Who's right and who's wrong? Wheel gun boolit sizing...

[DougGuy]

so a wheelweight + 2% tin bullet which you size to exact throat diameter today, which can be pushed through the throats with light finger pressure, will be an interference fit six months from now.

The mechanism we are talking about is cellular precipitation.

THAT is why you want to size cast bullets to 0.0005 to 0.001" under throat size, not to exact fit!

I have said often, that in a perfect world, the boolit needs to be .001" to .002" over groove diameter, and cylinder throats need to be .0005" to .001" over boolit diameter.

That is exactly why I size throats .4525" ~ .4528" when I size for .452" boolits, and I tell my customers to size to .452" and nothing over. Lee .452" sizer dies I have pinned have been .4515"

The longer the boolit? The greater the growth as they age.

500 S&W boolits a customer sent were sized .500" and 6mo later when he sent them to me, they were already .5015" and would not fit in the throats.

For the 475, the 480, and the 500 I do not recommend sizing larger to accommodate age hardened boolit growth, as this presents an even greater resistance at the forcing cone, and a sharp rise in pressure to accompany this interference. I recommend sizing cylinder throats .0005" to .0015" over groove diameter, and sizing boolits within a couple of weeks before they are used. You can't put up a ton of heavy for caliber ammo for these calibers and store them on a shelf, they simply will grow too large as they sit to fit in the cylinders.

[Grmps]

Something the bullet sizing advocates forget is that a ternary alloy Pb-Sb-Sn bullet will not emerge from the sizing die being the exact size of the hole through which it was forced, depending upon as-cast diameter, and the amount of reduction which takes place in the die. The sizing die you have which pins out .454" exactly, will probably yield wheelweight + 2% tin bullets which emerge from the die at .455". The die makers know this, and if you take a .452" marked sizer die, the actual hole will probably be .451ish. If you run a wheellweight .456" bullet through an actual .454 pin verified sizer, bullets will likely emerge .455", push the same .456 bullets through a .452 pin verified sizer and it will probably emerge .453-.4535, which is normal.

Binary, dilute tin-lead alloys such as 1:40 or 1:30 do not exhibit this behavior and their sized diameter will stay consistent within +/- 0.0002" over time.

When the bullet is sized, plastic deformation takes place, and the grain structure of the bullet is disturbed and as the strain in the grain structure is relaxed overaging the bullet will change size, usually GROWING in diameter, so a wheelweight + 2% tin bullet which you size to exact throat diameter today, which can be pushed through the throats with light finger pressure, will be an interference fit six months from now.

The mechanism we are talking about is cellular precipitation.

THAT is why you want to size cast bullets to 0.0005 to 0.001" under throat size, not to exact fit!

What you are saying, (and it makes a lot of sense!)
We need a different sizing die for each different alloy we size

from LASC

[robertbank]

I think we should go back to the notion:

Cast
Size
Lube
Shoot

repeat frequently.

This could look a lot like work. (Body shakes, then retreats to a tremble followed by copious amounts of perspiration). Ends with a hangover headache.

Take Care

Bob

[tazman]

There is one advantage of being, in my prime, an average shot. Discerning the effect on accuracy due to improper sizing is problematic at best. I may have slipped a bit since my days in my prime.

There is something to herding ones efforts when it comes to reloading and reloading home cast bullets in particular. By that I mean, with three different 38spl capable guns sizing all .358 makes sense to me. No leading, suggests something is working and my groups are pretty consistent from one gun to another so I have concluded nothing I am doing (casting, sizing, lubing) is affecting the outcome of my shooting.

I apply the same logic, if one can use that term in this context, to loading for my 9MM. Out to 15 yards all my handguns manage to shoot 2" groups off a rest. Beyond that they all manage to shoot within six to twelve inches to 20 yards. Between 15 and 20 yards the bullets have a tendency to yaw off course for reasons unknown to me as the trigonometry and the results just don't add up. Beyond 15 yards that blury thing at the end of the barrel tends to blot out the target if you get my drift.

Take Care

Bob

I understand whereof you speak since I am in much the same boat. In the majority of my handguns, jacketed bullets shoot the same groups size for me as my cast boolits. My 9mm pistols would be the only exception to that. Still more than good enough for practice and self defense if required.

[robertbank]

tazman get yourself a CZ 75B /SP-01 series and tune the trigger up. The guns are amazingly accurate when using 124/125 gr bullets. The 147's are too heavy in my opinion though they work well for their intended purpose as a sub sonic round. The =<115 gr go quick but I have never found them to be much for accuracy in my hands. By accuracy, I mean minute of pie plate at 20 yards. Hard bullets seem to work best in the 9MM. God bless those who can shoot sub 6 inches at 25 yards.

My Beretta CX4 Storm reaches out to 120 yards against a 12" plate but a longer barrel and the red dot sight helps. From a rest of sorts my handguns will make a ding about 30 - 50 percent of the time. Even ugly girls get lucky once in awhile.

Take Care

Bob

[Hans Gruber]

The reason the newly emerging .44 Special cartridge quickly eclipsed the .45 Colt is quite because of chamber size variation on the part of the .45.

The .45 Colt is a direct descendant of the original .44 "black powder" using a .454" round ball. When COLT decided to introduce the .45 Colt, they kept the .454" diameter and built the case around it.
Not long after, S&W, decided to keep the early case size and introduce the ".44" which actually measures .429" due to case size. The original Colt .44-40 was actually a .427" bullet.

As time went by, the .45 Colt revolvers ended up with chamber throats as large as .457" down to .451". In the day of soft-swaged, hollow-based slugs this didn't matter much, but when it came time to CAST solid-base bullets that could not "flare out" to seal whatever diameter they found themselves in, problems began. Then came Colt's own changeup when they introduced the .45 Auto with a .451" bullet. For many years the "rule" for .45 revolver shooters was to size their slugs to match chamber throat size....001" over is fine and will NOT result in any sort of additive leading.

Over the last 100 years the reason the .44 chambering became favored was due to accuracy secondary to a better "standardization" of chamber mouth sizes than with the .45. Even today one can easily buy a .45 Colt revolver with a .451" bore and .454" or larger chambers. Clearly .451" bullets making the transition from case to chamber mouth will be somewhat "upset" and for this reason for many decades "serious" .45 Colt owners did their own casting and loading to ensure bullets fit their chambers.

So, the bottom line is, if your slugs match chamber mouths or slightly larger, they should shoot just fine...and this is WHY, 150 years later, many who favor the .45 colt still load with cast lead boolits.