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-   -   Removing collar from the Mann (http://forums.thecmp.org/showthread.php?t=87647)

Cowboysnavy 10-13-2012 01:12 AM

Removing collar from the Mann
 
I see that it can be done how hard is it to do?
Do you have to remove the barrel to do so or will a couple of smacks from a dead blow hammer do the job?
Thanks in advance

VMFn542bob 10-13-2012 03:46 PM

Have you read WRMorrison's thread ?
http://forums.thecmp.org/showthread.php?t=78658
Walter "Rich" Morrison is the only person I know who has removed a MANN barrel and he can certainly help you. I can tell you that you need a means of holding the barrel and another means of rotating the reciever, without damaging either one. I would also suggest that before you remove the barrel you place a witness mark on the barrel, collar and receiver so that it can be assembled again with the same head space. You can eliminate the collar and replace it with a spacing washer of the same thickness as the base of the collar and then return the barrel to the same head space.
You can send Rich a PM or e-mail by clicking on his screen name in his thread.
Hope this helps.

Cowboysnavy 10-14-2012 01:25 PM

Ok I see now you have to remove the barrel and that would mess up that perfect headspace I'm looking for so I will just bed it in a stock from the collar back thanks

graywulf4570 01-16-2013 02:09 PM

Does the .308 Mann Accuracy Device currently offered
having the stainless barrel also have removable bushings or is it a solid piece?

kraigwy 01-17-2013 08:00 AM

My Mann is in 5.56 on a Remington Action. I've studied it every way from Sunday and still believe its part of the barrel and not a collar. I don't think it will come off short of chucking it in a lathe and cutting it off.

graywulf4570 01-17-2013 08:56 AM

Interesting; perhaps the 5.56 barreled Remington actions were machined as a solid piece in an effort to reduce the cost of production for testing the 5.56...while the .308 (7.62x51) have the bushing/collar installed as a product of that particular evaluation contract. Either way, I recently inspected a .308 conversion at a local gun show and it was a .308 without the bushing/collar.

VMFn542bob 01-23-2013 12:21 AM

Quote:

Originally Posted by graywulf4570 (Post 746321)
Does the .308 Mann Accuracy Device currently offered
having the stainless barrel also have removable bushings or is it a solid piece?

I suspect they all do have removavle collars but also suspect all do not have stainless barrels. Both of my 7.62 NATO MANN rifles had stainless Walker barrels and both MANNs had a parkerized removable collar on a Remington receiver. I have no idea what manufaturer barrels and receivers that remaining MANN rifles have, but I am pretty sure they will have removable collars. You can contact the CMP armorer and ask that question, and also probably determine what manufacturer barrels and receivers are available. I also have been told that there are more MANN rifles still crated and they probably won't be opened until the current supply dwindles. And sadly, the CMP won't even know what is in those crates they have until they do open them.

ODCMP 01-23-2013 08:55 AM

Here is a picture that I saved that shows the collar on the barrel with the barrel removed. This was a 7.62 device.

The collar will slide off freely once the barrel is removed. There is a smaller shoulder on the barrel, then a step to allow for the collar. If you look closely at the shoulder in the picture you can see the line between the barrel shoulder and the collar.

Dave

http://i250.photobucket.com/albums/g...1.jpg~original

graywulf4570 01-23-2013 09:17 AM

outstanding photograph; it is interesting that the collar can be slipped off if necessary.

very nice.

VMFn542bob 01-24-2013 10:20 AM

Quote:

Originally Posted by graywulf4570 (Post 752150)
outstanding photograph; it is interesting that the collar can be slipped off if necessary.

very nice.

You might be interested in reading this old thread.
http://forums.thecmp.org/showthread.php?t=78658

graywulf4570 01-24-2013 01:21 PM

Many thanks. I did read that thread.The background you have put together is greatly appreciated here. I tend to think it as being outstanding baseline guide for anyone wanting to work with the MAD. Aside from target competitions, I am convinced that the MAD has practical applications for further testing and evaluations . the Morrison build and your build as well have great merits. Looking forward to working with one very soon. CMP is an outstanding group. The MAD is a interesting piece of the puzzle to say the least.

v/r

Ed

wesvb 03-02-2013 09:02 AM

Quote:

Originally Posted by ODCMP (Post 752133)
Here is a picture that I saved that shows the collar on the barrel with the barrel removed. This was a 7.62 device.

The collar will slide off freely once the barrel is removed. There is a smaller shoulder on the barrel, then a step to allow for the collar. If you look closely at the shoulder in the picture you can see the line between the barrel shoulder and the collar.

Dave

http://i250.photobucket.com/albums/g...DSC02142-1.jpg

Good picture but I need a little more detail.
I have line on a couple of MANN barrels but the collars are gone. Question; with the collar removed how tall is the remaining shoulder? I'm trying to determine the barrel can be succesfully tightened to an action without the collar or will I have to make some sort of bushing to take its place?

Thanks

VMFn542bob 03-02-2013 06:05 PM

Quote:

Originally Posted by wesvb (Post 785778)
Good picture but I need a little more detail.
I have line on a couple of MANN barrels but the collars are gone. Question; with the collar removed how tall is the remaining shoulder? I'm trying to determine the barrel can be succesfully tightened to an action without the collar or will I have to make some sort of bushing to take its place?

Thanks

Hi wesvb - If you have a barrel that is threaded to fit your receiver, and you have an appropriate bolt in the receiver, and you have an unfired factory NATO 7.62x51 cartridge, I believe it's rather easy to determine the dimension you are seeking. Screw the barrel into the receiver to within about .2 inches of bottoming out the shoulder on the receiver, and then open the bolt, insert the cartridge and close the bolt. Be sure the safety is on. If the bolt closes easily just screw the barrel in until the chamber encounters the shoulder of the cartridge, then measure the gap and make a washer to fill it. If the bolt won't close, back the barrel out until it does close and then screw it in again until the chamber bottoms out on the shoulder at one end of the cartridge and the face of the bolt on the other. Then measure the gap. I hope this does not sound too simplistic but I believe it's easy to measure this way.


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