Here is a picture of the crown of “Rifle A”.
3.jpg
I sent my OP and the picture of the crown to BCM and they wanted to know if I used a Geissele alignment rod. I told them no, I don’t own a Geissele rod, and they said to ship my upper to them without the flash hider or the suppressor. They included a prepaid shipping label. I sent the upper to them and received it back about two weeks later without any information included. I emailed them asking what they found.
BCM Response:
“We confirm we received your upper receiver group back to our facility for inspection. We fully inspected and QC’d all of the individual components of the upper receiver group. These were all found to be well within spec.
We can only assume that there may be an issue with the muzzle device that was installed on the weapon system. If the muzzle device was not verified to be concentric prior to installation of the suppressor, this would cause an issue. We would recommend installing the muzzle device to the manufacturer’s specifications and using a good alignment rod, such as a Geissele Alignment rod to verify concentricity before installation the suppressor. Once verified and the suppressor has been installed, we suggest verifying concentricity again with the alignment rod.”
So according to BCM, the upper isn’t the problem.
I now email Surefire with my OP and they respond requesting pictures of the Warcomp and asking if there has been any baffle strikes. I send them pictures of the Warcomp and tell them no, there hasn’t been any baffle strikes.
I get a response saying the Suppressor Division would like to inspect my upper (w/o BCG) with the Warcomp installed as when I shot, as well as inspect the SOCOM300-SPS suppressor.
I ship the Upper, Warcomp, and Suppressor to Surefire.
About 6 weeks later I get back my upper and suppressor and what appears to be a new 7.62 Warcomp. No information is included in the packaging.
I email Surefire and ask if the old Warcomp was out of spec, or the cause of my problems.
Surefire Response:
“No issues with the original WARCOMP. However, to rule that out as an issue it was replaced. There were some minor spec issues with the Suppressor that were addressed.”
I ask if the “minor spec issues” would be individual to “Can1”, or is there a possibility of the same issues occurring within that batch of suppressors? (since “Can1” and “Can2” have sequential serial #’s and SF only inspected “Can1”)
I also ask, if possible, could they highlight what the spec issues with the suppressor were?
Surefire responds saying the issues would be individual to that can, with no detail about what the actual spec issues entailed.
I install the new Warcomp and finally get to the range. The results are the same as before. Large vertically strung groups whenever “Rifle A” is suppressed (with either “Can1” or “Can2”).
Again, this is shooting factory Barnes 110gr Black Tip at 40 meters.
There IS vertical stringing with:
“Rifle A” suppressed with “Can1” - (11” Extreme Spread) – (Picture 1)
“Rifle A” suppressed with “Can2” - (6.25” E.S.) – (Picture 2)
There IS NOT vertical stringing with:
“Rifle A” unsuppressed - (1.25" E.S.) – (Picture 3) - (Its either not stringing, or the stringing is too small to tell for sure. I really should've fired a 10 rnd group.)
“Rifle B” unsuppressed - (~1” E.S.)
“Rifle B” suppressed with “Can1” - (~1” E.S.)
“Rifle B” suppressed with “Can2” - (1” E.S.)
1.jpg2.jpg3.jpg
Notably, each time testing, “Rifle A” with “Can1” Extreme Spread is double the size of the E.S. with “Can2”. These E.S. numbers with each can have also been fairly consistent from range trip to range trip (~12” with “Can1”, and ~6” with “Can2”).
Lets list the possibilities that I see:
-Barrel threads not concentric to the bore. It is slight enough that it is unnoticeable with a regular FH, but with the added length of a suppressor, the effect is compounded and noticed.
- There isn’t an issue with any single part, but a “tolerance stacking” type of issue.
Solutions:
-Buy a new barrel and see if problem is remedied.
-Buy alignment rod to verify the non-concentricity. Then buy a new barrel...
-Break apart entire upper and reinstall barrel, gas block, the whole 9 yards. Im not sure exactly what BCM’s QC process entails, but I would assume they would have checked it all out for proper specs and assembly when I sent it back to them, considering it’s a factory upper. Still, this is the only thing I can think of that doesn’t entail a new barrel.
Any other ideas?
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