25-06 short barrel specs

[Keechi Kid]

I have decided to do something a bit different with a Mauser action I had sitting around. It’s an old Sears model 50, so it’s an FN commercial action that was chambered in 30-06.

I want to play around with pushing the Hornady 257 134 gr ELD-M bullet. I want to have it on the shorter side of things and threaded for a silencerco scythe.

I’m currently thinking a 25-06 1:8 twist and 17” threaded 1/2x28. I’m not certain what contour to have it profiled at though. Would like to make it as light as can be done reasonably.

Curious what thoughts people may have for how to do a modern quarter bore on a standard length Mauser.

 

[Koda_]

Look up the stability factor for the bullet you want....

I would go with a 7 twist for the .257 heavies.

 

[Keechi Kid]

I may do 1:7 twist.

 

[TxLite]

I like the path you’re on. I think it’ll be a sweet setup.

Who makes stocks for Mausers? Boyd’s? Not sure what weight you’re looking to hit in your quest for light weight but that may be hard to achieve when starting with a Mauser vs something with more aftermarket availability

 

[Rippey715]

I don’t think 25-06 with the new heavy bullet options is going to be able to perform that well or at least it will be harder and more round about than other options.

25-06 is designed around seating lighter bullets deeper into the case and velocity above 3k. Short barrel means you’re not going to get that velocity. New bullets are specifically heavier for better accuracy. They are meant to be seated long and have more free bore and jumped.

To shoot the new heavies, go shorter barrel, and maintain velocity you’d probably need to look at the 25PRC or SAUM. BUT you have a Mauser action and standard bolt face and that is bad ass.

So from real world experience; I have a friend that has modernized a 250 Savage to shoot the 134s and run them up to 3k. Built a dummy round and throated the chamber until it had plenty of jump. It shoots great and you can buy virgin 250 Savage brass.

A Mauser shooting modern 250 Savage would be pretty badass.

Good Luck

 

[Keechi Kid]

On the stock, I will probably try to find one of the Mauser gunsmiths having carbon fiber stocks made on their molds.

As to the chamber, I hadn’t really thought that far into the throating. May have to see about what I can do different there. Looking at Gordon’s reloading tool, 17” should let me start it pretty close to 2700 fps with RL26

 

[Keechi Kid]

Would a 25-06 AI chamber help with chamber throat geometry?

 

[Koda_]

Not certain what you mean by chamber geometry, but it will help add velocity because youll have more case volume. You need to keep the long bullet in front of the case shoulder area....

Im getting just over 3100fps with a 127gn HHT Hammer bullet, 7 twist, long throated, 26in bbl, 25-06ai chamber.

If you stay with the 25-06 caliber I do recommend ackley improving it. IMO throating long is essential to maximise case volume for velocity.

Its worth noting, the long heavy 257 bullets also have high sectional density for excellent penetration if thats an interest to you.

Look up the ballistics of the bullet you want in a ballistic calculator, with 3000fps muzzle velocity. You will be impressed at the downrange improvement. I think its well worth it to go heavy with the 25-06... but you have to maximize its velocity potential. I think with the right build choices you should be able to safely get at least 2900fps MV with the 130gn or heavier 257 bullets.

 

[Keechi Kid]

High sectional density ELD-M bullets are all I’m using for hunting now. Most of my shooting is shorter range while on foot stalking, so I can accept the lower velocities in order to have a handier rifle. Will be using it with a scythe on the end, so 17” barrel will have me around 23”

 

[sierracharlie338]

I don’t think 25-06 with the new heavy bullet options is going to be able to perform that well or at least it will be harder and more round about than other options.

25-06 is designed around seating lighter bullets deeper into the case and velocity above 3k. Short barrel means you’re not going to get that velocity. New bullets are specifically heavier for better accuracy. They are meant to be seated long and have more free bore and jumped.

To shoot the new heavies, go shorter barrel, and maintain velocity you’d probably need to look at the 25PRC or SAUM. BUT you have a Mauser action and standard bolt face and that is bad ass.

So from real world experience; I have a friend that has modernized a 250 Savage to shoot the 134s and run them up to 3k. Built a dummy round and throated the chamber until it had plenty of jump. It shoots great and you can buy virgin 250 Savage brass.

A Mauser shooting modern 250 Savage would be pretty badass.

Good Luck

So why would a 250 savage handle them and not a 25-06? I don’t believe 15ish bullet grains will be a deal breaker since the 25-06 has about 20 more gains of case capacity.

 

[sierracharlie338]

I have decided to do something a bit different with a Mauser action I had sitting around. It’s an old Sears model 50, so it’s an FN commercial action that was chambered in 30-06.

I want to play around with pushing the Hornady 257 134 gr ELD-M bullet. I want to have it on the shorter side of things and threaded for a silencerco scythe.

I’m currently thinking a 25-06 1:8 twist and 17” threaded 1/2x28. I’m not certain what contour to have it profiled at though. Would like to make it as light as can be done reasonably.

Curious what thoughts people may have for how to do a modern quarter bore on a standard length Mauser.

Do it. You won’t be disappointed. I built a 257roberts AI and love it. You definitely want to go with a 7 twist for optimal results.

 

[Rippey715]

Heavier bullets are longer than the traditional bullet options for 25-06. They are also made to be seated longer than a traditional 25-06. Bearing surface and ogive are very different in the longer bullets which can effect seating depth depending on the chamber. There’s no reason in trying to run a heavier bullet with a longer bearing surface if you have to jam it down into the case and start losing case capacity. Like running a 88 or 90gr Berger in 223 Remington. Totally doable but you have to throat the chamber to get the benefit of the longer heavier bullets.

I shoot 25 Creedmoor. It’s easy button. reach 25-06 velocity with less powder, less recoil, bullets seated long, and mag fed.
Again, 25-06ai slinging heavies would be cool, but it will be extra steps to achieve what some short action rounds are already doing.

As to twist, Hornady has minimum of 1:8 printed on the box. General consensus seems to be somewhere between 7-7.5

 

[Pickettpuncher]

Heavier bullets are longer than the traditional bullet options for 25-06. They are also made to be seated longer than a traditional 25-06. Bearing surface and ogive are very different in the longer bullets which can effect seating depth depending on the chamber. There’s no reason in trying to run a heavier bullet with a longer bearing surface if you have to jam it down into the case and start losing case capacity. Like running a 88 or 90gr Berger in 223 Remington. Totally doable but you have to throat the chamber to get the benefit of the longer heavier bullets.

I shoot 25 Creedmoor. It’s easy button. reach 25-06 velocity with less powder, less recoil, bullets seated long, and mag fed.
Again, 25-06ai slinging heavies would be cool, but it will be extra steps to achieve what some short action rounds are already doing.

As to twist, Hornady has minimum of 1:8 printed on the box. General consensus seems to be somewhere between 7-7.5

You still didn’t answer the question, why would a 250 savage handle it better than a 25-06. It’s not like the 250 savage was built for heavies. Both would need to have extra freebore to maximize case capacity. I too shoot a 25cm, but I’m not getting anywhere near 25-06 velocity. I have a 20” barrel and OP is wanting a 17”. The biggest issue I see with using a 25-06 sized case is mag length if he decides to have the freebore extended.

 

[Dave Thomas]

He is having it built, so he can have it throated any way he wants. The 2506 has more case capacity than the creedmore or the 250 savage. So why would those other 2 be a better option?

 

[Keechi Kid]

Would certainly need to be throated longer. For magazine I’m thinking I will do a blind mag setup. With that plan my figuring is it’s going to have to be built purely for this rifle anyways, so having it formed longer shouldn’t be anymore of an issue than standard length. That could turn out to be a larger issue than I’m anticipating though.

That’s largely why I started this thread. See what issues people point out I may not have thought of yet.

 

[sierracharlie338]

Would certainly need to be throated longer. For magazine I’m thinking I will do a blind mag setup. With that plan my figuring is it’s going to have to be built purely for this rifle anyways, so having it formed longer shouldn’t be anymore of an issue than standard length. That could turn out to be a larger issue than I’m anticipating though.

That’s largely why I started this thread. See what issues people point out I may not have thought of yet.

You won’t have any issues. I have a 30Nosler in a BDL mag set up and I can load them longer than the chamber will allow.

Wyatt’s extended mag box will give you plenty of room for the heavies. I’d highly recommend getting in contact with a quality gunsmith, talking over your goals and they will point you in the right direction as far as reamers go.

 

[Rippey715]

I was thinking about seating long and mag length with the 25-06. It would defeat the velocity if the free bore meant you had to seat so deep into the case you lost the velocity. Quick google shows new 131-135gr options are .3-4” longer than classic 85-110 options for example.

250 or CM is more about me thinking of the advantages of using a short action cartridge in a long action.

 

[khuber84]

The 2506 holds around 65-66gr capacity, plenty of juice to run a 134 eldm at 3000fps. It also has a 0.310 long neck, 140k freebore would be plenty for the long heavies. I personally would ackley improve the case, as it gets you a boost in capacity, but also case growth upon firing is FAR less, and the neck becomes even longer. It's basically a 25 prc at that point. If you desire to be different, go that route.

 

[Keechi Kid]

The 2506 holds around 65-66gr capacity, plenty of juice to run a 134 eldm at 3000fps. It also has a 0.310 long neck, 140k freebore would be plenty for the long heavies. I personally would ackley improve the case, as it gets you a boost in capacity, but also case growth upon firing is FAR less, and the neck becomes even longer. It's basically a 25 prc at that point. If you desire to be different, go that route.

I understand the concepts but don’t have the knowledge to know the actual numbers and measurements I would need for throating for the 134’s. Your opinion is the saami chamber is sufficient?

 

[Koda_]

I understand the concepts but don’t have the knowledge to know the actual numbers and measurements I would need for throating for the 134’s. Your opinion is the saami chamber is sufficient?

Forgive me for interjecting, but I recently had to do this with my 25-06ai build. You dont have to know the throat dimensions, all you need is to chose your seating depth on a dummy round....

Its not difficult, but what I did was order a sample pack of the bullet I wanted to use, this is the bullet the gun will be build around... but it will still shoot most others that are shorter. Then I created a blank/dummy round at the maximum coal that would fit and cycle in my magazine. This of course will not fully chamber or close the bolt on, but I could see if it would start into the chamber you want to assure it will feed. From there I seated it deeper in small increments until it properly engaged the neck of the case. Holding a separate bullet by its side lined up tells you how much your protruding into the case.
How deep into the case is your personal preference: I prefer the heel of a flat base bullet not to protrude past the first shoulder junction on the case. Boatails I let protrude deeper but the where the boattail begins I also prefer to keep at the first shoulder junction.
It doesnt have to be perfect, you will still be able to play with seating depth during load development.
When done, you send this dummy round with the build for the gunsmith to throat the chamber deep enough to chamber your dummy round without sticking the bullet with the bolt fully closed.

Note: you can do this with a standard case will work the same even if your ackley improving the chamber.

Here is a pic of my test, I did 3 dummy rounds to compare but went with the seating depth on the far right in the pic.