Guys, got a complete upper directly from LMT, and just snagged an LMT bolt carrier group from Bravo Company that arrived today. They both have stakes, but not even close to what I expected (and not like what the MOACKS did to my RRA). I’d say three of the eight stake points are ok, the others just touch the screw.
Here is the pic. Anyone else notice this? Or is this satisfactory and I’m being too much of a stickler?
Maybe it’s me but I think they look fine.
Two symetrical indents that flow metal against the bolt heads. What am I missing?
The BCG on the left appear to be properly staked but the right BCG is definitely not staked properly. Break out the MOACKS.
I have purchased carriers recently from LMT also.
One thing I have noticed in addition to the crappy staking, the gas key was NOT chrome lined. This was the first LMT carrier I have ever had but I don’t know if this is typical or if they are cutting corners to meet demand.
In addition I also noticed that the gas key is cast, as shown by the casting mark on both the LMT and BCM carriers. I don’t know if this matters for strength or not, but I can tell you that all of my Colt gas keys are milled from solid steel and not cast.
The one on the left is GTG but the one on the right is weak.
I’d call them
I am a nOObie and I am simply trying to learn at this point. I have followed the posts and here is what I see(have “learned”); the BCG on the right: the corners of the screw(hex) do not line up with the indentions on the body of the bolt so the screws need a little more tightening(to the right). Do you automatically line them up with the indentations or do you use a torque wrench to get them to the proper torque? If the proper torque was reached before the indentations were reached, then the screw is appropriately tightened. Once again, I am new to the AR and admit I don’t know s***. I am simply asking questions and trying to learn.
The screws should be properly torqued before the staking is done. The purpose of the staking is to deform the surrounding metal to press against the screws preventing them from working loose. The OP is questioning if the staking is done correctly… did it deform the metal enough to make a strong contact against the screws.
So the screws are tightened to the appropriate torque(manufacturer’s recommendation) and THEN the bolt is staked i.e.- the metal of the BCG is then deformed to hold the screw in place. I do have some mechanical aptitude, thanks to turning wrenches for John Deere(mainly hydraulic), but I am simply trying to understand a process I am just starting to learn about. After time has passed, rounds have been shot, is the original staking still correct, or, does a new positional staking need to be found due to changes in the BCG’s shape/size from heat deformation?
The staking is sufficient on both of those carriers…
Hey gotm4,
I do not mean my question to sound like it does(as in I’m an ahole). Why do you say it is sufficient? I am just trying to pick your brain since I am just a beginner and don’t know s*. Thanks for the info!
A properly staked gas key should never have to be staked again unless the key needs to be replaced due to damage…in which case, I’d just replace the entire carrier assembly anyway.
The staking is sufficient because the metal is deformed enough to retard rotational movement of the bolts.
6933
The staking doesn’t have to deform the screw heads to work, it only needs to push some of the metal of the carrier key into the screw head to prevent it from turning. The torque is what really keeps is from loosening the staking is just insurance.
Thanks for the info. So what you are saying, and I guess the original question about staking means, is that the BCG metal needs to be deformed(pushed inwards enough) to prevent the screw heads from turning(torquing) enough to become loose? What tool is used to do this? A punch with a small radius? The edge of a metal chisel?
What about using a high temp. hardening locking fluid? Yes, I know Loctite is worthless at high temps. Any other ideas, suggestions, info?
There are dedicated staking tools, such as the MOACKS, that do the job quickly and easily. But a hard punch and a big hammer will work just fine. I have a MOACKS now, but for 20yrs, the hammer/punch was used on all my carriers and I’ve yet to have a gas key come loose.
If torqued/staked correctly, locking fluid is a waste of time, IMO. If not staked/torqued correctly, locking fluid probably won’t help anyway.
I use 50-55in lbs of torque, Rocksett and a Ned Christiansen MOACKS tools (just because is very good and fast) but a punch/chisel and hammer will suffice. I also lap the bottom of the carrier key to ensure that it’s completely flat for a good seal.
gotm4,
Noticed you are an HK Sidearms Armorer. What do you think of the HK USP Tactical .45? Just bought one. Any suggestions on any changes/upgrades I should do? Love it already. Not too large a gun for me. Also considering getting a Glock 17 or 19. Leaning towards the 19. Any help or suggestions appreciated.
I sent my BCG to Gotm4 to have it properly staked and it should arrive home tomorrow in time to do some Saturday shooting.
Thanks Gotm4. 
Ive got one LMT carrier that has a key thats not chrome lined that I purchased last fall.So I’d say its not a corner being cut due to demand these days.Regardless this is not an issue to me and it functions 100%.
As far as the forge/cast mark,I have not seen that on any of mine.But I’d say most all the carrier keys are forged and then machine cut to a finished part.So your probably seeing something that was not completely scrubbed off in the finishing process.
LMT is not real concerned about how smooth and perty the finish is on parts from what Ive seen,and it caused me to cry,kick and scream at first.Finish of the parts also seems to vary from part to part.So dont expect bling…they are heavy duty and work 100%.Thats all that matters to me nowadays.
If you want smooth and perty parts I’d try another brand…but you may sacrifice durability for perty at a higher retail price IMHO…