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Magwell · May 3rd, 2021, 01:22

Ok folks... long/big update today.

A lot of this was completed before the dreaded C21 announcement killed some of the teching motivation, but trying to be optimistic. At any rate, got a lot of work done on this bad boy over the winter.

For starters, I'm 6'-0" tall but my legs are a little disproportionate as with many of us. Compared to an "average" human proportion my legs are a little longer and my torso/arms are a little shorter. As a result, and because fixed stocks on body armour really push any platform far forward I wanted to reduce the length of my M249 fixed stock. So I did what any normal/sane person would do and took a hacksaw to it... Seriously though I did a bunch of pre-planning, measured out 38mm (1.5") and predetermined where the new pin holes would end up and how much material I would need to remove from the butt plate, then went to town. It was pretty meticulous work planning it out, and a lot of dremeling but I'm happy with the results, really helps with transitions and supporting the weight of the LMG. More pictures later of the finished result.

Next I decided to remove anything that wasn't providing a purpose on the gun. The real MK46 for example removes the front mounting lug, so I chopped all 70 grams (yes I weighed it) off using my dremel and a cutting disk then cleaned it up with a file.

Next I turned my attention to the far front end, where one gram really gets heavy due to it being on the end of the gun, and there are a couple considerations. One is the barrel locking mechanism... or what at least tries to. The barrel sleeves into the fake gas return at the front, locks in at the rear, and is stabilized by a "U" shaped piece at the front. Not sure about you guys, but mine doesn't really do much for stabilizing it and allows what I'll guess to be 10 degrees play from left to right. So to combat this, I made a larger U shaped piece out of flat 1/8" thick aluminum plate, cut off a chunk of metal from the fake gas return that was serving zero purpose (34g) then drilled and tapped new screw holes to secure my new plate in place. I also threw some nuts on the end as I over-sized the initial holes so there wasn't as much thread as I had planned and one of the holes striped a bit. Some new paint and it blends right in, and it really locks the barrel in place, zero movement now with just enough gap for it to smoothly slide in/out. If I remember right, the barrel OD is 22mm.

Next, it was on to something I'm really proud of. I've never been a fan of the lower tri-rail on the MK46. It's bulky and not a great hand-hold even with a grip, the CA one at least has a poorly engineered attachment system of two Z brackets that are a soft metal and need to be bent back into the proper shape every now and then to keep the rail tight, and for me at least, I only use the lower rail.

So... why not fabricate one from scratch.

I went out to the Metal Supermarket (for real, it's a thing https://www.metalsupermarkets.com/) and picked up some 6061T6 hardened aluminum square tube, 1.5" square x 0.12" sidewall x 5.75" long. Then I cut it down to about 1.25" tall to get a U profile, sanded down the cut ends with 100 grit sandpaper to get rid of the burrs and rough spots, then started the slow process of removing sidewall thickness on the vertical sidewalls to get it to properly fit over the MK46 body. Not much was needed, but the material is pretty tough to sand down using a dremel.

Next I marked and drilled 4 holes to align with 4 pre-existing tapped holes on the MK46 body, countersunk the holes in the new handguard and secured it in place with four tapered machine screws.

Then the fun really started... I drilled and tapped four holes to secure a 2" rail segment in a couple different locations, or a 4" rail segment, to keep my options open. After that I took care of some weight reduction by swiss-cheesing the sides, followed by a coat of tan 'primer' as the base coat for my camo. I was really thrilled with how this turned out, but I didn't want to put the traditional heat cover back on, and wasn't a fan of the open top style of M249. So I dug around to see what I had that might work, found some brand new/never used rail covers that came with a gun I got at some point... busted out the drill and tap again and secured the rail cover to the barrel with 3 M4 machine screws to create my own style of heat shield. The great thing about this is it keeps the front end light weight and slim, to the point where I can get a C-clamp style hand grip if I choose to, although I have large hands.

With the above adjustments, I tossed it on the scale and was happy to see it pop in at 5.173 kg / 11.4 lbs. The 1500 round box mag and dummy rounds (fully loaded) came in at another 0.933 kg / 2.06 lbs. Combined 6.106 kg / 13.46 lbs and with nearly all that weight savings off the front end makes this LMG feel like a completely different gun.

Thats it for tonight, but I have a few more things to add soon with some unique tweaks to the 1500 round A&K 'nutsack' box mag and some hop up upgrades

Stay safe and keep OpFor suppressed!

May 3rd, 2021, 01:22	#42
Magwell Trader rating Join Date: Sep 2012 Location: Edmonton, AB	Ok folks... long/big update today. A lot of this was completed before the dreaded C21 announcement killed some of the teching motivation, but trying to be optimistic. At any rate, got a lot of work done on this bad boy over the winter. For starters, I'm 6'-0" tall but my legs are a little disproportionate as with many of us. Compared to an "average" human proportion my legs are a little longer and my torso/arms are a little shorter. As a result, and because fixed stocks on body armour really push any platform far forward I wanted to reduce the length of my M249 fixed stock. So I did what any normal/sane person would do and took a hacksaw to it... Seriously though I did a bunch of pre-planning, measured out 38mm (1.5") and predetermined where the new pin holes would end up and how much material I would need to remove from the butt plate, then went to town. It was pretty meticulous work planning it out, and a lot of dremeling but I'm happy with the results, really helps with transitions and supporting the weight of the LMG. More pictures later of the finished result. Next I decided to remove anything that wasn't providing a purpose on the gun. The real MK46 for example removes the front mounting lug, so I chopped all 70 grams (yes I weighed it) off using my dremel and a cutting disk then cleaned it up with a file. Next I turned my attention to the far front end, where one gram really gets heavy due to it being on the end of the gun, and there are a couple considerations. One is the barrel locking mechanism... or what at least tries to. The barrel sleeves into the fake gas return at the front, locks in at the rear, and is stabilized by a "U" shaped piece at the front. Not sure about you guys, but mine doesn't really do much for stabilizing it and allows what I'll guess to be 10 degrees play from left to right. So to combat this, I made a larger U shaped piece out of flat 1/8" thick aluminum plate, cut off a chunk of metal from the fake gas return that was serving zero purpose (34g) then drilled and tapped new screw holes to secure my new plate in place. I also threw some nuts on the end as I over-sized the initial holes so there wasn't as much thread as I had planned and one of the holes striped a bit. Some new paint and it blends right in, and it really locks the barrel in place, zero movement now with just enough gap for it to smoothly slide in/out. If I remember right, the barrel OD is 22mm. Next, it was on to something I'm really proud of. I've never been a fan of the lower tri-rail on the MK46. It's bulky and not a great hand-hold even with a grip, the CA one at least has a poorly engineered attachment system of two Z brackets that are a soft metal and need to be bent back into the proper shape every now and then to keep the rail tight, and for me at least, I only use the lower rail. So... why not fabricate one from scratch. I went out to the Metal Supermarket (for real, it's a thing https://www.metalsupermarkets.com/) and picked up some 6061T6 hardened aluminum square tube, 1.5" square x 0.12" sidewall x 5.75" long. Then I cut it down to about 1.25" tall to get a U profile, sanded down the cut ends with 100 grit sandpaper to get rid of the burrs and rough spots, then started the slow process of removing sidewall thickness on the vertical sidewalls to get it to properly fit over the MK46 body. Not much was needed, but the material is pretty tough to sand down using a dremel. Next I marked and drilled 4 holes to align with 4 pre-existing tapped holes on the MK46 body, countersunk the holes in the new handguard and secured it in place with four tapered machine screws. Then the fun really started... I drilled and tapped four holes to secure a 2" rail segment in a couple different locations, or a 4" rail segment, to keep my options open. After that I took care of some weight reduction by swiss-cheesing the sides, followed by a coat of tan 'primer' as the base coat for my camo. I was really thrilled with how this turned out, but I didn't want to put the traditional heat cover back on, and wasn't a fan of the open top style of M249. So I dug around to see what I had that might work, found some brand new/never used rail covers that came with a gun I got at some point... busted out the drill and tap again and secured the rail cover to the barrel with 3 M4 machine screws to create my own style of heat shield. The great thing about this is it keeps the front end light weight and slim, to the point where I can get a C-clamp style hand grip if I choose to, although I have large hands. With the above adjustments, I tossed it on the scale and was happy to see it pop in at 5.173 kg / 11.4 lbs. The 1500 round box mag and dummy rounds (fully loaded) came in at another 0.933 kg / 2.06 lbs. Combined 6.106 kg / 13.46 lbs and with nearly all that weight savings off the front end makes this LMG feel like a completely different gun. Thats it for tonight, but I have a few more things to add soon with some unique tweaks to the 1500 round A&K 'nutsack' box mag and some hop up upgrades Stay safe and keep OpFor suppressed! __________________ Last edited by Magwell; May 3rd, 2021 at 01:31..