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-   -   Mann Accuracy Caliber Designation? (http://forums.thecmp.org/showthread.php?t=65418)

drharm 01-19-2012 12:29 AM

Mann Accuracy Caliber Designation?
 
I recently purchased a Smith Corona with the Mann Accuracy Barrel. The tag that is wired to the trigger guard has various information about the rifle including the caliber and when is was broke in. I have completely looked over the rifle and other than a number on the barrel there is no caliber designation on the firearm. So, the question of the day is:

If the tag was to get separated from the rifle, does that number on the barrel give an indicator of the caliber?

Without taking the rifle to a gunsmith how does one verify that it is indeed a .308 versus 30.06?

Thanks for your time.

Darrell (aka drharm)

steelap 01-19-2012 05:30 AM

Given the difference in cartridge case length, it should be easy to demonstrate that a particular device is .308 or 30-06.

Reportedly the devices were built in multiple calibers. So far, at the South Store, I have seen only 7.62x51 (.308).

They make a fine rifle.

"Life is Good!"

ODCMP 01-19-2012 08:13 AM

The barrels on mine are in 7.62x51 and are marked "7.62mm". They are both Walker barrels. I understand that the barrels on the .30-06 rifles are marked ".30". I'm sure there could be exceptions.

Here is an article on the CMP site that provides info on the various calibers and markings observed.

http://www.odcmp.org/1001/mann_inc.asp


Dave

dpd3672 01-19-2012 08:19 AM

The easiest way would be to carefully try to chamber a .30-06 round. If the bolt won't close, it's likely .308.

Or am I overlooking something?

edlmann 01-19-2012 09:00 AM

Since I started paying attention, the only calibers I've seen offered were 7.62x51 and .30 Carbine. Makes sense that there would be some in .30-06, but I can't ever remember having seen one listed.

VMFn542bob 01-19-2012 10:48 AM

Quote:

Originally Posted by drharm (Post 510443)
I recently purchased a Smith Corona with the Mann Accuracy Barrel. The tag that is wired to the trigger guard has various information about the rifle including the caliber and when is was broke in. I have completely looked over the rifle and other than a number on the barrel there is no caliber designation on the firearm. So, the question of the day is:

If the tag was to get separated from the rifle, does that number on the barrel give an indicator of the caliber?

Without taking the rifle to a gunsmith how does one verify that it is indeed a .308 versus 30.06?

Thanks for your time.

Darrell (aka drharm)

Did you buy this from the CMP of a private party?
If it came directly from the CMP it is most likely chambered for the NATO 7.62x51 (.308).
If you purchased it from a private party it may have already been modified.
The MANN barrel was designed to test ammunition and a commercial 308 round will not chamber properly without the head spacing being modified.
But if you bought it from the CMP the head spacing should not have been modified and should work fine with legitimate NATO 7.62x51 ammunition or Commercial 308 resized with a SMALL BASE case sizing die.
This thread may give you some insight.
MANN ACCURACY DEVICE - Chamber Test-
http://forums.thecmp.org/showthread.php?t=21546&highlight=MANN+Accuracy+dev ice

drharm 03-02-2012 02:50 AM

Sorry for taking so long to reply. I haven't had the time to dig the Mann rifle out of the safe and take photos.

I appreciate all the input. I'm a little concerned that maybe this one is a fake. The barrel markings don't match any of the information contained in the Steve Rutledge article that was posted above.
http://i242.photobucket.com/albums/f...Y/IMG_1109.jpg
Here is a link to a 56 photo slideshow:
http://s242.photobucket.com/albums/f...view=slideshow

The photos on the blue background are ones that I took. I had a Smith Corona stock that got busted in shipment. So I bonded it back together and put it on this rifle. I want to take her to the range and test her out!!! I bought this rifle off Gunbroker. It was listed as a 308 Mann Accuracy CMP Smith Corona. The seller has an A+ 2345 rating. FFl dealer in Northwood NH.

If anyone is familiar with the markings on this barrel I would appreciate hearing about it.

Thank you.
drharm

ODCMP 03-02-2012 08:02 AM

I haven't seen those markings either, but that doesn't cause much concern since there have been a lot of odd markings on these barrels. I wouldn't be surprised at another barrel maker we haven't seen. The profile of the barrel also seems correct.

What is noticeably different though is the sleeve and/or the receiver end of the barrel. The sleeve on all of the Mann barrels I have seen extends all the way to the receiver and extends around a step on the end of the barrel. On your barrel, the sleeve stops well short of the receiver. Can you tell if there is a step in the barrel at that point, or has the sleeve just been cut down?

Dave

VMFn542bob 03-02-2012 10:15 AM

Quote:

Originally Posted by drharm (Post 510443)
I recently purchased a Smith Corona with the Mann Accuracy Barrel. The tag that is wired to the trigger guard has various information about the rifle including the caliber and when is was broke in. I have completely looked over the rifle and other than a number on the barrel there is no caliber designation on the firearm. So, the question of the day is:

If the tag was to get separated from the rifle, does that number on the barrel give an indicator of the caliber?

Without taking the rifle to a gunsmith how does one verify that it is indeed a .308 versus 30.06?

Thanks for your time.

Darrell (aka drharm)

Steven T. Rutledge's report is the most comprehensive document I have seen on what MANN Accracy Devices have been available from the CMP. I have two MANN barrels on Remington receivers and both barrels are engraved "7.62mm" (NATO 308). Keep in mind, these devices were designed to test ammunition and the head space will be set accordingly. I have seen many posts by owners who took their MANN device to a gun smith and was told the chamber had to be reamed. That is completely false information but it is true if all you want to do is shoot commercial ammunition in it. ANY brass that has been full length sized with a SMALL BASE base die will chamber in both of my MANN barrels.
(Update) You posted your photos while I was posting my comments. From the photos I suspect your MANN device is 30-06 but that would not be difficult to determine. As I wrote above, if it has not yet been reworked by a gun smith the chamber will be tight and commercial ammunition will probably not chamber in it. I advise against trying to put a live round in it until you have determined exactly what it is chambered for. If you have access to a small base 30-06 die, just size a case and try it. That would help you decide.

drharm 03-02-2012 12:46 PM

Here are some photos of the original portion of stock and the hang tag that was wired to the trigger guard.
http://i242.photobucket.com/albums/f...Y/IMG_1172.jpg
http://i242.photobucket.com/albums/f...Y/IMG_1169.jpg
http://i242.photobucket.com/albums/f...Y/IMG_1171.jpg
http://i242.photobucket.com/albums/f...Y/IMG_1170.jpg
I appreciate all the input.
I think I will contact the CMP and see if they have any records of this Mann device. I would think that if authentic it had to come from the CMP and they would have documented its' caliber.

drharm


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