We stake the rear buffer tube plate to the castle nut, why not stake the set screws on the gas block?  I have read and watch videos on people saying pinning the low profile gas blocks is a must, that the set screws could back out and in turn the gas block would move (it has happen).  Now I can understand the need to dimple the barrel before installing the gas block which it a common practice these days (mainly done by BCM from factory).  So...  Why not take a punch and stake the gas block into the set screw?  I've seen it done before, but I don't see it as common practice on gas blocks for those who choose not to pin them.

It can still slip with the screws tight and staked--loosening screws isn't the issue.  The cross pin presents a physical barrier to prevent movement.

I would assume the dimple in the barrel that set screw sits down in is not only for alignment but the keep the gas block in place so long as the set screws are in place and tight.  Again, staking the set screws would ensure they do not back out.  Hell, I forgot to compare it the gas key on the BCG

Lock tite?  Maybe, if it doesn't burn melt or burn off do to hot temps.  I'm not sure what the max temp rating on thread lockers that are used by ar builders?

When I first started building uppers I would stake the gas block set screws. Now I use an SLR dimple jig to dimple the barrel and Rocksett on the gas block screws. Hundreds of uppers later I have not had one reported problem. I also would on many uppers that I have not assembled myself. I have not noticed and loose screws. In fact, many of them are hard to loosen.

I have never found pinning, staking, or dimpling to be necessary w/ an aftermarket gas block. I understand the merits of each, just never needed to do it.

Then why not forgo staking the gas key allens?  Why not just some good lock-tite?  Both pieces channel the same gases into the BCG and are subject to the same gas pressures/vibrations.

Heat makes locktite lose its strength.

Total different applications

The gas block just sits on the barrel directing whatever gas comes up through the gas port and directs it back into the gas key/bolt carrier.  It doesn't move, nothing inside of it moves (not counting adjustable blocks) the primary concern is physical damaged causing the GB to shift.  Nowadays most of the low profile gas blocks are underneath the handguards where a physical damage is pretty rare.

The gas key is just sitting minding its own business when all the pressure suddenly hits it, violently pushing it backwards, the bolts holding it onto the carrier now get torqued as the much heavier steel carrier has to start moving.  Then when the spring pressure overcomes the rearward motion, the carrier reverses direction and gets slammed back into starting position with a forceful stop.  The violent instant starting/stopping can and will work fasteners loose.  Just because the gas key and gas block see the same pressure doesn't mean the forces applied are the same.

Staking the castle nut is done because of the twisting forces applied from the stock as the rifle is maneuvered.  The stock can act like a wrench putting a lot of torque on the castle nut causing it to come loose.

My opinion:  SHTF rifles have pinned front sight bases, if I want a low profile GB for the end of world rifle it will get pinned.  But I have done a lot of gas blocks with a dimple jig and haven't had any come loose.  I dont even loctite them, it's never been needed in my experience.

Same conclusion for me. I don't have the build count you do but all the builds I've done with dimples and Rocksett have not had any issues (same SLR jig). Also, friend's or customer's loose gas blocks re-installed with dimples and Rocksett have not had any further issues.

One manufacturer Young Manufacturing: Staking the gas key on the AR-15 and M-16 carrier does exactly that. They're the only ones to do so to my knowledge.

I staked two of mine after one came loose running a course. Now I agree pinning is best, but using the correct knurled cup screws helps too. I used the supplied smooth cup set screws. Staking does work, hasn't moved in last 1.5k rounds or so. Here's my experience.

https://www.ar15.com/forums/AR-15/Why-I-now-stake-set-screw-gas-blocks-/118-728442/

The gas key doesn't get pushed back by the gases, they travel thru it same as gas block.  Gas violently expand inside the carrier pushing the bolt forward, thus aiding the unlocking the bolt. The expansion inside the carrier is what causes the bcg to fly back.

This is why this system was not designed to be piston driven.  For example, carrier tilt problems and people even add springs behind the bolt to help the bolt go forward. The bolt is forced to unlock as the carrier is pushed back.  System still works, but not by design.

Guys, please I see this all the time.  The gases do not push the gas key back.  Yes it suffers a lot of stress, so the screws can work loose.  Staking solved that problem.  Now the modern day low profile gas block can see the same problem, hey why not stake the set screws on that too?

Truth.  Set screws have a concave tip that flattens out and actually cuts into the barrel.  If you remove a gas block that has been installed with properly designed set screws you will see the two circles where this happened.  Torqued properly and with a tiny bit of red Loctite  on the threads, they simply do not move and may be impossible to remove without heat in the order of almost 500 degrees.

A a low profile gas block of this type is under the handguard.  It is not connected to anything that is exposed to external contact like an A2 FSB would be.  They simply don't move.  Torque, flattening of the cup against the barrel and red Loctite keep the screws from backing out.   No need to stake or dimple. Go ahead if it makes you feel better, but not necessary.

Not enough to the point that vibration is going to cause the screws to back out.

As long as it is properly applied (cleaned, degreased, etc.) red Loctite will do the job just fine.  Been working for years on .mil rifles.

The key is pushed back by the gases. An AR will even run with the gas rings removed. It's a combination of the backward force against the key and the expanding gases inside the keep things reliable in the AR's.

This also. Dimpled and Loctited is fine. Pinned is better, but I've never seen a properly dimpled and loctited gas block fail. I've shot  one upper with a loctited gas block with no dimples in excess of 2500 rounds on auto to test out some BCGs on our M16 at work. Now 2500 rounds is not a large number by any standards, but its a real number on a gas block I used.

I just rocksett them.  Seems to be working so far.  As mentioned before it's good up to 2000 degrees.

I don't stake gas blocks or castle nuts...just doesn't seem necessary for them to stay solidly in place, and I'd rather retain the ability to easily remove them later for modifications if I ever feel like it.  If you're taking it into battle and don't expect to ever make upgrades or have access to tools, your perspective may be different.