Finally used my boroscope
- Thread starter JimD
- Start date
Well I at least temporarily stopped trying to get the lead out of my Caimans CZ barrel today when more slugs arrived. The lead is all in the first few inches of the barrel none near the crown. It is at worst thin now, seemed much thicker initially. I got a couple "Chore boy" pure copper scrubbers. I wrapped this over the first brass brush I used to make it tight in the bore. I kept the bore wet with Kroil but I am not sure it did much. I hoped it would loosen the lead but it seems tightly adhered.
I put a couple magazines of slugs lubed with WD40 through the gun late this afternoon. Velocity was about 920fps, about the same as before. 5 of the last 6 shots were 280mps and the other one was 281. It varied more on the first 14. Accuracy does not seem to be improved, may be worse. But I probably over lubed the slugs and haven't tried any tuning adjustments. The pictures are a couple areas with the most remaining lead taken with the mirror on the bore scope.
I put a couple magazines of slugs lubed with WD40 through the gun late this afternoon. Velocity was about 920fps, about the same as before. 5 of the last 6 shots were 280mps and the other one was 281. It varied more on the first 14. Accuracy does not seem to be improved, may be worse. But I probably over lubed the slugs and haven't tried any tuning adjustments. The pictures are a couple areas with the most remaining lead taken with the mirror on the bore scope.
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The first picture it looks like metal is missing from the barrel there 
. Don't know for sure just what it looks like to me.
. Don't know for sure just what it looks like to me.Upvote 0
So I've been using Ballistol wet patches, followed by dry ones pulled through with a Patchworm. I mostly shoot slugs in the 27 grain range with a few JSB MRD’s out of my choked standard FX liner. I'll follow that up with some Trewax because if it's good enough for Motorhead, it's good enough for me (I read his competition resume!). I'll get a few lead shavings and dark discoloration on the patches for the first few tapering off to relatively clean.
To those who think that leading isn't an airgun issue I submit the attached video, taken after a thorough cleaning. Note this only shows maybe 4”-5” of the muzzle end, the area of the choke. Maybe I should switch to the faster twist, un-choked slug liner, but haven't seen better results with it and light-ish slugs. I found the rest of the bore pretty clean and mostly lead free.
I’ve read here people mentioning brass brushes, and I wonder if they possibly confused brass with phosphor bronze. Brass appears to be a good bit softer. I Googled phosphor bronze and it said it's 92% copper, which makes me think that wrapping a phosphor bronze brush in copper maybe isn't necessary.
Just my $.02 and food for thought. Thanks to all for the good info and ideas.
To those who think that leading isn't an airgun issue I submit the attached video, taken after a thorough cleaning. Note this only shows maybe 4”-5” of the muzzle end, the area of the choke. Maybe I should switch to the faster twist, un-choked slug liner, but haven't seen better results with it and light-ish slugs. I found the rest of the bore pretty clean and mostly lead free.
I’ve read here people mentioning brass brushes, and I wonder if they possibly confused brass with phosphor bronze. Brass appears to be a good bit softer. I Googled phosphor bronze and it said it's 92% copper, which makes me think that wrapping a phosphor bronze brush in copper maybe isn't necessary.
Just my $.02 and food for thought. Thanks to all for the good info and ideas.
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carlos_hathcock,
I may be imagining it, but over the 4 or 5" depth of barrel bore you captured in that video, there seems to be no rifling twist at all. If you looked at the land impressions at the OD of the liner, is there an even twist from breech to muzzle?
If the twist stops 4" inches from the muzzle that would explain the leading - skidding slugs. Else, you managed to twist the camera at the same rate as the rifling, giving the impression that the rifling is straight. But that should show on the outside of the liner, if it is the case. Does it?
I may be imagining it, but over the 4 or 5" depth of barrel bore you captured in that video, there seems to be no rifling twist at all. If you looked at the land impressions at the OD of the liner, is there an even twist from breech to muzzle?
If the twist stops 4" inches from the muzzle that would explain the leading - skidding slugs. Else, you managed to twist the camera at the same rate as the rifling, giving the impression that the rifling is straight. But that should show on the outside of the liner, if it is the case. Does it?
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Subscriber,
I doubt the rifling at the muzzle end lacks twist, but I’ll snap a photo when I pull it apart for scrubbing. Not much will show though, since I’ve bonded a carbon sleeve to the liner. Twist is I think 1:24 so quite slow.
One magical day, I got five MOA and smaller groups at 100 yards from this liner.
I doubt the rifling at the muzzle end lacks twist, but I’ll snap a photo when I pull it apart for scrubbing. Not much will show though, since I’ve bonded a carbon sleeve to the liner. Twist is I think 1:24 so quite slow.
One magical day, I got five MOA and smaller groups at 100 yards from this liner.
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If the OD of the liner is hidden then we can't look at it 
. How about bore scoping the last foot length of the bore instead?
If it all looks the same, either your barrel has no twist, or the scope is rotating with the rifling. No twist seem unlikely, but because twist is programmed into FX's rifling machine, it can be anything from "regular", to gain twist to zero twist.
If the last 100 mm of your liner has "straight twist", the liner may have been made using a program for a shorter liner...
. How about bore scoping the last foot length of the bore instead? If it all looks the same, either your barrel has no twist, or the scope is rotating with the rifling. No twist seem unlikely, but because twist is programmed into FX's rifling machine, it can be anything from "regular", to gain twist to zero twist.
If the last 100 mm of your liner has "straight twist", the liner may have been made using a program for a shorter liner...
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Scrubbed the bore with a bronze phosphor brush after treating it with CLR for 30 minutes (something I read in an article by a world-class PB bench rest star). Bore at the muzzle looks much better and yes, the liner has twist.
Can't wait to shoot it at 100 yards to see if it has improved. I expect it has.
View attachment 547015
Can't wait to shoot it at 100 yards to see if it has improved. I expect it has.
View attachment 547015
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