Barrel leading question

[dsmw5142]

Is the location of the leading in a barrel symptomatic of a particular type of problem? For example, I shoot moly bullets in all of my Glock's without an issue at all, except my G35. There is always lead built up/streaked down rifling. The lead deposits are always toward the upper third of the barrel toward the muzzle.

I am using 180gr. Moly Black Bullets International, 5.0gr Unique, Wolf SPP and mixed brass. I think oal is 1.135, but I'm not at home to check my notes right now. PF is about 170-171.

The chamber and lower two thirds of the barrel are always squeaky clean after a few passes with a bore brush and CLP. The upper third of the barrel takes a heck of a lot of scrubbing to get the lead out though. It's not a horrible bad leading problem, but it was fairly significant after Sunday's 200 round match.

I tried less crimp/de-belling on some 180gr. bullets last night, and it didn't seem to help, any ideas? Both of my G21's and G34's have no problem with moly at all. I am thinking about ordering a KKM barrel for the G35 as a fix for the issue. maybe it's just one of the Glock's that doesn't like moly :dunno:

Thanks :wavey:

[GioaJack]

Leading at the end of the barrel is usually an indication of burning through lube buy you're running moly and only have the problem in one gun. Before you spend money on a new barrel simply get some JB or use fine valve lapping compound and lap the problem section of the barrel to smooth out any roughness.

This assumes your bullets are sized properly to begin with. Your flare and crimp has nothing to do with your problem.

Address the easiest solutions first, different powder, etc.

Typing on an iPhone sucks.

Jack

[fredj338]

Are you sure it's leading & not moly build up? I hate using moly bullets for that reason. Leading will be silver, moly grey.

[dsmw5142]

Fred, I will look at it again when I get home. It is pretty hard though. I was assuming lead because I've never had the moly build up in any of my guns. I will let you know later for sure though.

Jack, I would have thought a medium burner like Unique wouldn't give me this problem, since I never have an issue with Solo 1000 in my other loads? I will try some different powders this weekend and see what happens. I have read somewhere that, if a bullet doesn't obturate properly, sometimes because of too fast a powder or too hard an alloy, it can cause this issue?

Thanks for the advice guys and keep it coming :)

[PCJim]

Posted in another current thread....

http://glocktalk.com/forums/showpost.php?p=15638140&postcount=17

[WiskyT]

I can basically guarantee you it is not a powder issue. 5.0 Unique is a great quantity of a very appropriate powder for lead bullets. I use 5.2 with a 180LFP lubed with liquid alox and shoot them all the time with no leading. I use pretty soft lead sized at 0.401" and shoot them through my stock G27.

If it is leading, I would check just about everything else first before changing from your posted powder charge.

[fredj338]

Fred, I will look at it again when I get home. It is pretty hard though. I was assuming lead because I've never had the moly build up in any of my guns. I will let you know later for sure though.


Thanks for the advice guys and keep it coming :)
Guns will vary, but I shoot 175gr-180grLRFNFP o/ 5gr of Unique, great load, accurate, leaves zero leading in my 4006 or 1st gen USP. Only load tha tshoots better is 5.1gr of WSF.

[dsmw5142]

Well.... it's definitely lead. I'm going to pick up some chore boy and try that trick to clean it out. I guess I will look for some lapping compound and try that.

[WiskyT]

Well.... it's definitely lead. I'm going to pick up some chore boy and try that trick to clean it out. I guess I will look for some lapping compound and try that.

I simply hate to disagree with Jack:whistling: but I don't know if you can get a Glock barrel any smoother than the mirror finish it already has. Maybe moly just aint a good pistol lube? This is the second thread by two different posters about leading with moly bullets in the last day.

[GioaJack]

I simply hate to disagree with Jack:whistling:



Hate to disagree with me my butt... it's the highlight of your day, if not your life.

I must admit however, I don't know the first thing about Glock barrels... I only shoot real guns.


Jack

[PCJim]

Personally, I'd stay away from the barrel lapping until all other possible causes have been eliminated (as stated by Jack much earlier on). And as Wisky said, Glock barrels are pretty darn smooth and lapping could create other problems if not performed correctly. Curious whether this particular gun was previously owned, or are you the first owner? Have you slugged this barrel and compared the results to your other 40s?

[dsmw5142]

I simply hate to disagree with Jack:whistling: but I don't know if you can get a Glock barrel any smoother than the mirror finish it already has. Maybe moly just aint a good pistol lube? This is the second thread by two different posters about leading with moly bullets in the last day.

WiskyT,

I have four other Glocks that have eaten several cases of moly with no problems. I've also run a few hundred each through two 17's and two 19's with no issues. My G35 is the only problem child. :dunno:

I am at my agency training center today teaching a class. I'm going to run a couple hundred of these through my issued G22 since it's the only other .40 Glock I have. Maybe it's a gun/barrel specific problem, like has been suggested.

[Colorado4Wheel]

I dip a large glass in the ocean and scoop out some water. There were no fish in the glass. Does prove there are no fish in the ocean?

[GioaJack]

I dip a large glass in the ocean and scoop out some water. There were no fish in the glass. Does prove there are no fish in the ocean?



No, it means you're dipping your glass in the Gulf of Mexico... all the fish are dead.

BP... the ex-wife of the oil industry... Broken Promises. (I'm a marketing wizard.) :whistling:


Jack

[PCJim]

Steve, you know that it depends upon how large a glass you are dipping. Everything is relative. Go grab your calipers and measure....

Wait, maybe that's one BIG glass you're using and a bit too big for those calipers?

:supergrin:

[Colorado4Wheel]

Around here, unless it happened to someone personally it just did not happen. My Moly bullets leaded in my Glock barrel. So on this forum most people are going to assume that I think it will happen to everyone. Same goes for the "mine worked fine crowd". "Mine worked fine so you must be doing something wrong".

[Colorado4Wheel]

Clean the barrel really good. Then lube a tight patch, run it through the bore and see if the end of the bore feels different then the front 1/3. Glock barrels are a little different then most. I have noticed they don't always have a constant diameter in them. If the last 1/3 is bigger it can lead to leading and there aint much you can do about it. You could slug the barrel in my experiance a tight patch will allow you to feel a difference pretty easily.