New to cast bullets. Getting leading.

[uglysteve]

I went out and shot 64rds of my newly loaded cast bullets today from my Colt 1911 Wiley Clap and experienced significant leading in my barrel. My loads were as follows:
230gr LRN Missouri bullets .452 18BHN
Unique powder 6.7gr
Wlp primers
Slight taper crimp
32 rounds

185gr LSWC Friendswood bullets .452 18BHN
unique powder 5.2gr
Wlp primers
Slight taper crimp
32 rounds.

Any suggestions as to what could be causing the leading?

Steve

 

[Dakotared]

I would guess that you may have a few problems going on. First have you slugged your barrel to see what size it is? I have found that going .002 over the barrel size fixes 75% of the problems. 2nd they may be to hard for a low pressure round. I cast my own .45 and they are about a 14 bhn with a tumble lube and get no leading at all. 3rd it could be the lube. Before I started casting my own I bought "hard cast" bullets and all ways got some leading. If is is the lube you can heat them up to melt the lube out and relube them with a softer lube.

 

[howlnmad]

I would start by slugging the bore and go from there.

 

[918v]

Bullet too hard. Powder too slow.

 

[USSR]

Bullet too hard. Powder too slow.

Zactly.

Don

 

[FROGO207]

Don't forget to clean the barrel of copper fouling before shooting lead or that will allow some leading to occur also. Above 2 posts are spot on IMHO. Hopefully there is a faster propellant in your stocks to try. I like 700-X with 200 - 230 grain lead bullets.

 

[springer99]

First guess is that those are too hard and not sealing the bore completely. Especially true if your leading is occurring mostly right at the throat of the barrel.

 

[jcwit]

I'll agree the bullets are to hard. Hard lead bullets are way overrated.

 

[GP100man]

Bullets too hard & probably being resized (undersized) by the "slight" taper crimping .

Pull a couple & measure em with a micrometer ,not a caliper.
Then measure em against a never loaded bullet , differences???

Do you know the dia. of your bore ???

 

[uglysteve]

I slugged the bore of my colt at .450 and my springfield Range officer at .451.

Missouri bullet says that i need to have my fps at 850 and above to avoid leading.

So is Unique not a fast powder? I have titegroup as well, but that's my fastest. I cannot find bullseye around here currently.

What i will probably do next is take both my guns to the range and shoot different loads in each, inspecting the barrels afterwards.

Regarding the crimp, the bullets will not seat without at least a very mild taper crimp due to the slight flare. I can pull a bullet and remeasure it.

 

[918v]

It's not the bore. It's the throat. Your throat is .453" and your bullets are .452". This leaves a .001" gap in the throat which allows gas cutting because your bullets are too hard to obturate.

 

[Arkansas Paul]

This will be repeating some things already mentioned.

1. For .45 ACP, BHN 18 is too hard. 8-10 is plenty. Low velocity, which is what you have with that round and hard cast bullets are a match made in hell.

2. Use JUST ENOUGH crimp to remove the flare, no more.

3. If those 2 things don't fix the problem, then slug your barrel and make sure it isn't oversized, but I bet you won't find it necessary. I cast for 6 different handguns and have only had to slug 1 barrel.

 

[jr_roosa]

I get leading with that MBC bullet running about 830 FPS too. It's worse when I run them faster. All the MBCs lead on me a bit...maybe they are too hard. I just gave up on trying to prevent it, and I bought a couple of copper chore boys from Amazon (nobody in town carries them, Amazon Prime has free shipping), and I just clean out the lead with a few passes of an old bore brush covered with copper chore boy.

Once Zero starts having bullets available again, I'm going to switch to swaged bullets for most of my shooting.

-J.

 

[ArchAngelCD]

Bullet too hard. Powder too slow.

Zactly.

Don

I agree, too hard a bullet in a low pressure round.

I would also use a faster powder. I use nothing but W231/HP-38 for my 45 Auto ammo.

 

[LiveLife]

Missouri bullet says that i need to have my fps at 850 and above to avoid leading.

I get leading with that MBC bullet running about 830 FPS too

Ummmm ... Really?

I shoot MBC 200 gr SWC in 18 BHN (IDP #1) with 4.0 gr of Red Dot/Promo and that's rated for 805 fps out of 5" barrel. No leading in my Sig 1911, Kimber 1911, RIA 1911 and fullsize M&P45.

BTW, another user of W231/HP-38 and even with light charge of 4.8 gr and MBC 18 BHN 200 gr SWC, I do not get leading either.

Any suggestions as to what could be causing the leading?

Chapter 7 of Glen Fryxell's ebook covers definition, location, cause and prevention of leading - http://www.lasc.us/Fryxell_Book_Chapter_7_Leading.htm

 

[918v]

I shoot MBC 200 gr SWC in 18 BHN (IDP #1) with 4.0 gr of Red Dot/Promo and that's rated for 805 fps out of 5" barrel. No leading in my Sig 1911, Kimber 1911, RIA 1911 and fullsize M&P45.

Red Dot is a lot faster burning than Unique. The pressure curve is a lot steeper. It obturates the bullet better. The bullet then has the ability to seal the throat before any gas gets through.

 

[LiveLife]

Yes, I agree. I do not think we could arbitrarily say X fps will prevent leading as clearly illustrated by the 4.0 gr Red Dot load at 805 fps.

 

[USSR]

So is Unique not a fast powder?

No, Unique is not considered a fast handgun powder. Personally, I consider W231/HP38 and faster powders to be fast handgun powders. Check a burn rate chart to see what powders fall into that category.

Don

 

[RealGun]

Pull a bullet and measure maintained diameter, once after insertion and once after crimp. The problem could be in stuffing .452 bullets through an inherently .451 setup. I can tell you that swaging does happen.

 

[Sam1911]

The pressure is much more of the issue than the velocity. I think you're on the right track moving to a slightly faster powder with that bullet.

I shoot thousands of Brad's IDP1 (same hardness) with American Select or Clays and on those rare occasions where I clean the gun, I don't usually bother to even brush the bore. It stays nice and clean all on its own.

If you want to shoot lower-pressure loads, look at Brad's "Bullseye" listings (12 BNH) not the IDPA or Pin-Buster bullets intended "For Major Power Factor."

 

[uglysteve]

So last night I loaded up 32 rounds of 185gr lswc with 5.5gr of tightgroup. Will try again today. I will then shoot the remaining of the same bullet I have loaded with unique out of a different gun and compare.

I pulled a bullet and noticed that forward of the lube, the bullet was reduced in size to about .448. Behind the lube, however, it was still at .452.

 

[LiveLife]

uglysteve, consider this also.

Try using longer OAL/COL and less taper crimp.

Using the longest OAL/COL that will reliably feed from the magazine will move the bearing surface of the bullet base (part that rides the rifling) closer to the start of rifling. The sooner the bearing surface engages the start of rifling, the sooner the chamber pressure will start to build and reduce leakage of high pressure gas which will result in less gas cutting/bullet base erosion/leading. If you have enough high pressure gas leakage around the bullet, it may blow enough liquefied lube off the bullet to leave it naked/unlubed as the bullet travels down the barrel and lead the rifling (especially with slower burning powder).

With faster burning powders such as Bullseye/Red Dot/W231/HP-38 etc., bullet base deformation can occur faster to seal the bullet with the barrel as the bullet base pushes forward against the bearing surface resistance with the start of rifling to squeeze the lube channel and increase the lube seal diameter which will act as an "O" ring seal around the bullet and reduce high pressure gas leakage while liquefied lube coats the surface of the barrel and provide additional pressurized seal like pressurized oil around crankshaft bearing so the lead surface of the bullet doesn't come in contact with the barrel surface (which causes leading). With faster burning powders, OAL/COL is less critical than slower burning powders (slower than Unique/Universal) but I would still try to use the max OAL/COL to reduce leading and increase muzzle velocity consistency (lower SD) for greater accuracy.

Walkalong has an excellent thread for determining max OAL/COL - http://www.thehighroad.org/showthread.php?t=506678

rcmodel usually suggests adding .021" to the diameter of the bullet for the taper crimp. So for .452" sized lead bullet, try using .473" taper crimp and see if leading decreases.

You can make some test rounds with max OAL/COL and .473 taper crimp for the next range trip and shoot them with the same powder/charge and see if leading is decreased before you test other loads.

Keep us posted.

 

[Arkansas Paul]

Yeah, in post # 12 I meant low pressure and hard cast, not low velocity.
And no, Unique is not a fast powder. Try 4.5 grains of Bullseye with that bullet and see what happens.

 

[918v]

I pulled a bullet and noticed that forward of the lube, the bullet was reduced in size to about .448. Behind the lube, however, it was still at .452.

I think you're measuring wrong.

 

[Sam1911]

LOL. Ok.