Can you bed without using any Loctite?

[KCode]

Might sound stupid and if so my apologies.

But I was thinking of rolling the dice on a 8.3 BA Hanson barrel in 300 Blackout. While I would like to shim it if needed, I also want this barrel to be a place holder for a better barrel down the line if this one doesn't shoot decent.

I just didn't want to Loctite this barrel to my upper in the chance that I want to change it later.

 

[.505gibbs]

A little heat and it will still come out with loctite.

 

[KCode]

A little heat and it will still come out with loctite.

The green stuff, you can heat up and it goes back to liquid form?

 

[.505gibbs]

If

The green stuff, you can heat up and it goes back to liquid form?

I’ve never put that much heat back into it. All of them I’ve ever done basically turn your reciever into a thermal fit upper.

A bit of heat to get the old barrel out, remove any loose or flaking stuff, lightly rough the loctite present in the upper already, re-apply loctite to the new barrel extension. Lightly heat the upper and slide the new barrel in.

I’m sure you could spend tons of time stripping/chipping the old stuff out but I’ve never found it necessary.

 

[WeR0206]

Might sound stupid and if so my apologies.

But I was thinking of rolling the dice on a 8.3 BA Hanson barrel in 300 Blackout. While I would like to shim it if needed, I also want this barrel to be a place holder for a better barrel down the line if this one doesn't shoot decent.

I just didn't want to Loctite this barrel to my upper in the chance that I want to change it later.

Sounds like you already figured it out and should just use a shim with no loctite if you’re likely to replace the barrel soon and don’t want it to be too much work to remove.

 

[msgriff]

Some info that might be useful, These are the dimensions from the M16/M4 technical drawings for the upper receiver and the barrel extension, which can help in determining shim stock thickness. There is no requirement that a commercially available product meets these specs, though.

The ID of the bore of the upper receiver is 1.000" (+0.002"/-0.000"). The OD of the barrel extension is 0.9987 (+0.000"/-0.0008").

The greatest dimensional difference between those two components (LMC or least material condition) is 0.0041". In almost all cases for components manufactured to those specs, 0.002" shim stock is essentially a thermal fit, and thicker shim stock would definitely be a thermal fit.

 

[fedupflyer]

The green stuff, you can heat up and it goes back to liquid form?

I my experience, no.

Some loctite remover or Goop off will remove most of it and then maybe a little steel wool.

 

[supercorndogs]

Ya doesn't turn to liquid, but breaks down the bond between the two.

I woukd shoot a BA barrel before I went to any trouble shimming or bedding.

 

[redneckbmxer24]

Acetone takes it right off.

 

[Ronin22]

I wouldn't go through all the trouble on an 8.3 300BLK. You shooting F-Class with it? LOL

 

[supercorndogs]

Acetone takes it right off.

After getting it apart, or it gets in there and breaks it down so it can be disassembled?

 

[redneckbmxer24]

After getting it apart, or it gets in there and breaks it down so it can be disassembled?

After getting it apart. Never tried to let it penetrate but I’d imagine it would evaporate too quickly and you’d spend a lot more time reapplying and letting it soak than just heating it up a little with a torch to pull it.

 

[srt-4_uk]

I've taken off quite a few barrels that were loctited in. You need some heat, a barrel extension torque tool (which you should already have to tighten barrel nut), and a dead blow.

 

[msgriff]

Acetone takes it right off.

I'll have to try that to remove the dried residue. The product that they used to recommend was methylene chloride based paint stripper, which is now hard to get or illegal.

 

[supercorndogs]

I think I used crocus cloth. I had one thermal fit with green get stuck half way on and have to start over.

 

[TonyAngel]

Might sound stupid and if so my apologies.

But I was thinking of rolling the dice on a 8.3 BA Hanson barrel in 300 Blackout. While I would like to shim it if needed, I also want this barrel to be a place holder for a better barrel down the line if this one doesn't shoot decent.

I just didn't want to Loctite this barrel to my upper in the chance that I want to change it later.

You're over thinking this. First, this isn't going to be a precision setup. It's maximum practical range is gonna be about 200 yards. The difference in accuracy that bedding the barrel may make, isn't worth chasing.

Unless the barrel to receiver fit is super sloppy, I wouldn't worry about it. Still, if you choose to bed the extension, you'll probably be using loctite 620. This stuff does not turn back into a liquid when it gets hot. Ive never seen it do that anyway.

Using loctitie doesn't actually "glue" the barrel in. What you wind up with is essentially the equivalent of a thermal fit because the loctite expands as it dries.

I heat the face of the receiver up with a propane torch to get the aluminum to expand a bit and use a brass rod of appropriate size to tap the barrel out of the receiver. The extension is made of hardened steel and the anodizing on the receiver is pretty tough, so I use a single sided razor blade to scrape off the hardened loctite. If you hit the dried loctite for a second or two directly with the flame of the torch, it'll flake and then scraping it off is pretty easy.

As for bedding using only shim material without loctite, I dont see how you can do it. For any fit that's gonna be tight, it's gonna crinkle the shim material when you try to assemble the parts. All it's gonna do, if you can get them together, is make things less loose, in which case, the shim material may wind up working its way out of the back end into the receiver.

My vote is for slapping it together and shooting it. If you're that worried about it, just order a thermal fit upper. BKings has em. Ive also used a few of the cerro forge uppers from dirty bird. Under $75.

For what it's worth, I never use shim material any more. If the fit is so sloppy that I can fit shim material thicker than a sheet of paper between the extension and receiver, I relegate that upper to beater builds and go with another upper, if accuracy is a concern.

I do the loctite because its simple and why not? Loctite AND shim material is a PITA and messy.

 

[WeR0206]

You're over thinking this. First, this isn't going to be a precision setup. It's maximum practical range is gonna be about 200 yards. The difference in accuracy that bedding the barrel may make, isn't worth chasing.

Unless the barrel to receiver fit is super sloppy, I wouldn't worry about it. Still, if you choose to bed the extension, you'll probably be using loctite 620. This stuff does not turn back into a liquid when it gets hot. Ive never seen it do that anyway.

Using loctitie doesn't actually "glue" the barrel in. What you wind up with is essentially the equivalent of a thermal fit because the loctite expands as it dries.

I heat the face of the receiver up with a propane torch to get the aluminum to expand a bit and use a brass rod of appropriate size to tap the barrel out of the receiver. The extension is made of hardened steel and the anodizing on the receiver is pretty tough, so I use a single sided razor blade to scrape off the hardened loctite. If you hit the dried loctite for a second or two directly with the flame of the torch, it'll flake and then scraping it off is pretty easy.

As for bedding using only shim material without loctite, I dont see how you can do it. For any fit that's gonna be tight, it's gonna crinkle the shim material when you try to assemble the parts. All it's gonna do, if you can get them together, is make things less loose, in which case, the shim material may wind up working its way out of the back end into the receiver.

My vote is for slapping it together and shooting it. If you're that worried about it, just order a thermal fit upper. BKings has em. Ive also used a few of the cerro forge uppers from dirty bird. Under $75.

For what it's worth, I never use shim material any more. If the fit is so sloppy that I can fit shim material thicker than a sheet of paper between the extension and receiver, I relegate that upper to beater builds and go with another upper, if accuracy is a concern.

I do the loctite because its simple and why not? Loctite AND shim material is a PITA and messy.

This ^^^^.

Sounds like the OP's build is for a short range blaster and shimming/bedding doesn't really make sense for that use case. I've only done one build with a shim and I used a .0015" shim and had to heat the upper just to slide it in anyway so it was essentially turned into a thermofit. Now I just make sure to buy thermofit uppers regardless of use case, billet, forged, etc..

For those who don't know which uppers are thermofit I've compiled a list over the last year or so of doing research:

• Forged:
  • Thermofit
    • BCM Blemished Upper Receiver Kit ($80) (Thermofit, heat with heatgun on high for 60-90 secs, See here for good tools/instructions)
    • BKF M4 MOD-0 Assembled Upper Receiver ($76) (thermofit)
    • Bad Attitude Stripped Upper ($80)
    • SOLGW Stripped Forged Upper ($117) (thermofit)
    • Icon Defense Forged Upper ($130) (thermofit)
    • VKTR
    • BCM MK2 Stripped Upper ($130) (thermo?)
    • Mitchell Defense
    • Rise Armament Ripper
    • Munitionworks
    • Grey Ghost Precision (only available in receiver set)
• Billet:
  • Thermofit:
    • SOLGW Broadsword 89 Billet Upper ($313) (thermofit)
    • San Tan Tactical Billet Upper ($175) (thermofit)
    • Centurion C4 Billet Upper ($190) (thermofit)
    • Lantac Upper Advanced Receiver (billet) ($175) (thermofit)
    • CMT Ultra Precision Billet Upper (UPUR-1) ($200) (thermofit)
    • Icon Defense Ambi Billet Upper ($230)
    • Precision Firearms 1000 PF Billet Mod 1 ($225)

 

[flogxal]

Using loctitie doesn't actually "glue" the barrel in. What you wind up with is essentially the equivalent of a thermal fit because the loctite expands as it dries.

Yeah as a nerd I get antsy when I see that "glue" word used. It isn't like rubber cement where it functions to be "sticky" with adhesive qualities, it's more a space-filler that serves to reduce mini-vibrations that otherwise cause rattling, loosening barrel nuts, etc. But I don't think Loctite or other mfrs go out of their way to say "this ain't a glue, people".

There are true adhesive glues used in cylinder/bore fits, but "green loctite sleeve retainer" is not one of them.

 

[supercorndogs]

Loctite is not a glue (noun)

You can glue (verb) thigs with loctite.

So using loctite does actually glue (verb) the barrel in. But it is not glue. (Noun)

 

[flogxal]

Man, what about people mis-hearing lyrics... Jimi Hendrix, "scuse me while I kiss this guy" not "scuse me while I kiss the sky". Holy toledo.

I know for sure what people who know better are saying when they use "glue" as shorthand for liquid or something else to snug the throat/barrel extension. But hey I'm a nerd and that other side of it bugs me.

Besides, if you have tortured yourself reading AR build related things on barfcom, you know how easy it is to have Barney Hamfist hear/read "glue" and then go try rubber cement for his "shim" space filler.