Does lead deform in the barrel

[MosinRob]

I'd like to know if a lead round ball deforms in the barrel and kind of pushes outward like a minnie? I had a heated discussion one time about wheel weight round balls and the other gentleman said that a round ball does this. I have cast lead round balls from pure and wheel weight and didn't see any difference in the 5 that I tested. It was only 25 yards. So I guess my question too is does anyone use wheel weights for round balls regularly?

 

[tenngun]

Can't back it up so its just my first gut feeling to your question. Yes, any time you would apply pressue to one side of an object you should get some flating. Even loading should deform the ball ever so lightly.

 

[roundball]

I'd like to know if a lead round ball deforms in the barrel and kind of pushes outward like a minnie?

Not an authority, just my opinion:
Setting aside any microscopic scientific viewpoint and looking at it from a practical, observable point of view, I don't believe they expand.
I've personally recovered them from trap boxes at the range, from gallon jugs of water at the range, from dirt banks at the range, and from deer...I have never seen any land / groove marks on them to suggest that they expanded and I always use stout powder charges for my big game hunting loads.
(same results with a few T/C Maxi-Hunters from years ago)
If they do expand, it's so miniscule as to be of no consequence and not any sort of "goal" to be sought after during load development.

PS: Last year I experimented with solid brass balls out of my .58cal...zero expansion with that hard ball of course...extremely accurate, then took a deer with one in the fall...that I'd already fired once and recovered from a trap-box.

 

[roundball]

Here are the solid brass balls I recovered from a trap-box filled with rubber mulch last summer, then used one of these to take a Doe last fall.
Obviously much harder / zero expansion compared to any wheel-weight lead ball you'd be using.

 

[Rifleman1776]

Without getting into the cussin' and discussion about obturation/obduration. :shocked2:
When you load a soft lead round ball it is going to get deformed. It is pounded somewhat into the rifling and often stomped on by the rod from above. I believe what comes out whe fired is not much of a "round" ball at all.
To test ball/patch combos, I have started balls about 2" into the bore with a large piece of patch cloth then pulled it back. A larger ball (e.g. .445" vs. .440") will definitely show rifling engraving and patch weave impressions. What it looks like coming out of the bore is not important if it is finding 'X's.

 

[Travis Gregory]

I recoverd a ball from a buck I killed this fall and upon inspection the ball had weave marks on the back of it from the patch but it also had definate grooves engraved on it from the lands of the rifling. It was a .490 ball fired with only 60gr of 3f. I would say that it has more to do with the bore dimensions from diffrent makers. As I understand it there is not a real "set" standard for muzzleloaders like there is for centerfire bores. I know a lot of guys that use the same ball and patch set up for their .50 rifles that I use and they talk about how easy it loads. My rifle is really hard to load even cleaning between shots.

 

[ApprenticeBuilder]

For my rifle and patch ball combination I would have to say yes, there is definite deformation.

 

[roundball]

That's a good point about bore size variations, as well as variations in ball sizes now that you mention that...and I suspect far more damage is done to a ball at short start / loading time than from any 'set-back' force.

Obviously rifling does not have to be engaged for PRB ball accuracy, which seemed to be the point of the OP's question about using harder wheel-weight lead.
Firm patch grip is all that's required.

 

[S.Kenton]

I second what RB is saying. The rifling should not make contact with the round ball itself, rather the patch that is wrapped around it. I've recovered many round balls from deer, water jugs and other shooting targets, never have I seen the imprint of rifling in the lead ball.
My 2 cents...

 

[Billnpatti]

I'm going to have to go along with Roundball on this. I have never seen any sign of a deformation caused by the pressure of the expanding gasses inside a barrel. A soft lead ball can be deformed by the ramrod as it is being seated and it can be tight enough for the lands to make impressions on the sides of the ball but I have never seen any indication that any other doformations occur prior to the ball striking the target.

 

[Vaino]

The medium that "transfers" the rifling twist to the RB, is the patch. It's imprint on the RB is what grips the RB and ensures that the RB will spin at the RPM dictated by the rifling twist.

Most shooters attempting to achieve maximum accuracy load a very tight ball/patch combo....w/ these there's definitely a deformation when loading of the RB....it's sectional density has slightly increased because it's no longer round.

As far as a RB expanding because of chamber pressure, I doubt that the amount of expansion could be measured.

The TC Maxi-ball does expand because of chamber pressure because the smaller dias of the bullet collapse and this lead then swells the outside dia. rings.

The straight conicals again wouldn't expand in any measureable amount.

The miniball because of it's thin, expanding "skirt" does obturate the bore, but the body itself doesn't expand in any measureable amount.

Roundball's experience w/ solid brass balls is akin to shooting a smoothbore....the patch just fills the void. Any friction between the patch and brass ball would be insignificant upon ignition. The brass ball wouldn't spin and in effect, the rifle becomes a smoothbore.

The above opinions are just that but were arrived at w/ some deliberation based on some study of internal ballistics and common sense asre shooting MLers......Fred

 

[necchi]

Well Said,! :wink:

 

[Rifleman1776]

Obviously rifling does not have to be engaged for PRB ball accuracy, which seemed to be the point of the OP's question about using harder wheel-weight lead.
Firm patch grip is all that's required.

:hmm: HMmmmm.....that could be a :stir:
I prefer that the ball is guided by the rifling. The word "engaged" could be interpreted a couple ways. I believe rifling grasping the lead, even with a cloth wrap, is still "engaging". And that is how I prefer it to be for optimum accuracy. In fact, that is how I believe it should be.

 

[zimmerstutzen]

It is fairly relative. I have seen folks using big mallets to start their PRB's down the bore. Anybody who thinks that ball isn't changed from it's original shape, is delusional. A pure lead ball just dropped on a concrete floor from shoulder high will show a flat spot. The force of powder igniting behind the ball is again force upon the soft lead.

And how about those guys who feel the need to hurl their ramrods down the bore so they bounce almost back out. No ball flattening? Really?

I have pulled PRB's from my Dixie Mountain rifle. The lead ball shows indentation of patch weave all the way around the circumference, deeper where it contacted the grooves. I normally load very loose PRBs that require no palm bruising force to start the ball. I sometimes do shoot the other extreme, especially in my bench gun.

The question is whether the soft lead ball "pears" out at all from the force of powder igniting behind it is difficult to prove or disprove. Saying I never saw it, doesn't mean it didn't happen. Is sufficient to even be noticed with the human eye? It may have to be measured.

Then one poster added the complicating factor of hard cast balls made of wheel weights. First they shrink more than lead when casting and usually as cast are a few thousandths smaller. As a result of being smaller and harder, there is less likelihood that patch weave indentation will be seen.


I have a 54 cal barrel with rifling so deep that it is nearly impossible to shoot without mashing the ball into the grooves with a mallet. There is no way a hard cast ball could be shot accurately from 25 thousandths depth rifling.

it is nearly impossible to start a pure lead ball without at least some marginal mark on the ball. I know just from riding in the car with an idiot what happens to the passenger when the driver unexpectedly powers out from a stop. That is so minor compared to the g-forces exerted on the PRB when the powder ignites. Does a pure lead ball have such plasticity that the force of ignition can cause the ball to change shape? We know a minnie ball swells out to help seal the bore and with only a moderate charge of powder. Who would dare claim that there is no microscopic change to the shape of a minnie ball when fired? We all know the skirt is designed to be blown out to the barrel wall. Why not the same effect on a lead ball even to a minor extent?

 

[zimmerstutzen]

Alright, we have conflicting theories. What test will prove or disprove the theories?

 

[Dphar]

I'd like to know if a lead round ball deforms in the barrel and kind of pushes outward like a minnie? I had a heated discussion one time about wheel weight round balls and the other gentleman said that a round ball does this. I have cast lead round balls from pure and wheel weight and didn't see any difference in the 5 that I tested. It was only 25 yards. So I guess my question too is does anyone use wheel weights for round balls regularly?

Not in the calibers we normally use that I have ever been able to tell. HOWEVER. Pretty short elongated bullets will upset to a considerable extent.
The patched RB is already tight in the bore and covered with a patch that is already compressed to some extent. So I doubt it changes much. But this would have to be resolved by HS photography.
Elongated bullets definitely will expand to fill the bore if "naked" or paper patched.

Dan

 

[ohio ramrod]

I don't know if you would consider it a proper test, but after lapping barrels that have the breech plug removed I drive a "double patched ball through to remove any left over lapping compound. And the balls definitely deform! For all of my rifles I radius the ramrod tips and short starters the same as the ball to reduce the amount of deformation at loading. Before I retired I made ball end mills .350, .440, .445, .490 & .495.They are very useful. :idunno:

 

[AWsaddles]

I don't know that I have a theory but I have an oberservation and maybe you guy can provide some insight. I am guilty of a dry ball on occasion and in the instances when I have, the loading procedure was the same minus powder. When the ball was pulled, weave impressions were made in areas where the lands were present but only there. On balls I have recovered from deer, the ball always have a deep weave pattern inprinted deeply on the back of the ball. I think this would have to have been due to deformation from pressure of gass expansion. Any thoughts?

I do use Ww for shooting quite offen and have had good luck. Small game and targets only for me though. I do have to use a thinner patch. :idunno:

 

[Larry Pletcher]

Some time back I measured different sized balls removed from a .54 Rice barrel. Using .020" patch I short started a .526, .530, and .535 swaged ball in the barrel and pulled them back out. I measured the ball front to back and also the length of the mark the rifling left on the sides of the ball.

I wish I could quickly find my crib sheet that is undoubtedly in my vast piles of notes, but I don't know where it is now. To summarize. The largest ball (.535) had the longest rifling marks and was the shortest front to back. The smallest ball (.526) had the shortest rifling marks and was the longest front to back. The .530" ball was in the middle.

I dislike speculation without my sheet of numbers, but I think the shortening of the ball is done by lengthening the center section that contacts the rifling.

Dan mentioned high speed photography. I am better equipped now than when I took the photo of the patch separating from the ball. A better camera with better controls may?? allow a comparison between a ball pulled and a ball fired. At this point I don't know.

Steve Chapman and I were plotting a session or two shooting through balloons for the camera. Maybe we should tackle something more serious.

Regards,
Pletch

 

[roundball]

I suspect that 7000-9000 PSI or so along with the fire's heat on the back of the ball makes that weave pattern