel with 134s. Depending on how the rest of this year goes and the first couple weeks of Jan I may be getting a barrel spun up.

Are you a tikka or a 700 clone guy? I'm thinking 700 but can't remember?

 

[hereinaz]

Hell I’d be tickled pink to be running at 3100 in a 20 inch barrel with 134s. Depending on how the rest of this year goes and the first couple weeks of Jan I may be getting a barrel spun up.

Start buying more pink, cause you are gonna get tickled.

 

[sierracharlie338]

Are you a tikka or a 700 clone guy? I'm thinking 700 but can't remember?

Was a 700 guy for years. Started playing with the tikkas thanks to this place so either/or I guess at this point lol.

My wife unintentionally put me in a predicament this year after killing her first deer with my 25cm. She thinks she should get to keep it now!

So I have to decide where to go from there moving rifles around or building.

 

[WKR]

Looks like the Eld-m's are shooting a little better than the Bergers which surprised me.
I did break position between 3 shot groups. And had a lot of mirage coming off the suppressor.
I think when the barrel settles in and I use fire formed brass I will be able to tighten it up a bit.

 

[B23]

Any idea what case capacity is when necked to .257 I'm guessing it's just a sliver over what the 25 SAUM is and a little under what a 25 WSM would be.

My ADG 6.5 SAUM brass necked down to .257 holds exactly 73gr H2O.

I just got my ADG 270 WSM brass yesterday afternoon so I haven't had a chance to neck it to .257 and measure the case capacity but just guessing I think it'll hold around 79gr H2O but I'll know for sure here in a little while.

 

[WKR]

Any idea what case capacity is when necked to .257 I'm guessing it's just a sliver over what the 25 SAUM is and a little under what a 25 WSM would be.

My ADG 6.5 SAUM brass necked down to .257 holds exactly 73gr H2O.

I just got my ADG 270 WSM brass yesterday afternoon so I haven't had a chance to neck it to .257 and measure the case capacity but just guessing I think it'll hold around 79gr H2O but I'll know for sure here in a little while.

76.4 gr H20 ADG

 

[WKR]

Things are looking good with the 134's

 

[WKR]

Retumbo went 3220 at 67gr without any visible pressure or heavy bolt lift on virgin brass... definitely worth looking at. Accuracy potential is there too. This was 64-67gr in 1 grain increments

 

[Mike D Texas]

I have a 6.5 SAUM Improved that’s pushing 130 Terminal Ascents at 3250 with a 21” barrel.

I’m seriously considering having a barrel spun up for it in 25SAUM Improved.

It’s built on a Pierce SkeleTi action and the load port is long enough to run the UM short action BDM and still fit 3.150” in the magazine.


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[hereinaz]

I have a 6.5 SAUM Improved that’s pushing 130 Terminal Ascents at 3250 with a 21” barrel.

I’m seriously considering having a barrel spun up for it in 25SAUM Improved.

It’s built on a Pierce SkeleTi action and the load port is long enough to run the UM short action BDM and still fit 3.150” in the magazine.


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.25 is sweet, and you can keep much the same performance with a shorter barrel or cook it up faster. That 6.5 has to hammer critters.

What bullet would you shoot?

 

[Mike D Texas]

.25 is sweet, and you can keep much the same performance with a shorter barrel or cook it up faster. That 6.5 has to hammer critters.

What bullet would you shoot?

If I do the 25 SAUM Imp it would be the 134 LRHT most likely. They (LRHT in various calibers) are the most consistent bullet I’ve found in regards to drift/drop at really long distances out to 1 mile.

They line up perfectly with my Kestrel drops using advertised BC.

They seem to perform well on medium size game as well.


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[Robobiss]

This is really cool.

As someone who (like most hunters and shooters) has only ever messed with factory stuff, maybe paying for some light smithing, what does it cost to do something like this?

Like getting a reamer spec’d and made, all of it. Just for the sake of curiosity. It’s easy to price a prefit for a cartridge that exists and throw it in your cart to figure out how much it will cost to get, say, a 7PRC or 6 creedmoor Tikka. This is very obviously some next level stuff.

Assuming someone has an action laying around, and is motivated, what would this cost from the ground up like you did it? What would it cost now assuming someone can get their hands on your reamer?

 

[mtnbound]

Retumbo went 3220 at 67gr without any visible pressure or heavy bolt lift on virgin brass... definitely worth looking at. Accuracy potential is there too. This was 64-67gr in 1 grain increments View attachment 810160

I would also be curious to see if Staball HD would work. Around me the Staball line is almost always available.


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[hereinaz]

This is really cool.

As someone who (like most hunters and shooters) has only ever messed with factory stuff, maybe paying for some light smithing, what does it cost to do something like this?

Like getting a reamer spec’d and made, all of it. Just for the sake of curiosity. It’s easy to price a prefit for a cartridge that exists and throw it in your cart to figure out how much it will cost to get, say, a 7PRC or 6 creedmoor Tikka. This is very obviously some next level stuff.

Assuming someone has an action laying around, and is motivated, what would this cost from the ground up like you did it? What would it cost now assuming someone can get their hands on your reamer?

Barrel cost plus about $400 plus or minus for the chamber/thread job. The smith will return a shooting rifle.

You need to get the stuff to reload ammo. Another rabbit hole.

 

[WKR]

This is really cool.

As someone who (like most hunters and shooters) has only ever messed with factory stuff, maybe paying for some light smithing, what does it cost to do something like this?

Like getting a reamer spec’d and made, all of it. Just for the sake of curiosity. It’s easy to price a prefit for a cartridge that exists and throw it in your cart to figure out how much it will cost to get, say, a 7PRC or 6 creedmoor Tikka. This is very obviously some next level stuff.

Assuming someone has an action laying around, and is motivated, what would this cost from the ground up like you did it? What would it cost now assuming someone can get their hands on your reamer?

A finish reamer is around $320 for the tool itself. Then depending on the parent case and smith you use you might need a go gauge which was another $50, but if it was based on a more common case, it's likely the smith might already have one.

If it's your first design, if recommend reading a few books on wildcatting to get a better idea of chamber design and case interface. I read a couple with most information coming from PO Ackley. That man did it all, and most of his concepts still apply to the more modern cases of today.

I'd also recommend working with an experienced smith that will have time to talk about the dimensions and design.

So id say for the tools, minimum you would be into it will be $400. But if you are planning on changing the shoulder angle and body taper of a case, your costs could go up significantly. Then you have the associated costs of the thread and chamber job done by a smith. $400-$600 is the going rate today for a muzzle thread and chamber.

As far as renting my reamer, you'd have to pm me

 

[Unckebob]

As some of you guys know I've been putting together a wildcat, well it's here.

Purpose is a cartridge that fits good in a SA magnum launching the 130 class .257 projectiles at 3000 fps plus with a 20 inch or less suppressed rifle. Barrel life be damned

It's not anything too crazy, simply a 6.8 western necked down to 25 cal and the reamer was designed behind using the new ADG brass, freebore was set up to run the 133 Bergers and 134 eld-m's inside a short action magnum keeping the bearing surface up above the unsized portion of the neck.

Initially I was going to reduce body taper and take the shoulder to 40° but decided against that so I can use the parent case dies rather than going to custom dies. Also with the parent case already having 35° shoulders and .555-.539 from the .200 line to shoulder, I want to see what I can get out of it before I decided to go the "improved" route.

I will update the thread as I go. I am open to renting the reamer.

Excuse my ignorance, but how do you use the existing dies alone to create a 25 cal version?

 

[WKR]

Excuse my ignorance, but how do you use the existing dies alone to create a 25 cal version?

Full length size bushing die with the appropriate bushing diameter

Micrometer seating die with a 25 cal seating stem in place of the 27 it came with.