Glad the barrel seems to be working ok for you.
The original and spec version of 6 Arc (as for the 6.5 Grendel, which it was developed from) is for bolt face depth of 0.136", and an elongated bolt tail of 0.011" or so, so that a spec firing pin can be used (unchanged FP length). Some 7.62x39 bolt bodies were intro'ed by a mfr (not sure which one started it but toolcraft was doing it for a while, then changed over to real-spec) and the extractor modified so it would work for the Grendel/now 6Arc. When they "saw the light" and started making the 0.136 bolts as well they took it on themselves to name the 7.62 version "type 1" and the (real spec) 0.136 as "Type 2". If your barrel chamber needs that 0.125 (now called "type 1") it is important to use it... as you are finding out. The 0.136" is the spec, though... and has an extractor that is a bit stronger than the 0.125" depth bolts.
Some of the older toolcraft bolts, with that 0.125" face depth and "556" bolt length (0.011 shorter than a spec Grendel/6Arc), had to be kept as bolt, firing pin, and extractor set combined, you couldn't use a spec firing pin in them -- too long (IIRC) for striking/igniting the primer -- piercing them. And you couldn't use the bolt interchangeably with other FP's or grendel setups. When I had one of those (since then I got rid of it, I want interchangeability and spec parts) I had to keep all that together as a set. Took me a while to figure out what was going on. Those TC earlier bcg's/bolts etc caused some confusion and consternation for a while in the grendel community. We went through all of this a few yrs ago.
The bolts you can order now from Rexus (Rexus owner is the Admin for this site), are called "mark 136" to make a point that they are 0.136" face depth and standard spec dimensions, which some mfrs call type 2.
Even today, I confuse myself a bit with all the problems those bolts caused. But the problems were real and the interchangeability- lack thereof- was real also. So be careful with that barrel, to use parts that will work for it. Not every mfr will have them.
The original and spec version of 6 Arc (as for the 6.5 Grendel, which it was developed from) is for bolt face depth of 0.136", and an elongated bolt tail of 0.011" or so, so that a spec firing pin can be used (unchanged FP length). Some 7.62x39 bolt bodies were intro'ed by a mfr (not sure which one started it but toolcraft was doing it for a while, then changed over to real-spec) and the extractor modified so it would work for the Grendel/now 6Arc. When they "saw the light" and started making the 0.136 bolts as well they took it on themselves to name the 7.62 version "type 1" and the (real spec) 0.136 as "Type 2". If your barrel chamber needs that 0.125 (now called "type 1") it is important to use it... as you are finding out. The 0.136" is the spec, though... and has an extractor that is a bit stronger than the 0.125" depth bolts.
Some of the older toolcraft bolts, with that 0.125" face depth and "556" bolt length (0.011 shorter than a spec Grendel/6Arc), had to be kept as bolt, firing pin, and extractor set combined, you couldn't use a spec firing pin in them -- too long (IIRC) for striking/igniting the primer -- piercing them. And you couldn't use the bolt interchangeably with other FP's or grendel setups. When I had one of those (since then I got rid of it, I want interchangeability and spec parts) I had to keep all that together as a set. Took me a while to figure out what was going on. Those TC earlier bcg's/bolts etc caused some confusion and consternation for a while in the grendel community. We went through all of this a few yrs ago.
The bolts you can order now from Rexus (Rexus owner is the Admin for this site), are called "mark 136" to make a point that they are 0.136" face depth and standard spec dimensions, which some mfrs call type 2.
Even today, I confuse myself a bit with all the problems those bolts caused. But the problems were real and the interchangeability- lack thereof- was real also. So be careful with that barrel, to use parts that will work for it. Not every mfr will have them.