Lube Star question

[oneokie]

Have seen lots of references to a "lube star" on the muzzle of a barrel. But not much additional information about this.
Suggestions/reccommendations on where to find said additional info. and how to read the size and or shape of the lube star will be appreciated.

[rvpilot76]

Lube Star

http://i13.photobucket.com/albums/a271/rvpilot76/lubestar_1.jpg

I believe this is what you are shooting for. Enough lube to make it to the end of the barrel. This lube, in turn, gets distributed on the muzzle by the propellant gases. Hope this helps.

Kevin

[sundog]

I thought I recognized the pic.

http://www.castpics.net/ Go to Research and Data, then to Lube Star

There is additional information to go along with it.

[oneokie]

Thanks, just what I was looking for.

Edited to add:

Spoke too soon. What I am looking for is information on how to read the "lube star" as to the effectiveness of the lube or lack thereof.

Size of star in regards to whether the lube is too soft-too hard. Short radians vs radians that extend to the OD of the barrel.

Thanks again.

[oneokie]

Bump

Would like some additional information on this.

[rvpilot76]

If you get lube on the muzzle, you are good to go. If you have a boolit with multiple lube grooves, you can drop lube one groove at a time, until the star disappears, then go back one. The main thing though, is that you want lube protection all the way to the crown. Keeps down on leading, especially with a really good lube like Lar's Carnuba Red.

Kevin

[44man]

You have to be careful what you are looking at on the muzzle. Don't mistake dry carbon for a lube star. A dirty powder can make you think you are getting enough lube and I have always had my doubt's about there being too much.
I watched this close on my BPCR when I would have a dry residue. A lube change would then give me the wet, greasy star.
I can see a big difference in my revolvers when I use the lube sizer to size a boolit, they lead the bore some but if I hand lube and just remove the excess there is no leading. I don't like a dry sided boolit. I don't like a lube so hard that you can break junks out of the grooves either. A lube should be sticky enough to have some stay in the grooves evenly all the way to the target or soft enough to spin ALL out at the muzzle. I have picked up commercial boolits on the range with a hard lube chunk stuck in one side of the boolit. Might as well cast full of air holes! [smilie=1:
Filling large grooves with a hard lube might be the reason some guys say too much lube is no good, more chances for an out of balance boolit as lube chunks out.
I have seen commercial boolits with such a hard lube that just dropping one a few inches had some lube break out. The package they came in was full of lube chunks in the bottom. Half was gone from the boolits. Might as well use a shotgun.

[Pat I.]

Don't shoot pistols much so maybe this doesn't pertain to them but I can guarantee you that with a rifle the amount of lube and the outside temperature does have a big effect on a lube's performance and the gun's accuracy.

[Bass Ackward]

Mr okie,

I believe that you are studying a false indicator. I have seen guys lay old bed sheets out in front of their benches to look for lube hardness indications. One guy had a brand new truck that he was using the hood for a rest that found out about his lube star. It cleaned off, but bottom line was that he had to do it. :grin:

All you have to do is read here for awhile and you will find one guy that wants to make his lube harder and in the same post a guy wanting to figure out how he can thin his even more. Twist rate and velocity will always be changing the equation. Bottom line is that I have had beautiful lube stars that shot like a shotgun and leaded up the wazoo and no lube stars that cut holes.

Of every cast bullet trend or rule or formula, the superior indicator is called a target. Proof of the taste is still in the pudding.

[BABore]

Often times, top accuracy is achieved when you just start to develope a grey wash at the muzzle and little or no lube star. This is at above 2,000 fps. Every barrel/bullet/alloy/hardness/load/lube combination will have it's own criteria and it may not transfer to the next one. I'm less concerned about a lube star or even a little bit of leading or wash compared to how it shoots.

[felix]

It is difficult to tell by naked eyeball if the gray wash is powder residue, lube residue, or actually a true boolit wash. Agreed, let the target decide which is what. However, the next outing will help determine what the gray is. If the accuracy went sour on the next outing, say after a month or so, then the problem is likely to be a lube problem. Most lube formulations will get rock hard over enough time, especially if fired upon and mixed with more carbon. Pay attention to the throat area where a lube ring will appear if given enough shots on the previous outing. ... felix

[44man]

Very true, the shooting is the proof. You don't need a greasy muzzle (unless you are shooting BP) or a spray of lube. Light leading doesn't hurt if it is not stuck to the steel. Accuracy is what you should look for. What I am saying is don't read carbon on the muzzle as a lube star. The gun might be shooting perfect that way so don't try for grease if not needed. But to try and get rid of the grease by making the lube harder can destroy the accuracy as fast as too much lube. To try to get a greasy muzzle can be as bad.
I guess what I am trying to say is to ignore the muzzle because it doesn't tell you what the gun needs. Some accurate loads will leave grease, some will have carbon and some will be cleaner. Some guns, boolit and powder combinations need a lot of lube and others don't. Keep the gun pointed down range so you can't see the muzzle and look at the targets instead.
I have had guys at the range show me the great lube star and I found it was only hard, dry carbon and the bores were full of lead. I would suggest a lube change but they liked the clean, hard stuff.
Everything said here is true, my position is to not try and read the muzzle. I just feel it is better to have too much lube to start with then not enough. That is easy to correct but when a boolit can't carry enough or the lube is so hard it breaks out in chunks, you are stuck with a problem that you can't work around.
Since I don't have any more high power rifles for cast boolits, I can't say much about them and how much lube is best, just that it will change with the powder, charge and boolit design.
I do know my revolvers like more and also a soft lube is best.

[Buckshot]

.............I did a test several years back with my 30-40 Krag Infantry rifle. Nice Loooooooooong barrel :-). I was using a Bator designed 200gr FNGC slug with shallow lube grooves. The LG's are only .0015" deep. This did not start as a test but just loading hotter as I went. Lube was Javalina, as cast slugs sized to .312" with a Hornady GC. I have the info out in the shop but this chair is fitting me so well at the moment .................

What happened was the WW (type) alloy and javalina seemed to peter out before I thought it should have. Started out with a dark (looby dark) bore, lube star, good accuracy, etc. Just what I'd expected and velocities around 1600 or so. Before I'd gone too much further the lube star disappeared, bore kind of dried out, and groups began growing. Not wild, just a tad more radial dispersion then a guy would like to see.

Began getting flyers and groups began to go. Getting a bit wild. The bore was a dull gray with lead flashing. No REAL leading though, but that wasn't much of a "Feel Good" thing as you probably wouldn't be able to hit a Campbells soup can on purpose at 50 yards.

Sometime before that a ole timer member (I forget who now but one of the back easters :-) had sent me some hard modern commercial type heat lube. It was green so I called it Booger green heat Lube (BGHL). Name brand unknown. I decided to try it, and to make a test of it.

What I did was to load 3 types of ammo using the same Bator shallow LG slugs, and the same increasing charges. The test was:

WW alloy/ BGHL

Lino hardness/Javalina
Lino hardness/BGHL

I already knew what WW alloy and Javalina would do. As you might expect, the next to fail was WW alloy/BGHL, then the Lino/Javalina and the one to carry on accurately well beyond the original was the lino/BGHL. The velocity was a tad over 2200 fps, so I was at the design specs pretty much for the Krag.

They all exhibited the same indicators, although the modern lube didn't produce as 'Juicy' a looking bore to begin with, nor the same type of lube star either. Much diminished. It all progressed with a whitening of the bore, with a bright streak along the pressure side of the land, then on top of the lands. Finally ending up with widening groups, fliers and a flashed bore.

I should add also that while this rifle is a good shooter, it's barrel isn't near pristine. The lands are pronounced but they do have signs of wear. The grooves are dark. While this Bator design would engrave, as will a Lyman 311407, a Lyman 314299 will not, so it has a rather long (eroded some?) throat and leade.

Had I been really a thorough tester I prolly should'a done the test again and used the Loverin to see what difference it's gargantuan lube carrying capacity (and deeper LG's) would have done.

..................Buckshot

[oneokie]

Thanks for the information. Now have a better understanding of what to look for in whether or not a lube is doing its job.