KAC SR25 accuracy issues

[hmewrcknb4]

Riddle me this, reaching out for some tech help....not to give out to much info for opsec/persec reasons. Currently employed by a company that has us on task order and deployed as DDM's with KAC SR25's 7.62 system. last week during quals my fellow ddm was zeroing and qualing with his newly issued to him sr25. To give a quick back ground to negate any shooter issues, this DDM was an instructor at the USMC Pre- Sniper course and was deployed several times as a sniper. I also attended ddm school with him and know for a fact the guy can shoot....back to the issue at hand...the ddm was trying to zero the sr25 with its can on, through both our experices we both noticed the sr25 system is more accuate with the can, even though it gets fouled up internally substantially faster. During the zeroing process he takes note of his cold bore impacts were 1.5" at 10 oclock from POA. He continues his zero process and notices after every 5th or 6th round he gets a flyer 3-4" at 4-5 oclock from his zero. This eventually hinders from doing his zero & qual. The shooter put the rifle through the standard PCI/PCC inspection checking optics/level, setting bolts to proper torque, and rifle cleaning. The ammo is blackhills 175grn and was kept at a consistent temperature and is from the same lot #. We have checked the can and muzzle crown for burs or strikes. The can seats properly when mounted and has a good "carbon" seal according to the KAC feild manual. So we are running out of thing to check on the rifle. The armorer could really care less bc its not affecting his pay check, and now the shooters name and reputation is on the line. Which is not good as a new DDM.

Let me also add that the rifle was first issued in 2007, and the round count book shows right at 1k of rounds down the pipe. We are not sure if thats the only round count book, but know one seems to know where the other one is, if in fact there is another book. i believe there is a second book some where. The rifle doesnt look used or abused ascetically, which is usually a sign anywhere you go of how it was treated.

Is it possible that there is throat erosion at 1k rnds out of a 7.62x51 this early in its life? (if the round count is correct, which again i dont think is correct seeing that this rifle was first issued in 07) or are we missing something completely?? Any help or tips on figuring this out would be greatly appreciated!

[Sensei]

Riddle me this, reaching out for some tech help....not to give out to much info for opsec/persec reasons. Currently employed by a company that has us on task order and deployed as DDM's with KAC SR25's 7.62 system. last week during quals my fellow ddm was zeroing and qualing with his newly issued to him sr25. To give a quick back ground to negate any shooter issues, this DDM was an instructor at the USMC Pre- Sniper course and was deployed several times as a sniper. I also attended ddm school with him and know for a fact the guy can shoot....back to the issue at hand...the ddm was trying to zero the sr25 with its can on, through both our experices we both noticed the sr25 system is more accuate with the can, even though it gets fouled up internally substantially faster. During the zeroing process he takes note of his cold bore impacts were 1.5" at 10 oclock from POA. He continues his zero process and notices after every 5th or 6th round he gets a flyer 3-4" at 4-5 oclock from his zero. This eventually hinders from doing his zero & qual. The shooter put the rifle through the standard PCI/PCC inspection checking optics/level, setting bolts to proper torque, and rifle cleaning. The ammo is blackhills 175grn and was kept at a consistent temperature and is from the same lot #. We have checked the can and muzzle crown for burs or strikes. The can seats properly when mounted and has a good "carbon" seal according to the KAC feild manual. So we are running out of thing to check on the rifle. The armorer could really care less bc its not affecting his pay check, and now the shooters name and reputation is on the line. Which is not good as a new DDM.

Let me also add that the rifle was first issued in 2007, and the round count book shows right at 1k of rounds down the pipe. We are not sure if thats the only round count book, but know one seems to know where the other one is, if in fact there is another book. i believe there is a second book some where. The rifle doesnt look used or abused ascetically, which is usually a sign anywhere you go of how it was treated.

Is it possible that there is throat erosion at 1k rnds out of a 7.62x51 this early in its life? (if the round count is correct, which again i dont think is correct seeing that this rifle was first issued in 07) or are we missing something completely?? Any help or tips on figuring this out would be greatly appreciated!

It is possible but not at all likely that it's a barrel issue at 1000 rounds. However, 1000 rounds seems low for a weapon that is approaching a decade old. A couple of questions:
1) Has anyone else replicated the problem?
2) Does it occur when the rifle is benched or on sandbags?
3) Does the problem change when the suppressor is removed?
4) Have you tried different ammo?

[hmewrcknb4]

i agree 100%. the rifle is coming up on a decade old, which is what leads me to believe there is/ or was another log book somewhere with a substantially higher round count. and someone either does not want to get up and find it, or does not want to admit its lost or unaccounted for.

1) another solid shooter has replicated the same issue.
2) This does happen when benched & bagged
3) do to limited range time the rifle has not been shot unsupressed yet
4) No... the only ammo we are allowed to put through these guns is the issued match Blackhills. The only other 7.62 around is m80 ball, and that is not just laying around to shoot even if we could put it though the rifle. (its weird times)

so hypothetically lets say the round count is true @ 1k & there is no throat erosion...and he gets range time to shoot the rifle unsupressed and its zero's & groups. what could be wrong with the can if it fits properly and there is no baffle strikes/muzzle cap strikes? every time i have seen issues with cans and accuracy its link to baffle/muzzle cap strikes. i haven't seen everything in life obviously, but that's typically what i associate that with.

[Failure2Stop]

jleuba@knightarmco.com
Hit me back.
There isn't much I can't get squared away.

[hmewrcknb4]

jleuba@knightarmco.com
Hit me back.
There isn't much I can't get squared away.

email sent..thank you sir

[hotrodder636]

Interested to see what the issue was, if you are able to post....

[hmewrcknb4]

jleuba@knightarmco.com
Hit me back.
There isn't much I can't get squared away.

Thanks for all your help on the phone today and squaring this away, working with solid equipment with a strong support network makes the job easier down range. just another reason to run KAC kit.

[RetroRevolver77]

Did you try a throat erosion gauge? That would tell you right there if it has more rounds down range than it's logged.

[sinister]

Generally speaking a throat erosion gage won't tell you dick unless you know what starting depth was. GI bores are generally held to a fairly generous .mil tolerance, with throats cut to a .mil-specified drawing.

Borescoping will tell you fairly true condition of throat and gas port erosion because it's a visual check -- you can see how far your lands have eroded, gas checking, and port wear.

[trinydex]

Generally speaking a throat erosion gage won't tell you dick unless you know what starting depth was. GI bores are generally held to a fairly generous .mil tolerance, with throats cut to a .mil-specified drawing.

Borescoping will tell you fairly true condition of throat and gas port erosion because it's a visual check -- you can see how far your lands have eroded, gas checking, and port wear.

will throat erosion cause that kind of accuracy issue?