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Casting Lead Bullets - Excessive Barrel Leading?
hermiem
Member Posts: 261 ✭✭✭
Ok, I just recently started casting my own bullets again - after about a 30-year hiatus. I've only molded 9mm 125 gr round nose bullets so far. I'm using new Lee molds and they seem to be working just fine. Also, I use their Lee Liquid Alox for the lubrication. I sized the bullets to .356 as instructed. I finally got the opportunity to shoot them the other week. I had really mixed results unfortunately. The more I shot a particular firearm equaled deminishing accuracy results. I fired them out of 3 firearms (Ruger LC9, Walther P38/P10 and a Hi-Point Firearms 995TS carbine - a great gun for the money and very fun to shoot - BTW!)All 3 of these firearms were really leaded when I finally cleaned them over the weekend - particularly the 995TS. (They DO only recommend jacketed or plated bullets - right there on the gun and the instructions so I was forwarned on that one.) Now I've shot hundreds of commercially available lead bullets through all 3 of these weapons and have had no real noticable barrel leading issues. I think part of the problem is that the lead may be too soft. I purchased about 120 lbs of commercially available Lyman #2 mix. If I remember correctly this formula is toward the lower end of the hardness index. I have a Lee lead hardness testing tool hopefully coming this week. Do you think if I increased the hardness of the alloy that this may help correct the problem? If so do you recommend using tin, antimony and/or a mixure to increase the hardness? At what lead hardness do you suggest that I try to achive? As always, any constructive opinions are greatly appreciated.
Comments
Next step would be to add Wheelweights. Remember to not get the melt too hot, or you will be breathing (And Losing) Antimony.
EDIT: Oh yeah - You are using "Tumble Lube" Molds, right?
What is the actual land-land dimension of your barrel(s).
You want your lead bullets to be .001-.002 larger than your land-land measurement.
I like some of the Lee stuff but their molds leave a lot to be desired.
You might consider really cleaning the bore to get the copper/lead out then doing some work with JB bore paste.
My questions are : What are the specific's to your cartridge?
Primer, Case, Powder (and charge weight), and boolit?
Boolit casted - how much over or under the LEE weight are they?
How much Lee tumble lube Alox are you using, per how many casted boolits?
Do you have anyway to chronograph the muzzle velocity?
Or are you using a recipe from a reloading manual?
Too little velocity can also cause leading.
What is your reloading set up? Single stage, semi-progressive, or full progressive?
Have you ONLY put LEAD bullets through the barrel(s)?
To get to the heart of your question - Tin will harden up your alloy mix; but as I understand from the guidance of a MASTER CASTER, it will only harden it up a few points. It is added to help fill out the mold when casting.
Antimony - THAT will help harden your Alloy mix. Shotgun Shot has Antimony. You will have to do the math to calculate how much to add to your mix, but it will HARDEN your bullets.
Wheel Weights have Antimony to make them hard, but they also have a TRACE amount of Arsenic. Per the Lyman Casting manual, It doesn't have to be a LOT it just needs to be IN the alloy. TRACE...
As Handload suggested : Quenching helps hardening, at an increased rate. A week after water quenching is faster than air cooling for 2 or 3 months.
Hope this helps -
Did you slug your barrels? Did you verify that your bullets were AT LEAST 0.001" larger than groove diameter? Did you note where the leading was?
Personally, I shoot only as-cast bullets and tumble lube with LLA. All my 9mm cast bullets are 0.357-0.358" as they drop from the mold. I consider that to be perfect for at least 90% of all 9mm guns.
Hardness is almost never the issue, unless you are casting pure lead. Wheel weights are more than hard enough and 92-6-2 alloy (which, as I remember, is Lyman #2 alloy) is getting almost too hard. Commercial cast are almost all WAY too hard.
Antimony increases hardness. Tin increases cast ability and flow.
If you guns were leaded from the chamber out, then the bullets were too small. If the leading edge of the rifling was leaded but not starting at the chamber, the alloy may have been too soft or velocity too high for your alloy. However, your alloy is MORE than adequate for any 9x19 velocity.
Slug your barrel and then you will know the MINIMUM bullet size required to work in that barrel.
Turned out I was using too much taper crimp and swaging my bullets to a smaller diameter.
Backed off the crimp and the problem went away.
Best Regards,
Mike
Hope this helps