I have been making a load to be used for sale later. The punchline is it is a heavy (+P) .45 ACP hardcast load similar to what 03RN has been loading. It is a 250 grain flatpoint. That profile feeds well in lots of guns. I have shot it in my HK USP, a couple 1911s, a Smith 4506, a Glock 21 and a G30S.
some data: 250 grain hardcast
Baer 1911 5" BBL velocity avg: 956
S&W 4506 5" BBL velocity avg: 958
HK USP 4.41" BBL Velocity avg: 932
Glock 21 4.61" BBL velocity avg 920
Glock 30S 3.78" BBL velocity avg 861.
In the G3oS with its skinny slide, the rounds were pretty snappy in terms of felt recoil. These are pretty warm loads and in such a small platform you can feel it. If I was going to carry and shoot these frequently, such as for bear repellent duties (which is one of their primary purposes), I would invest in a heavier recoil spring for the compact .45.
If you have either firearm--the Glock 21 or 30--and a few JHPs that you're willing to sacrifice for the cause, you can always fire a few into water (an inexpensive, yet perfectly valid soft tissue simulant) to see if they will expand when fired from either pistol. Water is an "optimal conditions" simulant so if the JHPs won't expand in water, they probably won't expand in soft tissue either. If the only performance attribute you are seeking is to see if expansion will occur after impact, there is no need to collect any additional data to model terminal penetration depth and permanent wound mass/volume.
''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein
Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.
HST or Gold Dot should expand from a G30. Barnes almost certainly will.
The rule for .45 is relatively simple, for each 3/4" of barrel you lop off the end below 5", drop the bullet weight by ~20 grains (give or take).
So, in general 230 for 5" guns, 200 for Commanders, 185 for Officer's, 165 for Defender. A G30 is "Officer" sized gun, so 185-grain bullets should work well. And low and behold that seems to play out.
Remember that even at 185-grains, the .45 is still ~40 grains heavier than a "heavy" 9mm. The closer you can get to 900fps the more likely you are to get complete penetration and reliable expansion. These aren't "rules" but are guidelines and bullet design certainly plays a role. But speaking generally, if you can push a .45 JHP to 900fps you'll get expansion and penetration from it.
You can look at the Lucky Gunner data provided above.
The gun is a Kahr CW45, an 'Officer Length' gun (roughly 3.5" of barrel length).
Look at the Gold Dot loadings at the bottom, 185 and 200 give excellent penetration and expansion, 230 does not.
Look at the 230-grain Ranger T, which hits 900 fps on the nose and has perfect penetration and expansion.
There are exceptions, of course, the slow 230-grain Golden Saber did just fine.
This is merely an observation on my part looking at lots of data over the years. Nothing scientific about it, really. Just one of those things where my mind that looks at a lot of trends sees something like, "Hmm, it looks like everything around 900fps tends to do what it is supposed to do."
And in the case of what I mentioned regarding weight...the thing is, you start lopping inches off of .45ACP barrels, velocity drops quickly. What was a 900fps load from a 5" gun, is now a 750 fps load from an Officer's gun. Drop the bullet weight down and you get the velocity back. All things being equal, most folks would probably prefer a 185-grain load from a small gun than a 230-grain load. Probably due almost entirely to recoil characteristics, I've found the lighter rounds in smaller guns more accurate too.
That just leads me to have a general guideline on .45 that basically says, "As you cut barrel length, reduce bullet weight. Target ~900fps +/- 50fps for optimal bullet performance. Use a quality bonded or monolithic HP round. Hit what you're shooting at."
That last point being the real key.
I'm sure @the Schwartz has some thoughts on this overall and can likely point out where my observations/assumptions are incorrect better than I can.
Okay, thanks. I do understand the basic concept of reducing weight to increase velocity and the role of velocity in expansion. I had just never heard the .5" / 20 grains thing. My position has generally been that below about 4", .45 ACP is not the best choice of caliber.. I have never heard positive things about the performance of bullets lighter than 230, with the exception of some of the all-copper bullets, but things change and I am sometimes behind the curve. The .5" /20 grains thing was new to me and there may be more recent ammo selections that change that, so I was curious.
It has been years since I carried a .45 for work or defensive purposes although I have a few around and enjoy shooting them.