Lead deposits in bore crown

[Palladan44]

About 200 rounds into my new Colt King Cobra, and I'm really enjoying it.
Shooting loads from mild to hot, swaged lead, cast lead, plated and jacketed all are accurate and NO leading in the barrel, which I'm pleased with.
The only thing noteworthy is the lead depositing in the recessed crown of the bore, quite noticable at this point.
Any suggestions/other comments?
My guess is the soft swaged lead rounds caused this...
Never owned a recessed crowned wheelgun before....but it makes sense that hot/molten lead spits out the end of any barrel... This crown catches it real good.

 

[fxvr5]

Never owned a crowned wheelgun before....

Virtually all barrels are crowned. About the only way your statement could be true is if this is the first wheelgun you've owned.

That barrel has what is sometimes called a recessed target crown.
https://www.gunsupplies.co.nz/images/detailed/6/Different_Crowns_cropped.jpg

 

[Bazoo]

That's interesting.

 

[wcwhitey]

As long as the barrel is clear, kind of looks like what happens to a ported barrel shooting lead. But that should not be a problem no obstruction there just what comes out the end normally getting trapped a bit by that ridge. Your barrel is crowned yes but I would call that a recess not a crown.

 

[Pat Riot]

I would think that lead at the crown would mean lead is being smeared the whole length of the barrel.
When you clean the bore do you get stripes of lead coming from the grooves?

 

[Bazoo]

Did you shoot mixed ammo before looking for leading? If you had a load that leads and then shot others that didn't, it would have removed the leading.

 

[Old_Grouch]

I shoot cast bullets almost exclusively. All of my revolvers gather lead and bullet lube on the crown. As the bullet leaves the barrel the gasses are briefly directed to the side and even slightly rearward. I'd bet the front of your cylinder looks much the same. The amount of buildup is generally self-limiting and it's harmless, but if it bothers you visually a lead removal cloth will wipe it right off.
(use lead removal cloths on stainless steel guns only!)

 

[.38 Special]

Generally speaking, leading which occurs only near the end of the bore is indicative of inadequate lube - either not enough, or not appropriate for the conditions. Were I the owner of the OP gun, one of my experiments would be with a softer lube (I like LBT Blue Soft) and a bullet with a bigger lube groove.

I'm not sure that's the issue here, though. As @wcwhitey points out, that may just be lead "plating" itself to a surface much like it does to a compensator. As long as it is not affecting accuracy or function, I'd be inclined to ignore it, or treat it as a purely cosmetic issue.

 

[Palladan44]

Yes, "recessed" target crown is what I was referring to, apologies for not getting my nomenclature correct.
I suspect it was from a batch of soft swaged lead bullets I fired from the beginning of the session; they are Hornady 158 gr. LRN and they may be coated with a clear waxy-like lube, but I recall the sides of these projectiles also containing a knurling.....I must have hand loaded these 15 years ago or so.
I really suspect these the culprits, and not the hard-cast.
It is just is a lot (a surprising amount)of lead in the recession. It's "welded" in there, and only lead remover can probably remove it.

 

[JohnKSa]

Those recessed crowns are a pain to clean.

I think what happens is that the vaporized lead from the exposed bullet base escapes around the base as it exits the crown and plates onto the crown.

The more conventional angle crowns don't accumulate it as badly and are easier to clean. The recessed crowns like on your gun really accumulate stuff. I have a Beretta Elite II that had a barrel with a crown like that and I got tired of cleaning it. I finally put a standard 92 stainless barrel on it.

 

[Riomouse911]

The forcing cone and muzzle of a magnum revolver are places of great pressure and heat, albeit for a millisecond, as the bullet passes through. Vaporized lead certainly can be plastered onto the steel of your revolver at the muzzle, in the area of the frame around the forcing cone and in porting if so equipped.

Model 66 4”:



model 686+ 4”:


I’ve gone to plated and coated bullets, mainly because i shoot indoors, as I’ve found they’re much less smoky than plain lead bullets w/lube. A secondary benefit is there is less of that vaporized lead buildup to clean on the guns when I am done shooting

Stay safe.

 

[243winxb]

Should be coated with lube, not lead.

My Mag Na Ports on the M29, do produce some lead.

 

[trackskippy]

My Glock 44's have that same sort of crown and I get the exact same thing.

 

[Pat Riot]

I found this site that might help explain the leading at the muzzle.

13th paragraph down.
http://www.lasc.us/Fryxell_Book_Chapter_7_Leading.htm

Here’s one on rifles but it leads to the same conclusion.
https://leverguns.com/articles/leading.htm