Originally Posted By Dano523:
Are you using the alignment rod from chamber to muzzle?

If yes, then where is the rod sticking point. If at barrel shoulder to Supressor attachment device start point, then device may have been over torqued, to bend the barrel threaded section.  If sticking just before that at say the gas block passage in the bore, then may have to take a cleaning brush to knock off any burs at the gas port.

If binding before that down the barrel, and you can roll the alignment rod on a flat surface to make sure it not bent, then may have a problem with Bore not true/ straight on the barrel.

Also, photo's are not loading.

Originally Posted By Dano523:
Seen it too many times,
[url]https://adcofirearms.com/wp-content/uploads/2017/04/crown-1.jpg[/img),

Where FS or suppressor attachment device is over torqued when indexing them, puts a ton of torque on the barrel shoulder, and will cause the threaded section of the bore to be torqued off line.  Or, the suppressor/adapter takes a hit, which can cause the threaded section of the barrel to be canted as well.

As for Geissele, make sure they use a alignment rod to check the bore (one that fits the rifling Tightly like your does).

Originally Posted By Dano523:
"This time they have assured me that they will remove and install a new SureFire 4 Prong muzzle device and then have the bore checked in detail".

Problem is, if the 4 prong too over torque to index it on the barrel to bend the bore at threaded section shoulder, then new 4 prong installed is not going to solve the problem.  Hence problem is the barrel bore is now bent at the barrel shoulder onwards.

So with new barrel, instead of playing the shim game for index on the  4 prong,
[url]https://www-wp.silencercentral.com/wp/wp-content/uploads/2020/07/Product-Slider-SC-BNSH-30G-1-min-scaled-1-1270x1080.jpg/img]
better to just face the back of the 4 prong to square it up/get it to index against the shoulder with min amount of torque and no shim needed (touch over hand tight), then rock-sett it in place.

Hence you can still bend the last Inch of bore if the suppressor does take a side strike (why best to run a longer forearm, so less of the supressor is protruding out), but at least you know that the threaded section of the barrel is not bent at the shoulder to start with.

Originally Posted By Dano523:
All up to you, but unless your shooting MK262 ammo, the barrel twist rate is too fast for 55gr ammo, and maybe for some 62 grain ammo as well to print tight groups.
Note, I put it right up there with Melonite bore barrels, then tend to foul on the quicker side to grow groups in prolong shot strings as well.

Chrome lined on a hammer forged barrel may be great for full auto fire rates, but it a negative when it comes to semi auto that is going to shoot tight.  I bring this up since FM did manage to perfect chrome lining for their  police bolt action SPR rifles barrels that would shoot sub MOA with match ammo (but  not as tight as the 40X's with 5r rifling), but as for other manufacturers, just causes too much variances when air gauge for a barrel that is going to try to shoot sub MOA with match ammo.

As for you get the rig back and it still has the same problem, them maybe time to get adco on the phone.  As stated, the threaded section can be removed, muzzle Od set back to re-thread the barrel shorter .620", and they can open up the gas port for it to work with the shorter length off the gas port for around a C note.  Or if the plan is to run 55gr ammo in the rig, then maybe would be better off with swapping to  1-9 twist barrel for a few hundred more.