Excess Lead?

[Half Dog]

I have some Hornady SWC's and I pushed one through the barrel of my 45 ACP. The bullet was shinny but questions began to enter my mind when I noticed the amount of lead that was sheared off of the sides and gathered at the base of the bullet. Having a sharp base makes sense for accuracy but what should happen with the excess lead?

Would a harder bullet be needed to prevent this?

[dubber123]

My guess is that the shaving occurred because you caught the boolit on the sharp portion of the chamber that the case headspaces off. I doubt you would have that happening if the boolit was leaving a case instead of just dropped in the barrel. You may also have a very short, abrupt leade in to the rifling, which is very common. DougGuy here on the forum can help with that very inexpensively. I just got 6 barrels back from him and they are much improved.

[44man]

Can't beat that answer, been wondering why anyone would force a boolit through the bore anyway??? Beating on the base with a rod does funny things.

[Half Dog]

Thanks for mentioning DougGuy.

Well...I had some bullets shoot different. I began looking and found the Hornady SWC's had a diameter of 0.450 - 0.451" and now I am wondering what is acceptable for bullet / barrel fit.

I understand the rifling should compress the lead and because barrels might not be exactly the same, the base of the bullet is possibly compressed too.

If the barrel measures 0.452" what would be the maximum diameter of a cast bullet? Is there a standard for how much a bullet base should be compressed?

[Half Dog]

Just to share...here is a pic showing the result of pushing a bullet through my barrel.

151182

[mdi]

Well, when you push a soft metal through a smaller tube, the displaced metal has to go somewhere. What you did is called "swaging the barrel", and measuring the slug will give you some valuable information; the barrel's internal dimensions...

Hornady's LSWC are swaged from a very soft lead and usually used for lower velocity loads (now is when some one will report they have driven their swaged bullets to 2,000 fps :wink:). Normally, a cast bullet is sized to a couple thousandths over the groove diameter of the barrel (but in the case of a revolver, the diameter of the cylinder throats) to give a good seal and grip the rifling...

[Half Dog]

Thanks MDI. I measured the diameter of the bullet and it is 0.451".

Should I try and get a mould that casts a 0.454" diameter to allow 0.001" for bullet shrinkage?

[jcren]

No, .452 is plenty. Remember molds are sized by the manufacture to cast to size with a particular lead, commonly layman #2. While pure lead will shrink some as it cools, most antimony alloys don't change much.

[Half Dog]

Understood.

How about sizing? I'm looking at purchasing a RCBS Lub-a-matic. Is it best to size a bullet or rely on lead mixtures to maintain the correct diameter? If sizing is recommended, should I select a mould that is maybe a 0.453" diameter?

[jcren]

I size all my 45's to .452, but I tumble lube or powder coat, mostly powder coat anymore(I prefer shooting to cleaning). Don't worry about an oversized mold, but w will usually need to size to correct out of round if you are after precision. Some guys don't size at all and rely on a Lee factory crimp die to size the lead in the brass! Basically, this is a forgiving caliber and you don't have to be perfect to make great shooting ammo.

[bedbugbilly]

Half Dog - just for "illustrative purposes - i.e. "example" - I'm not loading for 45 ACP but I am loading for 45 Colt - a Uberti Cattleman. Since I'm not pushing the lead boolit hard - I'm using "mild" loads - here is what I've experienced.

I'm casting from soft lead in a Lyman 454-190 mold - which is supposed to drop a 250 ish grain round nose flat going boolit. My barrel slugs out at .452. Casting in the above mold, they are dropping at around .453 - sometimes .4535 or so. I just load them as they drop since they will swage themelves down to .452 when they enter the barrel. For all intent and purposes, they would end up just as your boolit looks. I just tumble lube them in alox/pastewax - but they are traveling below 800 fps so I have no problems with leading at all. If I were to use #2 alloy - I'm pretty sure that same mold would drop 'em at .454 or more. But . . . these are out of a revolver and my throats are .4535 so they swage very little on the way through the throat.

45 ACP . . . I'm guessing it might depend on how fast they are pushed. All i can speak to is 9mm. I have a Ruger SR9 and a Smith Shield. I cast out of "range lead" for those and use several molds. I like the Lyman/Ideal 358-242 RN - 121 gr. the best. With the range lead - they drop at anywhere from .358 to .360 but usually around .358 or a tad bigger - all depends on the batch of range lead I'm using at the time - I'm not a "high tech caster". In theory, they will swage when they go through the barrel as well but they seem to work just fine tumbled lubed in alox/pastewax. I don't have a crony but according to most of the manuals I have, they are probably going a little over 1,000 fps with the load I use. I've never had a leading problem in either of my 9mm. . . and of course, the "range lead" would be harder than soft lead.

When I bought my Shield, the salesman (I've known him for a long time and have purchased a number of hand guns fro him - he shoots a lot of IDPA) knew that I reload and convinced me to get a box of "store bought" coated hard cast .356 - 115 gr. boolits to try out. I was hesitant as I've always shot my own csst and I was a little concerned about maybe some leading . . but they worked just fine in both the SR9 and Shield.

If you like your soft swaged SWC and they feed and cycle just fine . . . I'd give them a try (perhaps you already have?) and just see what and how they do. Worse case scenario would be some leading but you might be pleasantly surprised as to how they work as well. If they load just fine and your finished cartridges headspaces correctly, I'm guessing they will work depending on how fast you're pushing them?

[gwpercle]

If you are reloading 45 acp, size them to .451 or .452. I reloaded 45 acp for decades sizing to .451, never had any problems . Lately got a .452 die, not any difference I can tell with an AMT Hardballer at handgun range ( 25 feet). My Lyman Cast Bullet Handbook 3rd Edition (1980) advised .451. So that was the size I bought . The new 4th Edition (2010) still shows size to .451.
I wouldn't go over .452, that can cause chambering problems.
I have a 45 acp revolver that will not chamber loads sized .452, size the boolits .451 and they chamber easily.
Comparing sizing boolits for the 45 Colt to sizing boolits for 45 acp is like comparing apples to water melons. The 45 Colt can have all kinds of bore, throat and chamber discrepancies . The 45 acp , if loading for a 1911 style, is rather easy. .451 or .452 will more than likely be just the ticket. I never have slugged the bores of my AMT Hardballer , a Star model PS or a Colt Gold Cup that I own and the reloads all work fine, with no leading either.
Don't try and overthink the sizing thing .
Gary

[rsrocket1]

When you shoot a bullet through a barrel, you will not get the same result as when you drive it through with a rod. The bullet base will be exposed to a uniform 12-35,000 psi pressure across the entire base and the base will remain flat provided it is not being scraped along the sides of the bore. Yes the bullet gets swaged down a tiny bit, but it is a very small fraction of the length.

I figured this out once, but have since forgotten the post. If you took a 0.452" cylinder equal to the length of a bullet, then squeezed it down by a few mils in diameter, the bullet will grow in length by a very small percentage. You can figure this out by knowing that the volume of lead remains the same. I also made measurements with a 9mm bullet that I sized down by 4 mils and the bullet grew by less than a mil because the lube grooves took up a lot of the displaced lead.