HK AR cut the barrel to 10.5"?

[dtibbals]

Has anyone bought the HK AR and cut the barrel down to SBR it? Just wondering if it is possible?
David

[justlikeanyoneelse]

By HK AR I'm assuming the MR556? If so then yes its possible, you need to buy a HK 10.4 Upper Gas block or permanently seal the front gas port on your existing gas block. I cant think of any other steps right now but that's the most important. I have included a link for the 10.4 gas block, right now it will run you $214.95.

http://www.hkparts.net/shop/pc/HK-416-10-4-Upper-Gas-Block-14p1543.htm

[dtibbals]

By HK AR I'm assuming the MR556? If so then yes its possible, you need to buy a HK 10.4 Upper Gas block or permanently seal the front gas port on your existing gas block. I cant think of any other steps right now but that's the most important. I have included a link for the 10.4 gas block, right now it will run you $214.95.

http://www.hkparts.net/shop/pc/HK-416-10-4-Upper-Gas-Block-14p1543.htm

Yup that is what I meant :) I found a used 16" at a very reasonable price and was thinking it might be worth doing, I haven't been able to locate a factory original 10.5" upper or complete rifle.

I did notice that HK says they tapper the barrel towards the muzzle for accuracy issues, will cutting 5.5" off the end of the barrel be an issue?

[justlikeanyoneelse]

I highly recommend the rifle, especially if you can find one at a reasonable price. I have a 10.4 factory upper so I can't answer your question, however I have never heard of someone suffering from accuracy issues because they sbr'ed their MR556. HK416 factory uppers are too overpriced/overhyped, besides most of the people who sell them smoke way to much crack.

P.S. to avoid any confusion the actual HK416 sbr barrel is 10.4 inches, people (including myself) generally refer it as 10.5

Hope it helps and good luck with whatever sbr you buy, they are a lot of fun. It's not everyday you see one at the range.


Yup that is what I meant :) I found a used 16" at a very reasonable price and was thinking it might be worth doing, I haven't been able to locate a factory original 10.5" upper or complete rifle.

I did notice that HK says they tapper the barrel towards the muzzle for accuracy issues, will cutting 5.5" off the end of the barrel be an issue?

[dtibbals]

I highly recommend the rifle, especially if you can find one at a reasonable price. I have a 10.4 factory upper so I can't answer your question, however I have never heard of someone suffering from accuracy issues because they sbr'ed their MR556. HK416 factory uppers are too overpriced/overhyped, besides most of the people who sell them smoke way to much crack.

P.S. to avoid any confusion the actual HK416 sbr barrel is 10.4 inches, people (including myself) generally refer it as 10.5

Hope it helps and good luck with whatever sbr you buy, they are a lot of fun. It's not everyday you see one at the range.



Yup yet another reason I am thinking of buying one :) I found a very nice MR556 for $2200 which is pretty good considering HK is selling the upper for 1900. Figure I spend 100 bucks cutting the barrel, install an AAC 51T flash hider for my M4-2000 and have a sweet set up! I think to be very specific the barrel is 10.39 LOL but yes I simply rounded.

[dtibbals]

Found this thread posted yesterday on HKpro and it was made by Dakota Tactical which is a very reliable source. I was wondering about the barrel taper "swag". Now I wonder if I can actually buy a barrel from HK or for the HK and convert a 16" rifle.


Don't cut your MR556 MR762 barrels!

While working tonight (morning) at the shop, it hit me... HK "swags" the barrels on the HK41x and I believe as well on the MR-series firearms. For those of you who do not know, "swag" is the term HK uses to refer to the bore tapering towards the muzzle.

My understanding is that the bore is slightly oversize at the chamber and several thousandths undersized at the muzzle. This "swag" is what HK attributes the ability to get better accuracy with shorter barrels.

What I do not know is if the degree of "swag" is constant with all barrel blanks or if it is based on barrel length. If based on barrel length, you could be ruining your MR-series barrels by cutting them down.

Since the specifics are R&D information from Germany, I doubt I will have any luck finding answers as the folk down in Columbus probably will not know either, but I will put a call in and see if someone can find out.

UPDATE:

Straight from the US/German Operations coordinator...

"Important dimension are the diameter at the beginning of the rifling and the diameter at the muzzle. Therefore the angle of the "swage" varies between the different barrel lengths. At HKO every barrel length is forged differently.

Cutting a barrel to e.g. a length of 14.5" - instead of using a "real" 14.5" barrel - will have a negative effect on performance of the rifle and is not recommended."

So take it for what you will as the type of shooting you do may not matter the loss in accuracy, however when I asked about the warranty the US Technical Liason answered...

"Absolutely voids any warranty."

[justlikeanyoneelse]

Hi I just came across this and felt it was very important with your accuracy question.

http://www.hkpro.com/forum/hk416-hk417-hq/158827-dont-cut-your-mr556-mr762-barrels.html

It basically states you might lose some accuracy but you wont be able to tell the difference. After all it is an HK barrel and I doubt your going to use a 10.4 for long range "applications."

[dtibbals]

Hi I just came across this and felt it was very important with your accuracy question.

http://www.hkpro.com/forum/hk416-hk417-hq/158827-dont-cut-your-mr556-mr762-barrels.html

It basically states you might lose some accuracy but you wont be able to tell the difference. After all it is an HK barrel and I doubt your going to use a 10.4 for long range "applications."

Yup I just found the same thing! Seems others say that the loss is hardly noticeable etc....I guess I can see the point of HK but also see the point of those who have cut them down, it is a short gun not trying to shoot sub moa groups at 100+ yards