Bullet Hardness Affect on Lubricating the Bore

[btroj]

I never saw what cartridge you are loading. Is it a 30-30? If so the there are many powders that will work.

What cartridge, gun, and powders re you using now? Detail could help us decipher the root cause.

[03lover]

btroj,

The cartridge is 30-30 Winchester. The rifle is a pre 64 Winchester Model 94.

I have been working with Unique and WC 820 at this point. I prefer not to get into using too many different powders if I can. Unique has always worked well for me and I usually can find a powder charge that shoot accurately without much trouble in a mess of rifles. It is a little position sensitive and my best accuracy using Remington #9-1/2 primers is always with the powder laying in the bottom of the chambered round. Not to the rear which is not as good and not to the front which is the worst.

Accuracy is not the issue with this rifle and loads, it is the minor leading with a couple of bullets and the Hunter Supply leads the most while still being minor in nature.

I will be testing a number of the bullets I am working with as soon as possible, at diameters smaller than I have been shooting, just to rule out a bullet size problem if that is the cause.

Bullet lube could be part of the problem. My Lyman 311291 and Lyman 311466 do not lead at 7.4 grains and 8.2 grains of Unique respectively. I believe I sized and lubed these bullets with LBT lube. The Saeco bullet #305 F5J does start to lead after (50) rounds and it appears to have LBT lube also. The Hunter Supply Bullet lube is anybodies guess.

Because the leading starts in the throat of the bore and progresses to a couple of inches forward I am guessing part of the problem can be the shape of the bullet noses and the pressure curve as some have suggested. It could be these bullet noses are slamming into the throat of the bore too fast, too hard, whatever and leave some lead in the bore before any of the bullet lube can do its work. The rest of the bore is free of any lead.

This suggests I should try an even slower powder with the Hunter Supply bullet to see if that fixes the problem. I will do that after I fire all the loads using smaller diameter bullets. One thing at a time. RIGHT. When best bullet fit is determined, I can go onto powder choice.

[btroj]

I really, really like 2400 in my 30-30. 16 gr, no filler, gives 1600 fps or so, good accuracy, and no leading. I use a GC bullet. Lube doesn't seem to matter much in my rifle until temps get below 40 degrees.

Powder burn rate makes a figure difference in many cases. I like to think of powders as fitting a velocity window in a particular case. Unique may work for 12 to 1300 fps in 30-30 but it fails when you want 1500. 2400 is awesome up to around 1700 but RE7 is better at 2K. Want max velocity? Try 4898, 748, RE15 or something like that.

[03lover]

btroj,

My WC 820 acts a lot like 2400. That is why I tried it. I will have to try 2400 to see if I can find any difference.

[runfiveslittlegirl]

i think the 820 is an AA#9 replacement which is pretty close to 2400 a bit faster but close.

[Iron Mike Golf]

...I am a believer in the idea that bore lubrication with cast & lubed bullets occurrs best when the pressure of the load in great enough to cause the bullet to obturate in the bore which then forces the lube in the grease grooves under pressure onto the bore....

This is all thought experiment, so take it with a dose of salt:

I suspect that what forces the lube against the bore is the displacement of the lube by the lands. If you've attained obturation, there's nowhere for the lube to go and it's an incompressible fluid (I think).

[DrCaveman]

You want a nice slow bump in the 30-30, try h414 powder. I seriously thought it would be too slow, but about 32.5 gr behind an rcbs 30-180-fn gives about 1950 fps from a marlin 336

Fine hunting accuracy. Prob 4-6 moa at 100 yds which is beyond my iron sight allowable range anyway. Stone cold killa at 75 yds and under, and mellow to shoot

Proper fit for these results is important. Proper hardness is less important, i think. Proper pressure curve (like btroj and others mentioned) seems to play a huge part in boolit performance, to the point that it can supercede hardness and lube choice.

It is all a dance, a balance, anyhow. Didnt you know that we are all actually ballerina yogis, earth(lead)-loving alchemists, recycling(reloading) reusing (lead recovery), environmentally and socially responsible folks? Not bs, i think the woods is the best place to be. Bless hunting season.

[BAGTIC]

I don't believe rpm's have anything to do with it. If it (centrifugal force) were enough to force the lube into the grooves I would not retrieve from target range berms so many cast bullets with grooves still full of lube.

I agree that if one starts with a large enough bullet in the first place there is no need for it to expand to fill the grooves.

[Old Dawg]

I suspect 'The Formula' is not an indicator of lubricity but instead an indicator of how much pressure is needed to expand an undersize bullet up to bore size. If one starts with a bullet large enough to fill the grooves in the first place it should not be of much concern.

BTW, the word is 'effect', not 'affect'.

[Bret4207]

Several years back we had a very lengthy thread on the hows and whys we think lube works. IIRC a lot of common sense theory was discussed. Things like the incompressibility of a fluid, the fact that there is no "pump and reservoir" pushing fresh lube out to the exterior of the boolit as it travels up the barrel, that rotation doesn't do it either, that basically we don't really have a clue how lube really works, only that we can observe when it works or fails. If you could find that thread it might shed more light on things.