Got Uzi Posted April 16 Report Share Posted April 16 I needed a “me” project….so I’m gonna build (or attempt to build) a semi auto SBR Swedish K. I have enough parts to build one complete (short an ejector and complete barrel shroud for a second) got the tubing in today (which I only needed 13.25” and had to buy 3 ft) I’m not sure when I’ll get to start on it, but I’ll take pictures of the process. I’m excited and nervous as to how the receiver tube machining will go. Going to put it in my indexer on the CNC mill to do that. It’ll be an interesting learning curve as my primary business is building HK clone guns….if all goes well perhaps I’ll branch out and make some K SBR’s and put them on the market as well. Link to comment Share on other sites More sharing options...
Got Uzi Posted April 17 Author Report Share Posted April 17 Here are some pictures of today’s progress…the receiver prints I have are for an SMG spec tube…didn’t realize this until I had the receiver tube in the bench…the cocking handle slot needs to be machined closer to the ejection port. I have to do the following: Lengthen the cocking handle slot, cut the back end off to length, machine in the tail cap lock notches, modify the sear height pin so the sear sits higher in the tube, machine the magazine opening wider (since I’m using semi auto spec tube/thicker side wall) and then it should be time to weld it all up. I’ll post more pics when I can get back to this. Took the day and decided to tinker for a few hours while I had the chance. Link to comment Share on other sites More sharing options...
USMCsean Posted April 17 Report Share Posted April 17 Nice!!! I assume you’re doing a striker fired build? Link to comment Share on other sites More sharing options...
Got Uzi Posted April 17 Author Report Share Posted April 17 Yes I’m using an Indianapolis Ordnance semi auto bolt group in this. They didn’t have any tubes in stock and they won’t sell the template only so I’m doing a tube on my own. Link to comment Share on other sites More sharing options...
Rekraps Posted April 17 Report Share Posted April 17 21 hours ago, Got Uzi said: Here are some pictures of today’s progress…the receiver prints I have are for an SMG spec tube…didn’t realize this until I had the receiver tube in the bench…the cocking handle slot needs to be machined closer to the ejection port. I have to do the following: Lengthen the cocking handle slot, cut the back end off to length, machine in the tail cap lock notches, modify the sear height pin so the sear sits higher in the tube, machine the magazine opening wider (since I’m using semi auto spec tube/thicker side wall) and then it should be time to weld it all up. I’ll post more pics when I can get back to this. Took the day and decided to tinker for a few hours while I had the chance. Holy moly Got Uzi! You are a feisty dude for sure, but nobody can doubt your talent! Great work, excellent detail. 1 Link to comment Share on other sites More sharing options...
Got Uzi Posted April 17 Author Report Share Posted April 17 Well thank you. I discovered a few other little details that the semi auto receiver needs a few more little details. Also had to modify the sear restriction height pin so the sear sits higher in the tube. Hopefully this weekend I can finish the tube machining then tack weld it together and try it out before finish welding Link to comment Share on other sites More sharing options...
Rekraps Posted April 18 Report Share Posted April 18 Let's see good pics as you progress.... Link to comment Share on other sites More sharing options...
Got Uzi Posted April 18 Author Report Share Posted April 18 If and thats a big IF this goes well, I might build a few of these as SBR's and offer them to the public. There aren't any on the market at this point so why not? Link to comment Share on other sites More sharing options...
Remo Williams 1 Posted April 18 Report Share Posted April 18 Mishaco has a nice video on his semi SBR’d K on YouTube Link to comment Share on other sites More sharing options...
USMCsean Posted April 19 Report Share Posted April 19 I was hoping to do the same. Figured they’d be somewhat easy to offload. Link to comment Share on other sites More sharing options...
NE Patriot Posted April 19 Report Share Posted April 19 They would be easy to sell, there's definitely a market. Link to comment Share on other sites More sharing options...
Got Uzi Posted April 20 Author Report Share Posted April 20 Hoping to get back on the project in the next week or so. Working on the interior of my new machine shop. I’m looking forward to getting this going. 1 Link to comment Share on other sites More sharing options...
USMCsean Posted April 21 Report Share Posted April 21 Looking forward to the progress! Link to comment Share on other sites More sharing options...
USMCsean Posted May 1 Report Share Posted May 1 Any update on the build or some pics of the shop? I am living vicariously thru you. 😁 Link to comment Share on other sites More sharing options...
Got Uzi Posted May 1 Author Report Share Posted May 1 Funny you ask about this today….I have been tinkering with the K project this week off an on when I get overwhelmed finding homes for stuff…took it out and test fired it today-shot well but was having trigger reset issues…came back to the shop and found the disconnector notch was dragging on the sear when trying to reset. Took off .030ish the tip of the hook and made the hook deeper by said .030ish. I also reprofiled the side and radius of the disconnect hook as well. It works perfectly on the bench now so I’ll test fire it again in the morning. This process I discovered that the receiver drawings I have are for a Full Auto spec tube and I was making a semi auto tube (more on this later) and with this I discovered that the Indy Ord bolt handle is in a different location (rotation angle wise) from that of the original K handle. I had to machine a plug, press it into the bolt body, then machine an offset hole into the plug (and into the body) followed up by machining a custom bolt handle to put it all together with. Now as long as the test fire goes well tomorrow morning, I plan to come back, mask, blast and paint it “Swedish K Green” This build is NOT for the faint of heart of for those who are not mechanically skilled or understanding of gunsmithing. Not trying to sound superior or talk down to anyone, just giving fair warning. I can honestly say that at this point I have 35-40 hours in this gun over all and selling on the open market for $5,000-$6,000 is where they would be. 1 Link to comment Share on other sites More sharing options...
USMCsean Posted May 2 Report Share Posted May 2 Glorious update!!! I am definitely curious to hear more. I have seen and heard that the Indianapolis Ordnance kit places the handle at a slightly different angle. They do that as a denial bar to keep a FA bolt in an SA tube. Ergo, their handles match their SA tubes. I am curious why you chose to fill the large gaps with weld instead of filler pieces. Also, do you plan to machine the weld where the tube meets the sides? I’d like to hear more about the trigger setup. Link to comment Share on other sites More sharing options...
Got Uzi Posted May 2 Author Report Share Posted May 2 The tube ID is also smaller so a standard K bolt won’t fit inside either. The semi auto bolt body is roughly .100 smaller than the standard K bolt. Thats the major denial block. The angle is somewhat of a “wtf” moment when you can’t get a tune from them and using specs you dug up from different sources. I’m working on a new set of prints for the semi tube and a new process sheet for order for the operations. I welded the gap instead of using a filler piece only because I wanted to play with my welder and test settings since I’m in my new shop. The amperage settings indeed are different now that I’m in town vs being in the country. I ground the weld seam to blend it in where the lower section meets the tube. I’m going to look at it again today to see if I like the results of that. 1 Link to comment Share on other sites More sharing options...
Rekraps Posted May 2 Report Share Posted May 2 On 4/18/2025 at 1:18 PM, Got Uzi said: If and thats a big IF this goes well, I might build a few of these as SBR's and offer them to the public. There aren't any on the market at this point so why not? I think they'd sell great! Link to comment Share on other sites More sharing options...
Got Uzi Posted May 2 Author Report Share Posted May 2 Test fired it today and it ran great. Might need to tweak the extractor spring as it’s super stiff. It does like 115 gr as it doesn’t have enough “umf” to get the extractor to snap over the rim causing it to OOB. Switched to 124 gr and it ran flawlessly…well after I realized I also had a bad mag in the mix LOL Link to comment Share on other sites More sharing options...
USMCsean Posted May 2 Report Share Posted May 2 4 hours ago, Rekraps said: I think they'd sell great! That’s why I want to get busy with making receivers. Link to comment Share on other sites More sharing options...
Got Uzi Posted May 2 Author Report Share Posted May 2 I’m looking at kit costs and working on the final total with parts, labor, and so on. Kit prices are going to be a big factor in the over all cost, not to mention consistency of getting said kits. I guess the question is, how serious are you in doing this USMCsean? No offense meant by this but you talk like you want to make receivers but do you have the equipment and an 07/02 to do all this or were you planning to farm out the work and just be the investor on it? The other obstacle of these is once the initial void is filled, they will slow down as most won’t want to spend the money. It’s the same thing that happened with the DK MP38’s. When the first run was sold out and void was filled, they became something people wished upon a star to have. Link to comment Share on other sites More sharing options...
USMCsean Posted May 3 Report Share Posted May 3 (edited) No offense taken. At this moment, I am looking at making the sheet metal receiver shell, for lack of a better phrase. Depending on how well this goes, i’ll see what happens next. Edited May 5 by USMCsean Spelling Link to comment Share on other sites More sharing options...
NE Patriot Posted May 4 Report Share Posted May 4 On 5/2/2025 at 4:21 PM, Got Uzi said: Test fired it today and it ran great. Might need to tweak the extractor spring as it’s super stiff. It does like 115 gr as it doesn’t have enough “umf” to get the extractor to snap over the rim causing it to OOB. Switched to 124 gr and it ran flawlessly…well after I realized I also had a bad mag in the mix LOL GUzi, Can you expound on the out of battery (OOB) discharge. The factory springs are really stiff. It's hard to believe that after so many years in service, it's a problem that hasn't been solved. Link to comment Share on other sites More sharing options...
Got Uzi Posted May 4 Author Report Share Posted May 4 (edited) It didn’t fire out of battery, the bolt was out of battery/aka not closed as the extractor didn’t lock into the case rim. Edited May 4 by Got Uzi Link to comment Share on other sites More sharing options...
NE Patriot Posted May 5 Report Share Posted May 5 Got Uzi, Got it. The orig. extractor springs are really stiff. I spoke w a Swedish officer, and they were having a problem with out of battery discharges during training. Didn't happen often, if fact very few, but when the gun fired before the bolt was fully down, brass shards spewed out, and it scared soldiers. The issue was pebbles are other debris getting into the open action while crawling through the woods. When fired, the pebble would get between the bolt and cartridge, hitting the primer before the bolt was fully down. They started using brass catchers during training, even combat training, to prevent anything getting into the open action. For actual combat the catchers were dropped. Joe 1 Link to comment Share on other sites More sharing options...
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