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anybody ever tried a 10mm magnum ak build i am tempted but would need help with barrel contour and chamber reaming and headspace any body have any info

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The last few weeks I've been looking in to doing a similar project myself but with the 10mm Magnum brass necked down for a 9mm bullet. Kind of a 9x25 Dillon but with 10mm Magnum brass instead of brass from a standard 10mm cartridge. The big question is how do you plan on doing the semi-auto design? Will it be a blow-back mechanism or will you be using the rotating bolt/gas operation of the AK? If you are going for a blow-back set-up there's a company out there making a blow-back bolt/slide for AK based pistols in 9mm/7.62x25 Tokarev. Shouldn't take too much to machine the bolt to work with the slightly larger 10mm brass.

 

If you will be using the AK style rotating bolt and bolt carrier via the gas operation system you have to keep the overal diameter of the barrel in mind when chossing the diameter of the bullet you plan on shooting. The AK gas blocks and front sights are machined for barrels around 0.580 to 0.600 in diameter near the muzzle end. This means the barrel will have to be pretty thin if you are planning on shooting a 10mm bullet (that's why I'm trying to use a 9mm bullet with a 10mm case instead). If you will be using the gas system with a short barrel then you will probably want to use a front sight/gas block combo from a Krinkov or Yugo M85 or M92 pistol. The only real difference that I've been able to figure out between the Krinkov and Yugo front sight/gas block is that the Krinkov front sight/gas block is set up with 24mm threads for attachments while the Yugo version has 26mm threads.

 

The nice part with the 10mm brass is that the rim diameter of the case is very close to that of the 7.62x39 round. So if you are using the gas operation system the bolt from the 7.62x39 cartridge should work for the 10mm case as they are real close in size. The big problem I see at the moment is getting the ammo from the magazine to the chamber. The AK is designed for a long rifle cartridge that has a taper to it. And because of the rotating bolt you have a section of open area that the bullet must cross in order to be chambered and you can't ramp that area due to the rotating bolt design. This is another reason I'm looking at a necked cartridge as I hope it will be a little easier to make work. I just got in some metal pieces I ordered last week to make a mock up of a receiver with in order to experiment with magazine placement and bolt interaction. Now I just have to wait for the front trunnion I ordered to come it to put it all together and begin experimenting.

 

 

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Last night I stumbled across this cartridge on an AR-15 web site and it made me think back to this thread since it uses 10mm Magnum brass but necked down to a 358 bullet.

 

http://www.ar15barrels.com/prod/357auto.shtml

 

Sounds like it would an easy build if you use an AR-15 set-up. Another necked down cartridge that uses the 10mm Magnum brass in an AR platform is the .338 Spectre.

 

http://www.teppojutsu.com/338.htm

 

If you are firm on wanting to use an AK for the base of the project you might want to check out the 358 Gremlin. It uses normal 7.62x39 brass for it's bass cartridge so the AK-47/AKM bolt would work just fine with it.

 

http://www.bfgcartridges.com/358Gremlin.html

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thanks for the info i am going to build piston driven ak's not blowback so it looks like the issue will be feeding. i think i read that some of the gas blocks are .630 also what do you think abouth saiga gas blocks i know the saiga 12 takes a larger one.

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Here's a link to a site that has some of the different dimensions between some of the different AK parts.

 

http://pookieweb.dyndns.org:61129/ak/docs/dimensions.htm

 

 

Now on to your pistol build. There are two different gas systems used on AK's, one that has the gas block and front sight block as two seperate pieces and one that combines the front sight and gas block in to one piece (as used on Krinkov pistols). The combined Krinkov setup allows for a shorter barrel. Some people have even taken a normal rifle gas block and welded the top part of a front sight on to it in order to make their own. So the first thing you need to do is figure out what style you to use, one patterned after a Krinkov or one using regular AK rifle barrel parts. Keep in mind the Krinkov/M85/M92 use a different rear site block called a rear hinge block. It moves the rear sight closer to the pistol grip end of the gun for better sight characteristics. This also mandates the use of a special Krinkov only top cover as it has to work with the rear hinge block. Another possiblity is to use a Krinkov style front sight/gas block combo with a regular rifle rear sight block and top cover. This will give you about a 9 to 10 inch barrel versus the 8.5 inch barrel of a Krinkov.

 

Okay, with the subject of gas systems out of the way let's switch over to the barrel and the sizes of some of the barrel components. Last week I got my hands on a Bulgarian AK74 front trunnion with the rear sight block so I could get some measurements from it and compare it to the same parts on my Norinco MAK-90. What I found is that not only was the hole for the barrel larger in the MAK-90 rear sight block the metal that wraps around the barrel was about 0.053 of an inch thicker then it's Bulgarian counterpart. So if you bore it out an additional 0.053" you have the same thickness of material on the rear sight block as that of the Bulgarian rear sight block. The catch with using the Norinco MAK-90 rear sight block is that it's wider than it's Bulgarian counterpart and you would need to machine it down a little in a couple of spots in order for it to fit in the upper notch on the top of a non MAK-90 front trunnion. The plus side is that if you enlarge the hole in it by 0.053" you will have a barrel diameter at the rear sight block of about 0.783 of an inch. This might be an issue for you if you set your creation up for a 10mm barrel as you will want a barrel around 0.800 of an inch or larger. For that you might want to look at using an RPK rear sight block as it's set up for a barrel diameter at that spot in the barrel of around 0.880". Keep in mind that an AK-47 trunnion is set up for a barrel diameter of 0.900" (23mm) at the trunnion. And an AK-74 trunnion is set for a chamber diameter of about 0.860" (22mm).

 

If you want to go the Krinkov route you might have some work on your hands. The barrel diameter on a Krinkov at the rear hinge block is 0.689". The M92 (a Yugo copy of the Krinkov) is a little larger at 0.736". While the pictures I've seen of the hinge blocks show that it has quite a bit of material that wraps around the barrel I don't know how much it can safely be punched out to. One possibility is to cut off the bottom parts of the Krinkov front sight/gas block and rear hinge block and weld the upper parts on top of a couple pieces of larger diameter round bar. Then machine out the centers to a larger diameter than they were before to handle the larger barrel for your 10mm.

 

Okay, hope I haven't bored you to death by now in my attempt to pass along my findings so far. But before I end this post I want to add one last detail that I'm not sure if you've taken in to account in your design. Have you looked at the underside of the bolt carrier group when the bolt carrier is sliding back after a round is fired? The bolt assembly has slid all the way forward from the bolt carrier and a large section of the bolt stem is exposed during this cycle. Since the ammo in the magazine is pushing up against the underside of the bolt carrier and bolt this large gap between the two might be a problem with a shorter pistol cartridge instead of the longer rifle cartridge. Depending on how fast the bolt carrier comes back the top cartridge in the magazine may take a beating from the low spot near the tip of the bolt that pushes the next round out of the magazine towards the chamber of the barrel when the bolt carrier group returns forward to chamber the next round. One mod I've been contemplating is seeing what it would take to fill in the original groove that controls the bolt location and re-cut it in a way that reduces how much travel the bolt makes as the bolt carrier cycles the next round. The problem I'm having with this idea at the moment is figuring out how to compensate for it on the hammer end of the bolt as the bolt wants to push the hammer back instead of the carrier if you don't let the bolt slide forward enough.

 

Well, after all I've detailed have I talked you in to switching over to an AR-15 receiver for your build yet? Makes you appreciate the AR-15's modular design, doesn't it? :D:

 

Anyhow, hope this helps you in some way. The more I look at my AK parts the more I'm toying with the idea of using a bolt from a Desert Eagle and machining a custom front trunnion and bolt carrier for it. Now if I could just come up with the cash that it would take for such an idea.

 

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i have talked to Tony Rumore at Tromix and he seems to think that it wouldn' be that hard of a build ordered a reamer today have brass and bullets and couple parts kits think it will be fun

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i have come to the conclusion that i will need single stack mags for the rifle to feed properly any body have any ideas

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Saw your post on another forum looking for a magazine and it reminded that I never responded to your last posting on this thread. For the magazine I wonder if a mag for a 41 Mag Desert Eagle would work. As far as your post on the other forum about single stack AK mags if the guy that reponded to your post doesn't come through here's a site that lists a 9 round single stack (don't know if they actually have any in stock though).

 

http://tickbitesupply.com/akmag.html

 

Speaking of single stack AK's, there are single stack bolts out there too. Might save you from having to machine down the sides of a standard AK bolt.

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i have come to the conclusion that i will need single stack mags for the rifle to feed properly any body have any ideas

 

Did you ever find a source for the mags? If not let me know as I just bought some AK parts and part of the deal was a couple of single stack mags that I have no use for.

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pm'd you about the single stack mags

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