Anyone ever heard of the 257 chuck?

[Striper Slayer]

THanks for all the replies! (AND Laughs!) I was thinking maybe cutting a chamber in a piece of aluminum and doing a cast of it to see what measurements I can get. Assuming I can't figure it out from looking at the reamer. THey have been shipped but I haven't had a chance to look at them yet. Either way it's gonna be fun to figure it out and build a load. I will keep everyone posted on what I find out!
Bryant

 

[Striper Slayer]

I got the reamers today and was able to get a reamer print from JGS. (Maker.) Looks like the chuck is a 7,62X39 necked down to 25 cal. Haven't had enough time to really compare the differences, but the print does say that 7.62x39 is the parent case.
GOing to have to make an AR barrel to go along with my 6mm Fat Rat! Be a nice little deer gun.

 

[Adam in WI]

That actually sounds like a lot of fun

 

[17VLD]

Better watch out Hornady will resurrect it and call it the 25 ARC

 

[ebb]

Is it an improved style with the 30 or 40 degree shoulder? Kind of sounds like a 25 PPC if it is improved like the current trend. Adam is right , it does sound like fun!

 

[Striper Slayer]

Reamer print shows 25 degrees for the shoulder. Body tapers from .4530 to .4100. (If I am reading correctly.)

 

[nakneker]

Reamer print shows 25 degrees for the shoulder. Body tapers from .4530 to .4100. (If I am reading correctly.)

Might post the print, should be straight forward but you might get some input that’s helpful. Sounds like fun to me.

 

[Striper Slayer]

Is it OK to post a reamner print that JGS said was private? I had to prove (Pictures) that I owned the reamer before they would send me the print. I don't want to step on someones toes by posting a private print. (Although I am pretty sure they guy the designed it has died.)

 

[Striper Slayer]

QUick update. The 257 Chuck is a necked down 7.62x39. Small rifle primer brass is definitely the way to go! (LRP flattens at a much lower vel than the SRP.)
70 Gr Speer TNT going about 2750. Shoots very well and is hella fun in an AR. Took it on a P-dog shoot and a 150 yard shot resulted in the most thoroughly disassembeled P-dog of my career. Even the 20 BR doesn't explode them like that did.
It's been a fun project and we have learned a lot from it. Best $60 for reamers I have ever spent!

 

[Bill K]

Ask the company you intend to buy the reamer from. They should know if they are making a reamer for said cartridge.

I am looking at buying some reamers for a 257 chuck. I have no idea what it is so it might be a fun project. Can anyone here give me some insight on what it is?
Thanks,
Bryant

 

[Beruisis]

since it's 25 caliber, it's gotta be cool!

 

[reed1911]

The quarter bore gets missed a lot in our 6mm and 6.5mm world. I caught the addiction when I got my 257 JDJ, lots more to follow and its a little unique.

 

[Ackman]

Don't you have to have a chamber to cast first?

It helps…a lot

 

[Ackman]

I am looking at buying some reamers for a 257 chuck. I have no idea what it is so it might be a fun project. Can anyone here give me some insight on what it is?
Thanks,
Bryant

Sounds like some wildcat a guy cooked up. First talk to the reamer maker, you want to make sure brass is available to make it. My 25 Chuck (demolisher) is a 257 Wby.