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Discussion Starter #1
Got the first part in today for my build!



Mostly complete G3 parts kit and a 2-stage buffer are oscar mike to my location as well.

This is my first foray into any sort of gun smithing, as well as into the world of HK firearms. I'm fairly mechanically inclined and I have enough machinery to get it all done though.

I've got a nice Rock River Arms Elite CAR A4, but it doesn't have the accuracy I'm looking for. I want something with good 300-500 yd accuracy, is fed by a magazine, and mounts a scope. Settled on a G3 clone. I'm not looking for historic accuracy or to make a near copy of a real HK, I'm just looking for a nice accurate 7.62 rifle.

Here's what I'm thinking:
G3 trunion
JLD 20" barrel
JLD receiver reinforcement rails
2-stage buffer
PRS adjustable stock
Navy-type composite pistol grip
Williams trigger job

I guess it'll end up resembling an MSG3, but I can't find any barrels longer than 20" that are easy enough to come by. I'll just add a flash suppressor for length LOL

I've been reading all the build instruction pages and I have a pretty good mental image of how all this stuff will go together, but is there anyone that would be free to shoot some build assistance over once in a while?
 

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Does your JLD barrel fit onto a triple sight frame? I bought a JLD 20" fluted barrel (full heavy profile) for a target rifle build. I believe your JLD barrel is going to require an MSG/PSG forearm.
 

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Discussion Starter #3
I shot an e-mail to JLD the other day:

"I saw the 20" barrel for sale on the website and I was curious if
this barrel will fit a G3 clone build without modification. The image
looks as if it is a bull style barrel and I was curious if it would fit
the triple frame dimensions, or possibly require a different trunion."

And their response was:

"The barrel will fit the trunion but the triple frame will need
modification "

I thought about an MSG90/PSG1 style build, but finding a forearm seems to be ridiculously difficult, that and it just wouldn't look right with a 20" barrel IMO.
 

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...I've been reading all the build instruction pages and I have a pretty good mental image of how all this stuff will go together, but is there anyone that would be free to shoot some build assistance over once in a while?
Can you list the build instruction pages you have seen. I'd like to do a build myself and am looking for resources.
 

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Discussion Starter #5 (Edited)
http://www.smcomp.com/~smurph/G3-build.html
Some good technical info on how stuff goes together and what you'll need. As a Noob it was hard to grasp how a lot of things went together, like barrel, trunnion, where the trunnion stops in the receiver, as I don't have any of the parts yet, but looking at pictures in other threads greatly helped me.

http://www.arizonaresponsesystems.com/notes/sw3build/pagesw3build.htm
Good pictures illustrating the receiver/trunnion/barrel/cocking tube fitting. Some good all around build pictures, less technical info.

http://www.ar15.com/content/manuals/G3_Armorer_Manual.pdf
Nice resource for maintenance and some mediocre assembly pictures

http://www.thehighroad.org/showthread.php?t=221454
General info on 922(r) compliance.

http://www.mg-42.net/ this was in m...op left. [url]http://hkpro.com/technical.htm
kind of technical explanation of the roller locking bolt action. Took me a few reads, but being an engineering student with half a brain helped me realize what was going on.

Those are the main resources. I've gathered smaller facts here and there, tidbits on what forearms fit what trunnions, which barrels are good and which are bad or at least questionable. The only part I dread now is that I'll probably go for an SEF trigger set & grip and try to clip and pin it, which I understand isn't terribly hard. The whole trigger mechanism still baffles me for now, have to work through that one as the time comes.
 

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g3 trunion

Scider,

If your looking for a g3 trunion let me know, I have a bunch of new ones.

Lugerguards
 

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It looks like your doing you homework.Research is the most important step!It seems most step-by-step builds have dissapeared off the net.

The PTR 20" bull barrel will not fit in that forearm,there's just enough clearance for the stock diam. barrel.As mentioned above...use a PSG-1 /msg90 handguard. Like this...
http://www.shop.black-market-parts.com/product.sc?categoryId=3&productId=9

Just remember...Barrel depth in the trunion is what you adjust for proper bolt gap.Which you can set up before you install the barrel/trunion assembly into the receiver.Then you install the cocking tube...and get to welding.

everything else is a piece of cake....

Good luck on you build! :)
 

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Discussion Starter #8
So basically my speed bump right now is barrel selection. Here's what I've got on the table...

20" JLD barrel + MSG/PSG1 trunnion and forearm, the forearm might I add seems to be impossible to find.

18" JLD barrel, kind of defeats the purpose of making an accurized clone

Joeken barrel, which are sort of reputed to be shady and of questionable quality

Urbach barrel, which is of the utmost quality but prohibitively expensive for my tastes and who knows when you'll get one.

The thought of getting the 20" barrel and having it turned down is still kicking about in my head.
 

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Discussion Starter #10
So I got my parts kit in today. Semi-auto FMP stuff all over. I contacted that link to Rim Country Mfg (thanks NSR500 :D ). They let me know that they wont do one off barrels, but they will chamber, flute and machine the trunnion end of a barrel for a very reasonable fee, sometime in the near future, after they get tooled up to do .308 barrels. Learned a few things as well. I've basically come to a fork in the road on overall design:

I can attempt to go with an MSG90 style build. This would require finding a near impossible to find forearm, using a pricier trunnion or trunnion extension, as well as finding out what modifications need to be done to the cocking tube to get it to work. Retaining iron sights is very important to me. Barrel selection would fall to a nice Douglas barrel. Probably a 26" Heavy Sporter (No. 4). http://www.benchrest.com/douglas/dimensions.html

OR

I can go with an accurized G3 style build, retaining a wide forearm. This would require a lighter and probably shorter barrel selection to keep from putting too much strain on the G3 trunnion. This would ALSO require me to get the barrel machined at a gunsmith to accept a triple frame, or modify the triple frame to accept the barrel.

I also have to fab up some sort of front handguard mount for the wide handguard because I have an old style narrow grip triple frame and cocking tube.
 

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Discussion Starter #11 (Edited)
Well things are progressing. I've decided to do a real MSG90 style build and have been ordering bits here and there. The hardest part still looks to be sourcing an authentic forearm.

I won a Douglas XX barrel in #3 contour .30 caliber on gunbroker. Overall it's about 25". I'm waiting for Rim Country Mfg to get tooled up and I'll shoot it over to them to be finished up. I plan to have the muzzle trimmed a bit and fitted for a flash hider locally. On another note, does anyone know what the amount of interference is for the trunnion press fit?

I also ordered some parts from Black Market Parts. The experience overall was good and I was pleased with what I got. Communication was a bit iffy, I got their 'order shipped' e-mail the same day it got to my door.

Here's some pictures of bits:


 

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Who did you get the cocking handle from? Is it the rubber one for the HK21?
 

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Hi Scider.

Is that barrel for a bolt action normally? Sounds interesting..

Your post from last month mentions an 18 inch from JLD? I have seen the 20 inch... but the shorter barrels that they sell on the guns seem to not be available... Also the triple tree would have to be remade it seems... there is not enough meat to use the triple Tree it seems...

keep us informed...

Anyone have a pic of their G3 clone that uses a JLD 20" heavy profile barrel?

LO
 

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Discussion Starter #14
The cocking handle is from Black Market Parts as well as the trunnion. I believe they market it as a 21/23E component, US made.

As for the barrel, it's a standard blank from Douglas. They're commonly used on bolt rifles, but I'm going to be sending it off to Rim Country to be chambered, fluted and have them machine it for a trunnion fit. I'll thread it for a flash suppressor myself. I may replace it eventually with a true bull barrel but I practically stole it off of gunbroker ;) Trying to keep the build at least somewhat budget minded.

I did a lot of research before deciding on an MSG90. First thoughts were an accurised G3 style, but I decided the barrel wasn't REALLY free floating (and I'm a perfectionist). It is in my opinion that the clearance around the cocking tube dissapears when you apply pressure to the handguard, so I went to an MSG style. The 20" JLD is a true bull barrel and with some conversing with the ever knowledgable JFK I realized it was too large for a normal hand guard.

As for the triple frame, well as far as I can tell the MSG90/PSG1 don't use one. It's omitted on both. Iron sights were incorporated on the MSG90A1 by means of what I would assume more of a 'double frame' attached only to the cocking tube. The most difficult bit I think will be getting it vertical. Retaining iron sights was one of my build criteria.
 

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Discussion Starter #15
Well I got the barrel sent out to Rim Country and I'm just waiting to hear word back from them when it's finished. In other news I got the parts kit taken more apart. The main thing I need is the cocking tube, but I managed to get it off without much trouble. I used a 3/8" endmill to drill out the welds for the trunnion and machine off the top bit with the cocking tube. I was surprised to find out how easy it is to get to the correct depth. The trunnion is made of a much tougher steel and it really doesn't like to be machined.

The trunnion that came out has a few knicks from the endmill bit but really not very much damage at all! A little cleaning up and I may decide to build a G3 LOL. The pictures look like crap because I hadn't cleaned off the shavings.




 

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Discussion Starter #16 (Edited)
Well my barrel came in from Rim Country and it looks AWESOME! Big plus to them. Also got a receiver in from Ohio Rapid Fire. Looking at rails. Most likely I'll make a rig and do them myself. I can't see paying $200 for decent 'T' rails when I can make them myself. Currently designing a tool to do it in the mill on CAD. I'll throw up some design pictures in a bit as well as updates of the project.

Most the rest of the bits I need (stock, grip, forearm) I just ordered from Adam at HKparts.net. Good guy I have to admit.

One question for everyone though. The barrel as it sits is 25.5" end-to-end. I plan to also mount a flash hider and I was curious if anyone had any thoughts on shortening the barrel some or not?



 

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Discussion Starter #17
Wow, ten years ago I boxed up this collection of bits. A lot has happened since then. I'm a decade older, a decade wiser, a decade more educated... I put all this stuff in storage because I didn't know what I was doing when I tried pressing in the barrel, and I thrashed it. Over the years though, I've been adding parts and learning. It's going to be a long haul to finish, but I've got some near term projects within this build that I can accomplish.

1) I've got a Magpul PRS2 stock and an HK heavy buffer. These two parts don't fit together, but I hear they will with some TLC. I've done some measurements and it should be possible.
2) Trigger work! I recently purchased a collection of parts to finish off the trigger pack. After I got it all together it was absolutely abysmal, I plan to improve upon this.
3) Fitting of all of the receiver components. This includes making T-rails, touching up the cocking handle tube, pressing in the barrel etc.

I do have to choose a barrel, so if anyone has any input on the topic, it would be greatly appreciated. Right now I'm leaning towards the RCM/Schneider PSG1 barrel, shortening it to 24" or so, and threading it for a muzzle brake. I had intended on doing an MSG90A1 build, but in the end, it might be a bit of a Frankenstein.
 

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The proof is in the pudding (accuracy), who cares if it's a monster.
 

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Discussion Starter #19
First project was adapting the Magpul PRS2 stock I have to accept the heavy buffer. After disassembling the stock make working with it on the mill easier, here it is set up:
20180127_190243.jpg
20180127_191554.jpg
20180127_191558.jpg

You'll notice that I filled the open volume in the forward piece of the stock. I used araldite, which is a 2-part epoxy, I'd recommend a long set mix. I used some 5-minute stuff, and it didn't really allow as much time to do the work as I had liked.

I realize it's a garbage setup because where I'm doing work is so far removed from where I've got it clamped, so I wasn't expecting great surface finish, but nobody would see that part anyway. First step was to drill out as much as I could, so I punched it down about 3-1/4" with a 7/8" drill. This makes some parts very thin, you'll see a few pictures down.
After drilling, I used a boring bar to get the final diameter to clear for the body of the heavy buffer:
20180127_195727.jpg
20180127_200134.jpg

Here's the rear stock part, notice how thin the plastic gets at the top. I'm not worried about it because it doesn't look like any load would go through that area anyway. The load bearing structures are all much farther down in the middle of the stock.
20180127_200339.jpg

Rear of the buffer coming out of the front part of the stock. There's no way to use the fastener into the back of the buffer, but I'm not stressing about it.
20180127_200452.jpg

Final surface finish. Not very good, but nobody will ever see it anyway:
20180127_200400.jpg

I had to clearance the stock adapter for the larger diameter of the heavy buffer. No way to fit it in the mill, so I just did a quick and dirty die grinder job on it.
20180127_202513.jpg

Finished product mounted to my PTR
20180127_210939.jpg
20180127_211055.jpg
 

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Nicely done and one heck of a clean shop! Your barrel question and stock issue is something that you should decide' accuracy at what cost? The barrel you've discussed is an option but go look up Holecreek's PSG-1 build and take what he say's into consideration concerning the barrel.

JFK has one of the first and better tutorials on a PSG-1 type builds and the PTR/Wilson barrel I had reviewed by Lothar Walter's Americans head Barrel maker was pretty eye opening. FYI some of the Wilson barrels had shallow flutes which made the weapon a single feed system...Always double check everything.

RCM's Lothar's barrels and John's barrels our great barrels but you will need to have the barrel notched correctly if your using a PSG-1 Bolt carrier system.

You may wish to investigate hand-guard options with a PSG-1 trunnion' If your not against it have JDowdy make you a custom one from wood. If not that route you have a machine shop fabricate something better!
 
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