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Posted: 6/7/2025 7:41:02 PM EDT
Bought a KAC 3 prong muzzle device so I could use the CRS/PRT I've been shooting with my LPR on my SR15E3 Mod 1 as well. Mounted it all up and the alignment rod didn't center, but also didn't appear to be touching the suppressor. The rod would drop through without making any visible or audible contact on the suppressor, but as you can see it isn't centered. Decided to test fire it. Proned out, lined up the shot and squeezed. No sound of impact, missed the target. Checked the suppressor and there's a very small shine spot where it looks like the bullet might have rubbed the portion of the end cap that the alignment rod was closer to.  I'm not even entirely sure this is a big deal, but if the suppressor is out of alignment I'd assume the threads on the muzzle aren't quite concentric. To rethread them I'd need to get it rebarreled because cutting it shorter means SBR paperwork and I'm not interested in that with this particular rifle. I sent an email to KAC inquiring but figured I'd run it by the brain trust here while I'm waiting for a reply. Tomorrow when the neighbors go to church I'll probably verify zero without the suppressor just to reassure myself whether that's part of the issue or not. So is this a big deal? Will they rebarrel it? What other options do I have? I'm guessing for what they'll want to charge to replace the barrel I might be better off just buying a different suppressor with a larger bore, but maybe I'll be surprised. What other smiths are trustworthy enough to rebarrel it if need be? If it was a regular AR I'd just do it myself but I haven't looked into what all the special sauce is with doing the work on an SR vs an AR. Do I need special KAC tools? I'd like to keep it all factory KAC if possible. I stuck a borescope in and there is no sign of any impact whatsoever on any of the internal baffles, and the closeup view of the end cap makes me wonder if I didn't hit it with the alignment rod and maybe that's what the shiny spot was from. I don't know, if it didn't take me months for the paperwork and all the ATF bullshit I'd probably just shoot it but anyway let me know what you guys think. 
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I’d remount the mount first w/o shims or rocksett, making 100% sure the mount shoulder and barrel shoulder are completely clean and don’t have any dried rocksett built up. Then check alignment. If it’s still off call the mothership. |
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Originally Posted By FRBaseball: I’d remount the mount first w/o shims or rocksett, making 100% sure the mount shoulder and barrel shoulder are completely clean and don’t have any dried rocksett built up. Then check alignment. If it’s still off call the mothership. After I first checked the alignment rod I took it all apart and cleaned it all up, brushed the threads, scrubbed the old rocksett off, made sure there were no foreign particles and reinstalled it all with the same result. |
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That doesn't look like an and cap strike to me. It would be shiny inside the hole also. The alignment looks fine for shooting. Not really understanding why it wasn't on target though. That parts seems weird to me. Between suppressed and unsuppressed, there's usually not a huge POI shift from my testing. Also, have you tried spinning the alignment rod when it's in to see if the rod may be bent slightly? |
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Originally Posted By Nobody69s: That doesn't look like an and cap strike to me. It would be shiny inside the hole also. The alignment looks fine for shooting. Not really understanding why it wasn't on target though. That parts seems weird to me. Between suppressed and unsuppressed, there's usually not a huge POI shift from my testing. Also, have you tried spinning the alignment rod when it's in to see if the rod may be bent slightly? I came to this same conclusion last night after looking closer at it. There is no mark on the inner diameter of the end cap hole, only right outside on the forward facing surface. I pulled the flash hider, recleaned everything and reinstalled. Still sits tight to the one side but I can see a gap all the way around when I hit it with a flashlight. Said fuck it and sent a magazine through it. Had to adjust the optic up and left about 2 inches each. No problems at all with the suppressor, so I'm chalking this up as me getting wound up over nothing. That's probably the largest POI shift I've experienced, but the rifle hasn't been shot since last year, so next time I can get more range than my back yard I'll confirm the zero at distance and then verify that the POI shift was true and I didn't just throw the first unsuppressed shot wide. If I'd shot at a larger target yesterday I probably would never have second guessed anything. Edit: Also I need to verify the zero for the right ammo. I just grabbed a loaded mag, not sure what kind of ammo it had in it other than caliber. Probably some cheap range garbage. I need to spend more time at the range this year. |
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Originally Posted By mdavis: Yeah I wouldn't blink at that rod alignment. Full send. That mark could also be the coating flaking off from the muzzle blast. /thread. The coating on these new KAC cans is pretty shitty and flake off super easy. |
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Originally Posted By Elvis121: I came to this same conclusion last night after looking closer at it. There is no mark on the inner diameter of the end cap hole, only right outside on the forward facing surface. I pulled the flash hider, recleaned everything and reinstalled. Still sits tight to the one side but I can see a gap all the way around when I hit it with a flashlight. Said fuck it and sent a magazine through it. Had to adjust the optic up and left about 2 inches each. No problems at all with the suppressor, so I'm chalking this up as me getting wound up over nothing. That's probably the largest POI shift I've experienced, but the rifle hasn't been shot since last year, so next time I can get more range than my back yard I'll confirm the zero at distance and then verify that the POI shift was true and I didn't just throw the first unsuppressed shot wide. If I'd shot at a larger target yesterday I probably would never have second guessed anything. Edit: Also I need to verify the zero for the right ammo. I just grabbed a loaded mag, not sure what kind of ammo it had in it other than caliber. Probably some cheap range garbage. I need to spend more time at the range this year. With higher end suppressors it seems like the POI shift is usually down a bit when the suppressor is installed due to the extra weight. Also, with an end cap strike you may see some copper on there from the jacket. I dread the day I have a baffle or end cap strike! |
| KAC reached out before 8:30 AM on a Monday. I told them it wasn't centered as much as I'd like but was centered enough for what it needs to do. They told me if I notice any accuracy issues that would indicate some type of deflection to let them know and they'd check it out. Overall a much more positive and responsive customer service encounter than I'm used to, so kudos to them for that. |
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