Testing CB in Glock 21 stock polygonal barrel

[7Acres]

Hi guys,
I'm new to cast boolits. I loaded up a batch of 100 boolits this week and fired them through my Glock 21. Can you tell me from the photo of the barrel below whether this amount of leading looks to be getting excessive? Looking down the barrel I could see zero signs of leading at all. It was a mirror gloss with no apparent build up anywhere. Looking at what I could see in the pic below definitely shows some lead streaks. So is this what "leading" looks like? I would assume this represents insignificant streaking and not really built up or fouled up to levels worth worrying about. But please correct me if I'm not interpreting what I'm seeing correctly. The groups I was getting were ~2" from 20' shooting off hand throughout the shooting session. The accuracy never really degraded from what I could tell. I'm feeling like I could run another hundred through it as I keep inspecting the barrel for amounts of leading that amount to anything I should start worrying about. How will I be able to tell that I need to go Kroil and clean the barrel before resuming running boolits through it?

FYI, the boolits I cast were from COWW ingots WD from a Lee 230gr TC traditional lube groove six banger. I slugged the barrel and it was measuring at between .4533" - .4538" on the driving band depending on which opposing grooves and I was measuring. Lubed with an LLA mix of JPW, LLA and mineral spirits. I sized the boolits in a .452" sizing die with the resulting sized boolits bouncing back to .453". Being new to cast boolits I just don't have a sense of when my barrel is fouled up and needs to be cleaned before resuming to safe shooting. I appreciate any wisdom and tips.

58195

[prs]

Been there and done that. At first my G-23 got a little soft streaky lead that did not adhere. It improved with each shooting session and cleaning. After session four the leading was insignificant. My OE barrel had previously digested a full case off WW180gr jhp. So the barrel barrel was impregnated with copper. I used OOO steel wool soaked with Johnson paste wax to easily de-lead and prep the barrel. Mild loads with AC WW or similar alloy lubed with liquid allox are no problem at all. Full house 40 loads still skid slightly, 45ACP may fare better. Follow top notch casting and reloading practices, check and clean between sessions until you learn how your barrel reacts.

prs

[Lloyd Smale]

My 20 gets about like yours but doesnt get any worse even with alot of shooting. I bought a wolf barrel for it and it doesnt show lead like the factory barrel but the odd thing is the factory barrel outshoots the wolf barrel even when its slightly leaded like yours.

[Bwana]

From the color that looks like an aftermarket bbl. The bore may be a little rough still or it could be a poor lube. I use a medium hard lube in my factory G30 bbl and it looks like a mirror after shooting my cast boolits. Unless you see large amouts of actual build up don't worry about it and clean after each shooting session. You don't mention the lube, or the load and both have influence.

[7Acres]

Thanks for the input, guys. The barrel is definitely the one that I bought it new with. My G21 is a gen4, not sure if barrel color changed at all as compared to previous gens.Bwana, I'm using a load of 5.1gr of Unique with CCI LPPs. Lube is an LLA mix with JPW.

So I'll just keep shooting then! I'll probably hit it with Sweets 7.62 just to get any copper out for sure. Only ran about 175 rounds of j-words through it though. This Glock will be fed a healthy diet of boolits primarily. It will only have to eat j-words if someone gives me a box :) (Thanks to my generous bro-in-law I've got 100 rds waiting to see some action soon!)

[9.3X62AL]

I had zero leading issues with a Glock 21, and I tried diligently to cause leading to occur. I used a fairly hard alloy (92/6/2), soft lube (Javelina Alox), and sized several boolit designs to both 452" and .454". Didn't matter--the barrel didn't lead at all, and accuracy was constant (and excellent!) through 450 rounds without cleaning. I have yet to re-try this work with the 40 S&W, but will get arount to it eventually. In the meantime, the G-23's Storm Lake aftermarket barrel does very well with the poured Lee 175 TCs sized @ .401" and lubed with Javelina.

[7Acres]

9.3, reading your write-ups while I was researching this recently were what convinced me I'd have no problems. I was also excited to see your success with .454"! Did you get any noticeable performance improvement/reduction from the .454" boolits?