I've long preferred the classic Sterling threads to the Spyder threads, but barrels are... elusive. I'm trying my hand at making a Freak back for one. And single-pointing a thread for the first time in 17 years, on a much smaller/ cheaper lathe than last time.
First things first - the barrel itself can be made up to 0.810" thick. Not a lot of material, but maybe it's enough to Freak bore. We'll see. (0.035" per side?)
Second - thread spec is 7/8"-14 1A, based on my measurements. Body is bored through at .815", and thread OD is right around .860". Every barrel I've seen has a tiny crest and huge root, though, so I pushed my compound wide and cut a few passes to widen the thread root. I need to get some wires to measure this correctly. Overall breech depth 2.125", with threads for the last 3/4" being "enough" (or more than enough, if you want to pull it more quickly).
Learning my "new" lathe in the process, though, including the fact that the feed has a ton of backlash. Might need to rebuild that mini gearbox. Also learned the diagram for inch threads is wrong when I realized the 127 tooth gear was engaged instead of the 120, after my first thread came out at 14.8tpi instead of 14. Oh, China... your documentation leaves much wanting.
Waiting on some properly long boring bars and bidding on some reamers to do the insert bore, and see if enough of the threads survive for a proper, usable barrel. But, even if my machining skill isn't all there, at least I've offered some info more people with better equipment and more time on it.
TLDR: 0.815" OD x 2.125", with a 7/8-14 1A thread for the last 3/4".
Stay tuned to see what comes out at the end.
First things first - the barrel itself can be made up to 0.810" thick. Not a lot of material, but maybe it's enough to Freak bore. We'll see. (0.035" per side?)
Second - thread spec is 7/8"-14 1A, based on my measurements. Body is bored through at .815", and thread OD is right around .860". Every barrel I've seen has a tiny crest and huge root, though, so I pushed my compound wide and cut a few passes to widen the thread root. I need to get some wires to measure this correctly. Overall breech depth 2.125", with threads for the last 3/4" being "enough" (or more than enough, if you want to pull it more quickly).
Learning my "new" lathe in the process, though, including the fact that the feed has a ton of backlash. Might need to rebuild that mini gearbox. Also learned the diagram for inch threads is wrong when I realized the 127 tooth gear was engaged instead of the 120, after my first thread came out at 14.8tpi instead of 14. Oh, China... your documentation leaves much wanting.
Waiting on some properly long boring bars and bidding on some reamers to do the insert bore, and see if enough of the threads survive for a proper, usable barrel. But, even if my machining skill isn't all there, at least I've offered some info more people with better equipment and more time on it.
TLDR: 0.815" OD x 2.125", with a 7/8-14 1A thread for the last 3/4".
Stay tuned to see what comes out at the end.
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