221 chamber neck size problem

[DanK]

If I have a .242 neck chamber. and the brass neck wall thickness is .014 to .012. measured with calipers. And a sized loaded round of .248.

That means I would have to trim the brass down to .240 to get it into my chamber.
And I would have to trim the neck down to .008.

That would leave me with .005.

Is this chamber to small? Or am I doing somthing wrong. :,

 

[alf]

Take your .242 chamber minus the .002 clearance leaves .240,

minus the .224 bullet diameter leaves .016,

divided by 2 equals .008, the diminsion to turn the necks to, which you had.

But you lost me with the .005.

Al

 

[DanK]

alf... You are right. But, if I trim off .008 from the brass, It will then have .005 thickness left. The brass is .013 to .014 thickness. Right?

 

[Preacher]

Every thing seems right on the mark for your chamber that is on the really small side. No one cuts chambers that small for any good reason anymore... Thats a lot of brass to turn off a neck for no good reason...
Keep em all cut to .008 and you'll do fine with it.....
Not sure bout the .005 either

 

[Preacher]

You need to remove .005 from a .013 neck wall to end up with a .008 neck per side.
You need to remove .006 from a .014 neck to get it to the .008 that you need for your chamber....
If you trim off .008 from a .014 neck you'll end up with a neck that is only .006 thick and that will be a total of .004 to loose, and is not needed......

 

[DanK]

Precher.. So .006 neck thickness is OK then? What would be the limit? Won't I get split necks from that being on the thin side?

If this is all ok.. how long will my brass last?

 

[DanK]

I still don't really understand.. But if you guys say that the chamber is OK, and it will work,and I don't have anything to worry about, then I am fine with that. You guys would know better than me, since I have not done this before.

I guess I will just have to wait until the gun gets here, so I can see what everyone is talking about.

In case I didn't mention it before, I was thinking of buying a rifle from a guy that said has a 242 neck.

 

[Preacher]

I honest & truly hope you have LOTS better luck with your new rifle, than you do with your math.:,

 

[DanK]

OH...... you caught on to that did you. I was never the sharpest pencel in the class when it came to math.. I always hated math until I needed to use it.. I guess I should have paid more attention in school.

 

[Ackman]

If you were ordering a reamer .250" would be a good size for an unturned .22 neck. It's what my .221's are. But it's a small case and the brass doesn't need to be that thick anyway. My 22BR has a .243" neck and it works just awesome. This was done in late 80's when BR cases were made from Rem. 7BR brass, that's all there was. So everything got spec'd out pretty much as the riflebuilder thought was proper. In my case, the guy who built the gun was real involved with benchrest and that was his reamer. Loaded rounds are .241", neck wall thickness is .0085 which is fine, the gun is very much the most accurate I have. So don't worry, your chamber will be fine. Turn your necks to .008" thickness. BTW - Neckturning isn't a big deal once the cutter is set up. It goes pretty quickly.

 

[SmokinJoe]

My reamer cuts a .252 neck diameter and it has worked well with most brass. If you want a copy of the print, PM your email address and I will be glad to send it. FWIW, what you are considering is not the way to go, believe me.

 

[3Ackleys]

If you were ordering a reamer .250" would be a good size for an unturned .22 neck. It's what my .221's are. But it's a small case and the brass doesn't need to be that thick anyway. My 22BR has a .243" neck and it works just awesome. This was done in late 80's when BR cases were made from Rem. 7BR brass, that's all there was. So everything got spec'd out pretty much as the riflebuilder thought was proper. In my case, the guy who built the gun was real involved with benchrest and that was his reamer. Loaded rounds are .241", neck wall thickness is .0085 which is fine, the gun is very much the most accurate I have. So don't worry, your chamber will be fine. Turn your necks to .008" thickness. BTW - Neckturning isn't a big deal once the cutter is set up. It goes pretty quickly.

The OP "DanK" was last on here ELEVEN years ago. He has either figured it out or not...

 

[ckaberna]

The OP "DanK" was last on here ELEVEN years ago. He has either figured it out or not...

With his math I hope he is ok.