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Discussion Starter · #1 · (Edited)
Been looking for 10 round mags for my 630. Yep they are hard to find. So today I started comparing a 4 round mag to an extra AR 10 round mag and decided I would mod the AR mag to make it fit. It fits, locks and feeds; test fired it tonight.

Here is how to mod the AR mag. The AR mags are a little shorter than the 630 mag and wider at the front, some fit if forced, some don't. Easy fix, remove mag bottom plat, spring and follower. Make several light hits with a body hammer on each front corner. AR mag becomes thinner and longer, do enough for a thight fit. File down the follower so it fits inside the mag body. The HK mag has four stops made to catch on the botton of the 630 receiver. Measure from the top of the mag and make four cuts with a Dremel tool into the AR mag. Then take a punch on the inside and hit just enough to flare out the mag sides to catch the inside receive body. Measure for the mag latch and file slot for the mag latch with triangle file. It took about an hour to figure how to make the first one.

Here it is:







 

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well thanks for the walk through. I was just eyeballing some brownells an magpul mags i picked up for an ar, and was planning to attempt a frankenmag on one of them.

From past picks of frankmags, others have made a "lip" on the front to catch like a stock hk mag does. did you do that, or consider doing it?

Did you change the feed lip angles at all?

also, did you do any "feed around, then pull the round" to see if you were getting any weird contact or feeds that might scar bullets, or drive them into the case? i ask because i've seen that before... not with this operation, but with some ammo... so i know the gun will fire rounds that have been pushed into the case. just something to watch
 

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Discussion Starter · #4 ·
well thanks for the walk through. I was just eyeballing some brownells an magpul mags i picked up for an ar, and was planning to attempt a frankenmag on one of them.
From past picks of frankmags, others have made a "lip" on the front to catch like a stock hk mag does. did you do that, or consider doing it?
Did you change the feed lip angles at all?
also, did you do any "feed around, then pull the round" to see if you were getting any weird contact or feeds that might scar bullets, or drive them into the case?
No, no front lip, that would make it to compilicated! I hammered the front edges just enough to make it fit tight, can't pull out the mag without releasing the mag latch. But then they don't drop out either, maybe a little to much. I think I'll try soldering or spot welding a spacer to the front. I didn't extract any rounds last night, but did today. There was a slight scraping on the bullet, so I bent the lips upwards, just slightly similar to the HK mag. Not a lot since the AR mag lip are 2/3 the length of the HK mags. Next bullet came out with no scrapes or markings. The slots (stops) in the side, seat the front mag body flush with the feed ramp. When the follower is installed it is 1/16th or so higher than the feed ramp. It is actually a wee bit higher than the HK mag. I looked in closely with flashlight as I closed the bolt with the gun unloaded. The bolt slides in between the lips to pick up a round, it was just slightly touching the lips and pushed the follower down. The bolt actually scraped the lip edges in the middle of their length. Look at my last picture, it is not clear; but you can see where the bolt scrape the lips. I dress up the lips and the follower with several strokes of a file and polished them with a dremal tool opening the width only several thousands of an inch and lowering the top center of the follower. Bolt picks up the round and feeds with no problem. I picked up the fired brass form last night, other than dirty from gases and dented case mouths they were normal. Tomorrow, I will test fire it some more.

How do I remove the safety lever from the stock? Where did you get the thumbhole stock?
 

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check your pm, I gave instructions on how to get the safety lever out there (basically, bolt closed, turn safety to "safe" position, then stick your fingernail under it and pull it outward while continuing to rotate the lever towards the muzzle.

the stock I've got was built by a guy at a gun store way back when when the rifle was new.

good to read your continued experiments... if you do a search for the frankenmag thread, you can see the stuff i played with.

I knew from looking at the different mags that the lips would be close to the bolt bottom, and that the angle of exit from the mags was different.

keep playing and keep us posted.

my first glance says that my magpul mags fit a little easier in the well... but i wouldn't be able to mod the lips and angles as easily as a metal mag
 

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Discussion Starter · #6 ·
Yes, I read your PM. I answered it, but not sure if it went. I was cleaning my computer yersterday and couldn't find it in my sent folder. I'm going to continue working on these, next step is to try epoxing a metal spacer to the front of an AR. The same height as the HK mag. The HK mags are about .110 longer than the AR mags. My gunsmith knows nothing about HK guns, but took in two rifles today. A 300 and a 630. He gave me two DPMS mags to mod, one for him and one for me. I'll check out the frankenmag.
 

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any updates?

I did some looking at my rifle today, and I really want to get a magpul 20-rounder in my hands.

In a stock, stock, the mag opening is tight for a metal mag. I looked at a 30-round magpul I have, and I think I'd only have to ease up some stability tabs that are on the front sides of the mag.

On my custom stock, I can fit either mag in without incident... but if I'm going to play with this, I want the solution to work in either rifle.

Something else I noticed. The hk mag points the round upward, where the ar mag basically lets the round sit level. I think if when you set the mag up to fit, and make the notch in the back for the mag release, if you just set the mag up with a tiny bit of tilt... you might be able to get the angle without too much screwing around.
 

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I did a bunch more work this weekend at making a magpul 20 or 30 rd mag fit the 630. These are easier to fit than metal ar mags since you just have to file a little material, not bend.
But... I've noticed something that will be an issue for either metal or synthetic mags... the followers in the ar mags are plastic.
The bolt face of the 630 is metal... and where it strikes the follower is a 90 deg flat face.... I'm not sure how long an ar follower will last when the bolt face smashes into it.
obviously, followers are cheap...but who knows what happens when one fails... does it gum up the gun, stop in the works... wind up in the chamber... etc.
I'm going to study it some more... thinking about laying metal on the top of the area that will strike, but I'm uncertain that I can affix it well enough so the reinforcement isn't more of a problem.
Also... I am making my mag so that it has the little lip on the front end. After studying the mags and operation of the gun a bit, I know why it's there on the stock mag. When the bolt slams home, the inertia, as well as the mag spring are pushing the mag downward. If you don't have the lip, it could throw the mag out of alignment. If you managed to get the mag uber tight in the well, you might avoid this... but I'm not sure.

EDIT: Did some tests... follower handled about 10 slams so far... no shattering.

I did my mags by taking pmags, filing the top "filling" corners on the mag a little bit so they fit the well. Then I took a piece of brass to make a face with the top lip, and a bottom tab so it's tough to shove the mag up too high in the gun. Attached the brass with some double-sided tape for now.

Did bullet feed tests... didn't get any bullets being shoved in from what I can see

Here's pics of my attempts.
Front of mag


Back of mag


Mag in my stock 630


And...I mocked one up with the 30 round mag... pictured in my custom 630 stock.
 

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This winter, I did test the mag. What I found was that the action of the bolt sliding over the rounds on the top of the mag while feeding will force the mag out of the bottom of the mag well. You''d either have to make it so there is no slop fore and aft with the mag in the well, or figure out a way to make the small tab at the top of the mag have enough pressure to keep the mag inthe well while firing.

Anyway, I threw up a dumb video with the mag in both my custom stock and standard stock to see if it would work.... The video doesn't show the problem (when the mag would eventually fall out after being fired x-number of times).

HK 630 with a Magpul Magazine - YouTube
 

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I've converted 4 AR mags for my SL6, the first one I followed the OP pretty closely, but since I didn't have the tools/skills necessary, they didn't come out so well. Functional, but pretty ugly, and a bit finicky to boot. The mag pictured is where my experimentation led me, yeah it won't win any beauty contest, but its been 100% reliable at a much cheaper price point and didn't take too long to make.

Squeezed the front of the mag in a vise, filed the follower to fit, filed a notch in the rear of the mag body for the SL6 magazine catch, drilled a hole in the front of the mag body and riveted a washer on the front to act as a spacer(without the spacer the action of the bolt stripping a round out of the mag will knock it out of position), cut the front top of the mag with tin snips and bent it forward with pliers to make the front lip.
 

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well, didn't manage to fully test my new idea... but here's the gist of it. the retaining bar that slides in and out of the trigger housing retracts at least 1mm "deep" into the housing... mneaning the tongue on it could be longer and still clear the well when a mag is inserted. i'm thinking of playing to see if i can tweak that length.
after doing some other testing... i know the front lip on these things is critical as well... so i'm going to play with ways to true up and optimize the dimensions on the pmag.
looking at the hk part... it's not super engineered... they just obviously know where to put in bumpers to take out any slop once the mag is in (like the two bumps just above the retaining slot on the rear of the 10 round mag.
i also noticed that their mags aren't bulletproof either, as i had a couple occasions where the bolt didn't strip properly and cratered the case on a shell and jammed :)
 

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I wish someone with a 3D printer would work up a SL7 mag and produce enough of them to sell a few. $200/mag is the best I can find and that's straight ridiculous.
 

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Eh? Not thinking about selling just because of mag price? The main issue with converting AR mags is adding length so they don't follow the bolt forward when its stripping a round out and thereby unseating the mag. And unless you use the magazine as a monopod or to hold it, the over insertion stops aren't necessary.

I did take a look at M14 mags for the SL7, and that looked to be way too much trouble, I've thought about buying an AR10 magazine to possibly convert, but I have no idea what their dimensions are.
 

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ar10 mags would be too big. your pics are working now... and i'm seeing more ideas for messing.
like you said... biggest issue is the force of the bolt stripping rounds knocking the mag out... i'm looking for anyway to set the mag up so it can apply a little more pressure to keep itself in place. on my custom stock gun, it may be easier since i can alter parts of it at will... but i'd rather my solution end up working in a factory stock as well
 
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