.25 Atihk (.25 SLR)

[1000yardstare]

Atihk is the Cree word for Caribou.

Just finished building a 6mm SLR for F Class. Bought new Lapua and Win .243 brass for same. Leaves me with a whack of low usage .243 brass from a previous F Class rifle.

Planning a Caribou hunt in northern Quebec. Am thinking of having PT&G cut me a reamer for the 6SLR necked up to .257. Why not use a unique cartridge on a memorable hunt? Should be great on Caribou which are not a large animal.

Has any Forum member experience with this cartridge? Should be a natural.

 

[dan06]

no experiance with .25 but I think you already have a reamer for 6.5x57 improved. I understand the need for just one more gun but how could you better that ctg for hunting medium game?

 

[1000yardstare]

dan06..........like you said, there is no such thing as too many rifles. What`s that old saying, "The guy that dies with the most toys wins".

Always liked the .25 as a hunting caliber. Have a .25-06 but don`t need that much horsepower for Caribou. The outfitter tells me that most of the shots are short range and that 100 years ago the most popular rig was an M94 lever gun chambered in .25-35.

Part of being retired is enjoying the luxury of following your dreams. Right now putting a new hunting rig together by rebarreling a Tikka T3 with .25 Atihk engraved on the side of the barrel is grabbing my fancy.

 

[crem1]

Sounds like an interesting build, I have a 25-284 that I really like. Now just wish the bullet selection would improve some for longer range target shooting. Good luck with the build and keep us posted.

 

[FroggyOne2]

[quote author=1000yardstare] "The guy that dies with the most toys wins".[/quote]

No the statement is

"He whom dies with the most toys, still dies."

 

[CanusLatransSnpr]

[quote author=1000yardstare] "The guy that dies with the most toys wins".

No the statement is

"He whom dies with the most toys, still dies."
[/quote]

Damndest thing is..... you can't take em with ya :/! Sure wish I could though .

 

[dan06]

I am truly envious......I have quite a few toys. and I hope some day when I die..... some one declares me the all time winner in the toy department.... ;D

I have lofty goals.

 

[lelongcarabine]

Atihk is the Cree word for Caribou.

Just finished building a 6mm SLR for F Class. Bought new Lapua and Win .243 brass for same. Leaves me with a whack of low usage .243 brass from a previous F Class rifle.

Planning a Caribou hunt in northern Quebec. Am thinking of having PT&G cut me a reamer for the 6SLR necked up to .257. Why not use a unique cartridge on a memorable hunt? Should be great on Caribou which are not a large animal.

Has any Forum member experience with this cartridge? Should be a natural.

That sounds like a 250 ackley with a long neck? Close? It should duplicate the .25/06 and have a long throat life, depending on the pressures. Greg

 

[1000yardstare]

P.O. Ackley`s "Handbook" lists the .25 Souper, a straight neck-down of the .308. With IMR 4350 he shows the .25 Souper as 100 fps slower than the .250 Ackley using a 100 gr bullet.

The proposed .25 Atihk would have a 30 degree shoulder instead of the 20 degree on the .25 Souper with no other change.

My `smith just asked me the question "Does the Tikka barrel have metric threads?" He doesn`t have metric indexing on his lathe. Anyone out there have an answer to that question?

Bill

 

[1000yardstare]

Found the answer to my question on Tikka threads.

Tikka barrel has a 25mm shank with 1.5mm thread pitch.

North American `smiths have found that a 1 inch shank with 16 pitch threading also works.

1 inch = 25.4mm
1/16 = .0625 inch; 1.5mm = .0590 inch

So looks like the conversion from metric to inches is close enough for a lathe without metric indexing.

 

[dan06]

I'm not trying to steal the thread but I once had a .257 bob ack.... built by PO himself...it was the only ackly that didn't give me a little more that a rifle of the parent cartrige..... I would expect some gain over the standard 25-08 I do like those improved ctgs I still have a .223 ack, 280ack and some day i'm going to build a 6.5X57 ack

 

[RJ338]

Hate to call foul on your assertation that you can use a 1'-16 pitch barrel shank in a 25mm 1.5 pitch reciever. 25mm is .984 and a1.5 metric is approx 17 threads per inch. As a toolmaker I can tell you that isn't even close to a fit. Please go to a profesional to have this done.

 

[lelongcarabine]

Found the answer to my question on Tikka threads.

Tikka barrel has a 25mm shank with 1.5mm thread pitch.

North American `smiths have found that a 1 inch shank with 16 pitch threading also works.

1 inch = 25.4mm
1/16 = .0625 inch; 1.5mm = .0590 inch

So looks like the conversion from metric to inches is close enough for a lathe without metric indexing.

Sorry, I have to chime in here! Thats a 0.0035" error per rotation. How many rotations until the shoulder is tight against the receiver? If there are 10 threads engaged (as an example). That is equal to a 0.035" error! "Close enough" is not acceptable, IMHO! A "pipefitter" works in tighter tolerances than this! Do it Right! Greg

 

[1000yardstare]

Thanks for the replies guys.

I took my Tikka thread calculations from the "Advanced Gunsmithing" section of this Forum. I didn`t bother putting the URL in my thread posting because I took it at face value.

Here is the 1 inch 16 pitch posting I found. After reading it you can make up your own mind.

http://www.accurateshooter.com/forum/index.php/topic,3759978.0.html

 

[flatlander]

I dunno what your 'smith meant by "not indexed" for metric threads. Most of the imported chicom lathes I've looked at have leadscrews with 8tpi, which means you've got to make a change of the end gears to cut metric threads. Once this is done, you have to leave the halfnuts engaged until the thread is completed. It's just a bit of a PITA to do, but nothing really complicated or difficult.

 

[1000yardstare]

flatlander...........thanks for the info. Looking around at other Forums I see the question of metric threading frequently being discussed. With more and more Tikkas being used in North America it is just a matter of time until there is a commonly understood solution to the different thread.

I don`t know what lathe my `smith uses or what methods he has tried. He just smack dab don`t like metric threading. But at the right psychological moment I will pass your comments on to him.

 

[1000yardstare]

Forum member Lutheran has just made me aware of the .257 DRG formed from the .260 Rem. Shoulder is pushed down to 30 degrees as per the SLR. Shoulder is blown out slightly. Has the advantage of necking down which may help to offset the dreaded donut.

Sounds interesting but think I will stay with the "unimproved" .257 Atihk. Using .260 Rem brass would be advantageous but I have so much low usage Winchester .243 brass that I will take my chances with the donut.

 

[riflehunter]

I know that this is a very old thread, but did you ever build the .25 Atihk (.25 SLR)? I am considering building a rifle in this same exact caliber. Did the "Atihk" name catch on, has any of the die manufacturers made a 2 die set for this .25-308 30 degrees or do I have to buy very expensive one-off custom dies?