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What's the best sequence to rivet the m2hb ? Trunnion? Top plate and related parts then bottom plate?
I think from the other thread that you already did the cocking bracket. I would have waited until you had the top plate and bottom plate riveted to install the cocking bracket. It will be hard to buck the top plate with it installed. It seemed much easier to just buck the two cocking block rivets than to work up a cantilevered setup for the top plate. I would also recommend doing the trunnion last. One of the long rivets on the front had to be done by hand as the M3 pawl brackets would not allow the plinker syle jig to reach. Good Luck it is a heavy box to manipulate, definitely a two person job.
 

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I'm sure there as many ways to do this as there are builders.

My first build, I did the trunion first and one side plate ran uphill and the other down hill :(

I now bolt the box together before starting. #10 screws in top and bottom plate to side plates. A large bolt thru the pintle hole. In the case of M2HB, I'm sure i had a couple 1/4" bolts in the long thru holes at the top of the trunion. Then check that's it all square.

Then I do a few rivets around the trunion and four rivets to each top and bottom plate. Then REALLY check its all perfect. Fron there it don't matter the order.

For sure cocking block is always the last thing to do.

Just my way
 

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PhD in Over-Engineering
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I looked this up on the M2HB forum long ago. The recommendation I found there- and what I have done- is to attach the stripped top plate to both side plates first. Then, install the top plate bracket and, if using it, the block for the bolt latch. Next, the bottom plate and the trunnion last.

DRH is correct in that putting the bracket in the top plate first complicates bucking the top plate rivets. Riveting in the bracket is fairly easy with the side plates in. I used a thick block of rolled steel about 4 x 5 inches, with a piece of harder tool steel on top, to rest the assembly on. That was tall enough to keep the side plates off the bench or anvil, with the bottom of the bracket and rivet heads resting on that block set up. Then it's a simple peening job on the top plate by hand and finish flush. Just check as you go that the rivets stay flush on the bottom of the bracket, against the bucking block. Things can move as you whack on it.

Getting the bolt latch block in takes a little more ingenuity, but that's doable too. You have four rivets in the side plate, plus 5 or 6 through the top plate. The first four I do with the Plinker's fixture, the others I do just by hammer, driver and anvil method, once bucked up properly. Definitely helpful to have a second pair of hands.
 

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....agreed..different ways..

Except for (1) bad day with squaring the box,I've had better luck putting the entire box together at the same time. Yeah...it can be a chore to do with just 2-hands...but manageable. And with 2-bucking bar sets. With bolts in the trunion,and with those rivets in and all the parts assembled,it is HEAVY. I also used the spade grip plate to keep everything even and square. Usually,do the bottom plate..2-rear rivets...2-front rivets. Check square. Then the top plate rivets...again,2-rear,2-front. Check square again. Then the front trunion rivets...top and bottom at the front of the trunion on each side plate. Check square ....again. Then working from the rear,every other bottom plate and top plate rivet. By this point,if it ain't square...you wasted a lot of time and energy. Then the bottom of the trunion...all 16-rivets,8-each side. Then go back and do all other rivets into the top and bottom plates,the side plates and trunion. After this is done,buck the cocking bracket on the top plate. Did all my M2HB's this way.
 

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I put the cocking bracket in last. I also put the pawl brackets on last. I rivet these in a press and then use a tool I made to put the pawl brackets on.
 

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Discussion Starter #7
Many thanks, in that previous pic my cocking bracket is just setting in the top plate not riveted. I've bolted everything together a dozen or more times with a hand full of 10-32 Allen crews and nuts. Just wanted to ask first, and not get ahead of myself.
 

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PhD in Over-Engineering
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Well, no doubt there are a variety of ways to skin the cat. Just took a few pics of the set up I used. I don't do enough of these to make a permanent set of fixtures, as M2 builds are not my line. But for the occasional build, this works for me. The side plates are riveted to the top plate already, and this makes it easy to smash the two top plate rivets into the chamfers and then grind them flush.

 

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Discussion Starter #9
ok awesome, bottom plate last to I can easily reach BHO rivets and cocking piece rivets. Guessing right plate to top plate first, Then BHO block, cocking piece , then the remainder, with lots of test fitting and checking with machinist sq in between
 

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PhD in Over-Engineering
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ok awesome, bottom plate last to I can easily reach BHO rivets and cocking piece rivets. Guessing right plate to top plate first, Then BHO block, cocking piece , then the remainder, with lots of test fitting and checking with machinist sq in between
Crap I forget if you have to do the BHO block first, or the cocking bracket. You can tell by looking at everything. You may be on the right track with the sequence. I don't have one of those blocks around to check, and that's why this piece I took pics of is still on hold. Keep meaning to get the bolt hold open parts set and get on with it. Personal build, not in a hurry, obviously!

Rollin, that anvil looks very familiar and well used.
I knew that you were going to see that as soon as I had it posted. Yes indeed, that anvil should look very familiar to you!! Definitely well used now. But you only loaned it to me about 8 or 9 years ago, so it has plenty of life left! Lord only knows how many rivets have been pounded on that, plates have been serialized, you name it. That's my workhorse. Since you told me you didn't want me to replace it, I should get you something you could use to pay you back! Just let me know, my friend.
 

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Just knowing that it's getting used is good by me. The wife kept telling me it was an isore sitting outside.

Only been a couple of times that I wish it was here but I used the dining room table instead! LOL, good thing she didn't catch me doing it! And her AR lower didn't know any different.

Probably one of the best things Harbor freight ever sold. I'm sure I can pick up another if I need one. If anyone needs one for doing an M2 or 1919 build, these are great! The small size makes it handy and by Rollin's pic can stand up to the punishment.
 

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Discussion Starter #13
Following the advice given I bolted everything together with 10-32 hardware, Top plate, side plates, bottom plate and trunion. Riveted top plated first, each end then middle then filled in the gaps while moving the bolts around to keep everything tight. Then I riveted trunion, similar alternating pattern. I then pulled the bottom plate and riveted BHO block, then cocking piece, a breeze with bottom plate off. Then finished up by riveting bottom plate.

Everything came out square and nice and tight.

I finished machining bolt, bbl extension and buffer today and began test fitting everything. Dont see any problems yet. I have to finish machining a bunch of suppressor parts tomorrow but hope to find a few minutes to finish test fit up.
 
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