.45 ACP bullet hardness

[Machado]

Gentlemen,
How hard should a cast bullet for the .45 ACP be?
I cast mine from an RCBS 200 gr SWC; my alloy is 50% lynotype + 45% pure lead + 5% tin, quenched in water. It comes out plenty hard after a few days. After reading comments in this forum addressing the need for softer, not harder, bullets, I'm thinking maybe I'm going the wrong way. Comments, please?

[PGBsuperior]

There is a formula for that, and it concerns itself with bullet obturation. Given sufficient study the formula makes clear that not in all cases is harder better. If you are going for power factor, that's one thing, if you are shooting cowboy action that's quite another.

Your bullet is TOO hard if you are not loading hot enough to push it into the lands and grooves with your given load. Harder is better does not always apply. I load for my 1911 with 5 grains of W231. If I get my bullets too hard I'll get blowby and leading.

There's more too this than just making bullets as hard as you possibly can.

Amy

PGB Superior Cast Bullets
Ranger Texas

[robertbank]

There is a lot of witch craft associated with this topic IMHO. I water quench bullets from wheelweights. As far as oblituration is concerned every spring I pick up some of my bullets that hit snow during the winter. They are as they came out of the gun. I have yet to find any oblituration in any of them shot with 5.3 gr 231 under 200 gr LSWC. I think leading in the first 1/2 inch of the barrel stems from bullets jumping into the grooves ie just a tad short, and smearing the lead. My leading disappeared when I made an adjustment in bullet length.

Measure the length of your bullet. Drop a bullet into the chamber of the barrel when the barrel is out of the gun. Measure the distance from the base of the bullet to flush where the base of the case would come. Add the two measurement and you have the maximum length of your cartridge for that gun and that bullet. Back off 10/1000 to allow for variations in seating depth and you should be good to go.

On the topic of oblituration my H& G type bullets come out of my mold with a bevel base and they aren't going to obliturate to the point of "sealing" the barrel when shot from a any gun I have.

Others may disagree but that is just my observations. This observaton is for 9MM and .45acp bullets.



Take Care

[454PB]

Your alloy is a little harder than wheelweights, and has a lot more tin. You could eliminate the tin you're adding and still have excellent castability.

I've shot lots of straight wheelweight boolits in 45 ACP with good results, so I see no problem with hardness in what you are using, if all other conditions are correct.

[S.R.Custom]

Gentlemen,
How hard should a cast bullet for the .45 ACP be?


No harder than it needs to be... I know it sounds smartass, but it's true.

One thing to consider is the rifling in the barrel. I've shot some .45s that had rifling so shallow that bullets wouldn't be "gripped" sufficiently unless they were as hard as rocks.

[Lloyd Smale]

I agree totaly. Oblitrution is something that may happen with pure lead bullets and with black powder but thats about it. My buddy and I have been doing some testing lately with 45acps and 45 colts both light and heavy loads in each 4 different bullet. 4 different powders and 3 guns in each caliber. Not once has a bullet softer then ww out shot the harder ones. We started this test because we both noticed a trend in our load develpment that favored bullets cast out of 5050 ww/lyno and wanted to put to rest the old notions of bullets bumping up. Going to a harder alloy in most cases has cut group sizes by 1/2 and even more in some cases. The trend is more dramatic the that with the semi autos. I think a good part of that is the harder bullets tend to resist damage when feeding and like was stated the 1911s and even the 25 smiths have shallow rifling and need a harder bullet to grap it. The 1911s and 25s did there best work with straight lyno. I just wish i had an unending supply of it. Im not a fan of water dropped bullet but they may have a place in these guns. Bottom line though is the only way to find out for sure in your gun is to shoot it with diffent alloys every gun is its own animal.
There is a lot of witch craft associated with this topic IMHO. I water quench bullets from wheelweights. As far as oblituration is concerned every spring I pick up some of my bullets that hit snow during the winter. They are as they came out of the gun. I have yet to find any oblituration in any of them shot with 5.3 gr 231 under 200 gr LSWC. I think leading in the first 1/2 inch of the barrel stems from bullets jumping into the grooves ie just a tad short, and smearing the lead. My leading disappeared when I made an adjustment in bullet length.

Measure the length of your bullet. Drop a bullet into the chamber of the barrel when the barrel is out of the gun. Measure the distance from the base of the bullet to flush where the base of the case would come. Add the two measurement and you have the maximum length of your cartridge for that gun and that bullet. Back off 10/1000 to allow for variations in seating depth and you should be good to go.

On the topic of oblituration my H& G type bullets come out of my mold with a bevel base and they aren't going to obliturate to the point of "sealing" the barrel when shot from a any gun I have.

Others may disagree but that is just my observations. This observaton is for 9MM and .45acp bullets.



Take Care

[StarMetal]

The Model 25 Smith in 45LC is where I have alot of time and experience. Smale is right that they have shallow rifling, very shallow....in fact I believe they rifled them as though they are 45 acp's. It's also true they will let the bullet strip. I have the 8 3/8 barrel. I've recovered numerous bullets out of the backtop that showed that. In fact I have bullet that have stripped in the rifling to the point that there way may 1/16 inch left and they would have made a whole 360 degree turn in the barrel while stripping. Guess what? Most damn accurate revolver I've ever owned. Ask 44man about the open sight group shot at 100 yards. Guess what else....it shoots the same with soft lead, medium hard lead, hard lead, and jacketed. So I would say the theory on that with shallow rifling you have to shoot hard alloy. Also I've shot pure lead in all of my 1911's with very good results. I've even shot the lead hollow base conical designed for the 1858 Remington Army by Lyman out of both the 1911's and my Model 25 Smith with terrific results except with one mention and that is if I drive it really hard and fast the gas pressure really flares the skirts on them when they exit the muzzle.

Joe

[felix]

If the boolit finally gets its rotation requirements met, even with significant stripping, other factors come into play when accuracy fails. ... felix

[felix]

Obliteration? You folks mean obturation, right? Two different words with meanings nowhere the same. ... felix

[ANeat]

Ive shot a lot of Star swaged lead bullets thru my 1911. Usually less that 800fps. From what Ive heard they are pure lead. I get very little leading in the barrel just past the chamber after a few hundred rounds. A bronze brush with a patch around it and a little JB bore paste cleans it up in a few passes.

Ill be getting a hardness tester here soon and find out just how soft they are.


Adam

[Machado]

Thank you for your answers. I'll reduce the tin content in the alloy. I'm driving this bullet to a little over 1,000 fps with 10.7 grains of Blue Dot, unnecessarily, I guess. I'll reduce velocity too, and maybe improve case life.

[Lloyd Smale]

I shur niver clamed ta no haw ta spel :)
Obliteration? You folks mean obturation, right? Two different words with meanings nowhere the same. ... felix

[MT Gianni]

Proper obturation should result in oblideration of the x ring. Gianni

[Maj Tom]

Obturation…. Is an interesting phenomenon to say the least; one of many that pertain to the subject of internal ballistics? To keep is simple (ya right) there are two types of deformation (plastic and elastic) that take place to the bullet as it is undergoing all the activity after the hammer falls and prior to leaving the barrel (internal ballistics). When that hammer falls, the base of the bullet gets kicked in the butt. The butt attempts to get closer to the head until the head starts moving. When the head gets going the butt goes back to where it was (the bullet gets shorter and larger in diameter and then it returns to its original dimensions, elastic deformation). It expands enough to reduce/close the gap between the bullet to the bore. One can examine a bullet after it has been fired and not see any evidence of obturation. I’m not sure what one would expect to see? The final diameter of the bullet, for the most part, is determined by the barrel. I’m not going to get into what happens when to the bullet it engages the rifling, what the barrel is doing, etc. That gets even more interesting. Just my penny and a half…..

[felix]

Tom, your clue is lube groove dimensions before and after the shot. Yes, obturation happens! ... felix

[StarMetal]

Felix,

How can you tell a bullet obturates when the bore sizes it down?

Joe

[Maj Tom]

Tom, your clue is lube groove dimensions before and after the shot. Yes, obturation happens! ... felix
Fleix,
I concur. Other dimensions that may change are overall length of the bullet, distance from base to lube groove, etc..... Many look at the base of the bullet and say it didn’t obuterate. I have yet to have anyone describe what the base of the bullet should look like. My intended drift was that it does and it isn’t readily apparent…………
Tom

P.S. Ever do any experimenting with hardness and its affects on accuracy (barrel harmonics) ?