I know I should tighten the castle nut to 40 in lbs but my wrench doesn’t allow for use of a torque wrench. So after the nut is hand tight…how much more do I have to tighten it approximately with the wrench? 1/4 turn 1/8 turn?
I don’t use a torque wrench and just go by my Mk1 Mod1 ‘feel o’meter’. Just as tight as I can get it by hand and making sure that the receiver extension doesn’t spin within the receiver which will result in a canted stock. Then I stake the end plate into the castle nut.
My new favorite castle nut wrench is the HammerHead Tool that I bought at the SHOT show. It works very well at getting through staking quite easily. The only time I notice I can’t tighten a castle nut is on Magpul ASAP plates because of the bar. The Hammer Head Tool engages all four slots in the castle nut and you use both hands on the wrench. Good design.
Thanks for the info. The Hammerhead looks great and I might get one in the future but for now I already ordered Gear Sector’s tool. It seems sturdy enough for just tightening the Castle Nut.
Robb, is there a reason you avoid torque wrenches? My initial assumption is that you’ve done enough to where you can pretty much intuitively get it right.
For a ham-handed, butterfingered putz like myself, I’m wanting a torque wrench so I can get it “right”.
Note: That Hammer head tool he linked to has a 3/8" square drive stamped into the center for use with a TQ wrench. I would buy that tool and use a TQ wrench. If you don’t own one, ask your pals… most guys that have ever rebuilt any sort of engine have at least one in the toolbox. I have 7 
If you need to borrow one, I’ll ship you mine as long as you promise to ship it back in a timely fashion.
In reality you don’t need a torque wrench. Apply some anti-seize and get the nut snug, then apply a little more umph. It’ll be fine. Just make sure that you stake it good.
what advantage does the hammerhead have over the multitool?
I have the multitool and it works just fine for me.
The Hammerhead engages all four lugs of the nut. So when some assclown has applied Loc-tite or other garbage to the nut it will be easier to help break it loose. I can’t count all the buttstock wrenches that I have trashed.
Thanks for the offer, bro.
I’m straight, but I wouldn’t mind a recommendation for a decent one solely dedicated to the AR toolbox.
My issue is a lack of self-confidence. I’ve managed to strip way too many threads, and have a serious issue with “it’s tight enough, now let’s just tighten it a little more”. My brother has an optic permanently attached to his XM17 that I installed for him. It will not come off. I’ve stripped the hex screws to hell and back, trying to get it off. Until he gets a new optic, he’s stuck with it. One of the four screws is completely missing, since I managed to shear the head off trying to remove it. No, I didn’t use red loctite…
The torque wrench’s appeal, to my overtightening ass, is that I can objectively determine “propper” mounting. In my case, adding a tool to the toolbox may assist in operator inexperience.
I know what you mean, I’ve trashed a few multitools myself. This hammerhead multitool would seem like a welcome addition to the tool box.
My garage phrase “Tight is tight enough, too tight is stripped.” I also use some made up words such as “MakeUmTaller” and “MakeUmStronger”. A MakeUmTaller is a milk crate (Hey, I’m short… 5’8") and a MakeUmStronger is a pipe placed over a wrench or ratchet to make you stronger! Fun in the garage!
I occasionally use the Harley Davidson method of torque application: tighten until it strips, then back off a quarter turn…
This is the wrench I have: http://www.gearsector.com/view/product/62/
It seems to be better then most castle nut wrenches out there. I just wish there was a cutout for a torque wrench.
On a side note; Brownells has some great video clips on how to assemble your AR15
http://www.brownells.com/.aspx/lid=11004/learn/
I guess that’s like the method I used for torquing the barrel nut when I installed the LaRue rail on my Sabre–three “snugs” on the wrench then just a smidge more to make the gas tube hole line up…
Whatever you wind up buying, do NOT buy a cheap one. With a precision/calibrated tool like a torque wrench, the extra dough you’re out going with a Snap-On/Mac/Matco/etc… wrench buys you consistency and accuracy–both of those characteristics are what you’re looking for vs. the brute strength you’d need form a simple one-piece wrench.
Cool deal. That’s what I was looking for. What ft/lb range fills most of the roles for working on our favourite gat?
On another note, everyone says the DPMS wrench sucks goat dangles, but no one recommends one that doesn’t…(Hammerhead aside)
Jvencius,
Not arguing on quality tools and thier merit (I own many Snap-On tools) but for an guy to buy a Snap-On or Matco for once every year or two is a bit of a financial overkill. You can buy a Craftsman 3/8" for about $100 and so long as you store it unloaded, it will last your lifetime of 1 or 2 times a year use.
If your an armorer who will use it once or twice a day, spend the money and realize that even your $400 Snap-On is worthless without being sent in and recalibrated. After some time, your Snap-On is no more accurate than the K-Mart special… until that old Snap-On gets recalibrated where then it is GTG again. Most places that use and depend on these items for critical applications have these on an anual recert schedule.
I would hate to see a guy that is 40 years old and never need one before in his life go out and buy the tier one TQ wrench so he can tighten 5 castle nuts and and 10 gas key bolts and then never use it again.
Keep your wits about you, and buy a decent TQ wrench. Craftsman or SK Tools will work fine for most average Joes to use once in a blue moon.
Go to Ebay and search for this: SK 74426
This link may work? http://cgi.ebay.com/ebaymotors/NEW-3-8-Micrometer-Torque-Wrench-250-ft-lb-SK-74530_W0QQcmdZViewItemQQhashZitem2c50bd4b26QQitemZ190333143846QQptZMotorsQ5fAutomotiveQ5fTools
You will find this 250 in/lb 3/8" drive tq wrench for under $100. Thats not a bad deal.
If you have a Sears you can find similar hanging on the shelf. SK is not top tier stuff, but it’s way better than the trash found out there in parts stores and wall marts. I have a Snap-On set of 1/2", 3/8" and 1/4" that I paid ungodly money for and still have, but I also have the SK version of the same sets and I like the SK just fine. I find SK to be a great VALUE (price vs quality) comapred to most other tool brands out there.
When you have the big jobs to do, put the SK tools away and grab for the Snap On or Matco tools.
I use a RRA wrench which engages 3 slots on the castle nut.
I just do it by feel too. Only issue Ive had is with BCM stock kits. I think they use crap hardware…castle nuts are soft, and the receiver extensions are inconsistent. IMO LMT makes a better setup. Ive had more than one BCM castle nut get bent around the slots for the wrench with what I consider moderate force, and one the receiver extension turned with the castle nut letting the tab on the end plate dig into the threads. I got an LMT kit, and I put quite a bit more pressure on it and it went together fine. Also used other kits (magpul) and never had that issue either. I generally like BCM stuff a lot but I’m not going to use their stock kits anymore.
Staking is important, and its not hard to do. You can touch up the staking with some blueing solution which makes it look nice and professional.
I’d like to know if anybody else had this happen with the BCM Kit…I’ll start a new thread about it.
I have THIS ONE and like it quite a lot. It’s more than just a plain-Jane stock wrench and if that saves some space in my toolbox w/o compromising functionality, that’s a good thing.