Quarter Bore Resurgence

[sapper299]

Love the Roberts, have 3 of them, But have always wanted something more. Bullet selection has always been the 25s enemy, but I see now that Berger has a 133gr Elite Hunter [0.613] and 135gr Hybrid [0.650] that look to be game changers. Yes they require a faster twist, but seeing these has rekindled my desire for a custom 25 something...

I'm looking for cartridge suggestions. The gun I am thinking about about is an old Winchester XTR Featherweight. Its got the longer action, but the short little box magazine. I'm not married to it, but its what I have on the shelf to start with, and I love model 70s. I see this as a target/competition gun, and also a long range hunter, deer/sheep/goat sized stuff.

Efficiency and barrel life is important, velocity is secondary. With 0.600+ BCs one can easily live with a little less speed. I am trying to come up with a cartridge list, 25x47 Lapua, 25 Creedmoor, 250 Savage, 250 Ackley, 25 WSSM, 25 Souper, 257 Roberts, 257 Ackley, 25-284, 25 PRC, 25 SAUM, 25 WSM, 25-06. What others am I missing? Any recommendations?

The 25-284 looks just tremendous! 3100fps+ with 135gr 0.650 BC looks other worldly, but is going to be hard on barrels.
250AI looking very close at. Can seat long bullets out and not intrude in the powder space. Decent brass, but requires a fireform.
Likewise the 257AI, but I worry a bit about seating depth with a long heavy bullet?
PRC, SAUM, WSM etc all seem like overkill and barrel burners.
Creedmoor, Souper and 284 all have great brass, and I believe just a die sizing, that's a plus.

I don't really know what I want exactly, looking for thoughts & experiences.
I've got lots of stuff, and don't really need another gun or cartridge to reload, but that's not the point right?

Thanks for any input.

I just finished another .257 AI in a 1-8 twist Brux barrel on a long action. The seating issue is addressed by Blackjack in making the reamer throat .131" long. Seats the 131 out where it needs to be and allows a full case no problem. Should be the same for the Berger bullets.

 

[FNSafari]

Love the Roberts, have 3 of them, But have always wanted something more. Bullet selection has always been the 25s enemy, but I see now that Berger has a 133gr Elite Hunter [0.613] and 135gr Hybrid [0.650] that look to be game changers. Yes they require a faster twist, but seeing these has rekindled my desire for a custom 25 something...

I'm looking for cartridge suggestions. The gun I am thinking about about is an old Winchester XTR Featherweight. Its got the longer action, but the short little box magazine. I'm not married to it, but its what I have on the shelf to start with, and I love model 70s. I see this as a target/competition gun, and also a long range hunter, deer/sheep/goat sized stuff.

Efficiency and barrel life is important, velocity is secondary. With 0.600+ BCs one can easily live with a little less speed. I am trying to come up with a cartridge list, 25x47 Lapua, 25 Creedmoor, 250 Savage, 250 Ackley, 25 WSSM, 25 Souper, 257 Roberts, 257 Ackley, 25-284, 25 PRC, 25 SAUM, 25 WSM, 25-06. What others am I missing? Any recommendations?

The 25-284 looks just tremendous! 3100fps+ with 135gr 0.650 BC looks other worldly, but is going to be hard on barrels.
250AI looking very close at. Can seat long bullets out and not intrude in the powder space. Decent brass, but requires a fireform.
Likewise the 257AI, but I worry a bit about seating depth with a long heavy bullet?
PRC, SAUM, WSM etc all seem like overkill and barrel burners.
Creedmoor, Souper and 284 all have great brass, and I believe just a die sizing, that's a plus.

I don't really know what I want exactly, looking for thoughts & experiences.
I've got lots of stuff, and don't really need another gun or cartridge to reload, but that's not the point right?

Thanks for any input.

See if you can find a good gunsmith that can put the parts in so as to comfortably accept and feed 257 Roberts cartridges successfully you would also need to check the length of you free bore as that might need lengthening with a throating reamer.

 

[SweaterDood]

See if you can find a good gunsmith that can put the parts in so as to comfortably accept and feed 257 Roberts cartridges successfully you would also need to check the length of you free bore as that might need lengthening with a throating reamer.

Blackjack recommends a 0.131” freebore for 25crud and 25x47L. My 257AI reamer was spec’d with 0.150” freebore from Manson to run OAL @ 3.200” with .020” jump. Keep in mind that neither of these will fit in a short action. Mauser, XM, or Long action will be needed to efficiently utilize the Mauser/Roberts case.

 

[FNSafari]

I thought you were talking about an old Winchester Model 70 XTR action.

 

[Kevin Taylor]

Don’t know how I missed this thread. Don’t know enough to help, but I do like the cartridge!

 

[SweaterDood]

Another option that I don’t believe has been mentioned yet, and one that I am also strongly considering for myself, is a 25 GT. Better barrel life than a 25 CM, faster than a BR/Dasher, just as consistent as the BR/Dasher, and good quality brass without fireforming. Should get you to ~2900fps from a 24-26” barrel with the blackjacks or new Berger offerings.

They don’t have a reamer yet, but I spoke with Patriot Valley and they were interested in adding the chambering. I also heard a rumor that Alex Wheeler may have already spun up a barrel on a 25 GT.

Or with the longer model 70 action, just have a longer mag box installed and build a 25 Souper so Std7Mag gets jealous...

 

[p-man]

The CM is very, very close to the 250 Savage Improved 30-degree; the 250 Savage Ackley Improved is a 40-degree shoulder and has a little more case capacity.

 

[2moreclicks]

Manson got a 25GT ace reamer spec with a 155 freebore. If that help you

 

[SweaterDood]

Another option that I don’t believe has been mentioned yet, and one that I am also strongly considering for myself, is a 25 GT. Better barrel life than a 25 CM, faster than a BR/Dasher, just as consistent as the BR/Dasher, and good quality brass without fireforming. Should get you to ~2900fps from a 24-26” barrel with the blackjacks or new Berger offerings.

Or with the longer model 70 action, just have a longer mag box installed and build a 25 Souper so Std7Mag gets jealous...

Dummy’d up a few cartridges last night:
257 GT & 25 Souper loaded to mag length with some clearance. Will add another photo with my QPC & 25-06 next to them for reference.

Might do a 25 SPC or a 25-223 for fun as well since I have a few pills leftover from my last lot of Blackjacks.

 

[284winner]

Dummy’d up a few cartridges last night:
257 GT & 25 Souper loaded to mag length with some clearance. Will add another photo with my QPC & 25-06 next to them for reference.

Might do a 25 SPC or a 25-223 for fun as well since I have a few pills leftover from my last lot of Blackjacks.

Souper being the longer of the two ???

 

[SweaterDood]

Souper being the longer of the two ???

Correct.

The GT is seated optimally (~0.150” of bearing surface in the neck & boat tail just into the shoulder area)

Souper is constrained by mag length. Optimal length would be around 3.050”

 

[284winner]

Correct.

The GT is seated optimally (~0.150” of bearing surface in the neck & boat tail just into the shoulder area)

Souper is constrained by mag length. Optimal length would be around 3”

Not familiar with either. I think the Souper is a .308/.260 parent case, correct ? Kinda thought about building one before deciding on the 25-284.

 

[std7mag]

Correct. Think of the 25 Souper as a 25-08.
I'm leaning heavily on a 250 Savage as a match rifle.
Might hold off a week ot 3 to see how Sweaterdood's 25GT works out.

 

[SweaterDood]

Correct. Think of the 25 Souper as a 25-08.
I'm leaning heavily on a 250 Savage as a match rifle.
Might hold off a week ot 3 to see how Sweaterdood's 25GT works out.

I probably won’t be making a move on the GT for a while. Just had a friend give me a worn out piece of brass to play with. I may send it to Manson or JGS to draft up a reamer print though. I know PVA is interested as well, so I may try to work with them to offer prefits.

I used a .243 case to neck up to the Souper in this example. I would use .260 Rem brass if I were actually loading them to shoot. This just happened to be laying in the Ziplock of “stuff I don’t shoot”. I didn’t have a .260 Rem case...

 

[SweaterDood]

Here are some more basic neck up/down quarterbores for size comparison, all with the BJ 131 Ace:
25-223 (Useless, unless you have a R700 SA with a .378” boltface and want to single feed...)
.257 Russian (6.5 Grendel with a 20* shoulder, I messed up...Similar in length to a dasher, but smaller diameter)
.257 SPC (6.8 SPC. I actually like this one)
25 GT (Probably my next barrel...)
25 Souper (.308 family necked to .257 dia.)
.257 Roberts (Seated to jam, fireforming load)
.257 QPC (After firing the ‘Bob in my chamber)
25-06 (Still haven’t shot my 25-06 AI yet, so I don’t have the promiscuous version to show at this time...)

 

[std7mag]

Instead of the 25-223, you might get a little more ompf by going to the 257 Kimber.
Essentially the 222 Rem Mag improved.
Would give you a little more case capacity.

Guess i'll order that 250 Savage barrel then. Possibly today. Want to get it before prices go up.
Steel has gone way up lately.

I think i'm sticking with the traditional 1:10 twist. Found an excellent load with Sierra 75gr HP Varmint bullets. Then Sierra discontinued them.
I bought the last 2,000 they had for sale online.
Might have to take a road trip to their factory store. They still have them for sale by the pound.

 

[284winner]

I probably won’t be making a move on the GT for a while. Just had a friend give me a worn out piece of brass to play with. I may send it to Manson or JGS to draft up a reamer print though. I know PVA is interested as well, so I may try to work with them to offer prefits.

I used a .243 case to neck up to the Souper in this example. I would use .260 Rem brass if I were actually loading them to shoot. This just happened to be laying in the Ziplock of “stuff I don’t shoot”. I didn’t have a .260 Rem case...

I have some .260 brass if you need a piece.

 

[Orr89rocz]

Souper seems interesting i guess because you can get decent brass for it im sure. I like my 257 roberts. Loaded hot to real pressures instead of anemic factory levels it really starts to shine. I kinda wish i went ackley improved tho and a longer barrel

 

[Sniper338]

I'd be inclined to choose something lapua or Peterson has brass for for a parent case.

284 was my first idea too. But barrel life would suck. 25x47 would be comfortable, 25BRA would be very enjoyable.

25XC would hammer I'm sure.

308 parent case is always an option. Between a 243 and 260..

I'd personally be looking in the 47 lapua case size area.

 

[AWS]

Instead of the 25-223, you might get a little more ompf by going to the 257 Kimber.
Essentially the 222 Rem Mag improved.
Would give you a little more case capacity.

Guess i'll order that 250 Savage barrel then. Possibly today. Want to get it before prices go up.
Steel has gone way up lately.

I think i'm sticking with the traditional 1:10 twist. Found an excellent load with Sierra 75gr HP Varmint bullets. Then Sierra discontinued them.
I bought the last 2,000 they had for sale online.
Might have to take a road trip to their factory store. They still have them for sale by the pound.

Interesting that you bring up the 257 Kimber, I looked seriously at it in 2005 for a deer rifle. At the time the 204 Ruger was the new kid on the block and it had specs that made it nearly a clone of the 257 Kimber case. I necked the 204 case to 257 and had a clone of the 257 Kimber with no fireforming.

It has turned out to be a great deer rifle with 100gr Partitions at 2800 fps. 75gr HP's at 3150 are brutal on coyotes.