Air Gun Home :: View topic

Fastsc92 · Member

I'm wondering if anyone could post pictures to what a poor barrel crown looks like. I have a 1077 and to me, the crown looks alright, but this is to the untrained eye. I was wondering if someone could post up a few pictures of what a bad crown looks like. I'll get some pictures of my barrel up here shortly for comparison/critique.

Alstone · Moderator & Site Supporter

Welcome to AirGunHome Fastsc92, The link below has a photo of a bad crown.

A crown should be smooth with no rough bits where the hole exits and even all around.

http://airgunhome.com/agforum/viewtopic.php?t=343&highlight=crown

Al

Slavia · Moderator

Dab at it with a cotton swab. If it snags fibers, it needs polish.

Fastsc92 · Member

Here is my barell (muzzle end)....from what I can tell, it looks alright, but I'll most likely try to polish it anyways. I've read in a few places that peope have used a countersunk bit and spun it by hand, and then followed it up with some fine steel wool.

I've had this gun (1077) for 5 years, hardly used it and finally pulled it out of storage to have some more fun out of it. It always shot to the right with open sights (once adjusted it was ok). Recently I added a 4x32 centerpoint scope to it and it still seems to shoot to the right during initial sighting. At 10 yards the groupings (if you can even call them that...) are about 3" to the right. It's hard to even dial in the scope, as I can never get repeatable shots with this gun. I recently got a barrel stabilzer and I'm waiting for it to come in before I do more testing. Perhaps its the pellets I'm using as well...they are cheapy Daisy Precision Max pointed 7.29gr.

Anyhow, here are the pictures, some are clearer than others...:

Teryx · Veteran Member

A good muzzle crown should be concentric to the bore, and cleanly cut. Ideally the surface should be lapped with a fine compound. I recrown every rifle I buy just as a matter of routine because the factory cuts are always rough. You should be able to clearly see the lands of the rifling at the muzzle. I can't see the lands in your picture. I either use lathe cut brass laps with a pilot rod, or in some cases small brass ball bearings coated with 1000 grit lapping compound.

In your case though, the poor groupings could be any number of things

Teryx

Fastsc92 · Member

I cleaned up my crown a little, or as best as I could. I think it looks good, the rifle seems to shoot ok, but I didn't notice any drastic change in groupings. They do appear slightly tighter.

Black Lab · New Member

The crown looks pretty good to me now. In the first pics. You could see a couple small burrs. I would be trying different pellets. I haven't heard one good thing about Daisy pellets.

fritz · Silver Status Member

Change pellets. Your crown looked OK to begin with. I would probably go for a pellet in the 7gr range because of the 1077's lower power, BUT whatever is accurate is what should be used.