A question on safe practice

[LittleBill]

Call me a noob, call me a sissy, but I would rather ask questions that make me look stupid, or at least repetitive, rather than find out some things the hard way. Much is written about fitting the boolit to the barrel, with the emphasis on too small being a Bad Thing. But what about too big? Obviously, there is a limit to too big, since at some point the round will not chamber.

But am I right in assuming that if it chambers, it is safe to shoot?

I have several guns that are chambered for .45 ACP. I made up some dummy rounds yesterday from boolits that had been sized (run through a Lee sizer) to .454. One barrel has been slugged, the others not. The four dummy rounds I made up chamber easily in two semi autos and one revolver. The other semi performed as I expected, and refused to chamber two of the four. But for the ones that these rounds fit, am I good to go?

The same goes for my .45 Colt experience. I have a revolver and a carbine. I slugged the revolver, but have not yet worked up the fortitude to slug the carbine. Rounds sized to .454 fit just fine in every chamber of the wheel gun as well as work through the lever gun action with no problems.

Maybe I am imagining all this and the casing is just swaging the lead down to the size where it was expanded. But I don't think so. I would expect to see lead shavings at some point rather than the boolit being squashed down. Perhaps someone with experience will care to address that.

In my own profession I have seen too many people who just go ahead and do something one might think was safe, only to find out in a very abrupt and violent way it really wasn't after all. That gives me a healthy respect for machines of all types. I would rather ask here and suffer some finger wagging than find myself in the emergency room waiting for some intern to pick parts of Winchester out of my face.

[leadman]

The boolit has to be released by the case when fired. If it is too large it will not do this readily and pressures can soar. So the easiest way to tell if the boolit will release is to fire a known safe load full power load and measure the inside of the case mouth. Since the brass "springs back" some from the chamber wall after the pressure drops this give you a safe max size for the boolit.
On a rifle you want to fit the boolit to the throat area of the rifling which probably will be larger than the rest of the bore if it has been fired some. Excessive cleaning wear from the muzzle does occur so keep this in mind. I will slug the throat and the muzzle on a rifle and call it good.
On a revolver one needs to check every chamber throat and try to size the boolit to fit the largest of them. Slug the bore also because some revolvers have larger bores than chamber throats. Ideally for a revolver you want the cylinder throats the same or .001" larger than the bore. If your cylinder throats are say .004" over bore size a softer boolit would be good so it will swage down easier in the forcing cone.
I slug the bores of semi-auto handguns and size .001" over this normally. I have not found a 45acp semi-auto that needs a boolit over .452" yet, but it might exist.
If you want to see if your boolit is sized down by the case pull one from a dummy round and check it.

[LittleBill]

Thanks for a detailed reply. So too big can be a problem. I think my head is going to explode before any of my guns. :veryconfu I thought I had the size thing licked with my first run of cast boolits, but it turns out measuring some of the leftovers, they were just a hair on the small side. Now I've got some more stuff to check on.

[dverna]

A "too large" bullet of pure lead will react differently than a "too large" bullet of linotype. There is a reason we do not use linotype to slug a barrel.

If you stay less than .003 over bore AND work up your loads so you can watch for pressure signs and you will be safe.

[LittleBill]

A "too large" bullet of pure lead will react differently than a "too large" bullet of linotype. There is a reason we do not use linotype to slug a barrel.

If you stay less than .003 over bore AND work up your loads so you can watch for pressure signs and you will be safe.

Thanks. I spent some time reslugging one gun, the Ruger .45 Colt. I had sort of put it off after my first slugging experience, which involved lots of beating in of lead with a hammer, deforming a couple of sticks, bad words, and fear of ruining something. But that was in order to try and figure out what mold to buy. This time I used some of the boolits I had cast and the whole process was a lot easier. The chambers all slugged real close to .451. I took several measurements around each slug and got variances on some of .451-4515 on my Mitutoyo micrometer. The bore slugged easier too. I got three measurements off that slug as well, one for each set of grooves - .450, .4506, and .4515.

Then I took two of my sized boolits and wiped all the lube off them as best I could. They are measuring right at .453 with very little variance. I found one spot on one at .452 and another on the other at .4539. All these boolits are approximately half wheel weights and half pure lead.

So it looks to me like the chambers are squashing the boolits down about .002, and the barrel is then squashing them down another .001, except for that one spot where it is .0005 bigger. I was able to tap them through the various holes they needed to transit with little effort, but little effort for me can be a lot for other people (I'm a big guy). In any case, for this gun I think it is going to be safe, as you say, to start with some light to moderate loads and work my way up from there.

[MtGun44]

"The chambers all slugged. . . " - are we talking about the throats in a revolver or a chamber in
a semi-auto? Many years ago, a Ruger .45 ACP would have to be a convertible BH revolver. Nowdays,
there is are several Ruger .45 ACP semiautos.

Since nobody slugs a chamber normally - I am guessing that you mean throats (front of the cyl of
a revolver). Is this correct? The chamber is the back end of the cylinder, the throat is smaller and
is the front end of the cylinder.

I think you mean that your boolits will be .002 over throat diam and that throat diam is .001 over
barrel groove diam. Is this correct? Don't want to be a pain, but this is kinda technical stuff and I
can't see what you are doing, so using the correct technical terms is important to proper communication.

If what I think is going on is what is actually going on - then you will be safe. I would start with about
throat diameter or throat diameter plus .001 for boolit diameter. If your throats are running .451, (good to know
you are using a very good brand of micrometer!, bravo) then you should do well with .452 diam boolits. No
reason in the world that .453 will be unsafe, but may not be optimum for accuracy. Some folks get very
good results with boolits even .001 or .002 under throat diameter, but this does give the boolit an opportunity
to tilt as it exits the case mouth, which is theoretically less than the best way to do it. Of course, Mr. Target
is the final authority on what is "right".

If your throats are the same or .001 larger than the barrel groove diameter, you should have a good chance of
good results. The problems usually come from throats smaller than groove diameter, so they make the boolit
undersized for the barrel.

I had a Ruger convertible .45 Colt/.45 ACP that had substantially undersized throats in both cylinders.

Bill

[LittleBill]

"The chambers all slugged. . . " - are we talking about the throats in a revolver or a chamber in
a semi-auto? Many years ago, a Ruger .45 ACP would have to be a convertible BH revolver. Nowdays,
there is are several Ruger .45 ACP semiautos.

Since nobody slugs a chamber normally - I am guessing that you mean throats (front of the cyl of
a revolver). Is this correct? The chamber is the back end of the cylinder, the throat is smaller and
is the front end of the cylinder.

I think you mean that your boolits will be .002 over throat diam and that throat diam is .001 over
barrel groove diam. Is this correct? Don't want to be a pain, but this is kinda technical stuff and I
can't see what you are doing, so using the correct technical terms is important to proper communication.

If what I think is going on is what is actually going on - then you will be safe. I would start with about
throat diameter or throat diameter plus .001 for boolit diameter. If your throats are running .451, (good to know
you are using a very good brand of micrometer!, bravo) then you should do well with .452 diam boolits. No
reason in the world that .453 will be unsafe, but may not be optimum for accuracy. Some folks get very
good results with boolits even .001 or .002 under throat diameter, but this does give the boolit an opportunity
to tilt as it exits the case mouth, which is theoretically less than the best way to do it. Of course, Mr. Target
is the final authority on what is "right".

If your throats are the same or .001 larger than the barrel groove diameter, you should have a good chance of
good results. The problems usually come from throats smaller than groove diameter, so they make the boolit
undersized for the barrel.

Bill

Oh no, not a pain at all! You are correct, I am describing the throats in a revolver cylinder. Also correct, the boolit is .002 over throat diameter and the throat is .001 over the barrel groove diameter. As for accuracy, this revolver has a groove for the rear sight and a blade for the front. I think it is designed to be minute of gunslinger. In any case, there is no danger of me punching out single hole groups with any handgun, although I have been known to do it with a rifle on occasion.

The sizing issue is as follows. I have a Lee lube sizer in .454. I stopped at the local shop to see about one in .452, but he did not have any. I see they are in stock now at Midway. I would like to buy a Star, just because I like really nice equipment, but I don't see me shooting more than a few thousand boolits a year, at least for now.

Yeah, I bought this micrometer off EBay last year for $25.00. With all the digital ones out on the market now, these old fashioned analog ones are real cheap. This one has a vernier that is good for ten thousandths.

[MtGun44]

OK, great that we are communicating.

You have a top quality mic, a tool for your lifetime if you take care of it, and your grandchildren,
too, if they do.

See if you can order a .452 from Buckshot or Lathesmith here in a reasonable time frame.

Save the Star for when you are lubing 1000 or so of the SAME IDENTICAL design. Read my post on
"What lubrisizer to buy?" thread. Stars are great, but I really get a bit irritated at the folks that
recommend them for beginners with limited budgets who are going to be casting 400 rounds
per year of two or three designs. Not sensible to sink way more than $200 into a lubrisizer which is
intended for REALLY serious quantities. Stars are great, but about like buying a backhoe with
a hydraulic auger attachment to build a fence in your backyard in suburbia. Will really work
fine once set up, but kinda massive overkill. Great tool, works well, but if the budget is limited
it should be well down the list. I have two Stars, but also an RCBS and Lyman that get a lot of
use. The Stars are used only for mass quantities, for a small range of designs that are all similar
in having a single lube groove.

Best of luck.
Bill