Go Back   CMP Forums > CMP Sales > CMP Bolt Action Rifles > Mann Accuracy Device
Register FAQ Members List Calendar Mark Forums Read

 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #1  
Old 06-02-2014, 12:54 PM
steelap steelap is offline
 
Join Date: Oct 2009
Location: North AL
Posts: 5,656
Default Building New Mann Rifle - Need Recommendations

A few years ago I bought a Mann Accuracy Device barrel and collar, with vague thoughts of building it into a Mann rifle.

I decided that the time is now. I recently purchased a M1903 action (sans barrel, stock, and a few other parts). I will mount the Mann barrel on the M1903A3 action, and find a stock for it.

Questions:

1. What headspace should I strive for? 7.62x51 NATO min or .308 Win GO? I have both.

I will have to shim the barrel, that is a given. The Mann device, or at least the one this barrel is for, was first built for the NATO 7.62x51mm round. However, I plan to shoot .308 Winchester out of it as well.

This post may mean that it is a moot point, but I'd like opinions:

Quote:
Originally Posted by normannewguy View Post
Ok here it is again.

Saami 308Win:
GO 1.630
NO GO 1.634
FIELD 1.638

FN FAL:
GO 1.6325 (FN & Brit/commonwealth) (Canadian is 1.6315)
NOGO 1.638
FIELD 1.640

7.62NATO (M14 US MILSPEC):
GO 1.6355
NOGO 1.638
FIELD 1.6445


Chamber and cartridge drawings. 308 WIN and 7.62 NATO


http://s1052.photobucket.com/user/f6...tml?sort=3&o=2

http://s1052.photobucket.com/user/f6...tml?sort=3&o=3


Both cartridges are the exact same dimesions . The only difference between the two is usally the weight of the brass, NATO weighs in at 175 grains to 188. SAMMI brass is about 155 to 165 grains.

Looking at the go for SAMMI and NATO there is a .005 difference. This will not be a problem in using NATO ammo in a 308 chamber.

The only time you run into a problem is overseas ammo companies who make ammo to NATO standards. They will let stuff go that headspaces at 1.633 to 1.635 which in a NATO chamber is fine but is .003 to .005 to large for a Win chamber. Most US ammo companies , Winchester being one, who make NATO ammo go to the minimum spec and hold it there, 1.628 and that allows it to be chambered in both.

If you have a minimum chamber 1.630 you can run into feeding problems with some NATO spec ammo but normally only overseas stuff, like PPU.
2. Recommendations on a stock, probably to alter.

For my first Mann rifle I used a cut down M1903A3 scant stock. It had been previously cracked and repaired, so I didn't mind chopping it down.

I have a NOS USGI C-Stock replacement purchased from the South Store a few years ago. I don't think I want to chop it up, but it is a possibility. I like the C-stock pattern.

Another possibility would be to find a stock for a heavy barreled rifle that has some "meat" in the forearm, and hollow it out to fit the Mann barrel. That would also likely mean fitting the action to the stock. Suggestions for one to use that requires minimum action fitting would be appreciated.

A last possibility would be to get a custom stock made. I think that is possible, though I don't know about costs. Suggestions/recommendations on where to look for one gratefully received.

Thanks for the help!

"Life is Good!"
Reply With Quote
 

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 06:46 PM.