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5.45x39 pistol??

7K views 74 replies 19 participants last post by  Toten Kopf 
#1 ·
I am thinking that when the AWB sunsets that a pistol in 5.45 would be sweet. Here is a pic of the barrel I am thinking of using. (the one on top, the bottom one is a krink barrel for comparison).


Now if I figure this correctly, that when the AWB ban goes away there are no weight restrictions for pistols, am I correct to assume this? Also would front handguards be a big no-no or can they be used on a pistol? Lastly I am thinking of one of these front sight combos




Would one be better than another? I figure also that if front handguards can be used - great. If not I am sure there could be found another way to help the gun to balance right (like using one hand on the magazine the other on the pistol grip). Do you all think this would be a great project or not? I'm sure others have already thought of it, but am curious.
 
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#2 ·
they are sold by K-var as is the barrel that is already in the trunnion.
 
#3 ·
I just bought the receiver/barrel stub and the larger combo gas/sight block for a similar pistol project. The larger gas/sight block was on sale for $54 so I ordered one... I bought an undrilled Romanian 7.62 barrel and a few other parts. I also bought some other 5.45 parts for a 9mm conversion project down the road.

The downside to using the receiver/barrel stub with the larger gas/sight block will be the clearance for the handguard retainer. Even with the block pressed on to the barrel 1/2 way, there is hardly any space left between the block and the HG retainer location. If you want to use the receiver/barrel stub, I would suggest the smaller Krink gas/sight block. If you compare the 2 blocks, the Krink block is almost 1/2 the length of the larger.

The muzzle will only be about 1/2 way down the hole for the barrel in the larger block. That may not be an issue as it would provide an expansion chamber similar to the brakes on the Krinkovs to allow proper gas operation.

BTW The receiver/barrel stub was cut with a chop saw. There is absolutely no muzzle crown and the end of the barrel is not square on either of the ones that I bought. They will need to be trued in the lathe and then crowned.

With either block you may need to make a custom gas piston.

After my findings, I will use the larger gas/sight block on the undrilled barrel. I'll just order the Krink gas block for use with the receiver/barrel stub after Sept. 14.
 
#4 ·
interesting info rhino_66. So with the pictures posted the krink gas/sight block is the bottom one if I remember right. Would I have to use a krink gastube also? And I am assuming that this would mean handguards would be ok on the pistol?
 
#6 ·
The Krink would be the lower one of the blocks in your pics. I think the only difference in the Krink gas tubes is the flanges that are welded onto the tube for the upper handguard. This makes the gas tube as short as possible. Looking at the pics, I think you could modify a standard gas tube like some of us have done for the AMD-65s. When I get home from work I'll throw my modified AMD-65 gas tube on and see where it ends up. compared to the end of the barrel. If it's too close to the end, there may be no other option than a Krink gas tube (or your own custom flanges).

I'm confused about having a forward handguard or grip on something that doesn't have a shoulder stock. I'm concerned that a foreward handguard might make it an AOW. I am not up on that portion of NFA regulations, so I plan on doing some serious research. A quick check makes me think that an AK pistol with front handguards after Sept. 14 would be legal. The sure cure would be to just eliminate any forward grip or handguard, chop an AMD-65 gas tube to length and reshape the end of the tube. Then you could use either block, put it where you want it, and make a custom gas piston for whatever length it needs.

EDIT: I just found this page.

http://www-2.cs.cmu.edu/afs/cs.cmu.edu/user/wbardwel/public/nfalist/nfa_faq.txt

"ATF has made the decision that a handgun (but not a machine gun,
since a machine gun is not also an AOW) with more than one hand
grip at an angle to the bore is an AOW. This is based on the gun
a) being concealable on the person, and b) not meeting the
definition of a "pistol" in the regulations promulgated under the
NFA, since they say a pistol has a single grip at an angle to the
bore. However, at least one federal magistrate has decided that if
the grip is added later, the gun is not "originally designed" to be
fired by holding in more than one grip, and thus putting a second
grip on a pistol does not make it an AOW. ATF does not regard the
decision as binding. The case is U.S. v. Davis, Crim No. 8:93-106
(D.S.C. 1993) (Report of Magistrate, June 21, 1993). The
prosecution was dismissed at the request of the Government before
any review of that determination by the trial judge."

According to the above "...more than one hand
grip at an angle to the bore is an AOW." An AK handguard is parallel to the bore, not at an angle. Would this make it legally not an AOW?
 
#7 ·
Here are some pics of the barrel with a regular gas tube that was modified to fit an AMD65. I'm not sure of the exact dimensions of the gas block/front sight combos but my thinking is that you are right and the krink combo gas block/front sight would be best. Hope these pics help. Edit: I apologize in advance for the crappy ruler used in the pics, it is my boys ruler and was the easiest one to get to - but at least it gives an idea.
 

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#8 ·
I think it's okay, but I'm still weirded out by the originally manufactured as a rifle.

I guess if you made your onw reciever (Ace blank) then it was of you own manufacture as a pistol, right?

My Dad wanted to make an old Enfield he was given into a pistol because the barrel was bent over. He found out it's not legal to do so unless he made a new receiver.
 
#9 ·
well my plans are to use either a flat bent into a receiver or some type of bent blank. My major concern is starting a project then having to do heavy mods to parts to make them work. If the krink front sight/gas block combo works then that would be great. Also using a block like this one:

would be best, and that way no regular stock could fit. Maybe I will have to get into using rivets in my builds, lol :D.
 
#10 ·
The downside I can see to using a cutdown standard gas tube would be the amount of barrel left inside the gas block. Even with the shortened standard tube, there's only an inch of barrel past the end of it. This looks like it is only going to allow about 1/2" of barrel in the Krink gas/sight block.

The Krinkov gas tube only looks to be about 1/8" sticking out past the handguard. This would change the amount of available space to about 2" of barrel sticking out past the end of the gas tube.

The Krink HG retainer has the latch pin flipped around so it's closer to the receiver. This leaves the front of the retainer flat so it can be pushed closer to the gas/sight block.

Now here's the rub... Krink parts prices:

$30 for Krink gas tube
$40 for Krink lower HG retainer
$70 to $110 for Krink handguard/pistol grip sets.

As in the following pic, I think you could use either block by shortening the standard gas tube even more (or use a Krink tube) and mill some material off the front of the standard handguard retainer. The yellow line is where I would cut mine.



This would allow room for getting both retainer pins in the gas/sight block, there would be room for sliding the handguard retainer, and there would be almost an inch of barrel in the gas/sight block. A standard 24mmx1.5mm AK-74 brake fits on the block in the pic, or you could use a Krink cone type flash hider to get more back pressure for the gas system.

I think it would work well using standard AK parts. There's no need to dump big money into Krink parts (except maybe the gas tube) if the standard parts can be modified. I'd make my own gas piston too, it'd save $90 over buying a Krink carrier from K-Var.
 
#12 ·
Sangrun Hunter, here's the LINK on how to utilze a virgin receiver in a pistol build. Basically, it could be a "rifle type receiver" but couldn't have been used previously on a rifle. You would also have to obtain a letter from the manufacturer verifying its authenticity. Doesn't seem to hard, if you want to use a pre-fabbed receiver. I would assume you could skip most of these steps if you built from an ACE, or bent your own.

Looks good Rhino and Sniper! I knew there were some of you guys stocking up parts to build these. This will put a really nice twist and turn on our "standard" builds!

I can see it now..."Gunco's AK-47 Pistol Homebuilder forum"

:2guns: :2guns: :2guns:
 
#13 ·
SangRun Hunter said:
I think it's okay, but I'm still weirded out by the originally manufactured as a rifle.

I guess if you made your onw reciever (Ace blank) then it was of you own manufacture as a pistol, right?
Right. That's about the best way you'll get an AK Pistol. Those K-Var barrel assemblies are ideally suited for this!
 
#14 ·
I suppose you could use the rear trunion from an underforlder and it would serve the same purpose.

As for a forward grip, I agree that if it is at an angle to the bore, like on a Romanian AK, it would be considered an AOW.

As for the pistol idea, I have heard of others, before the ban, having the manufacturer log the receiver as a pistol and marking it as such. This was done with numerous AR receivers prior to the ban.Then, you could do with it as you pleased. AS far as I know, it is ok to make a pistol a rifle( if the barrel is long enough) but not legal to do it the other way around.
 
#16 ·
Rhino that's great info! I just have a few (maybe dumb) questions on this. What's the best way of marking the correct location for the gas hole in the barrel and what size are you going to make the hole? I understand that the shorter the barrel the bigger the hole should be. Also what's the easiest way to make the slots on the barrel for the gas block/sight block retaining pins? TIA
 
#17 ·
Shortrnd said:
Rhino that's great info! I just have a few (maybe dumb) questions on this. What's the best way of marking the correct location for the gas hole in the barrel and what size are you going to make the hole?
Use a centering jig for a drill press.

I understand that the shorter the barrel the bigger the hole should be.
Never heard that. The standard size hole for 5.45x39 is 0.076" diameter, same as a #48 drill bit. The 7.62x39 is almost exactly 11/64" diameter. Depends on the action I suppose, but if using a krink flash hider, it will act as an "expansion chamber" and should compensate for the short barrel.

Also what's the easiest way to make the slots on the barrel for the gas block/sight block retaining pins? TIA
Ideally, use a reamer. Easiest way is to chuck the already-assembled barrel assembly into the drill press and drill halfway through, flip over and drill the other half. Using lots of oil and going slowly. Retaining pins are standard Metric 3mm x 12mm dowel pins from McMaster-Carr, part #91595A213.

hth,
- Jerry
 
#18 ·
Dang Hcpookie, your genius simply boggles my mind. I have one of these cut barrels and would love to build it up but I don't know if I have the skill needed. I think I'd need a board member present to walk me through it.
 
#19 ·
Use a centering jig for a drill press.
Ok. That makes sense. I guess what I was wanting to know is how to locate the proper location (how far from the muzzle). Sorry I think I didn't word that right originally.

As far as the gas hole size needing to be bigger I was thinking it would be the same as shortening an FAL barrel where you need to open up the gas port for proper gas operation. Thanks for correcting me on this.

I appreciate the help.
 
#20 ·
Polish Taipan said:
Dang Hcpookie, your genius simply boggles my mind. I have one of these cut barrels and would love to build it up but I don't know if I have the skill needed. I think I'd need a board member present to walk me through it.
To quote Han Solo, "sometimes I amaze even myself"

:D :D :D lol

I'm just very very technically/mechanically minded is all. Also, lots of "been there, done that" experience ;)

I must admit, my AK skills are directly attributable to following the lead of others. I had quite an experience converting my preban '47 to an AK-103 config, complete with folding stock.

IMO anything is possible, you just need enough determination and willpower. Look at Lance Armstrong.


Anyone thought about one of those 9mm PPSH barrels for use in a conversion? Would like to build a Bizon clone ;)
 
#21 ·
Shortrnd said:
Ok. That makes sense. I guess what I was wanting to know is how to locate the proper location (how far from the muzzle). Sorry I think I didn't word that right originally.
Been there, done that. Is a real pain. I had to use the eyeball 1.0 method.

http://pookieweb.dyndns.org:61129/AK/gas_port_replace/gas_port.htm


As far as the gas hole size needing to be bigger I was thinking it would be the same as shortening an FAL barrel where you need to open up the gas port for proper gas operation. Thanks for correcting me on this.

I appreciate the help.
Hrm I didn't know that about FALs. Seems to make sense. I recall reading a thread sometime back where a guy was making an AOW AK and had this short short barrel. Seem to recall that he discovered the port size wasn't terribly important, thus my conclusion that it doesn't matter. Still, seems that with the expansion chamber up front, this is a moot issue???
 
#23 ·
Let's go for even cheaper... I'm brainstorming tonight.

Got a MAPP gas torch? Good. Here's what I'm thinking... take a $20 vertical gas block and a cheap-o front sight, and dremel the front sight down to fit onto the gas block. Then weld. I did this for my AK-105 "clone" but why would it not be suitable for this application? Some reaming may be required but it would be cheaper/easier than shelling out the big bucks for the combo sight block...

http://pookieweb.dyndns.org:61129/AK74/sight_block.htm

Now I know what you're thinking... what about the threads for the muzzle device? Well I was thinking about that too... following the Romanian AK page's lead, thread the end of a 3/4" bolt to make an "adapter" for the 22mm threads...

http://www.gunsnet.net/Linx310/fsbhome.htm

Viola! You have a poor-man's krink FSB. Done.

OTOH, one could simply delete the FSB altogether, put a riflestock.com sight rail on it, and red dot/laser it. "Flat-top AK".

Only thing left would be drilling the gas port.

Now where to get the parts? Get the Krink FSB at K-Var and you'll spend $90. Get these parts separately and you'll spend $20 for the gas block and $20 for the FSB. OR you could get this if you wanted to try 7.62 caliber:

http://www.aa-ok.com/AK_Barrel_Section/Barrel_Parts.html

AK-154 as pictured with late AKM or early AK74 style Gas Chamber & Front Sight complete. Bayo Lug is intact on Gas Chamber !

$40. Remove the parts from the barrel and play. Note that this comes w/ the handguard retainer too. 45-degree gas block so would not work for 5.45x39 caliber.
:(

Cut handguards to length, and cut down a gas tube in the same way many have cut down a normal gas tube for those AMD-65/63 clone builds, and everything forward of the receiver is "done".



Oh, and for the rear trunion, to save some more money, I was thinking again... I have some 1.25" aluminum square tubing. Seems like this could be used as the rear trunion... a recoil buffer would be required of course, but it would be a cheaper (and lighter) alternative than the K-Var rear trunion. Just a thought. For that matter some scrap steel could almost be used. Sure, there would be some dremel work (or milling work) for the recoil spring notch and top cover notch, but it COULD be done. Or not... just brainstorming here. And trying to save another $30 :D


Here's yet another thought - could, or could not, the bolt carrier have "lightening holes" drilled into the main mass, toward the rear (and away from the action)? This could help the overall balance of the pistol.


Final thought - Post-sunset, can we, or can we not, have a detachabe mag on a pistol? I know that NOW the Bushmaster AR pistols have detachable mags, in a post-ban offering:

http://www.bushmaster.com/shopping/carbon15/az-c15p21.asp
 
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