"...Another point I would like to make is this if a jacketed bullet has less friction resistance in its passage through a barrel why then do we not use jacketed bullets to slug our barrels? ..."
The above statement is a great clue.
I am wondering it the Western Powders post was dated 4/1/14.
Not buying that about slugging a barrel. Pure lead is softer than pure copper and lead forms easier to the barrel.Originally Posted by Camba
"...Another point I would like to make is this if a jacketed bullet has less friction resistance in its passage through a barrel why then do we not use jacketed bullets to slug our barrels? ..."
The above statement is a great clue.
I am wondering it the Western Powders post was dated 4/1/14.
Lead bullets Matter
There are three kinds of men: The ones that learn by reading. The few who learn by observation. The rest of them have to pee on the electric fence and find out for themselves. - Will Rodgers
Jacketed bullet are also to hard to seal the bore completely. This causes gasses (pressure) to escape past the bullet wasting energy and reducing pressure. Kinda like worn out rings on your pistons.
Check you manuals, really check them.
You will find hundreds of examples were the jacketed bullets required More powder to achieve the same pressures as the lead bullets. You will also find hundreds of examples where Lead bullets generated more pressure than jacketed bullets with the same or less powder.
Western Powders is correct, as is Lyman, Handloader Magazine and Hornady.
I think the above post makes sense. Pat
http://m.youtube.com/watch?v=C2aQpVKiCN8
Interesting video that makes me wonder if hard cast bullets really do conform to the bore more readily than jacketed bullets.
Last edited by Mik; 04-23-2014 at 05:35 AM.
I am still learning about this bullet casting but if this is true why due we not slug the bore with a jacketed bullet?
I don't know.
Maybe because lead is less resistant to shearing forces than copper? I've only slugged a few bores but I always have a ring of lead left at the muzzle that was sheared off when I tapped the slug into the bore. I don't see this happening with copper.
In my head, this is what allows a jacketed bullet to be pushed harder than a pb lead bullet. The copper jacket offers more resistance to the shearing forces applied by the rifling. It's also my theory as to the reason you can get away with firing undersized jacketed bullets. You don't need as much material to engage the rifling because the jacket is more resistant to shearing. With a lead bullet, you need to fill those grooves, not necessarily to prevent gas escape, but to keep the bullet from "pushing" past the rifling.
All theories and guesses. Not based on science, knowledge, or experience! Someone please correct me if I'm on another planet.
Last edited by Mik; 04-24-2014 at 05:20 AM.
That's been brought-up three or four times in this thread...
Jacketed bullets wouldn't work for slugging the bore... but not because of friction.
For one thing, copper is "harder" than lead and would "spring back" so we wouldn't get anything close to an accurate measurement. But a jacketed bullet isn't that difficult to drive through a barrel, I've had a squib load stick a copper-condom bullet in the bore more than once and they ain't anymore difficult to drive out than a cast. We use soft lead (not hard-cast) to slug a bole because it's malleable, it easily conforms to the shape (like putty would) and doesn't spring back when it exits... we don't use it because it's because it's slippery. Don't confuse "friction" with "malleability"... they ain't the same.
Listen, I ain't defending what Western Powders has stated on their website... there's plenty of evidence, such as some load data, indicating it ain't so. But at the same time there's plenty of evidence, such as some load data, indicating it is. I just don't believe it's as simple as that... I don't believe you can say "always". I have personal (observational, non-scientific) experience of it being both ways depending on gun, load, projectile, and whatnot. But using comparisons to "bore slugging", "engine bearings", and other such don't work... they ain't the same dynamics as a projectile being forced down the barrel under pressure.
Someone would have to make a mould cavity that would cast an exact copy of a jacketed bullet. Then pressure test enough of them to rule out random variations. then the data would be valid for that boolit and that load.
Start decreasing the loads and fire them. which projectile will stick first? The friction is also dependent on speed.
The man who invented the plow was not bored. He was hungry.
Don't forget, Western Powders are the ones with Millions of Dollars worth of pressure testing Equipment, while most of the people claiming Western is full of ****, have a loading press, a PC and an Opinion. Not much of a comparison if you ask me.Listen, I ain't defending what Western Powders has stated on their website... there's plenty of evidence, such as some load data, indicating it ain't so. But at the same time there's plenty of evidence, such as some load data, indicating it is. I just don't believe it's as simple as that... I don't believe you can say "always".
Ya mean like Hornady data found here.
Take a look at Hornady #7 45 ACP data for example.
230gr FMJ COL = 1.230. This bullet measures .651 inches.
230gr Lead RN = 1.245. This bullet measures .640 inches.
So the Jacketed bullet is .011 longer and is seated .015 deeper, for a total of .026 deeper.
Data.
N-340 Lead, Max = 6.6gr. Jacketed. Max = 6.7gr.
Even with the .026 deeper the jacked bullet used more powder.
Clays Lead, Max = 6.2gr. Jacketed. Max = 6.4gr
Even with the .026 deeper the jacketed used more powder.
231 Lead, Max = 6.2gr. Jacketed. Max = 5.7gr
Here the Lead bullet with less seating depth used more powder. Maybe due to COL, maybe due to the lead bullet.
Unique Lead, Max = 6.3gr. Jacketed. Max = 6.1gr
Again we have more powder with lead than we do with Jacketed.
Western apparently hasn't read anyone else's manuals...
Warning: I know Judo. If you force me to prove it I'll shoot you.
I cant help thinking about the fact the a guilding metal jacket without lube or for that matter a cartridge case without pushed into a die will act quite differently than a lead bullet pushed into a die without lube.
Anyone ever have a stuck case in a sizing die from not using enough lube? Bet ya wont do that again! How about a jacketed bullet in a swage die with insufficient lube? Bet ya wont do that again. Consider that you can push a lead billet into a squirt die and swage it to a larger diameter to the point that excess metal is squirted out a little vent hole but still the swaged lead billet will push easily from the die without lube.
That being said which has the greater friction?
Considering that all our lead and lead alloy boolits are lubed and none of our jacketed bullets are lubed which one would seem to offer the greater resistance in its passage through a barrel?
The guilding metal jacket is harder so harder to initially deform or displace metal to the rifling but that is only for the length of the bearing surface initial entry into the lands. Once it has passed that far the deforming is over and what is left is friction.
I don't understand how say at 40,000 psi one typ can exert more pressure against the barrel wall than the other. Neither can exceed the chamber pressure and once the pressure is sufficient to obturate either type the the outward pressure of the bullet sides to the barrel should be the same.
I have seen .451" jacketed pistol bullets fired in a 45 cal ML where the bullet was small enough to slide down the barrel without engraving fired with black powder and the recovered bullets were fully engrave by the rifling and by the way produce excellent accuracy. By this it would seem that there is not all that much difference in the pressure required to obturate a jacketed bullet over a cast.
I have no theories, or pressure data or scientific anything these are just things I have observed that lead me to my conclusions.
Ya mean like Lyman, that says this:
Lyman 48 page 99 says,
A soft bullet may cause higher pressure because the bullet is so malleable that the sides will push hard against the bore when high pressure is exerted on the base.
...and Hornady that says this:
230gr FMJ COL = 1.230. This bullet measures .651 inches.
230gr Lead RN = 1.245. This bullet measures .640 inches.
So the Jacketed bullet is .011 longer and is seated .015 deeper, for a total of .026 deeper.
Data.
N-340 Lead, Max = 6.6gr. Jacketed. Max = 6.7gr.
Even with the .026 deeper the jacked bullet used more powder.
Clays Lead, Max = 6.2gr. Jacketed. Max = 6.4gr
Even with the .026 deeper the jacketed used more powder.
231 Lead, Max = 6.2gr. Jacketed. Max = 5.7gr
Here the Lead bullet with less seating depth used more powder. Maybe due to COL, maybe due to the lead bullet.
Unique Lead, Max = 6.3gr. Jacketed. Max = 6.1gr
Again we have more powder with lead than we do with Jacketed.
...and Hodgdon says this.
.44 Magnum handgun--
240 cast/ 22.0 IMR4227/ 33,300 CUP
240 jacketed/ 22.0 IMR4227/ 28,400 CUP
.38-55 rifle--
250 cast/ 27.0 H322/ 27,000 CUP
255 jacketed/ 27.0 H322/ 25,500 CUP
250 cast/ 24.0 IMR498/ 36,200 CUP
255 jacketed/ 24.0 IMR4198/ 31,400 CUP
Please not that even though the jacketed bullet in the .38-55 weighs 5 grains more, pressures are less with the same powders charges. And in all the above instances, the STARTING load with jacketed bullets is the MAX load with cast bullets.
And THIS!
Code:Jacketed IMR SR 4756 .451" 1.200" 6.4 762 12,900 CUP 7.0 867 16,500 CUP Lead,IMR SR 4756 .452" 1.200" 6.3 813 14,200 CUP 6.8 892 16,400 CUPCode:Hodgdon Jacketed HS-6 .451" 1.200" 8.0 790 14,400 CUP 8.2 825 15,400 CUP Hodgdon Lead HS-6 .452" 1.200'' 7.0 751 12,900 CUP 8.0 859 16,600 CUPCode:Hodgdon Jacketed, CFE Pistol .451" 1.200" 6.0 815 16,000 PSI 6.8 934 19,800 PSI Hodgdon Lead, CFE Pistol .452" 1.200" 5.4 816 14,600 PSI 6.2 942 20,100 PSICode:Hodgdon Jacketed, Universal .451" 1.200" 5.1 716 11,800 CUP 5.6 844 16,800 CUP Hodgdon Lead, Universal .452" 1.200" 4.5 703 11,400 CUP 5.4 857 16,800 CUPCode:Winchester Jacketd, WSF .451" 1.200" 5.7 766 12,100 CUP 6.4 851 15,700 CUP Winchester Lead, WSF .452" 1.200" 5.8 832 14,500 CUP 6.3 892 16,800 CUPI would suggest that those that disagree with Western Powders should take the time to Read Their manuals as well.Code:Winchester Jacketed WST .451" 1.200" 4.1 733 13,900 CUP 4.9 848 16,100 CUP Winchester Lead, WST .452" 1.200" 4.0 776 14,300 CUP 4.3 812 16,400 CUP
It would appear that those that disagree with Western would have to disagree with Hodgdon, Lyman, Hornady, Speer and just about every other $$Ballistics$$ lab that supplies us with usable data.
Read your manuals, really read them.
I think there are other factors involved other than just the one we are looking at. I do read those manuals and much of what I have read has been proven wrong. Just because they say so does not necessarily mean it is so.
Just as every gun is a law unto itself so too is everybody's loading conditions somewhat different than everyone else's.
How about this, will a 44 mag loaded with 10gn Unique and a boolit cast from pure lead have more pressure that the same 44 mag firing the same charge of Unique under a boolit cast in the same mold but of COWW and will the COWW load have higher pressure than the same charge of Unique loaded under a boolit cast from the same mold but using linotype? If what they are saying in the book that because lead is softer than a jacket the pressure is higher then it would have to follow through the same because each example of cast boolits given is progressively harder than the previous.
This is a much better comparison to prove a theory because everything is the same accept the alloy.
Nothing is equal here since both jacketed and cast bullets/boolits are entirely different from one another. One also needs to examine the hardness of a cast boolit too and if it has a gas check sitting on its ars end. Looking at the online Hodgdon data one can see in the 454 Casull section a 325 grain jacketed soft point has more pressures and a bit faster velocity vs a 335 grain Cast Performance hard cast (18-21BHN) boolit with a GC. Again bullet/boolit length is not known but the heavier Cast Performance boolit is seated to a shorter OAL as well. It doesn't matter if it's 4227, H110, or LilGun the hard cast boolit shows less pressure and less velocity for the same starting/minimum charge weight in powder. More interesting is the results in the Cast Performance hard cast 325 grain plain base bullet that is nearly the same loaded OAL as the 325 grain jacketed soft point.
Check it out www.hodgdon.com
Also similar info on the hodgon site above for the Ruger/TC/Freedom Arms 45 Colt load data as well between those same two 325 grain bullets/boolits that was used in the 454 Casull data.
As we talk about the deformation/obturation of a cast boolit are we discussing a swage boolit or??????BHN????? None the less the discussion here will be supported both ways as there are variables to cast boolits.
Looks like as I was typing Bullshop just above was getting to what I wrote regards to difference in boolit hardness.
Last edited by RobS; 04-25-2014 at 06:58 PM.
I did read the manual and I disagree with Western.
Lyman 48th had this to say on page 137:
222 Remington
55 grain JSP
Powder Max Load Velocity Pressure (CUP)
748 24.2 2885 44,200
55 grain #225415 (#2 alloy)
Powder Max Load Velocity Pressure (CUP)
748 25.0 2881 25,000
And on page 211:
30-30 Winchester
170 grain JFP
WLR primer
Powder Max Load Velocity Pressure (CUP)
IMR3031 28.5 2054 36,900
#311291 (#2 alloy)
CCI200 Primer
Powder Max Load Velocity Pressure (CUP)
IMR3031 28.5 2095 32,500
The list goes on but the correct answer is it depends.
It only took me a few minutes to find two examples of virtually identical loads with 4,000 to 19,000 CUP between them and the lead boolit is the lower of the two. Western's mistake was to make a blanket statement. They should know better.
Read your manuals.
Warning: I know Judo. If you force me to prove it I'll shoot you.
Ah, but you are again forgetting, Western Powders has Millions of dollars invested in pressure barrels and pressure testing equipment and thousands of hours and pages of Actual Data. You have a PC, a Manual or two and an Opinion.
Their load data falls on both sides of the fence as does Hornady, Lyman, Hodgdon and Alliant. This is a fact and cannot be denied, agreed.
Western powders put the jacketed vs Lead into generic perspective, "All things being equal" based on their actual Pressure lab tests and came up with the same results as Lyman, Hodgdon, Hornady and Handloader Magazine.
When you getcha some Pressure Trace Software and test Lead vs Jacketed for yourself, post your results here. Until then I'll put my faith in those that have the $$ Equipment$$ and the Knowledge to determine Pressures and not with an internet opinion.
Carry on gentlemen.
Here is a comment from a Handloader that has a Pressure testing system not just an opinion and a PC.
In every test I run with a pressure gun (piezo sensor), with the same powder load lead bullets gave higher pressures respect to jacketed ones; and with the same pressure, lead bullets gave higher speeds.
Link, Post #8
http://forums.1911forum.com/showthread.php?t=447626
Might want to turn the page to 138.I did read the manual and I disagree with Western.
Lyman 48th had this to say on page 137:
222 Remington
55 grain JSP
Powder Max Load Velocity Pressure (CUP)
748 24.2 2885 44,200
55 grain #225415 (#2 alloy)
Powder Max Load Velocity Pressure (CUP)
748 25.0 2881 25,000
55gr #225646 #2
748, 26gr = 3058fps @ 42,700CUP
Seems to me that data you quoted is an anomaly or a Mis-print.
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