What do you use to build your upper?

[bob4432]

As title states, what do you use to build your upper? Clamshell, Reaction Rod or Magpul BEV Block? Note that the upper will have to be heated up pretty good as I will be using a Bravo Company Lower and they state they are tight to begin with (on purpose) and the one I have is in fact is very tight, as even a upper w/ a standard m4 extension would only go in 1/2 way before heat was applied, so if that is a consideration, please let me know.

[Recondo]

After doing research I went with the Bev block. My reasoning was added strength of using the bolt carrier body with it and no stress on the indexing pin. So far used it to change a muzzle device and no problem. Works as advertised.

[A5BLASTER]

Bev block, unless I'm taking a barrel off then I use a clamshell so I can put a piece of broom handle in the upper and give the barrel extension a few pops and get it moving out.

[grayfox]

I use a clamshell, the delta eng series I think? anyway, with BCM uppers, heat the upper in the oven to 175 for 15 min and place the barrel in freezer, watch out for condensation (I didn't see any but some folks have), then they slip together nicely. Everything else can be done in the clam in the vice. use counter-force to prevent over torqueing. I've built probably 10 uppers in the past few years, no problems at all. For any muzzle devices use jam nuts and locktite so you don't have to clock them.

eta: o and some anti-seize on a few barrel nut threads.

[bob4432]

I use a clamshell, the delta eng series I think? anyway, with BCM uppers, heat the upper in the oven to 175 for 15 min and place the barrel in freezer, watch out for condensation (I didn't see any but some folks have), then they slip together nicely. Everything else can be done in the clam in the vice. use counter-force to prevent over torqueing. I've built probably 10 uppers in the past few years, no problems at all. For any muzzle devices use jam nuts and locktite so you don't have to clock them.

eta: o and some anti-seize on a few barrel nut threads.

Thanks for the suggestion, sounds good. Out of curiosity, since I eat out of this oven, the BCM uppers have, I believe teflon on the inside - maybe not teflon but there is a coating on the inside of the upper in addition to the anodization - you know of any issue of any type of off-gassing (not sure if that is the correct term, but I think you know what I am talking about).

Thanks.

[grayfox]

I haven't noticed any, 'course we eat of our ovens too.
Remember that teflon (the generic term is ptfe IIRC) used to be the non-stick that coated every pot n pan you could own...
If it is teflon, that won't cause any troubles at 175, and for only 15 minutes. Now heat it up to -- i don't know -- 500 or more, or something then you got gasses coming out!!! (but I forget the actual temp, might even be hotter than 500..... old brain cells lol).
Temperature control is the thing here.

175 is about as warm as you would heat your left over pot roast for eating on day 2...

[bob4432]

I haven't noticed any, 'course we eat of our ovens too.
Remember that teflon (the generic term is ptfe IIRC) used to be the non-stick that coated every pot n pan you could own...
If it is teflon, that won't cause any troubles at 175, and for only 15 minutes. Now heat it up to -- i don't know -- 500 or more, or something then you got gasses coming out!!! (but I forget the actual temp, might even be hotter than 500..... old brain cells lol).
Temperature control is the thing here.

175 is about as warm as you would heat your left over pot roast for eating on day 2...

Thanks, I will see how low my oven will go.

[Klem]

Can't remember the last time I used a clamshell. They also don't fit some non-MILSPEC uppers.

Working on the premise that we isolate torque as close to the spot we are working on I use a Reaction Rod for barrel nuts and a barrel vise or clamps for muzzle devices. I prefer not to load up the aluminium upper. If the upper is a tight fit then clamp the barrel vertically, grease the mating surfaces and use a rubber hammer to tap the upper on. 'Slow and steady wins the race'.

[maxxmojo]

I used a reaction rod, forget where I got it from. Used a Lilja barrel and an Aero cerakoted upper. The fit was pretty tight, enough where I couldn't get the barrel in all the way by hand. What I ended up doing was sticking the barrel in the freezer, then after a half hour or so I took a hair dryer to the upper to warm it up. Once it got pretty warm I pulled the barrel out of the freezer and it went into the upper like butter. I held both parts together until the temperatures normalized enough to where the barrel would stay in on it's own. I didn't torque the barrel nut down until the next day, had to use the vise at work for the reaction rod.

[SDW]

Note that the upper will have to be heated up pretty good as I will be using a Bravo Company Lower and they state they are tight to begin with (on purpose) and the one I have is in face very tight, as even a upper w/ a standard m4 extension would only go in 1/2 way before heat was applied, so if that is a consideration, please let me know.

The BCM lower is "tight"?? How so?

[Swampfox]

I use the Bev block

[bob4432]

The BCM lower is "tight"?? How so?

They are manf that way, and they do deliver. Can't get any barrel in more than 1/4-3/8 by hand. Heat gun is necessary unless you are the Hulk. It is listed on their site, so it is on purpose, not a surprise. Have wondered if mixing their tightness with a coated extension would be high enough to deform the upper enough to cause accuracy issues, but judging by the amount they sell, seems to not be an issue.

[SDW]

I think you might have meant to say Upper. The extension doesn't touch the Lower. That's what confused me. I'm not sure the lower is actually relevant:

I will be using a Bravo Company Lower and they state they are tight to begin with (on purpose)

FWIW though, I have removed a BCM stainless RECCE barrel from its BCM upper and reinstalled it, when I switched to free-float. Yes it's a very tight fit and took a little effort, but I didn't need to apply any heat; just yanked hard to get it out and maybe employed a plastic mallet to get it back in.

BTW, I used my plastic clam-shell upper holder.

[Kswhitetails]

Use the RR myself, never wanted anything more. I also use a bagwell block I got from Brownels, works like a champ.

[Jakegsxr11]

Reaction rod... Works well.