I agree with you doc that the crown could be causing a ton of issues.
The transition angle is already way wider than it should be. Do you know anyone with a lathe that would clean off that face. Then it would only take a minute with the brass screw.
Try any old white toothpaste instead of the 600 grit.
Sean
I find it odd that there is no recess to the crown at all on this bbl. Even the cheap little 22-XX Crosman bbls have more protection than this.
I have no ready access to a lathe. There's a drill press with some slight run-out I could use. Since I have these new end mill cutters to play with....
...I'd end up with a home done crown inside a recess of my liking. The tooth paste hint is almost as good as what Heloise used to put in the newspaper hereIf I don't try, I'll never know....
Regards,
Doc Sharptail
"Ain't No Half Way"
-S.R.V.
Ya thats true " If you don't try you'll never know"
Oddly enough right beside where I work a ship docks once a year and drops of this pure white fine sand. it must be really expensive because they lay down tarps to catch the spillage which is swept up and loaded onto trucks with the rest of it....heading for the toothpaste factory in Buffalo.
Who knew!
On to your crown. The recess has always been a bit of a quandary for me. You want the recess for protect but any recess at all will actually affect accuracy to some degree. So on my target barrels I don't put a recess I just store and transport with a protection cap
Sean
Ground calcite- they also strip-mine this stuff in Ontario and Quebec- it's the processing that apparently takes up all the money (they tell me it's done with water and creates a super-thick gooey gunk similar to far-too-dry mixed drywall compound and sticks to anything/everything- making cleanup also a huge expense).Originally Posted by SeanMP
I'd say I care- but I'd probably be lying...
Really....Ground calcite cool
That is pretty rare knowledge....where or how did you learn that?
Sean
Did a bit more work with the D tonight.
The idea of using the .25" mill cutter in the drill press worked surprisingly well, despite unexpected chatter on the drill press. Must be a bit more run out there than what I originally suspected. I've got a nicely recessed, even crown now. I passed on the tooth paste, and went with chinese green valve lapping compound. Did a final polish with a dry bullet shape polishing pad from the dremel set. Haven't had time to test it for group yet...
Dressed the gun up a little with brass accent rear caps from scopes and ammo. Had to shim the big tube cap with a bit of electrical tape- with these guns it could simply be over machining of the tube. It still looks nice.
The gun would look a bit more complete with brass bbl. band, and muzzle brake....
Regards,
Doc Sharptail
"Ain't No Half Way"
-S.R.V.
I like brass...nice
For every mile of road, there's two miles of ditch
Brass always adds a nice look, but if you shoot a lot, an oversize bolt handle is a good upgrade to consider. Cocking is so much easier on the hand, since these cock on "push", rather than "pull" of the bolt...
Looking good, Doc!
Sorry- missed the comment earlier;
They strip it out of the ground somewhere in northern Lanark County, truck it down to a plant west of Perth to process it, then ship to Drummondville Quebec where there is another processing facility. I've been through the company's (OMYA is the name) offices, haven't seen the actual processing activity first-hand, however- only been told about it.
I'd say I care- but I'd probably be lying...
Finally got to the bench with the re-worked crown. Major improvement over the lateral stringing it was doing before. Seems to be holding p.o.i. consistently- after some 30 odd shots. Looks like it's time for a new box over the shrink wrap trap.
It took a bit of doing to arrive at a consistent group:
I think I'll be happier once I get the gun off co-2. My shot count is dropping, and I still haven't got the bottom end of the gun apart yet.
I still think I've done well, especially on price. A few more weeks of tweaking and shooting, and the comfort zone should be enough to go ahead with the conversion tube. I really would like to be able to put more time into it...
Regards,
Doc Sharptail
"Ain't No Half Way"
-S.R.V.
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