Locktite on gas blocks & strap wrench Q's

[MH64]

Have a low profile gas block that I need to install on a barrel. The gas block has two set screws on the bottom and the barrel already has a dimple for one of the set screws.
What type of locktite should I use on those set screws?

Also, I need to get a strap wrench to install a DD M4 rail and was wondering if there is anything you guys recommend? Or what to look for or avoid?

Figured I'd try to find something local (Lowe's, HD, auto parts...) instead of ordering.

[uranus]

Red threadlocker on the set screws.

A thinner wrench with a thinner strap seems to work best. There isn't a lot of space between the handrail and the upper receiver, and it can be difficult using a wrench with a wide base or wide band. Lowe's and Home Depot have strap wrenches, but there will likely be a better selection at an auto parts store. IIRC, I paid 6.99 for a two-pack of strap wrenches with plastic/composite handles. I also have a heavy-duty aluminum strap wrench, but I don't use it on handrails. (The auto parts store will have the Locktite or similar, too.)

[talbalos]

Red threadlocker on the set screws.

No more than a drop on the thread of each set screw before screwing them in. No need to bed the block to the barrel.

And I use blue threadlocker on fasteners as small as gas block set screws.

[Robb Jensen]

For guns that I'm trying to squeeze all the accuracy I can out of I use green Loc-Tite to bed the block to the bbl (it keeps the rounds from stringing in between distances) and I red Loc-Tite the bbl to the upper receiver. I also use red Loc-Tite or Rocksett on the set screws after dimpling as least the rear one into the barrel a tiny bit (at least 1/8" on a .750" bbl). When it's an option I prefer to cutdown the FSB and make it fit under a FF tube or rail as a pinned gas block is the most reliable (and use green Loc-Tite to bed it and use a tiny bit on the pins).

I use a small strap wrench from Brownells.

[Jinete_Palido]

Gotm4,

Could you explain a little more about bedding the gas block? Where are you putting the Loctite (i.e. so it doesn't get into the gas port)? Also, when you put red Loctite on the barrel, will there be issues if you ever want to separate the barrel and upper?

I am starting to get a little more serious about tinkering with ARs, and am curious about some of the tricks used by those with more experience. Thanks in advance.

JP

[Ellery Holt]

Gotm4,

Also, when you put red Loctite on the barrel, will there be issues if you ever want to separate the barrel and upper?

I don't use the red loctite in the barrel-to-receiver mating, but it wouldn't be a problem because I, like at least a few others, consider the barrel and receiver to be a permanent pairing. When I retire a barrel the receiver gets retired too; buy a new barrel I buy a new receiver to go with it.

[Robb Jensen]

Gotm4,

Could you explain a little more about bedding the gas block? Where are you putting the Loctite (i.e. so it doesn't get into the gas port)? Also, when you put red Loctite on the barrel, will there be issues if you ever want to separate the barrel and upper?

JP

The LocTite makes the gas block/FSB fit the barrel fit very tightly and glues it to the barrel. This keeps the assembly tight, if it's slightly loose (so little that you can't feel it) the FSB can move a tiny bit which changes the harmonics of the barrel and makes the rounds string up and down when shooting at longer distances because everytime the rifle fires the harmonics are acting differently. If the gas block/FSB to barrel relationship are rock solid the harmonics are always the same. I've never had enough get into the gas port where it effected function. The 20K psi and heat pretty much keeps it clear. If I ever want to remove a gas block mounted in this way or a receiver from a barrel a very hot heat gun is my friend. On ARs where I've painted the gas block and barrel with GunKote or Norrells I don't use LocTite to bed as it's not required then. The finish makes for a tighter fit.