Jacketed And Cast Bullet Loads Are Not The Same, Part 1

[Der Gebirgsjager]

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About 25 years ago a fairly regular customer came into my gunsmithing shop with his M1 Carbine complaining that something was broken. It wasn't too hard to see that one of the locking lugs had separated from the bolt body. Kind of unusual, so I asked what had happened. The customer said nothing unusual had occurred, he was just shooting and the gun quit working. The following conversation ensued: "O.K., what kind of ammunition were you shooting?" "Same as always. My reloads using a 110 bullet over 14 gr. of H-110."
"Got one with you?" "Yeah--right here in my pocket." "But this is a cast lead bullet!" "Yeah--I picked up a box at the gun show 'cause they were cheaper than the jacketed bullets." "Did you change the load?" "Nope, same load, 14 gr. of H-110." So we had a further discussion about how jacketed and lead loads aren't the same, and how you need to significantly reduce the powder charge when switching over to lead, because the lead is softer and more difficult to push through the bore which raises pressures. The customer
learned the lesson, but was a bit miffed at why the replacement bolt and labor cost $65.00. The lesson was reinforced in my mind as well, and very recently bubbled to the surface again in another incident which I shall describe in Part 2.

[Bullshop]

Can-0-worms opener. I predict this will become a passionately debated evenly split topic. My participation will be one sided, I will listen only. Participants should put on their thick skin suit.

[462]

Hmmm . . . just checked Hodgdon's website. Now, I'll just sit back and see how this plays out.

[GhostHawk]

I'm with bullshop, I'll be reading but I have no dog in this fight.

[uncle joe]

No dog in this one either, other than I use an old lyman manual that lists cast loads for cast loads. I have never really compared loads between manuals for cast vs jacketed.

[500MAG]

Thank God Elmer Keith didn't know that.

[Newtire]

I always heard it was the other way around. I use 12.5 gr H110/Win 296 with the 118 grain (weight with my alloy and lube/gaschecked) 311359. Guess Hodgdon recommends as much as 15.0 grains.

Maybe bullet was too heavy or seated too deep?

[500MAG]

Lyman manual max for 110gr FMJ for h110 is 15.5gr. 10% backed off of that, is what I would be willing to go for cast without any other data, is 13.95gr. Doubt the 14 gr. would cause this problem. More likely a reduced load would cause issues, which is dangerous with h110.

[waksupi]

I don't see why it would start an argument. Cast bullets are advanced handloading. If you don't know reloading inside and out, it is something to venture into cautiously, to unlearn some of what you think you know, and to learn other things you NEED to know. As my tag line says, it's a whole new ball game.

[roadie]

I don't see why it would start an argument. Cast bullets are advanced handloading. If you don't know reloading inside and out, it is something to venture into cautiously, to unlearn some of what you think you know, and to learn other things you NEED to know. As my tag line says, it's a whole new ball game.

That say's it all.

I am impressed with the OP's abilty to remember load details of 25 years ago.....I have trouble remembering yesterday.

[Larry Gibson]

That is the common lug break off in M1 Carbines. I've seen numerous of those over theyears, several with M1/M2 carbines that only had US .30 Carbine ball ammo through them. I've had 2 such bolt breakages myself over the years in myown M1 Carbines. Too many variables in the story to draw aconclusion.

As to “all things being equal” and the cast bullet developing higher psi.......I know how the story line goes but in reviewing the numerous pressure reading of jacketed and cast bullets over the last 5+ years I can’t seem to find anything that would confirm that, I find just the opposite though..........

Also referring to that 8.2 gr load of Blue Dot under 125 gr bullets, cast or jacketed, in the 9mm case; I would refer the OP to the test done in this sticky on Blue Dot (Hercules & Alliant) and reflect on how Blue Dot acts when compressed;
http://castboolits.gunloads.com/showthread.php?51566-Blue-Dot-Hercules-vs-Alliant-test. The photo is of 8.2 gr of Blue Dot in an unsized 9mm case. Seating a 125 gr castor jacketed bullet will severely compress the load.

Other than that I’m just going to watch also

Larry Gibson

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[357maximum]

What ,, No one wants to get their feet wet or hands dirty???

I would say post #1 is about 110% theee exact opposite of the way I have always seen it work....seating depth/case fill by projectile and boolit weight being equal and barring a "crush fit" into the lands which boosts pressure...cast gives less pressure and a bit more speed compared to jacketed.

Sometimes well used gunparts/machine parts break...that is why there is a used parts market for guns and cars, and boats, and tractors, and snowmobiles, etc, etc, etc ad nauseum.


There...now I gotta go change my shoes and wash my hands.

[PAT303]

Stuff the lot of you then,you can't load cast as high as jacketed because the lead slugs into the throat at ignition raising pressures to a dangerous level before dropping because cast can't be shot over 1200fps because the lead will strip as it goes past it's tensile strength because the PSI at the base is spread evenly even into the chamber walls which grips the case raising pressure more because of obturation of the loaded round.Man I need to lay down. Pat

[Larry Gibson]

Man I need to lay down. Pat

That's 'cause you all are upside down way down there, the blood rush's to your head

Larry Gibson

[GrizzLeeBear]

+1 to what Larry posted.

It takes 2 minutes to do a google search for "common m1 carbine bolt broken" etc. to see that is indeed a common failure in the carbine.


As to part 2. Blue dot is one of those powders that has been shown to do some "spooky" things under certain conditions like compression. A few years ago Alliant came out with the warning about using it in the .357 with bullets either lighter or heavier than 125 gr. (I don't recall which one right now). I would not make ANY conclusions about the pressures and velocities of ANY bullets when using Blue dot.

To jump to the conclusion that cast bullets increase pressure because of the bolt failure of one carbine (which is common with any ammo) and reloading manual data for a powder like Blue dot is ridiculous.

[Newtire]

What ,, No one wants to get their feet wet or hands dirty???

I would say post #1 is about 110% theee exact opposite of the way I have always seen it work....seating depth/case fill by projectile and boolit weight being equal and barring a "crush fit" into the lands which boosts pressure...cast gives less pressure and a bit more speed compared to jacketed.

Sometimes well used gunparts/machine parts break...that is why there is a used parts market for guns and cars, and boats, and tractors, and snowmobiles, etc, etc, etc ad nauseum.


There...now I gotta go change my shoes and wash my hands.

Sorry Mike, beat ya to it, see post #7. That's what I like about cast boolits!

[357maximum]

Sorry Mike, beat ya to it, see post #7. That's what I like about cast boolits!

OK...YOU WIN The plaque is in the mail.

[Newtire]

OK...YOU WIN The plaque is in the mail.

Thanks Mike! I'll put it beside my "Most Wonderful Person in the World" award on the bathroom wall of the Star Mercantile Store.

[onceabull]

Newtire:if the fine print on that "award" of yours says anything about for all time. You best take it home and ship it (with big insurance) to The Smithsonian !!!..BECAUSE there has been a significant # of highend ego types pass through that place over the years.... Onceabull

[2ndAmendmentNut]

I am going to be on the side of people that believes a properly sized cast bullet or boolit will result in less friction and pressure on the bore. While there is a difference I don't believe a safe load with a jacketed bullet will suddenly become unsafe when a cast one is used or vice versa. Not unless other factors come into play such as leading.

That being said I agree with the OP's point that you can't simply interchange components and expect all to go well.