Description

Very nice billet receiver in stock. Just got notification these were back in stock, don't know how many they have but they probably won't last long.
Mega Arms SBU Billet Upper, W/O Side Charging Handle Slot
Features a stout octagonal shaped profile for increased strength, weight, and stress resistance.
Works great in long barrel applications.
Machined from billet 7075-T6 aluminum vs. the more commonly used 6061 for a 70% increase in strength.
Black Hard anodized with a surface hardness of 60 Rockwell.
Finished in Black.
Machined from billet 7075-T6 aluminum vs. the more commonly used 6061 for a 70% increase in strength.
Item No: M0301

Comments (13)

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Even forged Mega uppers are tough to barrel. Their .1% tolerance shows when fitting a quality SS barrel in. Vise the upper, line it up, and use a rubber mallet; taking your time. I've been looking for these uppers for a while, but it seems they're only milling cover/FA model only.

These get picked up by the 450 Bushmaster crowd, as the large cases eject without modifying the upper.

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Oh I attempted putting it in a vice and hammering it with my mallet...just started to score the edge where the outside of the barrel hits the inside of the hole. I had to take the anodizing almost completely off before I could get it to hammer in. It is still so tight you cannot pull it out with your hands alone, it must be tapped out from the inside. Maybe I just got one slightly out of tolerance. As mentioned I tried several barrels, 6-7 maybe, none of them would even start to go in. It's ok now but not after some very careful sanding.

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So I finally decided to just build a completely from scratch upper with this receiver. I finally got all the parts together and started the build this last weekend. One thing I discovered I was a bit dissapointed with is that they are not in spec due to an ultra thick anodizing job. I could not get a single one of my barrels to fit and the barrel nut will not screw on due to this. Well, it will screw on but not without fear of screwing something up by putting too much torque on it. I pulled out my micrometer and began making measurements. The hole for the barrel, compared to the tightest upper I own (RRA) it is 3-4/1000 on an inch smaller making this anodizing job maybe 2/1000 on an inch thinker than usual? I had to get a air sander and a 120 grit "flapper wheel" type of sanding bit to take down some of the anodizing. The barrel nut threads were even more time consuming using a wire wheel bit to get things down between the teeth of the threads. I've got it all together now, everything fits extremely tight now which I guess is good for accuracy. I would habe preferred something out of the box that went together without having to "DIY" it myself like this.

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Arrived today! I am honestly very impressed with this thing. Itis much beefier than I expected. The walls feel like they are 1/4" thick and it has some considerable weight, about twice that of a regular forged upper. Clearly made for a match gun build. I was going to just swap it with one of my other builds but now that I have it I think I will build a bull from the ground up. I am more than satisfied so far.

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Honestly when was the last time you used your Forward assist? I dont mind not having it if it's a nice upper...I dont like not having a dust cover though, just personal preference.

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Personally I think it is a very sexy upper. Made for longer, heavy, match type barrels the need for a dust cover is really questionable. It has nice clean lines and a very modern look. Considering the cost difference between a forged and billet lower is about $100 it seems that $34-44 differenc is a real bargain. I broke down and ordered one. Can't decide which gun this will go on yet but will likely replace my RRA 6.8SPC upper with this. Will report back when I have it in hand.

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This seems like a decent price. I don't think I'd call it a deal, but a strong upper for a competitive price. I might grab one of these in te coming month for a bigger cal gun.

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More than a deal is that they are rarely available. Even before the frenzy these were slim in stock.

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Didn't realize that. I've seen these popping up on a few sites lately. I've NEVER seen the one w the side charging handle slot(mentioned in link below). That's pretty sweet there if you have/want that look.

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What mean "W/O Side Charging Handle Slot". Charging handle slot does not exist. It is a Forward Assist that is missing and there is no way to install a dust cover as there is no place to fit the rail.

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http://www.stonefire-arms.com/view/product/9/...
Is an example of what doesn't exist....

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Got it. Something I really was not ware off. Anyway - the concern here is that it is a competition upper w/o FA or dust cover. Not that it does not have a charging handle slot on the side.

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If you go to the website you Can view one with a side charging handle slot, it does exist.

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