What do you see in your bore scope and what does it mean
donnie last edited by
Upon bore scoping some of my barrels, I am obviously seeing some signs of wear and tare. I have 2 barrels in the 800-900 rnd range that I haven't cleaned for some time (800 rnds +-), one a 308win and the other a 300wsm. These are my main shooters. I am seeing fire cracking, what appears to be a carbon ring that some refer to as the "ring of death", pitting, and different colors of fouling along the bore but little copper fouling. These are benchmark barrels.
When I bore scoped my factory ruger 220 swift, the fire cracking was 10x worse than other rifles and the throat in rougher shape. I can only estimate the rnd count around 3000-4000 rnds. I have taken the approach of shooting my rifles without cleaning the barrels and fine tuning loads after that 250 rnd range where you see the 2nd spike in velocity as discussed in the dirty barrels experiment thread. So far it appears the barrels start pushing out as much fouling as they're taking in around that 250rnd range, so I haven't seen large amounts of buildup in the bore.
My main questions are, at what point is a barrel visually going down hill as seen in a bore scope, and are there any safety concerns I should be watching for as I continue shooting these barrels? The carbon rings just ahead of where the case mouth would be look very thin, like microscopically thin so don't know if that would be an issue? Also, I don't know if the fire cracking is anything to be concerned about? Both barrels still shoot 1/2 moa, sometimes better depending on me.
orkan last edited by
donnie last edited by
@orkan thanks for posting this up. I tried searching but the only thing that came up under PR was a thread you posted on a customers barrel that came in dirty as heck and needed a good cleaning. Where can I find this on the PR website?
I am shooting fairly mild loads in both my 308 & 300wsm, so I don’t know why I would be seeing fire cracking due to high pressure? I’ll watch this video again to see if I miss heard you, maybe it was an effect from pressure in general, not high pressure? Also only 800-900 rnds. Either way, I’ll continue shooting them until groups start opening up to unacceptable levels. Out of curiosity, tonight I’m going to see where quickload is estimating the greatest spike in pressure down the bore and see if that lines up with where I’m seeing the fire cracking.
orkan last edited by orkan
Where can I find this on the PR website?
Home page > Library > YouTube
so I don’t know why I would be seeing fire cracking due to high pressure?
Just because you've never seen it before... doesn't mean it isn't 100% normal. Every single barrel with any appreciable round count with every single cartridge has that kind of geography in the throat. If the rifle is still shooting well, then ignore what you see. A bore scope is what you whip out to SOLVE PROBLEMS. You don't pull them out to look, get freaked out, and create problems. ;)
The hotter the load, the worse it will be... but this will happen eventually with even the most mild cartridges and the most mild loads.