Re: T JENSEN 22-250AI VARMINTER
Base color going on now Tom.
As for crowns, I look at it like this:
Guns like this aren't cheap to buy, build, or own. They require an elevated skill set to maintain. If you clean guns like a bunch of "Lance Criminals" with multi piece cleaning rods and the mindset of "just get it over with" then maybe consider an alternative.
Everytime you stick anything down a barrel in the effort to clean it, you run the risk of damaging something. It's why I advocate to every customer to NOT clean their bore until they see a change in performance. That can mean anything, accuracy, pressure signs, whatever. If it's not broke, don't try and fix it.
How this applies to a crown. If 11* truly is the "magical answer" as advocated by so many bench rest and target shooters, then in my mind (and a few others) a 45* chamfer at the bore completely defeats the purpose.
I personally think a crown just needs to be cleanly machined and at a uniform breakaway angle. If it's at 90* just buzz it and be done. No need to indicate a thing. Square is square whether there's .00005" TIR or .100" TIR.
Alter by even 1* though and the bore should really be dialed in.
This is assuming we all single point a crown. Many just use a piloted crowning tool. I personally don't like them. Again, every time you stuff something inside a barrel, you risk damaging it.
We all learn from different mentors. There's a lot of ways to peel the skin from a cat. Proof is in the paper down range so if your gun shoots and you crowned it with a hacksaw then by all means, leave it alone. If nothing else, you'll be the source for great conversation!
I like razor sharp crowns. I tell clients to either remove the jap upon exit or to carefully guide it back in the bore with their hand. Never just "yank and hope for the best."
Hope this helped.
C.