Lead bullet pressures are greater than jacket bullet pressures of the same weight

[Bullshop]

My faith is in my experience and ability to read the signs of what is happening with my loads. The manuals are a handy reference to find a safe place to start but beyond that have little to do with what is happening with your or my particular gun.
It really matters not which will produce what pressure as long as you read that pressure and load accordingly.
The point that is being argued is irrelevant.

[Whitespider]

Seems to me that data you quoted is an anomaly or a Mis-print.

Hard to say... but it does make ya' wonder...
I mean, a .222 Remington load at only 25,000 CUP listed as maximum??
It sure does throw up a red flag though... don't it??
*

[RPRNY]

And yet the 55gr 225646 #2 alloy load (page 138) Is is still lower pressure (at 2 grs more powder) than the 55 gr jacketed load.

[jonp]

I may understand if a jkt bullet maker tried this out to subtly push their product but I don't see what Western has to gain from putting out a statement like that. They must have the pressure equipment to test out their powders.

[steve4102]

And yet the 55gr 225646 #2 alloy load (page 138) Is is still lower pressure (at 2 grs more powder) than the 55 gr jacketed load.

Yes it is, now go to page 323 and 324 and look at the 9mm 147gr data.

Titegroup Lead=2.8gr @30,300CUP...Jacketed=3.6gr @31,900CUP

Bullseye Lead=3.5gr @31,600CUP...Jacketed =3.9gr @29,900CUP
...Jacketed used .4gr more powder with Less Pressure.

700X Lead=3.3gr @32,200CUP...Jacketed=3.6gr @30,700CUP
Jacketed used .3gr more powder with less Pressure.

Universal Lead=3.4gr 31,000CUP...Jacketed=3.5gr @29,200CUP
...Jacketed used .1gr more powder with less Pressure

Unique Lead=3.8gr @31,800...Jacketed=4.5gr @29,100CUP
...Jacketed used .7gr more powder with less pressure.

WSF Lead=3.9gr @32,100CUP...Jacketed=4.4gr @30,800CUP
...Jacketed used .5gr More powder with less pressure

HS-6 Lead=5.0gr @31,900...Jacketed=5.8gr @30,500CUP
...Jacketed used .8gr More powder with Less Pressure

AA#7 Lead=7.1gr @29,300CUP...Jacketed=7.2gr @29,000CUP
...Jacketed used .1gr More powder with less Pressure

Blue Dot Lead =5.9gr @31,200...Jacketed=6.6gr @28,600CUP
...Jacketed used .7gr more powder with less pressure.

In all of these examples thye lead bullet used less powder to produce higher pressures than the jacketed bullet.

[303Guy]

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.

Actually, a softer boolit will exert more sideways pressure on the bore with the same chamber pressure as a jacketed bullet. There's an experiment one can do to demonstrate this. Take a cloth patch and roll it into a ball and push it into the bore, then another and another until they form a plug that cannot be moved. The harder one pushes on them the faster they grip the bore. To remove one needs a thin hooked device to pull the patches out from the other side. The first ball puts some resistance on the second one which expands outward a little which resists the next one even more and so on.

But things are not equal. Just changing the lube will change the friction as will the alloy hardness (ability to resist outward expansion). Then some jacketed bullets will smear in the bore - that's no longer friction but shear strength plus friction. So the bore condition will have an effect. That means the test barrel results may differ from our results.

I don't think any of the manuals are wrong or have typo's - the results were as per their test barrels.

Then we have differences in bullet/boolit shape. A jacketed bullet with its longer ogive has to move further before it seals the bore allowing more gas leakage.

[JonB_in_Glencoe]

If a gun's barrel has a J-word "stuck" midway down it, and then a cast boolit is then shot through the same gun...

WHICH PROJECTILE CAUSES THE MOST PRESSURE ?

[freebullet]

Lol, I bet cast makes higher pressure than titainium bullets too, lol.

Bullet profile, oal, the gun fired from, cases used, primer used, powder used, and other variables affect pressure. I've found book data too hot for my tastes that conflicts with other books. Posting all the charge weights means nothing because it doesn't give the whole picture.

I guess nobody at western has ever pushed a jacketed bullet or cast boolit out of a bore or they wouldn't make a statement like that, otherwise I want some of their alloy.

[Reg]

OK, just to throw a little gas on a open fire, referring to a article from the October 1993 Guns and Ammo by Ross Seyfried. Ultimate Cast Handgun Bullets. Yes this came from a comic book but I think Ross Seyfried has more than proven his ability and no, this isn't EXACTLY what the discussion is but I think there is a shown relationship.
In referring to two identical bullet molds he had cut, 305 gn., 44 caliber, one plain base and one gas checked. Both loaded with 21.9 gn. H-110 and then sent to Hodgdon for pressure and velocity testing.
I quote " The plainbased bullets averaged 5,000 PSI or about 13 percent more pressure than the gas checked ones, while gaining only 37 FPS or 2.6 percent more velocity. At the same time the standard deviation of the plainbased loads was more than double that of the gas checked ones. "
Page 61
There is a graph in the middle of the page showing two different weights of bullets tested both plain base and gas checked showing actual pressure's and velocity's.
The 305 gn. w/gascheck showed 33,000 PSI @ 1,383 FPS
The 305 gn. plainbase showed 38,200 PSI @ 1,346 FPS
This from the Hodgdon lab.

He also goes on to state that in general the gas checked bullet will tend to shoot more accurately but lets not go there !!
Point being in a round about way he backs up the concept guilding metal riding down the bore tends to do it slicker than just plain lead.

[RobS]

Point being in a round about way he backs up the concept guilding metal riding down the bore tends to do it slicker than just plain lead.

and/or more deformation/obturation of the lead boolit without GC at whatever BHN it was. more variables here

[steve4102]

I guess nobody at western has ever pushed a jacketed bullet or cast boolit out of a bore or they wouldn't make a statement like that, otherwise I want some of their alloy.

That statement is idiotic at best.

I guess you have never tested ammunition with expensive Pressure Testing Equipment, otherwise you wouldn't make an idiotic Statement like that.

If You have $$$ Pressure$$$ testing equipment and actual data, I apologize. Please post your Pressure data for all to see.

[JSnover]

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.

And Lyman doesn't? What do they have, some bearded mountain hick with a bullet-ridden tree stump? My apologies to bearded mountain hicks. I come from a long line of hicks.
Indeed, their data falls on both sides of the fence. That's why I thought it was somewhat foolish of Western to publish a blanket statement like that when virtually every manual proves them wrong. Like I said, it depends...

[JSnover]

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

Ok, so there are at least two pressure testing systems operational in North America, three if Lyman owns one. I doubt the author has tested as many loads. His data is accurate and correct, but only as far as it goes. In fact - on that same thread - you had this to say: "This is not necessarily true, in fact in many instances just the opposite is true." So which is it? Are pressures higher with lead or with jacketed? I'll help you out… It depends.
Pressures are generally higher with cast but every time I flip to a different cartridge in my manual I manage to find a case where the opposite is true.

[freebullet]

That statement is idiotic at best.

I guess you have never tested ammunition with expensive Pressure Testing Equipment, otherwise you wouldn't make an idiotic Statement like that.

If You have $$$ Pressure$$$ testing equipment and actual data, I apologize. Please post your Pressure data for all to see.

Guess that's a retard statement at best since you are talking trash and didn't provide any of the data from your super duper scientific testing either. Back under your rock you go.

[Bullshop]

How about jacketed to jacketed. Are pressures higher, lower, or the same with steel jacketed bullets than with guilding metal jacketed bullets?
If the analogy presented for lead/jacketed is true then steel jacket bullets would have to produce lower pressure because they are harder.
Well?

[JSnover]

Might want to turn the page to 138.

55gr #225646 #2

748, 26gr = 3058fps @ 42,700CUP

Seems to me that data you quoted is an anomaly or a Mis-print.

Take the discrepancy up with Lyman, I trust them and their equipment more than your opinion. There's another alleged misprint in the 45-70 section for Ruger #1 and #3 rifles. 53 grains of 322 produces 2,000 cup less under a 405 grain cast boolit. Velocity is almost identical to the 400 grain jacketed bullet.

[steve4102]

And Lyman doesn't? What do they have, some bearded mountain hick with a bullet-ridden tree stump? My apologies to bearded mountain hicks. I come from a long line of hicks.
Indeed, their data falls on both sides of the fence. That's why I thought it was somewhat foolish of Western to publish a blanket statement like that when virtually every manual proves them wrong. Like I said, it depends...

Of course Lyman has Pressure testing equipment, I never said otherwise. In fact if you would read you will find I posted Lyman Pressure tested data for the 9MM in post #85.

In post #85 it shows that the Lead bullet produced higher pressure with less powder.

[steve4102]

Ok, so there are at least two pressure testing systems operational in North America, three if Lyman owns one. I doubt the author has tested as many loads. His data is accurate and correct, but only as far as it goes. In fact - on that same thread - you had this to say: "This is not necessarily true, in fact in many instances just the opposite is true." So which is it? Are pressures higher with lead or with jacketed? I'll help you out… It depends.
Pressures are generally higher with cast but every time I flip to a different cartridge in my manual I manage to find a case where the opposite is true.

Two(2) Pressure testing System in North America? Really??

Nosler has a Pressure lab.

Hornady has a Pressure Lab.

Hodgdon ha a Pressure Lab.

Western Powders has a Pressure Lab.

Barnes has a Pressure Lab.

Alliant/Speer has a Pressure Lab.

ATK has a Pressure Lab or 3.

Lyman has a Pressure Lab.

...and I'm sure I forgot a few.

Yes, I said that and since that post I have been convinced, by those with Pressure Testing Equipment, that with "All things being equal a lead bullet will generate higher pressure than a jacketed bullet".

[Rick Hodges]

[ Yes, I said that and since that post I have been convinced, by those with Pressure Testing Equipment, that with "All things being equal a lead bullet will generate higher pressure than a jacketed bullet".[/QUOTE]

And there lies the rub. All things are NEVER equal.

[62chevy]

How about jacketed to jacketed. Are pressures higher, lower, or the same with steel jacketed bullets than with guilding metal jacketed bullets?
If the analogy presented for lead/jacketed is true then steel jacket bullets would have to produce lower pressure because they are harder.
Well?

Don't forget about copper plated bullets.