Armory Sponsor
Posted: 10/31/2007 4:40:45 PM EDT
This is my Surefire FA556AR; I want to know if the wear to the front aperture is normal. It hasn't been fired excessively, maybe 60 rounds in 10 minutes max. 
|
Thank god surefire has expanded their warranty lifetime...go buy a lotto ticket |
| I am fairly certain it is erosion. At first I thought I hadn't attached it securely and I had a strike but the wear is uniform and it was very tight; if it was a strike I think the end cap would be deformed and evidence of the original aperture cut would be present (at least a partial smooth round edge). It is properly mounted on factory threads. |
|
That's wear? It looks like bullet strikes to me. Can you tell what the innards look like? Have bullets been colliding with the baffles on their way out, causing enough upset to clip the sides of the can? Barring any really obvious screw ups on your part I'd be sending it back to Surefire. |
I had a good look around the inside with one of those nice fiber LED lights they have at costco (they are really nice by the way). The baffles appear undamaged but it isn't easy to tell, its so dark and filthy in there. |
|
Surely, those are baffle strikes, not wear. It may even be that small pieces of jacket caused the damage at the muzzle end. A single bullet would likely have been eccentric and quite obvious. Your problem looks like multiple marginal strikes with the majority of the bullet still clearing. When I got my new 6.8 upper, it had factory threads. I had a custom built .308 onto which I was mounting the .308 can and the gunsmith was very particular about the threads. When I brought the 6.8 home, I used three things to check out the alignment. 1 ) a boresighting laser - it went straight through when the can was mounted to the 5/8 X 24 factory 6.8 threads, with no contact with the can. 2) a Bore snake with the muzzle facing down, and the upper detached. I dropped the brass collet through and it went right down with no hang ups. 3) I simply sighted down the bore from the breech using a light . Turn the barrel 20 and then 45 degrees in relation the light sitting on a table, and if you can see the can, you probably aren't in alignment. Not that scientific but mine has worked beautifully, and my gunsmith gave my threads the big "thumbs up". |
This happened while I was shooting Ultramax ammo; some of the fire was full auto. To answer the other question that has come up: This is an LMT MRP barrel, well they both are I have one in 16' and one in 14.5. I really don't see bad threads being the issue. This is the surefire full length suppressor. The adapter for it extends over the barrel about 2 inches and it fits quite snug. I would think it would bind on install if the threads where bad. The only thing I can think of is maybe I didn't ratchet down the retaining nut enough when I mounted it that day. Although it felt very snug (I couldn't make it shift/wobble by hand). |
Interesting, keep us up to date with how surefire handles it... |
I read the utramax reviews with no mention of them coming apart but it got me thinking. it is a 1/7 barrel; perhaps a few of them shed their jacket. |
Surefire should be able to tell you for certain. After my experiences, I check, re-check, and check again. You should be able to remove the bolt and see a perfect bore alignment all the way down the barrel and can. Even a slight non-concentric condition will be pretty evident. |
|
I would guess frangible ammo or jackets separating. The damage is not limited to one place. All the typical baffle strikes caused by concentricity/alignment problems that I have seen have resulted in damage in one particular place. This shows damage all around the circumference of the end cap exit hole. And if truly only ~60 rounds were fired… My money is on ammo coming apart for some reason. But weird things do happen. Mark |
i'm also waiting to see what the repair bill is. mine isn't broke yet, but it's seen 10k+ of f/a and will be coming due for a rebuild sooner or later 
|
Armory Sponsor