Quote:
| Originally Posted by MONITOR
As far as polishing too much, you don't need to worry about that so much as people seem to think sometimes. The rear bolt only needs to make an air-tight seal in the rear of the powertube so that the blowback stage forces the bolt out of the power tube for the next cycle. |
Yeah, If the seal was so critical there, they wouldn't have made the receiver split in half like they did.
The key to think about the bore-size (after sanding) is how the O-Ring fits; not the metal bolt.
Also, you may need to install a new O-ring to obtain the proper fit if the old one is heavily used.