Is there a way to deal with this, short of cutting and re-crowning? I’m not sure how much this affects accuracy. 20” CZ 17.7 twist from a priest 2.
Thanks for any advice…..
Thanks for any advice…..
If you put a Q-tip in the bore, it'll reflect a lot more light and help you see everything better.
I’m curious how this happened...
I’m curious how this happened...
Perfectly concentric scoring is almost certainly from a piloted crowning tool. Shavings or some other contamination gets trapped and damages the bore as it spins.
Even an 800lb gorilla would have a hard time pulling off that trick with a cleaning rod.
I’m curious how this happened...
Perfectly concentric scoring is almost certainly from a piloted crowning tool. Shavings or some other contamination gets trapped and damages the bore as it spins.
Even an 800lb gorilla would have a hard time pulling off that trick with a cleaning rod.
Yeah my guess would be a dirty live piloted crown chamfering tool.
I'm also not sure if RTI has CZ machine their barrels for them A-Z like Taipan does, but I know that CZ blues them afterwards. Those threads are blued, so I'd wager a bet that the crown chamfer was too.
Now if RTI does have CZ doing all of their barrel machine work for them, then it's a known fact that CZ screws up the crown chamfers at the factory, leaving that nasty burr behind. In that case, it's plausible that RTI removed the burr and made that mistake.
I’m curious how this happened...
Perfectly concentric scoring is almost certainly from a piloted crowning tool. Shavings or some other contamination gets trapped and damages the bore as it spins.
Even an 800lb gorilla would have a hard time pulling off that trick with a cleaning rod.
Yeah my guess would be a dirty live piloted crown chamfering tool.
I'm also not sure if RTI has CZ machine their barrels for them A-Z like Taipan does, but I know that CZ blues them afterwards. Those threads are blued, so I'd wager a bet that the crown chamfer was too.
Now if RTI does have CZ doing all of their barrel machine work for them, then it's a known fact that CZ screws up the crown chamfers at the factory, leaving that nasty burr behind. In that case, it's plausible that RTI removed the burr and made that mistake.
In my experience,
Bluing the bore of an airgun barrel is not good. Yes, most barrel bores ARE blued, but most good MATCH barrels are not. Bluing prep chemicals and bluing salts can etch bores and degrade accuracy.
A slightly unrelated thought to the op’s post, but still …..