.45 Diameter: .452" v .451"

[sniper58]

Besides the .001" difference in diameter, what's the difference, pros/cons to using one size or the other in a .45 ACP? Berry bullets are .452" and every other projectile and commercially available round for the .45 is .451." I read Berry is widely used in IDPA, but cannot find any other manufacturer that makes/sells .452" bullets for use in a .45 ACP (only for .45 Colt).

I ask as I had a bad experience with an over-sized reloaded projectile. Thanks!

[DefensiveCarry.com]

[jem102]

This goes way back when the .45 LC was charged with black powder and the original diameter bullets were .454 soft lead.
Over the years(including the .45 ACP in its infancy) .452 became the standard as lead bullets became better and is still the preferred number for swaged and cast bullets in "modern" arms. Although I knew one person that shot black powder duplication loads in an old single action Colt and had Lyman make him a set of blocks in .454 with a Keith style bullet that weighed 255 gr. and the gun shot very well.
When "hard" copper jacketed bullets became commonly available that "hold" the rifling better, more consistent in diameter and able to take higher pressures to cause better bore obturation the number was changed to .451. Berry's, at least the ones I use, have a copper plating over a soft swaged bullet so they stay at .452 to get good bore fit.
I shoot their 200gr. RS with either 6.8 gr. of Power Pistol or 7.4 gr. of AA#5, WLP primer and Federal .45 ACP cases.

Hope this was of some help.

[HotGuns]

Lead bullets are typically size .001 over.

Examples: 9MM lead is usually .356 even though standard is .355
.357 magnum is .357 but lead is normally .358
.44 is usually .429 but lead is .430

Most lead bullets that are plated with copper or brass are usually .001 over.

Are you using the lead plated Berry's ? As noticed, they will be .001 over because they started out life as lead, then they were plated. Plating usually adds just a few tenths of a thousandth, or .0002 - .0003 to the diameter.

[sniper58]

Thanks. I'm thinking of buying some Berry plated or Rainier for my .45 ACP in 230 grain. Berry advertises .452" and Rainier is .451" - also plated (I think). I loaded some Hornady .230 grain FMJ (.451") and it works flawlessly - perfect lock-up, perfect operation. That's what made me wonder what the .452" Berry would (or would not) do.

[CherokeeSlim]

This goes way back when the .45 LC was charged with black powder and the original diameter bullets were .454 soft lead.
Over the years(including the .45 ACP in its infancy) .452 became the standard as lead bullets became better and is still the preferred number for swaged and cast bullets in "modern" arms. Although I knew one person that shot black powder duplication loads in an old single action Colt and had Lyman make him a set of blocks in .454 with a Keith style bullet that weighed 255 gr. and the gun shot very well.
When "hard" copper jacketed bullets became commonly available that "hold" the rifling better, more consistent in diameter and able to take higher pressures to cause better bore obturation the number was changed to .451. Berry's, at least the ones I use, have a copper plating over a soft swaged bullet so they stay at .452 to get good bore fit.
I shoot their 200gr. RS with either 6.8 gr. of Power Pistol or 7.4 gr. of AA#5, WLP primer and Federal .45 ACP cases.

Hope this was of some help.

I've never heard this before and I load LC& ACP. Thanks for the information, I just never thought about before.
Cherokee Slim

[Archie]

I've shot both sizes in several 45s over the years. Both give more than adequate results. I suppose if I did some very serious testing, a couple of my target guns (all Colt Government models; one wadcutter and two hardball guns) might show a preference, but they all shoot the wadcutter and hardball duplication ammo I make with 'whatever' 200 grain lead semi-wadcutters and 230grain round nose - respectively - better than I can hold on a given day.

The only potential problems one might have is a seriously oversized bullet and cases with very thick case walls. It's possible to load a round that will not chamber due to that combination. However, at normal .45 ACP load levels, that extra .001 inch is not going to push pressure over the limit. If it does, that load with a smaller bullet is going to be over pressure as well.

[automatic slim]

As others stated and as I've understood it, lead bullets are .001" larger than jacketed bullets. I've also heard than in worn barrels, oversize bullets are more accurate.

[Hamour]

As long as the revolvers cylinder throats are bigger than the bbl, lead bullets shoud be sized to the cylinder throats. The bbl forcing cone will size the bullet to the bbl size. In most 45 LC revolvers .454 is the correct size but you must measure your revolver throats to be sure.

In 45 semi auto the bbl should be slugged and the lead bullet sized .001 or .002 over bore. The bbl throat will size it perfect for the bbl.

The lead must be the right hardness for the pressure of the load. WW's plus 2% tin is perfect for the 45ACP or 45 LC

Lead that is too hard will not seal in the bbl and causes severe leading 8 to 10.5 Brinnel Hardness has worked well for me.

[Majorlk]

As long as the revolvers cylinder throats are bigger than the bbl, lead bullets shoud be sized to the cylinder throats. The bbl forcing cone will size the bullet to the bbl size. In most 45 LC revolvers .454 is the correct size but you must measure your revolver throats to be sure.

I must disagree. In revolvers, bullets should be sized for barrel diameter, just like semi-auto. The cylinder throats have nothing to do with it. My Ruger SBH slugs out at .4515, so cast and sized .452 is a perfect fit.