Rough bore picture New picture added.
This rifle shot pretty well too.
It is my theory that the value manufacturers know exactly how many barrels they can ream before the tool gets too dull to give good accuracy, and they keep making bores with the tool getting duller and duller until the limit is reached.
They probably save the rougher bores from the end of a production run for their value models.
This is from a .22 LR. I hope the reaming marks on the lands weren't scraping lead off the bullet, especially by the hollow base where the firing pressure was pressing the bullet into the bore.
If it was scraping lead, it would seem to have created more airborne lead dust at the range for me to breathe and for the staff to clean up, and more would have probably wound up on the floor when I cleaned the gun.
Comments
Here is a picture from a walnut stocked model from the same company. It looks like it could use a little copper solvent but is otherwise much better.
My understanding is that all machine tools have a tolerance range they operate in .Once a tool exceeds the limit it gets replaced . Looks like maybe the QC dept may have slipped up a little
If you are worried about airborne lead dust at the range.............Dr. Fuachi says to wear a mask. Wear a mask. Wear two masks.
Worried about lead dust? Really? Just reclaim it and re-sell it.
your theory ? may be or maybe not as posted all tooling wears they may have waited a bit late and QC said ship it
a little lead dust I think there is more to worry about happing now in this country
besides we all go to go , no one gets out alive
The first picture tells me that who ever was running the machine that day had the feed rate turned up and was making some good piecework for that time and a half pay.
I don't really believe .22s need much to pretty much get them in there. I am not talking biathlon level, but squirrel hunting level.
lead will fill in the nicks and craneys
Here's another one. The chamber on this one was a little on the long side so the hollow bullet base of the 22 LR surely swept across the end of the throat before engraving into the rifling. The lands themselves are a little rough too.
Remember, the hollow base of a high velocity 22 LR bullet is being pressed in to this roughness by 24,000 pounds per square inch in the chamber, although the pressure soon gets lower as the bullet moves out.
The lead must have been swept away after every shot because it is right outside the case mouth.
This is not like leading because the lead is not melted onto the barrel metal but simply scraped off. It is probably much freer to be blown away by the powder.