The .257 Marksman (25 western)

[AZ_Hunter]

Any new updates? I am curious what you could get a 80gr TTSX up to, just for fun.

 

[Article 4]

Great idea - really appreciate the easy button portion of this, not saying it was easy, but supporting your decision not the change the shoulder angle and continue to use available dies and just change bushings. Innovation is Bad*ss and its likely gonna run great when you finish tuning it.

Really like your bbl choice too - IMO - IME, that barrel will help you take out any bbl deflection or heat issues in your testing and long term us.

Agree - sometimes barrel life be damned!!!

Did the same with a 300 PRC about 5 years ago - turned it into a 7mm doing the exact same thing. Have tested 175 and 180s in mine with both RL 25 and N568. 568 won
Just about my Fav rifle now.

 

[WKR]

Any new updates? I am curious what you could get a 80gr TTSX up to, just for fun.

Sure,
I've got 113 rounds down the tube now, so I'll start tuning a load on fired brass soon.

So far have pressure tested
Retumbo (67gr 3224 fps no visible pressure signs)
H1000 (66gr 3200 fps with mild bolt lift)
H4831sc (need to re-do this one)
N555 ( 61gr 3146 fps swipe pressure signs)

Retumbo and 555 have been the most accurate and consistent,

I have a retumbo load that I am torture testing 3 pieces of brass with. So far they are on 7 firings and the primer pockets have held up great. I did get some click at 4-5 firings, but found out the sizing die I had was no good. Switched to a Redding and solved that issue.

Today I'll load up a set with the Retumbo load at 64.5 gr and Chrono them to see if the barrel has sped up yet. 64.5 was producing 3110 on once fired.

As far as your curiosity on the ttsx, I'd imagine they would be extremely fast out of this chamber, I have some 25 cal lrx, but don't really want to copper up the barrel while I'm tuning other loads. I might mess around with them later.

 

[AZ_Hunter]

I love 25’s even if that love is irrational… I am really interested in this cartridge and look forward to your updates.

 

[WKR]

Great idea - really appreciate the easy button portion of this, not saying it was easy, but supporting your decision not the change the shoulder angle and continue to use available dies and just change bushings. Innovation is Bad*ss and its likely gonna run great when you finish tuning it.

Really like your bbl choice too - IMO - IME, that barrel will help you take out any bbl deflection or heat issues in your testing and long term us.

Agree - sometimes barrel life be damned!!!

Did the same with a 300 PRC about 5 years ago - turned it into a 7mm doing the exact same thing. Have tested 175 and 180s in mine with both RL 25 and N568. 568 won
Just about my Fav rifle now.

Thanks, yeah after the initial neck down and forming process, it has been pretty easy truthfully. The 6.8 western parent case so far has been nice to work with. It's also a testament to using good components and a good smith.

I just ordered a keg of 570 and some Grand to play around with. I want to see what they will do before I make a decision to run the Retumbo load I have been using.

 

[WKR]

I love 25’s even if that love is irrational… I am really interested in this cartridge and look forward to your updates.

It might have been irrational or illogical 10 years ago, but now there are some really good bullet options. The 25's of today are a better choice than anything 6.5 for me.

 

[Article 4]

Thanks, yeah after the initial neck down and forming process, it has been pretty easy truthfully. The 6.8 western parent case so far has been nice to work with. It's also a testament to using good components and a good smith.

I just ordered a keg of 570 and some Grand to play around with. I want to see what they will do before I make a decision to run the Retumbo load I have been using.

great plan. i tried 570. was a bit too slow - kinda runs like 50BMG but at higher temps.

chafes a chamber like bad underwear lol

 

[WKR]

great plan. i tried 570. was a bit too slow - kinda runs like 50BMG but at higher temps.

chafes a chamber like bad underwear lol

Yeah...we shall see, if 570 gets it up past 3200 without pressure I might run it and accept the throat erosion. But if it's not producing any significant advantage over Retumbo I won't.

The ramshot grand is completely new to me. And its a ball powder. But if you look at load data for the parent case, it's the fastest. I need to see how hot and clean/dirty it burns.

 

[Article 4]

Yeah...we shall see, if 570 gets it up past 3200 without pressure I might run it and accept the throat erosion. But if it's not producing any significant advantage over Retumbo I won't.

The ramshot grand is completely new to me. And its a ball powder. But if you look at load data for the parent case, it's the fastest. I need to see how hot and clean/dirty it burns.

Love metering ball
If you find some Win staball HD. it falls right about retumbo and it ball as well.