I own no AAC cans, but I’ve read from some on here and other forums (I believe markm once posted something like this) that it is possible to wear out the latch/locking teeth on either the can itself or the mount by ratcheting the can down. Rather, it is suggested to hold the latch down so it doesn’t drag along the locking teeth, and then release it once maximum engagement is achieved.
I realize that Surefire cans have a different mount, but the locking latch still has teeth that lock into a ring of what looks to be finely-machined locking grooves. Would the same principle apply here? That ratcheting the can onto the mount will eventually wear out the teeth on the latch and/or the locking grooves? Is it an advisable practice to then hold the latch down so the teeth and locking grooves do not drag against one another and only make contact once full engagement is achieved and the latch is released?
If this is indeed a valid concern, how long is “eventually”? Is this something that would happen over the course of thousands of attach/detach cycles, or a few hundred? I can’t imagine such a tank of a suppressor being vulnerable to such an issue over a small period of time, but thought it was worth asking so I could take proper care of my equipment.
I have an AAC m4-2000 that was part of a batch with improperly heat treated latches. It eventually wore to the point that I wasn’t comfortable shooting it. I sent it back to AAC for repair and it was back in my hands within a week with a new latch and had been refinished.
I have not gone out of my way to hold down the latch while attaching the can. It took several years to develop the problem I had with bad parts, I expect it will last much longer with the better quality replacements.
I know I haven’t answered your question about SF cans, as I have no first hand experience with them, but I have heard excellent customer service stories from them as well. All mechanical things will eventually fail. The difference becomes, who will take care of you the best when you have a problem? I believe you would be in good hands with either AAC of SF.
No idea about longevity of the teeth but I’ve had great responses/results from working with SF personnel. The way I turn the collar (index finger and thumb around it pulling rearward as I tighten it) I naturally am covering the latch. So I guess I’m inadvertently avoiding possible wear.
I wouldn’t worry about it. Search for a while to see if you can find any customer complaints. I did and could find some issues with AAC, but none with SF.
Yup! That’s exactly what I did and I too found nothing about SF and only with AAC. Definitely added a bit of confidence.
That said, Surefire’s CS is indeed pretty legendary and I doubt I’d have any problem with them should I ever wear the latch out. I’d just prefer to not have to go that route if I can take a few prior precautions to avoid it, especially with the uncertainty of legislation and such in the future. Whatever I can do to keep my suppressor safely functional for as long as possible is what I intend to follow!
Yes, the same design considerations apply when selecting an optimal depth, angle, pitch, number of teeth, and materials. The propensity for wear - galling and pitting is determined from the surface strength of the mating materials. The number of cycles, the surface finish, the hardness, lubrication and operating temperature impact the substrate surface strength. To my knowledge, everything on Surefire’s suppressor is Inconel, except for the cam locking ring assembly which is heat-treated stainless. So I assume the teeth on the body of the suppressor is also Inconel, or some series of high-nickel alloy content. Hardness wise, the teeth on the body of the suppressor is most likely harder than the latch. How much so will be determined by the series of heat treated steel used to machine the latch. I’m sure Surefire ran the numbers or even performed fatigue testing to predict a mean cycles before failure, and endurance limit. However, in the eventuality of such serve wear that the teeth no longer engage, the latch does look to be a user-serviceable part, and would be an easy fix. Surefire also goes to the added step, by using only certified materials, these certifications ensure the proper heat treat and alloy content is maintain from lot to lot, batch to batch.
I wouldn’t bother, I’m confident between Surefire’s design, rigorous QA/QC procedures, and customer service I wouldn’t be worried about it. But if it makes you feel better, sort of like aligning the gas rings on an AR bolt, go for it, it won’t hurt anything.
More like millions of cycles, if properly designed, and fabricated. For more reading look up literature in mechanical design, for gears. Specifically the Buckingham surface endurance strength equation (based on Hertzian stress theory), or materials from AGMA (American Gear Manufacturers Association). Here’s a quick summary though, in 1949, Earle Buckingham summarized in the Analytical Mechanics of Gears, a series of tests examining fatigue at 10 to the 8th cycles (100 million cycles). Of which he found that cast materials had an endurance limit of 30,000,000 cycles, while hardened steel rollers showed on endurance limit up to 400,000,000 cycles, with subsequent tests showing hardened steel having effectively no endurance limit as it exhibits such high fatigue strength.
To chime in again, I haven’t heard of any issues with Surefire cans. As far as I’m aware, I believe that the locking ring (latch) is only a secondary anchor for the suppressor and very little load is put on it, unlike the AAC option, which is held primarily by the latch and ACME threads.
I actually just got done sending AAC an email. My M4-2000 has to go back for the second time in 2 years to get another latch.
The teeth are soft, and unimportant. The pawl has Sharp teeth of its own, and will lock even if the teeth area on the body was perfectly smooth. The teeth on the body are only there so that you can have tactile feel for tightening the ring as it ratchets over them. They are superflous. It’s the pawl thats the workhorse, and its very durable. Forged, if I’m not mistaken. Heat treated, etc.
As far as I can remember we have never had a suppressor from any generation that came in from the teeth being worn off. We have had latches broke by the operator in the past where they used something to pry under the latch thinking it needed to be pulled upward to disengage the teeth but it caused the breaking the latch. We have not had that problem since we engrave “Push” on the latch face now. There is no need to hold the latch down when rotating the lock ring.
i asked Barry the same thing at shot show or 3 gun or somewhere. he said no way. since u guys rebuilt my can after i shot a hole in the side, i guess u will take care of a few teeth wearing.
not l.o.l.“”“”“”“”"
