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[#1]
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[#2]
Originally Posted By Type7SOT: A3 stock rails cut down. First step in converting them to reinforcing rails. These are very hard. https://www.ar15.com/media/mediaFiles/490765/1000006760_jpg-3260807.JPG https://www.ar15.com/media/mediaFiles/490765/1000006759_jpg-3260808.JPG View Quote Is this just to make the receiver more rigid? I assume the higher rate of fire takes a toll on the standard receiver. |
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Tactipug. The ultimate compact firepower!
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[#3]
Originally Posted By mah827: Is this just to make the receiver more rigid? I assume the higher rate of fire takes a toll on the standard receiver. View Quote I assume so, I'm flying by the seat of my pants here. All variants of HK21's have the rails, and there are different styles. These kits would have the early teardrop style, which appears to be similar (maybe identical?) profile to a set of A3 stock rails. So thats what I'm making them out of. |
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[#4]
Originally Posted By mah827: Is this just to make the receiver more rigid? I assume the higher rate of fire takes a toll on the standard receiver. View Quote I’ve always assumed for the extra rigidity and to keep the rollers from denting the rails. Now and then you’ll come across an HK roller lock with a bunch of dents in the rail from the inertia of the bolt slamming into the buffer and pushing the rollers out at the rear of the recoil stroke. |
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[#5]
I haven’t been doing much with my kit. Ordered a PTR receiver this evening… need some receiver rails and I’m back to making some progress .
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[Last Edit: rssc]
[#6]
Nevermind. Century is not currently taking orders.
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[#7]
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[#8]
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[Last Edit: cms81586]
[#9]
Originally Posted By Type7SOT: Got the rails fitted https://www.ar15.com/media/mediaFiles/490765/1000006787_jpg-3263904.JPG https://www.ar15.com/media/mediaFiles/490765/1000006788_jpg-3263905.JPG View Quote Looking good. When’s the welding start? Don’t forget that ejection port is going to need opened up. |
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[Last Edit: barbcue]
[#10]
Originally Posted By cms81586: “It’s Happening…….” https://www.ar15.com/media/mediaFiles/2980/IMG_2459_png-3263622.JPG View Quote At that price, are those Cryo barrels CHF and true reproductions of the originals ? Im betting they are. |
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[#11]
I think they are + chrome lining. Also he is advertising they will ship with all the hardware which is significant.
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[#12]
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[#13]
Originally Posted By cms81586: Looking good. When’s the welding start? Don’t forget that ejection port is going to need opened up. View Quote Today ![]() ![]() |
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[Last Edit: cms81586]
[#14]
Originally Posted By Type7SOT: Today ![]() https://www.ar15.com/media/mediaFiles/490765/1000006790_jpg-3264231.JPG View Quote Those welds look nice. Any tips for welding the reinforcing rail into place? Did you use a heat sink inside the receiver? |
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[#15]
Originally Posted By cms81586: Those welds look nice. Any tips for welding the reinforcing rail into place? Did you use a heat sink inside the receiver? View Quote I work at a metal shop. I handed it to one of our welders and said "please weld this." ![]() No heat sync, I suppose it might be a good idea to throw the bolt carrier in there to suck up some heat, but it seems to have worked fine without it. |
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[#16]
That’s the way to do it right there. All my friends bring me their shit to weld on but I am really not a great welder. I’m actually kinda stalling because I’m just a bit nervous of dicking that part up.
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[#17]
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[#18]
Is there different types of receivers besides flats? I talked to a builder and with a 4k labor fee, to have a german receiver made for my kit, it's an additional 2k for a G3 receiver.
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[Last Edit: barbcue]
[#19]
Originally Posted By cms81586: They are. They're CHF and Chrome lined. https://www.ar15.com/media/mediaFiles/2980/IMG_2464_png-3264200.JPG View Quote Outstanding ! Also UPDATE Atlantic more than came through with regards to my broken back plate and out of round triple frame. They sent me what appears to be a BRAND NEW stock , back plate/cap and recoil rod. the paint looks mint. And also a perfect Shroud !!! (which i didnt even ask for and in fact said ill keep the one i have) So far,, Atlantic Firearms has been OUTSTANDING on Customer Service and replacement parts with regards to these kits Pics of the parts they sent me later today when im not so *spent* - tired and spun out - (Night shift Truck Driver) |
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[#20]
What is the best receiver to use on these? I think PTR has their serial number on the top rib, but their maker info is on the mag well which gets cut off. Is that ok / legal? I read someplace, maybe WG that guys were bending their own flats so they didn't have to mess with the makers info deal.
Thoughts? |
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[#21]
Originally Posted By Polycop: What is the best receiver to use on these? I think PTR has their serial number on the top rib, but their maker info is on the mag well which gets cut off. Is that ok / legal? I read someplace, maybe WG that guys were bending their own flats so they didn't have to mess with the makers info deal. Thoughts? View Quote On title 1 firearms you can remove anything besides the serial number. |
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[#22]
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“How dare we whine at our inevitable return to that prior state from which the vast majority have never stirred?”
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[#23]
Originally Posted By M-60: More motivation... https://photos.smugmug.com/Shooting/Organized-Gatherings/CABIN-SHOOT-24/i-wfXrvwj/0/Nb5mXmb8CcpFT3h4n5CjKGq9RJjwSXS59RrNKWWhs/XL/CABIN%20SHOOT%20'24-2-XL.jpg View Quote Niiiice! |
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[#24]
Originally Posted By M-60: More motivation... https://photos.smugmug.com/Shooting/Organized-Gatherings/CABIN-SHOOT-24/i-wfXrvwj/0/Nb5mXmb8CcpFT3h4n5CjKGq9RJjwSXS59RrNKWWhs/XL/CABIN%20SHOOT%20'24-2-XL.jpg View Quote Beautiful. What are the details on the E? |
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[#25]
Originally Posted By M-60: More motivation... https://photos.smugmug.com/Shooting/Organized-Gatherings/CABIN-SHOOT-24/i-wfXrvwj/0/Nb5mXmb8CcpFT3h4n5CjKGq9RJjwSXS59RrNKWWhs/XL/CABIN%20SHOOT%20'24-2-XL.jpg View Quote Beautiful. What are the details on the E? |
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[#26]
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“How dare we whine at our inevitable return to that prior state from which the vast majority have never stirred?”
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[#27]
Got one of my kits hand cycling at this point
![]() Real question is where to find a barrel /borrow a barrel from on short time preferences? Anyone with an old FMP barrel want to turn it into 2x cryostructure barrels? |
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[#28]
Originally Posted By 7insert: Got one of my kits hand cycling at this point ![]() Real question is where to find a barrel /borrow a barrel from on short time preferences? Anyone with an old FMP barrel want to turn it into 2x cryostructure barrels? View Quote Did you get in on the first batch of Cryostructure barrels? If so, I would just be patient and wait as they should be shipping in the next 2 1/2 to 3 weeks. |
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[#29]
Originally Posted By cms81586: They are. They're CHF and Chrome lined. https://www.ar15.com/media/mediaFiles/2980/IMG_2464_png-3264200.JPG View Quote Thanks, just ordered a pair without hardware. |
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[#30]
Would a g3 picatinny mount go on these or would you need a specific type to fit properly?
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[#31]
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[#32]
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[Last Edit: cms81586]
[#33]
Time to get moving again on this. I want to have the receiver ready to weld the trunnion and shroud on by the time CryoStructure ships my barrel. Rails, ejection port expansion, and magwell chop are on the to-do list this week.
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[#34]
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[#35]
Get yourselves one of these! Just got mine, it works amazing well!!
https://youtu.be/IEjyBuVyVEo?si=NJhKHzzfsUphpfv9 |
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[#36]
Visiting family left today so I spent a few hours in the garage tinkering. Got the magwell cut off, feed box receiver remnants removed, and ejection port lip cut off (to be able to put on the feed box…I will trim the port back later). Still have some fine clean up work to do but rough fitting went well and everything is looking great so far. Feed ramp alignment looks good too. Not ready to start welding anything yet and still have a lot more work to do. Gotta trim back the cocking tube farther, drill holes for the trunnion welds, get the receiver reinforcing rails done up and welded in, and then go from there. Not welding on the shroud until I have the barrel on hand to ensure alignment.
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[#37]
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[#38]
Originally Posted By Type7SOT: Rear sight base welded https://www.ar15.com/media/mediaFiles/490765/1000006894_jpg-3275669.JPG https://www.ar15.com/media/mediaFiles/490765/1000006895_jpg-3275670.JPG View Quote Any tips on getting the sight base welded on straight? |
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[#39]
Originally Posted By cms81586: Any tips on getting the sight base welded on straight? View Quote I used a machinist vice with parallel jaws to hold it in place while I tack welded it, which made it perfectly level. One clamp jaw on the sight base, and one jaw on the bottom of the receiver. Once tacked, I pulled it out the vice and handed it to my welder. He used a 3/4" OD aluminum round tube as a heat sync and went to town. |
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[#40]
Originally Posted By Type7SOT: I used a machinist vice with parallel jaws to hold it in place while I tack welded it, which made it perfectly level. One clamp jaw on the sight base, and one jaw on the bottom of the receiver. Once tacked, I pulled it out the vice and handed it to my welder. He used a 3/4" OD aluminum round tube as a heat sync and went to town. View Quote Appreciate it! |
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[#41]
Rails arrived today. These are the ones RTG had before STS bought up their stock to convert for the same purpose. Got lost in the mail for a while and miraculously made it. Will be doing some surgery later tonight.
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[Last Edit: cms81586]
[#42]
More slow progress. Slowly trimmed back the cocking tube until the receiver bottomed out on the shroud inside the rear bipod mount. This has the trunnion seated exactly where it was originally before I removed it from the kit. Drilled my receiver holes for the four plug welds on each side. Cleaned up my cocking lever slot in the cocking tube a bit and finished some minor hand fitting. Still have to do the conversion on the stock arms into teardrop reinforcing rails…but I’m away for work this week so that will have to wait until this weekend.
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[Last Edit: lightguy]
[#43]
I have two kits.
One with HK bolt carrier and one with FMP. The FMP carrier has fairly significant wear to the guide slot cut in the bottom. HK bolt looks nice. Contacted Centerfire but so far no response on their FMP carrier kit. HK carrier kit was bought on GB. |
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[#44]
I think well worn components are to be expected in these things. I did return one buttstock assy to CF and it was replaced with one that was completely destroyed, looks like it was run over by a tank. I figured, hey can't hurt to ask... but I probably should have just dealt with it. Not saying you shouldn't try but be aware it's just another roll of the dice.
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[Last Edit: Alaska-Shooter]
[#45]
I was looking through old Somalia pics I had. Check out the two guns in the lower part of the pic. These were confiscated guns taken by the Australians near Baidoa.
https://imgur.com/a/0TrlFMh |
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[#46]
More progress tonight. Trimmed the A3 stock rails and welded up the locking notch to make sure they’re as strong as possible. Still have one more to fit but the right side is done sans trimming it to length to close the gap. Still have to do the left side rail. Also tacked up the cracks on my lower housing at the rear tab.
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[Last Edit: cms81586]
[#47]
Been busy so no real updated. Waiting on a barrel to proceed with the build. Have the reinforcing rails done. Everything is really straight right now. That will probably change when the welding starts.
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[#48]
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[#49]
Wanna try to unfornicate the RTG flat I have? 🤣
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[#50]
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