Flash hider/comp wrench Stick put it in a thread

[Striker071]

I can't find it .....don't remember where I read it.... good multi wrench........

Help Stick.....

I want to put my BattleComp on and the wrench i have wont accept my big torque wrench.... Comes in 2 flavors steel and titanium.... goodness I can't remember who made it

[Quib]

This it?

http://www.weaponevolution.com/forum/showthread.php?2217-HammerHead-Rifle-Tool&highlight=hammerhead

[Striker071]

QUIB thanks

[Striker071]

Just bought one......... can't wait

[Quib]

QUIB thanks

Not a problem. Glad to help.

[Hmac]

What not just use the crush washer that comes with the BattleComp? I'm not sure why you'd need anything more than that and a plain old open-end wrench. What does a torque wrench do for you in installing a BattleComp? Just curious...

[Striker071]

I use a torque wrench on most everything that has to do with a barrel. Is it needed maybe not. Can some people do it by approximation and never have a problem sure. Barrel nut is supposed to be 30 to 85 ft pounds and i do most to 55 to be right in the middle. KX3 is torqued at 35 ft lbs to Noveske specs. Seems like a good place to be for most. I have a tube of AeroShell ... are there other alternatives sure but that is the proper grease. I do the traditional Frakenguns. When I get to a carbine course I want my rifle to stay together. So I think a torque wrench will limit Ole.... Mr. Murphy at least in theory.

I don't want to be one of the folks that screws up a class because my weapon fails. I buy top quality parts and assemble them. There should be no real good reason that anyone can't put together a 100% reliable weapon on their own and not rely on a company to do it for you.

[Hmac]

I'm sure there are a lot of right ways to do it. I am confident that when using a crush washer, anywhere between 90-110 degrees of rotation of the muzzle device will give a constant amount of torque and within the appropriate range for a muzzle device. IOW, once the crush washer begins to crush at about 90 degrees, the torque stays pretty much constant until you hit 110 degrees (although some gunsmiths say that you don't need to do the tighten/back-off every 90 degrees method, just crank 'er down). Obviously, somewhere within that 90-400 range the device will clock correctly. Torque wrench might be useful if not using a crush washer. Mfgrs say that 20-30 of rotation over shims or a peel washer will also give the appropriate amount of torque. Hasn't been my experience.

http://www.brownells.com/.aspx/lid=11441/learn/

I just can't see the need for a torque wrench. But...I also can't see anything wrong with using it if one doesn't mind that added complexity.

IMHO

[Quib]

I think the question here is: What method of installation does Battle Comp call out in their install instructions?

[Hmac]

There are a limited number of ways to use a crush washer correctly, and crush washer is what BCE has supplied me with every BattleComp I've bought from them. Here are the installation instructions I got with all of them...

http://SSEquine.net/battlecomp018.jpg

[Quib]

I've seen 45 ft/lbs thrown out there. I'm interested in hearing if this is what Battle Comp recommends.

[Hmac]

From this thread (http://www.m4carbine.net/showthread.php?t=62138)on another forum...Alan and Marty at BCE.


Good man! Of course, for the lawyers, "Professional Installation Recommended" ;)

A little birdy said 1/4 turns and backing it off will gain about an 1/8th turn by hand every time. So, by repeating this method, you will be able to time the BattleComp properly -- without imparting excessive stress -- by trying to turn it all at once. 45 lbs. of torque (from 3 to 6 PM if looking at the comp) is adequate, and you don't really want to induce more than that.

Simply, if you are facing the comp, and you timed out with the logo at 3 PM (if facing the comp), and you have only "3 hours" to go -- that's about perfect. Wrench a 1/4 turn and stop -- being careful not to go beyond 6 PM -- as you don't want to have to back off again.

Best,
Alan



The crush washer will allow at least 320 degrees of rotation after contact, maybe more. I routinely have BattleComps hand tighten with the solid section at just past the 6 o'clock position and using the above mentioned 1/4 turn technique have been able to properly clock the device with the solid section at 6 o'clock. You can also use shim or peel washers for mounting. Contact us if you have any problems and we'll be happy to help you out.
Cheers,
Marty


So, my interpretation of BCE's opinion is that 90 degrees of twist on a crush washer will give you about 45 ft-lbs of torque. The point of the crush washer is that that 90 degrees gets you in the rather broad torque range for a muzzle device that's somewhere between twisting the threads off the end of the muzzle and being able to shoot the device loose. The only time I've ever had one come loose was an FSC556 that I put on with their shim kit. Apparently 30 degrees wasn't enough for a shim. Crush washer has always done the trick for me, in my admittedly limited amateur gun plumber experience.

[Quib]

Thanks for the info.

Sort of off the topic a bit.....but I see quite often recommendations to tighten the crush washer in increments, backing off, then re-tightening to reach the correct timing. The -23 warns against this practice. Pre-crushing of the washer is seen recommended quite often as well.

From the -23:


Install compensator (16) on barrel assembly (8) using combination wrench (15). Tighten compensator hand tight and then tighten a minimum of 90 degrees but no more than 450 degrees to align center of middle slot (25) with post of front sight assembly (10). Tighten compensator to complete alignment with front sight post to top dead center (TDC). Do not over rotate. If compensator is turned backwards, the compensator will loosen, so procedure must be started again with a new recessed
washer.


From my understanding of crush washers, both on the AR15/M16, and from the use of similar washers in aviation maintenance, the crush washer achieves its self-locking feature from the spring tension it applies after installation.

A new crush washer is designed with an amount of spring-back built into the design, and this spring-back is what gives the crush washer its self-locking feature.

When crushing in increments, the washer takes on a "set" after each tightening sequence, so that the next tightening sequence is easier than the previous, and further advancement towards the correct timing position is the result. I believe both pre-crushing or crushing in increments defeats the whole purpose of the crush washer and reduces the amount of torque the washer applies to the FH after installation.

Now, I'll be the first to admit, I've reused crush washers on my AR15's. But I do so with the understanding of how the washer functions, and knowing that I take the risk of loosing a FH to lack of proper torque. Has it happened yet? Nope. But, the risk is there, hence the warnings and cautions in the Mtx Manual to discard the washer and replace with new.

[Hmac]

I tend to look at it differently. I agree that spring-back is the end goal, thereby holding the device on by "clamping pressure", but I think that that's the goal of any threaded fastener, whether it's using a lock washer, crush washer, or no washer. I view the crush washer as a means of providing the proper amount of torque to provide the right amount of clamping pressure/spring-back (45 ft-lbs, apparently) and I believe that crush washers are designed so that about 90 degrees of rotation/crush gives the right amount of torque to provide the right amount of clamping pressure/springback to keep the thing from coming off. I think that the backing off every 90 degrees is done so that one never applies more than 90 degrees of twist, thereby not over-torquing and risking thread damage. I agree that one should not back off after that last 90 degree twist to the clocked position or the washer will indeed be crushed and lose its spring-back-iness (another way of saying that the final result will be an under-torqued muzzle device). I disagree that each subsequent twist after backing off makes the next one easier...I think that every 90 degree rotation from finger tight to about 360 degrees on a crush washer will have the same amount of torque/same amount of spring-back.

I think the only way it would work to re-use a crush washer is if one is still able to crush it more than 90 degrees from finger tight. But I wouldn't reuse one on my rifle. I do agree that pre-crushing is totally pointless. All that would do is change your starting point, not the end result.

[Quib]

Our AR15/M16 Crush Washer is a form of Belleville Washer. Here's some related info:


Belleville washer manufacturers may say to flatten the washer and then back off slightly. They do mean slightly. If you back off too far and flatten the washer a second time to get it right, the washer will have lost much of its clamping force.


http://216.139.157.252/rexelusa/pdf/096_v5n2_Belleville_2.pdf

[Striker071]

WOW this turned into a extremely technical thread.....;)

[Hmac]

WOW this turned into a extremely technical thread.....;)

LOL. Just obsessing over the mystery of the crush washer. It generates a lot of confusion on various gun forums.

[Quib]

LOL. Just obsessing over the mystery of the crush washer. It generates a lot of confusion on various gun forums.

LOL.....[:)]

[Striker071]

I am a simple person. I just need to know what works.... and sometimes why.... but most of the time the technical stuff gives me a headache:P

[Quib]

I enjoy discussions revolving around the technical side of the weapon. The “mechanics” of the AR15/M16 have always interested me, and if / when possible, I like to include a bit of that in all my material here on Weapon Evolution.

ETA: I come from a technical background though, so to what level I get into the tech side of things, I understand might not interest others.

[Striker071]

Got the hammerhead wrench absolutely love it. Works like a dream.