40 S&W leading problems.

[Trapperscott]

Hello everyone,

I have a problem that I am hoping someone here can help me with. I have a brand new, stock Glock 22, 40 S&W. I bought a lee 175 gr TC 6 cavity mold to mold for it. I am using COWW for alloy.

I cast up a bunch of these boolits with that mold hopeing to shoot this pistola a lot. I slugged the barrell and it measured .401 on the nose. I bought a Lee .401 push thru size die for it. I used it at first to size these boolits.

I used the 45-45-10 lube that I read about here. I really like the ease of use it provides.

After the first time shooting that combination I had severe leading. So, back here I came for more reading. Found out that I needed to size the boolit at least .001 over what the barrell slugged at. Also read that the Lee size die could be opened up easily. But first decided to mike an as cast boolit to see what the mold was dropping them at. I measured about 10 of these boolits and they all measured from .4019 to .4023.

So, that lead to my bright idea of not sizeing them at all. I lubed up 15 of these as cast boolits this morning. I put two coats of the 45-45-10 lube on them. Loaded them with 5 gr of Unique, with a CCI small pistol primer and went outside the shop and shot them.

Now I have more lead in my barrell from those 15 rounds that I ever did from shooting over 100 of the same boolit sized at .401.

What am I doing wrong? Wrong alloy? Need an aftermarket barrel?

Any help would be appreciated.

Scott

[rsrocket1]

I cannot speculate for the polygonal rifle barrel in the Glock, but 5.0g Unique is a pretty light load for that boolit if you are seating at 1.135", which is a tiny bit higher than where the boolit cone transitions from vertical. If that's where you seat your boolit, you can easily go to 6.0g Unique and still have margin.

[Trapperscott]

Rocket1, I'm seating them to 1.130. I wonder if I need to speed them up a little? That's about the only thing I can think of doing, short of changing the alloy.

[geargnasher]

The two things you did right were decide to quit sizing them to .401" and to use Unique if you choose to try to shoot COWW alloy that's presumably air-cooled.

Now, here are the things everyone does wrong or that just are wrong with the .40 that cause the severe leading:

Case swage-----This is caused by the hard, tough, springy brass and undersized expanders that are too short and too small in diameter for over-groove-diameter cast boolits. This is a MAGNUM PRESSURE CARTRIDGE DESIGN. It ain't granpa's 1911 in .45 ACP that lopes along at 1600 PSI, it's designed to operate at over twice that, so the brass is MUCH thicker, tougher, and harder than a lot of the auto brass, which means you have some extra work to do in order to get it to work with factory dies and cast boolits. The issue is that factory expander dies don't open the case up large enough, or deeply enough, for your delicate cast boolit, so the boolit that was .402" when you lubed it becomes .399" when you cram it down in that .393"-ish case ID. Undersized boolits cause leading with boring regularity. Measure the ID of an expanded case and you'll see what I mean. Seat and pull a boolit and measure it, and you'll see even more clearly.

Another thing that causes undersized boolits is the Lee factory crimp die for pistols. The carbide post-sizer ring is dimensioned for jacketed bullets, which are about .003-5" smaller than cast lead at proper size, so the seater die tends to swage boolit and brass together, ruin case tension, and leave your boolit too small for the poly barrel.

Too small for the barrel causes leading just about every time because it allows powder gas to jet around the boolit through the gaps and this erodes lead as dust particles and deposits them on the bore. Anything that allows loss of obturation (seal) will do this to some extent. Think of the boolit as a cork or a piston in the bore, and build your ammunition so that when fired, the boolit seals fully in the bore and DOES NOT LEAK. Do that, and you can get away with very high-pressure loads and even marginal lube.

45/45/10 is a pretty decent lube for a lot of things. The .40 isn't one of them. This is the voice of a great deal of experience and frustration. Use real lube, I recommend White Label Carnauba Red mixed 2:1 with BAC.

To fix the case swaging the boolits, you will need to either make your boolits harder than hammered cat poop to resist being crushed by the case, or have a custom expander spud made that will open the case enough, and deeply enough, to prevent it. Your cases should be about .399" on the ID all the way to about .025" below where you are seating your boolit base.

Don't kill your work with crimp, you only need enough taper crimp to get them to chamber reliably. Do you know what the "plunk test" is, where you use your chamber as a case gauge? Seat the boolits out until the case headspaces on the boolit itself, and only remove enough bellmouth to get the cartridge to fully chamber under it's own weight if you hold the barrel muzzle down and drop it in. It should fall flush with the barrel hood, or maybe .005" below. Make a few "dummy" rounds with no powder or primer to test seating and crimp, and when you're happy with how they chamber, try cycling them through the gun from the magazine by hand to prove function.

That should get you started. I had a custom expander made for my Lee PTE die by a member on this forum, but he doesn't do it as regular production work. Someone else does, I think, but I can't remember who it is.

Gear

[fredj338]

The 40 is a high pressure round, even at lower vel. I have no problem using ac COWW, but I never have had good results w/ Alox &/or tumble lubing. Maybe I am doind something wrong, but other lubes seem to work better for me. Lead in the GLock is always problematic, I think more so in the 40 than say 45, agai, back to the higher pressure issue. you can try water dropping, sometimes a harder alloy works better in 9mm & 40.
Gear is absolutely correcxt about the LFCD &/or over crimping. Seat a bullet, crimp, then pull it & measure it. If you are reducing the dia, you need to change something you are doing during seating.

[randyrat]

As mentioned above .399-.400 +or- expander button will help a bunch with a.402. With cast you don't need.005 difference between between size of lead boolit and the inside of your brass...Another thing is .402 is fine unless you have a real tight chamber then you may have to size to .401......Oh, the forty will kick your but until you figure it out.. It's a balancing act...
I know there are several guys here on cast boolits that sell custom expander buttons..I hope they chime in because I don't recall all the names right now.

[harley45]

Tagged I need to know who makes the expander s

[crawfobj]

Tagged I need to know who makes the expander s

Me too.

[randyrat]

It came back to me.BUCKSHOT and deltaenterprizes are two fellows I have bought from in the past. All top of the line to deal with.
Here is another guy that is a Vendor sponsor that I have dealt with
http://castboolits.gunloads.com/forumdisplay.php?131-ThePerfessor

[popper]

Try dipping your expander in a good epoxy paint and let drip dry vertically. Use several coats if needed. Not intended to be a permanent fix but it's held up fine in my RCBS die, over 1K sized. I started with that mould and unique but changed to HP-38/w231, not quite as dirty. Mine's an XD and slugged @ .400. I tried .402 but .401 works better, fewer jams.

[geargnasher]

Epoxy might make it bigger, but it won't make it longer. If your expander is about 1/8" long like some of them are, it won't help you a bit. Deltaenterprises is the person I was thinking of specifically for Lee dies, but it's just straight dimensional lathe work so anyone should be able to get it right if you tell them the dimensions you need and supply the original part so they can duplicate the necessary dimensions.

Gear

[Muddydogs]

Not sure what I'm doing wrong with lead in my .40 XD. I'm using Lee 175 grain SWC sized to .401 which is .001 over slugged diameter, tumble lubed with 45/45/10, 5.2 grains of Unique, belled cases with the Hornady PTX in the powder measure, crimped with the Lee FCD and bullets dropped on the case with the Hornady bullet feeder die. I have not had a problem with leading and have shot 150 rounds in one setting. Guess for once I might have got lucky.

[fcvan]

I have shot the heck out of the Lee 401-175 TC through my Glocks using 5 grains of Unique. I generally use either range scrap, wheel weights, or a 50/50 mix of both. I've used 5 or 6 types of lube, including some home made loob, and haven't had a leading problem. I would have to go with the case mouth not being expanded enough. I use Lee dies and flare the case mouth to easily accept the base of the boolit but not much more. I'm sizing to .401 with a Lyman 450. I'm thinking the boolit is getting swaged in the case mouth.

As far as .40 S&W being 'magnum' pressures it is certainly right up there. 5 grains of Unique is a light load when compared to Alliant specs for jacketed bullets. As Alliant doesn't list a load for lead boolits you have to look at other sources for guidelines and work your way up. Gun-writer John Taffin has tested and written lots of articles on numerous cartridges including the .40 S&W. He lists 5 grains of Unique with a 175 grain boolit at 946 FPS and 5.5 grains for 1046 fps. Taffin did not publish pressures but it is reasonable to assume the pressures weren't excessive.

The latter load is on par with velocities published by Alliant using a 180 jacketed bullet. 5 grains of Unique works very well for me and I'm sure I'm not working the brass too hard at level. Yes, the 5 grain load is 100 fps slower than than the factory loads I carried and used before retiring but they were still good practice rounds. I didn't and still don't have a leading problem as I don't let my cases resize the boolit. Sizing to .401 has been working for me in my Glocks.

[Ed_Shot]

Realise that each barrel has its own rules. My Glock 22 w/LW barrel really likes Lee 401-175-TC (standard lube) sized to .401. I have to seat to 1.110. I use Lyamn dies. If you have the short M-Die body an extra expander plug with screw for any caliber was only $6 from Lyman. I got one to use the M-Die for 45 ACP with Lee dies not long ago. I certainly use the LEE FDC for 40 SW and have zero leading and great accuracy. I have to crimp to .421 to get reliable feeding which is a full turn after contact on the Lee crimp die. My aloy is 3% antimony using RotoMetals SuperHard with 2% tin added and I use WL 2500+ lube.

I can't find it right now but there was a post here in the last month with a leading problem in a 9MM with COWW sized to .358. As it turned out when the WW were sweetened with a little linotype the leading stopped. Might be a cheap fix to play with your alloy.

[Trapperscott]

Thanks everyone for the replies. Looks like I have my work cut out for me. I'll start on it tomorrow. If/when I get it figured out I'll report back here and post my findings.

Thanks again.

[Hounddog]

+1 on all of what gear and others have said. First rule of success when loading cast is that "Fit is king". Some where along the line I'll wager that your boolits are getting swaged down. Could be a number of things but you should load up another round and then pull the boolit and mike it out. These guys on here are a wealth of info and can get you headed in the right direction. If you do change anything just do it one thing at a time till you find the problem. Keep at it and you will get it running soon.

Hounddog