Barrel polishing and an array of equipment

[rangur1]

Yes , I have descended down the airgun rabbit hole to the depths of trying to understand barrel polishing. The concept is pretty easy, the equipment - not so much.

bore mops - self explanatory, especially critical if you are in the metal brushes will damage the barrel group.

brass bore brushes - considered essential by some if you wish to get the barrel cleaned and polished properly. Now I saw a youtube guy take a brass brush put it in a drill and shoved it in the barrel and ran it for minutes and barrel showed NO damage of any kind. Not sure if it was a firearm , but if so, are they different from airgun barrels? I am not counting FX liners in this question.

JAGS - What do these do? Not knowing I would have guessed they are for heavy corrosion in a smooth bore barrel like a shotgun. But I have no real clue. 

Lastly, on all the vids I have watched , the speaker in said video states importance of removing all residual barrel polish when finished AND to make certain NOT to let the brush applying the polish to exit the crown / muzzle of said barrel so as not to negatively affect the accuracy. So does one who has finished polishing the barrel remove the contaminated brush / mop and clean the residual compounds by sending the rod through the barrel out the muzzle and then attach a new mop / patch and pull it back through the breach end to remove the residuals. 

final detail - Is it imperative to remove the breach o ring for the polishing step? 

 

[Greg_E]

If you are using a polish that cuts deeply enough to damage the crown, you are probably wrecking other parts of the barrel.

 

[nervoustrig]

A jag is just a barbed brass fitting to hold a cotton patch, thus you can load an abrasive compound on the patch and go to work. Or you can use a mop or Brownell's VFG stuff (fiber pellets that thread onto a brass fitting). As long as you are getting a firm fit to the bore, any one of these is well suited to the task.

The reason for not pushing the patch outside of the muzzle is because it will expand out and then recompress as you draw it back in and it will round over the crown. If it happens once or twice, don't sweat it. The caution is geared toward not doing it repetitively. It's easy to avoid entirely by clamping a stop block at the muzzle.

Pull through patches lightly moistened do fine for cleaning the bore of polishing compound when you're done.

Regarding a breech O-ring, I prefer to take it out but be advised the groove will pack with sludge and cleaning it out can be tedious so you may want to consider leaving it until you're done and then install a fresh one.

 

[RM.510bigbore]

In the air gun community polishing bores is generally accepted. From experience working at a large barrel manufacturer er shaw I learned a thing or.two about barrels. I would just buy another quality barrel that is lapped from the manufacturer. After having had many custom barrels the interior finish is superior to any mass produced barrels. I tried buying a cheaper shilen 4140 barrel blank that was not hand lapped from the factory. It was terrible and fouled horribly. So I lapped it until it looked like my Benchmark rifle barrels. Went to the range and shot it. To my surprise the bullets were now key holing the target. My experience. Cheap barrels suck save up for a quality one. At least with air guns barrels never wear out.

 

[Greg_E]

This is a horrible picture, but here is the tool I made for polishing barrels. I was not happy with the stock jag that came with these felt pellets, so I bought an #8-32 brass screw and some brass nuts. Tightened the nuts and put the assembly in a drill. Used a file to cut everything to a smaller diameter because the #8 screw head and nuts were too close to the 357 bore I was working on.

Substitute a 5-40 long screw and nuts for smaller calibers.