A few more in 7.62x39mm

[armoredman]

Had to try this in my CZ 527. Just for grins and giggles, I took two pictures of the bore, with my cell phone camera, at the range. Before and after.
We'll do this in order, just to show off. Shot kneeling, no rest, 50 yards, breezy, going up into something we might call windy.

Before round number one, just dust.

http://i16.photobucket.com/albums/b13/armoredman/527/Cleanboreattherange_zpsae8b07be.jpg (http://s16.photobucket.com/user/armoredman/media/527/Cleanboreattherange_zpsae8b07be.jpg.html)

http://i16.photobucket.com/albums/b13/armoredman/527/762x39mmcastpowdercoatedontheline_zpsa9a41d98.jpg (http://s16.photobucket.com/user/armoredman/media/527/762x39mmcastpowdercoatedontheline_zpsa9a41d98.jpg. html)

http://i16.photobucket.com/albums/b13/armoredman/527/129grainpowdercoatedinmagazine_zps91224d91.jpg (http://s16.photobucket.com/user/armoredman/media/527/129grainpowdercoatedinmagazine_zps91224d91.jpg.htm l)

http://i16.photobucket.com/albums/b13/armoredman/527/Powdercoat4_zpse9beb3bf.jpg (http://s16.photobucket.com/user/armoredman/media/527/Powdercoat4_zpse9beb3bf.jpg.html)

http://i16.photobucket.com/albums/b13/armoredman/527/Powdercoat2_zps3f34d63e.jpg (http://s16.photobucket.com/user/armoredman/media/527/Powdercoat2_zps3f34d63e.jpg.html)

Yeah, I know. I tried for a six o'clock hold at 50 yards, and that's what I got. Oops. :) Great group.

Oh, and the bore after 40 rounds?

http://i16.photobucket.com/albums/b13/armoredman/527/boreafter40roundsofpowdercoatedleadbullets_zpsda64 defb.jpg (http://s16.photobucket.com/user/armoredman/media/527/boreafter40roundsofpowdercoatedleadbullets_zpsda64 defb.jpg.html)

More dust. :)

[OptimusPanda]

The cs527 is a really nice rifle, Ive had mine a few years now and it never disappoints at the range. Havent started reloading for it quite yet though. Say, what bullet are you shooting? Is that the lee?

[armoredman]

NOE 129 and the Lee 160 was what i used that day. The NOE works quite well. The Lee didn't do as well, but it's a work in progress.

[stephen m weiss]

Those are awesome pictures. Am I mistaken or are there longitudinal cracks in the bottom of the bore right where high pressure spikes appear? If after a very thorough cleaning you conclude that those are cracks, you may want to limit the number of rounds you fire, and keep the pressures below half of stock pressure. Fracture mechanics inside barrels is a difficult issue, and I have been thinking of ways to observe it. I have a hard time believing those are cracks but they sure dont look like dust or smears, especially down where the lead cant touch.

[LAGS]

I do not think those are cracks at all.
The lines do not line up in the before and after pictures.
And there are more lines in the after picture then in the first.
But if Armoredman wants me to, I will do a chamber casting just in case to see.

[ioon44]

What is the dust in the bore pic after firing? I found the same stuff in my pistol bore's after firing PC boolits.

[LAGS]

I find the same type of dust in my barrels even with J bullets.
I think it depends on the powder you are using.
Some powders seem to do it more than others.
I also noticed, that the bore will look clean when I leave the range.
But then when I get home, it seems like the dust settles to the bottom of the bore, and is more visible in a line.