CROWN, WHAT CROWN?

[mudduck48]

I got my 1300 back together and tried to sight it in. It was shooting pellets like a Daisy BB gun. Why? I took my 10 power loop and looked at the muzzle and found that Crosman never crowned the barrel. You can see the burrs where the tool cut the refiling in the barrel. But they never cleaned up the end of the barrel.

[bgmcgee]

I've seen worse. Looks like a good candidate for the brass screw and polishing compound. From here the rifling looks pretty even though.

[mudduck48]

I tried to take the best picture that I could. What you don't see is the burrs from the tool that cut the riffling hanging into the hole of the bore.

[WyoMan]

Looks like it needs some duckwork there, sorry to HVAC folks...couldn't resist 
I've come to believe that a showroom crown is much overrated but...
you got to get rid of the burrs...also, is that paint in the bore or is it the pic 

[mudduck48]

Looks like it needs some duckwork there, sorry to HVAC folks...couldn't resist 
I've come to believe that a showroom crown is much overrated but...
you got to get rid of the burrs...also, is that paint in the bore or is it the pic 

It must be the picture. It looks like bluing inside the barrel. I'll try to take a better pic after din-din here in a little bit. Try to show the burrs better.

[K.O.]

yup that crown looks a little quackerd...   ( sorry couldn't resist )

[mudduck48]

OK, I'll try again. If you look close you will see the metal hanging into the bore at the muzzle.

[WyoMan]

Bad crown but not real deep...600 grit over a round screw head or round bolt handle turned by hand 
Bad bore...tight patch with cleaning oil, tight patch dry, tight patch with small amount of metal polish, tight patch with cleaning oil...
check with flashlight for mirror shine...repeat as necessary 

[K.O.]

If the crown look like that I think I would take a good look at lead in and check for burrs at port also...

My PC77 needed both cleaned up  went from rather large groups to 1/2"- 3/4" groups after a quicky cleanup ( I think I need to do just a bit better on lead in)

[bgmcgee]

I see now says the blind man.   Still it looks like a relative easy fix just a little of your time and she will be all shiny and pretty.

[mudduck48]

If the crown look like that I think I would take a good look at lead in and check for burrs at port also...

My PC77 needed both cleaned up  went from rather large groups to 1/2"- 3/4" groups after a quicky cleanup ( I think I need to do just a bit better on lead in)

This is a Crosman Medalist II. Some how they attached the barrel to the steel breech and I do not think it is removable like on your PC77, but I will take a look at the lead in, good idea. Thanks.

[1377x]

This is a Crosman Medalist II. Some how they attached the barrel to the steel breech and I do not think it is removable like on your PC77, but I will take a look at the lead in, good idea. Thanks.

the last i checked i could still get the breech/barrel combo. i think you are right they are one piece thats how they are/was sold

[mudduck48]

Well, I worked on the crown a little. I took a tapered grinding stone, by hand and ground a taper then took a piece of 800 gt sand paper with the stone to smooth it up. It definitely works better now. The target is 3 shots at 17ft. on the rest with my Crosman 1399 shoulder stock installed on the gun.

[KevinP]

That looks much much more  gooder ...   

[BDS]

Nice Duck