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9/22/2017 12:11:25 AM
Posted: 8/6/2005 11:24:49 AM EDT
Hello all,

I seem to remember hearing that it was possible to install a flash hider on the barrel of the during ban (damn, all the ban nomenclature is confusing) Bushmaster bullpup by simply removing a washer or something at the end of the barrel. Has anyone done this? Is it hard? Is there instructions on how to accomplish this somewhere?

Thanks in advance.
Link Posted: 8/6/2005 11:43:34 AM EDT
[Last Edit: 8/6/2005 11:48:49 AM EDT by mobius]
I'm not 100 percent sure, but I believe those "washers" are silver solder on........which if they are, you would have to heat the barrel again to some unbelieveable temperture to get them off. as for having a FH on during the ban, you could only have 2 "evil features" on the rifle (pistol grip, detachable mag, FH, bayo lug, folding stock) and since the 17 came with a detachable mag and a pistol grip, it was maxed out on "evil features". now if you jad permentely attached a mag in the rifle, so it could not be taken out then you could put a FH on the thing.........but why?
Link Posted: 8/6/2005 11:47:31 AM EDT
[Last Edit: 8/6/2005 10:31:46 PM EDT by _DR]

email KKF, he is the mod king of the M17s.
Link Posted: 8/6/2005 9:06:00 PM EDT
The threads on the end of the barrel are standard AR-type. Any AR muzzle device will work on the end of the M17.

They aren't silver soldered on. At least none of the ones I've seen, nor the one I owned.

The post-ban end nut can be removed with a CAR-15 stock tool. In fact it's like it was made for it.

There are two lock washers behind the nut. There is not enough threads IMO for the FS to thread on there completely. I'd remove one of the lock washers and use a thinner second washer. The nut/FS holds a bunch of crap on the rifle, and is how the barrel tensioning system on the M17 works, so you want a good solid hold for the FS and it needs to be propely torqued. Failure to do so will result in the FS coming loose, and the gun coming apart.

Do not use any type of muzzle brake. The way the tension system works is incompatible with any type of brake. Your accuracy will absolutely blow.

Not that it matters since the ban is dead, but there was only one evil feature allowed on a US gun. "detatchable mag" isn't an evil feature, but a requirement for the ban to apply, "just like semi-auto". While the math comes out the same, if you considered a detachable mag an "evil feature" you would be short-changing yourself on many other guns. The M-1 Garand could have as many evil features as it wanted, because it didn't have a detachable mag. So it couldn't be an AW no matter what was on it. If detachable mag was an evil feature, then you'd be limited in what you could do with your Garand.

Doesn't matter as the ban is dead, but it does matter that you know any law in detail so you can get the most out of the "loopholes".

Link Posted: 8/7/2005 8:05:28 AM EDT
The m17 has something like 5/8" of barrel end threaded while standard AR is threaded for 3/4". This is from memory so i stand to be corrected. Point is, there is a slight difference which affects what you can put on. Kurt has a compensator that fits the m17 and is a do-it-yourself install- replaces both washers on barrel end i think.
(Note- Yes, be sure to heat up washers to loosen industrial bushmaster installed loctite in threads, or you will tear them up and still not get them off. it isn't silver solder but might as well be if you don't apply a little heat. I used my plumbing propane torch, it really didn't take much. you will smell something like plastic burning when the loctite is "un-bound". I dropped mine a couple years ago on the first trip to the range before i even shot it-ouch. it landed mostly on the scope rail and the blow stripped the screw holding it on that runs from the inside of the reciever. i got new rail, screw and washers from bushmaster and reinstalled. confession time: i needed new washers because i didn't heat them up before trying to remove them the first time.)
I put Kurts m17 comp on in January and it works great- no muzzle jump at all, esp with weight of gun being what it is. Note2: with your head being as close as it is to the barrel end, you will notice more noise tossed back at you but it isn't intolerable by any stretch.
If you are looking to install military style flash hider, I don't think they will fit on the standard M17 without professional mods. I'm sure Kurt can do it but his services are in heavy demand (ie it will take a loooong time).
U could look in Kurts forum, verify there. Or email Kurt per above.
Hope this helps- good luck. BH
Link Posted: 8/7/2005 8:13:38 AM EDT
Post #1That's goofy. Not many and not frequent but there have been others. at least 3 or 4, anyway- LOL. BH
Link Posted: 8/7/2005 11:00:26 AM EDT
The reason not to use any muzzle brake on the M17 is that the muzzle device places the tension on the barrel that is required, and a muzzle brake will pull on the end of the barrel (which is how a muzzle brake works) and changes that tension, and can effect accuracy. The barrel tension system is responsible for accuracy, similar to the way a Dan Wesson revolver works. This info is per Bushmaster. Since KKF designed his brake for the M17, I wouldn't hesitate to use one on an M17. I wouldn't just throw on a muzzle brake designed for the M16, but KKF's is designed for the M17.

My post-ban M17 may have been different than others, but an M16 FS screwed right on with no mods at all. On my barrel at least, the threads extended under both lock washers all the way to the front end of the barrel shroud.

My M17 was an earlier post-ban which may account for some of the differences. It didn't have the fixed sights in the carry handle, though it was definately a post-ban. I bought it new from BM so it was indeed factory the way it came. There was no lock-tite anywhere, and after some shooting the nut came loose. I had to lock-tite it on myself. BM probably started using lock-tite after people started complaining.

Link Posted: 8/7/2005 5:14:56 PM EDT
While i was in my shop this afternoon, I pulled it out and checked how it was installed again. I think i bought mine in early 2003 fnew rom Bushmaster and it definitely had some thread lock under the washers. Not only did i destroy the washers trying to loosen them, i broke the special wrench (was just FAL gas wrench) i purchased from bushmaster with the replacement scope mount. Bushmaster was pretty good about it - they figured i'd suffered enough and threw in a free replacment wrench when i ordered the new washers.

You've obviously had yours apart and would be familiar with what follows., but the m17 is such an oddball gun i figured this might be helpful to someone else:

The two "fat" washers that tensioned the sleeve over the barrel were removed. A much thinner washer that Kurt shipped with the brake is threaded on against the sleeve, then the brake (obviously) follows. Combined, they perform the same double-washer tension function as the original did. The sleeve is maybe 4 inches long and is not threaded. The tension pulls this sleeve snug against the angled piece that fits into and centers the barrel into the end of the reciever tube. The only other connection point between the barrel and reciever tube is all the way back at the trunion(?) block where one screw tightens it against the bottom of the tube. Loosen this screw and the washers and the barrel plus all the washers, sleeves, etc fall apart.

I have a trijicon reflex that i bought used from stokes thru e.e. mounted on the gun and the rig seems to shoot as well as it did sans brake. I've got a weaver rail blank that i am planning on mounting onto the reciever in front of the carry handle so i can do away with the factory mount. the plan is to keep the carry handle but drop the reflex sight closer to the barrel.

Link Posted: 8/8/2005 8:36:13 AM EDT
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