quote:

Originally posted by starmetal:

quote:

Originally posted by SR4759:
I will not suggest a method of analyzing the data
but if you examine the results of the lever gun performance data you will find that there is some potential for the RPM limit to exist.
This data was not generated to test for such a limit so it would be difficult for it to be biased.


Lever gun performance studies

BTW there is a lot of Lazer cast data here
but it carries a disclaimer to use at your own risk.

Not necessarily. You'll notice on many of those that the upper velocity was smaller. The problem with that test is they used pistol powders and larger loads of that really "shock" the bullet. I looked at particularly the 32 Special. I load a cast with that and get almost factory jacketed velocity with very good accuracy. I don't feel very fast powders such as they used are the best for good accuracy at the higher velocities.

quote:

Originally posted by 303Guy:
Is this actually a case of bullets deforming due to excessive radial forces or is the bullet simply stripping through the rifling? Or both? I have recovered bullets that have partially stripped through the rifling (or is 'wearing through' more appropriate?) This does lead to gas escape and flame cutting sometimes. I seem to remember getting better velocity and accuracy with softer bullets that would upset in the forcing cone and seal the bore. (Un-gaschecked bullets and hotter loads).

quote:

Originally posted by starmetal:
Here's a little info on how good Larry is on twists. I hope you don't mind me copying your post from Castboolits Larry, but you've been bottom feeding lately too.

This post by Larry is in reply to another members question about using heavy bullets in the M1 Carbine. Larry replied:

Larry Gibson
Boolit Master

Join Date: Jul 2005
Location: University Place, WA
Posts: 2,814

If you are asking about in an M1 Carbine the slow twist will not stabilize any bullets much over 130 gr. Also the heavy bullet driven to any velocity will have a much higher gas port pressure which could damage things. If you are using an M1 Carbine you'll do well to stick with 125 gr or less bullets.

Larry Gibson

Ok first Larry knows that I have shot 150 gr cast bullets out of my M1 Carbine with good results. His first statement to me when I told him that over the phone was what distance. Fifty yards was the distance which is ample to show if bullet is going to keyhole. His second question was what twist is my carbines barrel, that some (which I never have seen, but will give him the benefit of the doubt)was. Mine is the standard Carbine twist of 1 in 20. Third question was what bullet was it. Now pay attention here to those of you here that don't believe you can size a bullet down or up much. The bullet was a 150 gr RCBS SWC for the .357 magnum swaged up. Plain base too. Well I was just fooling around today with the swager and tried another bullet, so no Larry, it's not the same 150 RCBS SWC. Oh yeah, Larry said I probably got results because the bullet was short and stubby.

Here is a picture of the bullet I used today. The swaged up bullet is on the left and the bullet it was made from on the right, which is a 150 gr Lyman Loverin. Again no gas check and I used IMR 4227 powder and will not disclose the charge as to protect those that really know what they are doing from having an accident.



Now here is the 50 yard target. I don't see any keyholing. Wasn't a hot load either.



So in closing Larry doesn't know as much as he leads on to know and his rpm threshold is phooey.

quote:

Originally posted by SR4759:

quote:

Originally posted by starmetal:
Here's a little info on how good Larry is on twists. I hope you don't mind me copying your post from Castboolits Larry, but you've been bottom feeding lately too.

This post by Larry is in reply to another members question about using heavy bullets in the M1 Carbine. Larry replied:

Larry Gibson
Boolit Master

Join Date: Jul 2005
Location: University Place, WA
Posts: 2,814

If you are asking about in an M1 Carbine the slow twist will not stabilize any bullets much over 130 gr. Also the heavy bullet driven to any velocity will have a much higher gas port pressure which could damage things. If you are using an M1 Carbine you'll do well to stick with 125 gr or less bullets.

Larry Gibson

Ok first Larry knows that I have shot 150 gr cast bullets out of my M1 Carbine with good results. His first statement to me when I told him that over the phone was what distance. Fifty yards was the distance which is ample to show if bullet is going to keyhole. His second question was what twist is my carbines barrel, that some (which I never have seen, but will give him the benefit of the doubt)was. Mine is the standard Carbine twist of 1 in 20. Third question was what bullet was it. Now pay attention here to those of you here that don't believe you can size a bullet down or up much. The bullet was a 150 gr RCBS SWC for the .357 magnum swaged up. Plain base too. Well I was just fooling around today with the swager and tried another bullet, so no Larry, it's not the same 150 RCBS SWC. Oh yeah, Larry said I probably got results because the bullet was short and stubby.

Here is a picture of the bullet I used today. The swaged up bullet is on the left and the bullet it was made from on the right, which is a 150 gr Lyman Loverin. Again no gas check and I used IMR 4227 powder and will not disclose the charge as to protect those that really know what they are doing from having an accident.



Now here is the 50 yard target. I don't see any keyholing. Wasn't a hot load either.



So in closing Larry doesn't know as much as he leads on to know and his rpm threshold is phooey.

Starmetal,
1.Parts of you post make no sense.
2.Second you assumption that 50 yards is enough to show key holing is just an assumption.
3. Will your carbine load reach 100 yards without tumbling? What is the velocity?
4. Is your .30 carbine load of any possible practical use? Will it feed, is it always stable, has it been tested in other firearms.

quote:

Originally posted by Pat I.:
I'd like to know how you made a swaged up .357 bullet shoot in a .30 carbine?

quote:

Please make any further posts regarding the RPM threshold on this thread.

quote:

As I stated; the bullet is "short and stubby". It's length is about what a 130 gr normal cast bullet would be. The stability of the bullet in a given caliber is governed by twist and length. Thus you shortened a 150 gr bullet down to the same length as a normal 130 grain bullet.

quote:

Originally posted by Larry Gibson:
Starmetal

As I stated; the bullet is "short and stubby". It's length is about what a 130 gr normal cast bullet would be. The stability of the bullet in a given caliber is governed by twist and length. Thus you shortened a 150 gr bullet down to the same length as a normal 130 grain bullet.

Larry not going to work. I know about rifling twists. You read the book and still come up with a threshold theory because you CAN'T shoot accurately at higher rpms. You'll end up making yourself look foolish here as you have on Castboolits.

The heavy 30 Carbine has to do with reverse Larry Gibson rpm threshold. That is achieving a stable bullet with decent accuracy out of a twist that really shouldn't support it. You weren't able to do and write it off as because the bullet is short, which if you remember in one of our phone conversations, I told you that's what I thought it was. Tell you what, I'll play with some much longer bullets. By the way the 130 Lyman isn't anyways near as long as my short bullet. Look at my short bullet in the picture and see it's nearly as long as the 7mm Loverin.



I stated; "in an M1 Carbine the slow twist will not stabilize any bullets much over 130 gr." Thus your bullet should have stabilized about as good as a 130 gr bullet. Your group at 50 yards is a little over 2" so at 100 yards we are talking 5+ moa. That is about the accuracy I got with 130 gr 311410s and is a sign of instability. I did not say the bullets would "tumble" at 50 or 100 yards. A good M1 Carbine with good cast bullets of appropriate weight (less than 125 gr) should be able to shoot 3 moa at 100 yards. It would appear your swaged bullets (they are no longer cast) are doing no better.

I suggest you read the book on ballistics I mentioned, then you may learn something about twists and stability.

As you recall I took your results at face value and did not say you were wrong or did not do it. The reason I accepted it is bause the fact is the swaged bullet you used is about the same length as the cast bullets I was talking about. It should have stabilized them about the same, which it did.

BTW; Since the RPM of these carbine loads, or any M1 Carbine loads, does not come close to the RPM threshold what exactly is the relavence of this example to the RPM threshold? There is none Joe. This is just another of your convulated, cockamamey ideas to disprove something which you do not understand.

Read the book Joe and then conduct the test I've asked you to. Then perhaps you may understand.

Larry Gibson

quote:

Originally posted by idabull:
Goodness,Starmetal(aka MaxPayne,Joe, et al,ad naus.) Isn't it about time for you to play a trump? Perhaps your "laughing guy at Sierra ballistics"could use another outing ??? Idabull

quote:

Originally posted by 303Guy:

quote:

Please make any further posts regarding the RPM threshold on this thread.

Getting back to the original topic (the subject matter so far, although presented as a debate, is of interest to me as I too am pushing the bounderies) which is RPM threshold. I would like to ask about bullet length and stability but this is actually off topic but bullet length and stability has been raised here, so, if I may ....

quote:

As I stated; the bullet is "short and stubby". It's length is about what a 130 gr normal cast bullet would be. The stability of the bullet in a given caliber is governed by twist and length. Thus you shortened a 150 gr bullet down to the same length as a normal 130 grain bullet.

First question; this 'shortened' bullet is not only 'short enough' but also has more stabilizing mass where it counts, right? Meaning it is 'dense'.

Second question; would a longer but more compact (ie. dense) bullet be more stable than a shorter one that is less dense, like a boat tail spitzer? My thinking here is that by placing more mass on the OD of the bullet, more gyroscopic stability would be achieved. Taking this thinking one step further, if one were to hollow this 'long' bullet, would it be more stable still? Even if it were to be made longer with the same weight?

Folks, I'm not trying to be funny here! This is an interesting discussion with what I consider to be of value.
Consider this, I have been able to shoot 60gr spire point 224 bullets with good accuracy and range from my 1-in-16 twist hornet. However, 55gr boat tail spitzers - although I did manage to stabilize them - were less accurate and took some doing!

Third question; how long does the barrel need to be to shoot heavy cast bullets with any kind of reasonable velocity?

quote:

.... the 300 Win Mag with a paper patch bullet to 3000 or slight over fps with if I remember correctly something like 1.5 inch accuracy at 100 yards.

quote:

Originally posted by 303Guy:

quote:

.... the 300 Win Mag with a paper patch bullet to 3000 or slight over fps with if I remember correctly something like 1.5 inch accuracy at 100 yards.

Wow! Well, I have always wanted to go into paper patching but have not gotten that far yet. Among other things, thay say that paper patching polishes the bore real good! What I actually want to do is swage the bullet into the paper patch in the die. I am looking for a suitable 'pressure melting' lube for the job. Any one have any ideas while we are here? I suspect the die will need a slight taper for bullet ejection reasons.

quote:

Originally posted by starmetal:.......
Just ask Larry to explain to you why you can shoot a paper patched bullet that is made from the alloy that a cast bullet is from, to such high velocity with very high rpm and accuracy. One comes to mine in the NRA Cast Bullet book. They used the 300 Win Mag with a paper patch bullet to 3000 or slight over fps with if I remember correctly something like 1.5 inch accuracy at 100 yards. Come on Larry, explain why paper patch can beat your threshold.

quote:

Originally posted by 303Guy:

Getting back to the original topic (the subject matter so far, although presented as a debate, is of interest to me as I too am pushing the bounderies) which is RPM threshold. I would like to ask about bullet length and stability but this is actually off topic but bullet length and stability has been raised here, so, if I may ....

quote:

As I stated; the bullet is "short and stubby". It's length is about what a 130 gr normal cast bullet would be. The stability of the bullet in a given caliber is governed by twist and length. Thus you shortened a 150 gr bullet down to the same length as a normal 130 grain bullet.

First question; this 'shortened' bullet is not only 'short enough' but also has more stabilizing mass where it counts, right? Meaning it is 'dense'.

Second question; would a longer but more compact (ie. dense) bullet be more stable than a shorter one that is less dense, like a boat tail spitzer? My thinking here is that by placing more mass on the OD of the bullet, more gyroscopic stability would be achieved. Taking this thinking one step further, if one were to hollow this 'long' bullet, would it be more stable still? Even if it were to be made longer with the same weight?

Folks, I'm not trying to be funny here! This is an interesting discussion with what I consider to be of value.
Consider this, I have been able to shoot 60gr spire point 224 bullets with good accuracy and range from my 1-in-16 twist hornet. However, 55gr boat tail spitzers - although I did manage to stabilize them - were less accurate and took some doing!

Third question; how long does the barrel need to be to shoot heavy cast bullets with any kind of reasonable velocity?

quote:

Originally posted by Larry Gibson:

quote:

Originally posted by starmetal:.......
Just ask Larry to explain to you why you can shoot a paper patched bullet that is made from the alloy that a cast bullet is from, to such high velocity with very high rpm and accuracy. One comes to mine in the NRA Cast Bullet book. They used the 300 Win Mag with a paper patch bullet to 3000 or slight over fps with if I remember correctly something like 1.5 inch accuracy at 100 yards. Come on Larry, explain why paper patch can beat your threshold.

303Guy

The test was done with a Steyr rifle. the reduced load averaged 1.47" but the 3000+ fps load with a PP'd 160 gr bullet cast of linotype Starmetal is refering to averaged 2.94". Not bad all things considered but still shows PM was getting to the PP'd bullet. The test did not include an accuracy load for a regular cast bullet so we have nothing to compare to.

As to why PP'd bullets can obtain a higher velocity with accuracy than regular cast bullets? Back in 1965 when the NRA began re investigating the use of PP'd cast bullets it was thought (quote from the NRA Cast Bullet Supplement - it's on page 93 Starmetal): "The limitating factor (of regular cast bullets) has become clear; it is softening of the lead bullet surface by the hot, high pressure propellant gas, which can not be kept off it by methods used hitherto.....This limitation is removed by wrapping the bullet in paper." It is also believed (evidenced by recovered bullets) that the PP supports the cast bullet almost it's entire length preventing unwanted obturation during acceleration.

It does appear that RPM affects PP'd bullets cast bullets about the same as jacketed bullets. PP bullets do not "beat" the RPM threshold because as with jacketed bullets it does not apply. Starmetal is continuing to show his ignorance of the subject.

Larry Gibson

quote:

Originally posted by Larry Gibson:

quote:

Originally posted by 303Guy:

quote:

Please make any further posts regarding the RPM threshold on this thread.

Getting back to the original topic (the subject matter so far, although presented as a debate, is of interest to me as I too am pushing the bounderies) which is RPM threshold. I would like to ask about bullet length and stability but this is actually off topic but bullet length and stability has been raised here, so, if I may ....

quote:

As I stated; the bullet is "short and stubby". It's length is about what a 130 gr normal cast bullet would be. The stability of the bullet in a given caliber is governed by twist and length. Thus you shortened a 150 gr bullet down to the same length as a normal 130 grain bullet.

First question; this 'shortened' bullet is not only 'short enough' but also has more stabilizing mass where it counts, right? Meaning it is 'dense'.

Second question; would a longer but more compact (ie. dense) bullet be more stable than a shorter one that is less dense, like a boat tail spitzer? My thinking here is that by placing more mass on the OD of the bullet, more gyroscopic stability would be achieved. Taking this thinking one step further, if one were to hollow this 'long' bullet, would it be more stable still? Even if it were to be made longer with the same weight?

Folks, I'm not trying to be funny here! This is an interesting discussion with what I consider to be of value.
Consider this, I have been able to shoot 60gr spire point 224 bullets with good accuracy and range from my 1-in-16 twist hornet. However, 55gr boat tail spitzers - although I did manage to stabilize them - were less accurate and took some doing!

Third question; how long does the barrel need to be to shoot heavy cast bullets with any kind of reasonable velocity?

303Guy

You need to get a book on ballistics and read it. Some of your questions are going to require "chapter length" answers. I suggest; Understanding Firearm Ballistics by Robert Rinker. I noticed the local Cabella's had them for $25.

Larry Gibson

quote:

Originally posted by starmetal:
To show your ignorance Mr Gibson there are lubes today that will defeat that softening of the surface lead. Your explanation still doesn't clear up one of your main statements to beat down the naysayers of your rpm threshold and that statement from you is that RPM magnifies the imperfections in a cast bullet...such as voids. Apparently the NRA's paper patched bullets were perfect huh Larry???
Try again pal.

quote:

Originally posted by Larry Gibson:

It does appear that RPM affects PP'd bullets cast bullets about the same as jacketed bullets. PP bullets do not "beat" the RPM threshold because as with jacketed bullets it does not apply.
Larry Gibson

quote:

Originally posted by 45 2.1:

quote:

Originally posted by Larry Gibson:

It does appear that RPM affects PP'd bullets cast bullets about the same as jacketed bullets. PP bullets do not "beat" the RPM threshold because as with jacketed bullets it does not apply.
Larry Gibson

Hmm.... On the Lazer cast bullet thread, Jan 09,2009 4:19 pm you posted;
RPM does, in fact, have a adverse affect on jacketed bullets.

Now you've stated it both ways so you can say your correct. I guess doublespeak is your forte! Funny how RPM doesn't effect PP boolits with all those imperfections in them.........EH!!!!!!

quote:

Originally posted by starmetal:
Larry,

I'm not buying the NRA's theory that you recited on the paper patched bullets. I'll explain why. In a nutshell the NRA isn't always right, nobody is. You use fillers as do I and many other's Larry. Well the NRA has been wishy washy on fillers. In their Cast Bullet book they used and recommended them. Then they came out with bulletins not to use them, that they were dangerous. That they could ring your barrel or worse. I know what happened. There were loaders out there, that myself and many others warned about the proper use of fillers and that was to NOT tamp or pack them down over top the powder. Many probably done this and some unfortunately resulted in ringed chambers...and that squealed to the high heavens. Next the bullet isn't in the bore but a micro second. Simply not enough time to soften the surface alloy. There isn't even enough conclusive proof that hot powder gases melt bullet bases. Gas cut yes. If gases did melt bases why don't they melt bases on the FMJ bullets that have the base exposed and the cores of those are more towards lead then alloys used for cast? I too have recovered countless number of fired bullets. It's been a childhood fascination of mine and later on as an adult it became a good teacher. I can't say I've ever recovered a cast bullet that showed the effects of what you said the NRA claims. Now I have recovered a bullet that showed a raised edge on the force or stress side of the rifling groove. I took pictures of this and sent them to Bass one day. We both asked the same question. How could there be a raised edge/fin along the entire length of one side of all the rifling grooves on that bullet when it's contained inside the barrel and the bullet fully obturated to the bore? What say you Larry, Bass and I came up with the same answer too..

quote:

Originally posted by starmetal:
Too further discredit Larry's rpm threshold I noticed that the Lyman Cast Bullet Manual had loads for a number of 6.5 cartridges that were fired out of barrels with fast twists and the top velocities were well out of Larry's threshold. I brought this up to Larry as why would a reputable company like Lyman whose livelihood is reloading and cast bullets, print information like that if Larry's threshold was true. His reply was that they didn't actually test all those loads. Don't deny Larry. Well guess what? I contacted Lyman and asked them that very question and here's the email I just received from them:

Hi,

Yes, Lyman tests every load that is printed in the manuals. For each caliber you will see "Firearm used" in most cases it is a universal receiver.

Lyman customer service

----- Original Message ----- From: <starmetalXXXXXXXX>
To: <custsvc@cshore.com>
Sent: Saturday, January 10, 2009 12:11 PM
Subject: Lyman Contact Form

What say you now about Lyman's out of your threshold loads Larry? That they aren't accurate? Why would they publish loads that they KNOW weren't any good?

quote:

Originally posted by Larry Gibson:

quote:

Originally posted by starmetal:
Larry,

I'm not buying the NRA's theory that you recited on the paper patched bullets. I'll explain why. In a nutshell the NRA isn't always right, nobody is. You use fillers as do I and many other's Larry. Well the NRA has been wishy washy on fillers. In their Cast Bullet book they used and recommended them. Then they came out with bulletins not to use them, that they were dangerous. That they could ring your barrel or worse. I know what happened. There were loaders out there, that myself and many others warned about the proper use of fillers and that was to NOT tamp or pack them down over top the powder. Many probably done this and some unfortunately resulted in ringed chambers...and that squealed to the high heavens. Next the bullet isn't in the bore but a micro second. Simply not enough time to soften the surface alloy. There isn't even enough conclusive proof that hot powder gases melt bullet bases. Gas cut yes. If gases did melt bases why don't they melt bases on the FMJ bullets that have the base exposed and the cores of those are more towards lead then alloys used for cast? I too have recovered countless number of fired bullets. It's been a childhood fascination of mine and later on as an adult it became a good teacher. I can't say I've ever recovered a cast bullet that showed the effects of what you said the NRA claims. Now I have recovered a bullet that showed a raised edge on the force or stress side of the rifling groove. I took pictures of this and sent them to Bass one day. We both asked the same question. How could there be a raised edge/fin along the entire length of one side of all the rifling grooves on that bullet when it's contained inside the barrel and the bullet fully obturated to the bore? What say you Larry, Bass and I came up with the same answer too..

Starmetal

I didn't say I bought off on the NRA's answer either, I only quoted it. I did that because as happened on the other forum when I didn't I was "challenged" by you know who. I added my comments which is what I believe to be the reason patched cast bullets can be driven faster with accuracy.

BTW; it wasn't the NRA that stopped using wads in it's Cast Bullet Handbook, it was Lyman I believe. I do use a dacron filler in many loads with medium or slow burning powders. I also use a filler sometimes with 5744, 4759 or 4198 if using a large capcity case. I do not use wads. I quit using wads not because of the "potential" of ringing but because of powder migration from recoil. I was getting hang fires with rounds that had been in a magazine when 2-3 rounds were fired previous to them. I've chronographed thousands of rounds with dacron fillers in them and now pressure tested over 3,000 rounds also and have not had one indication of a pressure spike from the use of the dacron filler. To the contrary I've had nothing but improved ignition and more consistant velocities when using the dacron filler.

I don't think that the hot gas "melts" the base. I do think the base can be distorted by the pressured and yet unburned powder particles, particularly if the bullet is seated below the case neck.

"How could there be a raised edge/fin along the entire length of one side of all the rifling grooves on that bullet when it's contained inside the barrel and the bullet fully obturated to the bore?"

I imagine you are about to inform us that the bullet continues to "twist/rotate" as it exits the barrel thereby causing the "raised edge/fin". However, there is another possibility; the muzzle end of the barrel is worn. They do that you know, That's why they have "muzzle gauges". By the time the bullet is in the muzzle end of the barrel there isn't sufficient pressure to obturate the bullet at that stage in the barrel. However there is enough rotational force to cause the leading edge of the groove on the bullet to swage up into the larger groove depth.

I'm not sure that is the whole answer because I've not thought about that situation much. If you have such a barrel short of replacing the barrel or cutting and recrowning there isn't much you can do other than not shooting cast bullets in it. Now that wouldn't be right would it?

Larry Gibson