The spec for 6.5 Grendel bolt is .136 bolt face depth with a tolerance up to .002.
I suggest you compare the bolt from the Grendel hunter to the Monster bolts. Measure the bolt face depth, length/width of the lugs and the bolt overall length. I have several Monster bolts where I have compared all their dimensions and they all are vey close.
Honestly with the track record of short chambers on Satern/Liberty barrels I wouldnt be surprised to find more variations in the Satern/Liberty barrels than the Monster bolts. There was a group buy of Satern Liberty barrels where the chambers were out of spec. Instead of owning up to the PTG reamers not being SAAMI spec S/L went on to bash the 6.5 Grendel design then offered the Grendel II chamber. This debacle hasnt helped S/L reputation on this forum.
I have two Friends who bought Satern/Liberty barrels sold as Brownells house brand. Both have short chambers and are over gassed. One barrel would not cycle factory ammo and destroyed a bolt in short order because it was so over gassed. Using hand loads with an adjustable gas block permitted this barrel to function. The barrel was accurate so the owner decided to keep it.
If I were in your situation Id measure the seating depth of various bullets in each barrel and record where the bullet is into the lands. I have two Faxon Group buy barrels, a 16 & 18. Using the same bullet in a Hornady COAL comparator tool the same bullets are within .003 on average. So close it is hard to get exact measurements with the tool.
I think if you take careful measurements you should be able to get an idea of the issue. Id compare the seating depth of bullets in your Grendel hunter barrel to your other barrels.
I suggest you compare the bolt from the Grendel hunter to the Monster bolts. Measure the bolt face depth, length/width of the lugs and the bolt overall length. I have several Monster bolts where I have compared all their dimensions and they all are vey close.
Honestly with the track record of short chambers on Satern/Liberty barrels I wouldnt be surprised to find more variations in the Satern/Liberty barrels than the Monster bolts. There was a group buy of Satern Liberty barrels where the chambers were out of spec. Instead of owning up to the PTG reamers not being SAAMI spec S/L went on to bash the 6.5 Grendel design then offered the Grendel II chamber. This debacle hasnt helped S/L reputation on this forum.
I have two Friends who bought Satern/Liberty barrels sold as Brownells house brand. Both have short chambers and are over gassed. One barrel would not cycle factory ammo and destroyed a bolt in short order because it was so over gassed. Using hand loads with an adjustable gas block permitted this barrel to function. The barrel was accurate so the owner decided to keep it.
If I were in your situation Id measure the seating depth of various bullets in each barrel and record where the bullet is into the lands. I have two Faxon Group buy barrels, a 16 & 18. Using the same bullet in a Hornady COAL comparator tool the same bullets are within .003 on average. So close it is hard to get exact measurements with the tool.
I think if you take careful measurements you should be able to get an idea of the issue. Id compare the seating depth of bullets in your Grendel hunter barrel to your other barrels.