Posted: 6/20/2012 2:50:27 PM EDT
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Mega Ma-Ten Upper
Armalite NM Stainless Barrel DPMS Free Float Tube I have gotten the FF tube decently tight with a strap wrench but am unable to move it the next 1° or so required to allow for the gas tube to feed through. I broke a Husky strap wrench and also tried a fabric oil filter type strap wrench that use a 1/2" ratchet, no luck. DPMS makes a tool with two allen screws that engage the rear holes but I don't think the tool will work due to the large size of the upper. This is a two piece tube that has the same holes on the inner area that I can engage with a wrench but I am unable to separate the two halves, even with a heat gun. Ideas? 
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You may need some heat to soften the locking agent. Quoted:
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The FF tube should come off so you can gain access to the front of the nut. Correct? Yes, but this was off of a built rifle so I think the two halves are locktited together. It's not budging even with a pipe wrench over some rubber. |
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Post your location and I'm almost certain there's an ARFCOMer in your area with a proper upper receiver block, armorer's tool, and torque wrench.
The way you're doing it is... very redneck. If you absolutely must continue as you are, use the "snug three times" technique. Back the nut out about a quarter turn, then snug it up again, and repeat once more and everything should line up. Of course, the FF tube will then be at the incorrect angle of rotation, but at least you'll have a shootable rifle. ETA: Red Loctite releases at 450*F, FYI, in case that's what was used. |
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take it/send it a smith so I does not get fucked up, for $500 Alex? Lol, at least you're not biased. Please tell me what they would do that I can't? When I took my USP to one to get sights installed they were going to use a hammer and punch. I bought a sight tool. |
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Quoted:
Post your location and I'm almost certain there's an ARFCOMer in your area with a proper upper receiver block, armorer's tool, and torque wrench. The way you're doing it is... very redneck. If you absolutely must continue as you are, use the "snug three times" technique. Back the nut out about a quarter turn, then snug it up again, and repeat once more and everything should line up. Of course, the FF tube will then be at the incorrect angle of rotation, but at least you'll have a shootable rifle. ETA: Red Loctite releases at 450*F, FYI, in case that's what was used. I have an armorers block for an AR-15 but it does not fit the AR-10/Ma-Ten. It is very secure in the vise. Most people use the bolt on vise block thing (claw) on the lower part of the upper and a block of wood on the rail section, I don't see the difference. It's not twisting. I hit it with the heat gun but not that hot, I don't want to mess up the finish but that's still an option. I actually can't break it loose it's on so tight. Maybe the armalite barrel and DPMS tube are not able to be used together. I see daylight between the FF tube end and the upper so I think it can still be torqued a bit more. I have another like this (AR-15) that I had to back off to align the tube and it's my most accurate rifle, go figure. I want this one tight though being .308 and all. |
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Quoted:
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take it/send it a smith so I does not get fucked up, for $500 Alex? Lol, at least you're not biased. Please tell me what they would do that I can't? When I took my USP to one to get sights installed they were going to use a hammer and punch. I bought a sight tool. IDK maybe use the right tools?  If you were in southern oregon Id hook ya up but after that little snip I've changed my mind.
get a action block and the nut wrench. Get the tube apart by holding the nut end with the wrench and gripping the tube with a strap wrench then heat with mapp gas torch. Once apart then tighten nut to torque. You do have a torque wrench in your plumbing supplies right? |
| Ok, everyone, correct me if I'm wrong, but no one makes an armorers block for the Ma-Ten upper. The clam shell style etc. If a strap wrench or pipe wrench on rubber is slipping, it is not a problem with the clamping method. I have a heat gun but don't want to use the torch. |
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Cant tell from the pics, but it looks like the new nut is flush up against the upper receiver and that's why it wont turn any more. Seem like it ought to be offset a bit so the face of the nut doesn't contact the front of the receiver. eta. if the face of the nut is contacting the front of the receiver, no amount of force is going to move it further - something will give and ultimately break. You'll strip the threads in the nut or on the receiver, or even break the front off the receiver. Then someone like me will pile on and tell you the front fell off.
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Quoted:
Cant tell from the pics, but it looks like the new nut is flush up against the upper receiver and that's why it wont turn any more. Seem like it ought to be offset a bit so the face of the nut doesn't contact the front of the receiver. eta. if the face of the nut is contacting the front of the receiver, no amount of force is going to move it further - something will give and ultimately break. You'll strip the threads in the nut or on the receiver, or even break the front off the receiver. Then someone like me will pile on and tell you the front fell off. I thought so too, but there is a slight gap, light comes through when I shine my uber cool tactical light behind it. I only need to move it a smidge. The hole is almost lined up for the gas tube. I'm surprised how strong forged aluminum is but I definitely don't want to ruin anything. |