Residual lube in grooves during flight affect accuracy?

[ghh3rd]

I've been pondering on this for a while, thinking about asking so here you go.

I used to assume that when I shot a lubed boolit, the extreme gyration would throw all of the lube off the boolit as soon as it exited the barrel. I use Felix Lube which is soft, so I can't imagine how that could hold on to the boolit in flight.

I have seen several pictures of recovered boolits with varying amounts of lube remaining in the grooves. Isn't having chunks of lube stuck in the lube grooves detremental to accuracy? Wouldn't it be desirable to have all of the lube either stay in the grooves or have it all leave the grooves to maintain an even balance?

Randy

[paul h]

Yes, I agree the ideal is either all or nothing regarding the lube in the grooves. The question regarding a retrieved bullet is did the lube come off in the media that stopped the bullet, and did the media remove the lube in a consistant matter?

Just remember when casting, sizing and lubing bullets. You can get caught up in all sorts of what ifs, but all the matters is consistant accuracy at the target. If you're getting consistant good accuracy, then all is well. When things aren't working out, then start troubleshooting and analizing.

[44man]

I recover hundreds of boolits to study. I have never found one with Felix left in a groove. That is what I want.
Some lubes will have a chunk here and there, they throw a boolit out of balance just like when you lose a WW on your car.
I never lose a GC either until the boolit hits, I fit them tight.

[David Bachelder]

I guess I'm too simple minded. If lube remains on a spent bullet, wouldn't that indicate there was too much lube to begin with? If it's not used then why have it? I'm wondering if this lube business is overrated.

I think it is.

[felix]

Yes, it is! It's no different than the need to get to the moon (and beyond). ... felix

[beagle]

I ran some tests years ago with a scoped M94 .44 Magnum and the Lyman 429303 which is a real lube hog with excessive capacity lube grooves.

Accuracy wasn't there for me but I was surprised at the amount of "lube boogers" on the target face at 100 yards so lube is definitely being shed in flight and I can't help but think this affects accuracy by shifting the aerodynamics/weight in flight. Now, to what extent, I can't say./beagle

[geargnasher]

I guess I'm too simple minded. If lube remains on a spent bullet, wouldn't that indicate there was too much lube to begin with? If it's not used then why have it? I'm wondering if this lube business is overrated.

I think it is.

The good news is you still have a whole lot to learn about how lube functions and how much difference lube quality/formulation can make, so your potential for boredom in this hobby is low for a while yet.

Gear

[45-70 Chevroner]

I have used a lot of different lubes, and when I have recovered boolits from the berm, I have never found one with lube left on it. I have also shot a lot of commercial cast boolits that had fairly hard red or blue lube and the ones that I have pulled from the berm have never had any lube left on them. As for accuracy I don't think it effects it at all. If you weigh a one or two grove 38 boolit with and with out the lube there is only about .02 to .03 of a grain difference. If some of the lube did stick to the boolit it would not effect the accuracy of the boolit. I have shot boolits with slight casting wrinkles and they have shot into the group and I have tested this. If a boolit were effected by a little lube a wrinkle would be worse.

44man, I'm not trying to pick on you but, I have shot thousands of rifle and pistol boolits with gas checks that were not crimp on GCs and they allways fall off in flight and it had no effect on the accuracy of the boolit. When "Ideal" was making gas checks they did not make crimp on checks. The checks even came off in my hand once in a while when reloading and all I did was slip it back on and load it. I never found a gas check at the berm unless I was very close to the berm and they were usually right on the surface.

[btroj]

The good news is you still have a whole lot to learn about how lube functions and how much difference lube quality/formulation can make, so your potential for boredom in this hobby is low for a while yet.

Gear

Well stated. A lube is more than we think yet less than we think. It does more than lube and shouldn't be taken for granted.

I don't care if lube stays on or if it all comes off. It just needs to be consistant from shot to shot.
I got lots of lube boogers on 100 yard targets with CR. never get them with many other lubes.

Why would we want a bullet with changing weight/balance during flight?

[geargnasher]

Here's a couple of many recent examples of "lube matters".

You can't see it in the pic, but there were specks of unmelted lube on the 50-yard target after firing the soap lube group.



Gear

[44man]

I have used a lot of different lubes, and when I have recovered boolits from the berm, I have never found one with lube left on it. I have also shot a lot of commercial cast boolits that had fairly hard red or blue lube and the ones that I have pulled from the berm have never had any lube left on them. As for accuracy I don't think it effects it at all. If you weigh a one or two grove 38 boolit with and with out the lube there is only about .02 to .03 of a grain difference. If some of the lube did stick to the boolit it would not effect the accuracy of the boolit. I have shot boolits with slight casting wrinkles and they have shot into the group and I have tested this. If a boolit were effected by a little lube a wrinkle would be worse.

44man, I'm not trying to pick on you but, I have shot thousands of rifle and pistol boolits with gas checks that were not crimp on GCs and they allways fall off in flight and it had no effect on the accuracy of the boolit. When "Ideal" was making gas checks they did not make crimp on checks. The checks even came off in my hand once in a while when reloading and all I did was slip it back on and load it. I never found a gas check at the berm unless I was very close to the berm and they were usually right on the surface.

Gas checks are like wads. If they all fall off the same distance it is OK. It is when one hangs on to the target but another left fast.
Berms are not good to recover boolits. Too much damage. A boolit can lose lube at different distances too. So what happens before all lube is gone?
You have to look at how fast a boolit spins and how little weight is needed to throw it off. I find many commercial boolits with a chunk of lube left here and there.
All lube should be gone instantly at the muzzle or all should stay in until impact.
It is strange store bought boolits can lose half the lube to the bottom of the box yet retain some to the target.

[popper]

It's a gyroscope problem. Faster & lighter will be affected more by lube sluffing. Compare losing a tire at 5 vs 50 mph.

All lube should be gone instantly at the muzzle or all should stay in until impact.

Consistency is the name of the game.

[Bigslug]

This lube-flinging topic is really beginning to fascinate me. . .

You would THINK that with the rotational speeds of bullets being what they are, lube would be kicked clear immediately at the muzzle. I've done experiments with 12 gauge tactical buckshot loads through rifled barrels intended for sabot slugs - the result is a near-useless, donut-hole shaped pattern at only ten yards. Obviously, there's a lot of gyroscopic torque with even slow shotgun twists and modest 1200fps velocities. Yet we still have lube spatter on targets as far away as a hundred yards. Curious. . .

I do know that the center of mass of a bullet does not usually coincide perfectly with its center of shape. A bullet starts out spinning around its center of shape, because the barrel forces it to do so. The bullet will tend to wobble for the first bit of its travel through the air as the rotation shifts from center of shape to center of mass. VLD target bullets are especially known for this - they do not usually group as tightly as flat-base slugs at short range because of the wobble, but as they "go to sleep", they are much more stable over the long haul of hundreds of yards.

I'm wondering if this wobble over shorter distances might have something to do with a bullet hanging onto lube. If there is still lube on the bullet at 100 yards but not at 200, I have to wonder if this is due to the bullet settling down and the gyroscopic forces becoming more consistent, or if the lube has simply been subjected to those gyroscopic forces for a longer period.

[btroj]

Haven't really shot many cast bullets on paper at 200 yards. I do know that I could reliably find bits of Carnuba Red on 100 yard targets with my 45-70.

With the relatively short, blunt bullet design of many cast bullets I wonder how quickly they "go to sleep"? I would expect pretty fast. A 420 gr flat nosed 45-70 bullet is about as far from a VLD as you can get.

Interesting concept.

[popper]

Gyro action (stability) is immediate from the muzzle. Sluffing lube erratically upsets the gyro action and can throw the bullet off the desired trajectory. The effect is lesser for high rotational mass, i.e. heavier or faster bullet.

[Bigslug]

Gyro action (stability) is immediate from the muzzle. Sluffing lube erratically upsets the gyro action and can throw the bullet off the desired trajectory. The effect is lesser for high rotational mass, i.e. heavier or faster bullet.

This does raise some interesting "chicken before egg" questions.

A bullet is not spinning in a perfect circle when it leaves the muzzle, or, more accurately, it isn't spinning in a perfect circle very shortly after leaving the muzzle - UNLESS the center of mass and center of shape are on exactly the same pole through the bullet. They'll usually be close, but not dead-on the same.

The result of this is that the nose and base of the bullet wobble like an imperfectly thrown football until that center of rotation shifts from center shape to center mass. Keep in mind that the point of a bullet may not be precisely aligned with the center of mass, so that even after the wobble "goes to sleep" and the sides of the bullet are parallel to the flight path, the nose may not be in the center of that spiral.

At any rate, the initial wobble is likely to be less on a bluntish cast pill than would be seen on a long, skinny, jacketed VLD. Some of questions that arise would then be:

1. Does this wobble delay the ejection of lube in any way?

2. Is what some of this forum's casters are perceiving as instability caused by uneven lube retention actually just part of the bullet's normal early-flight characteristics?

3. If lube retention is NOT the cause of any accuracy problems, do we need to be looking at concentricity of the molds or uniformity of cast?

4. If lube retention IS the cause of any accuracy problems, is the mix of the lube the ideal approach (as Geargnasher is on a Holy Quest for), or should we be looking at shaping the lube grooves in the mold for more effective release of lube?(I'm thinking a square-bottomed groove would be the ticket)

[felix]

Shape of the lube groove should be set up to release from the mold with the integrity of the boolit in mind, and nothing else because of the importance of boolit uniformity first and foremost. ... felix

[popper]

wobble "goes to sleep"

Never happens. Yes, the bullet will transition from the bbl to air, but any wobble will only get worse. Now if halfway to the target a big chunk of lube from one side flies off, the bullet changes it's precession and the path will change. A large enough chunk and it can tumble. Like Felix says, bullet integrity, but the lube is part of the bullet. Considering tensile strength is what holds lube on a bullet and is what makes the lube hard. There isn't much lube in the groove, it doesn't weigh much but it has high energy e=mv^2), lost when it falls off. Soft lube has lower tensile strength and should release sooner and more evenly. So I think no, the shape of the lube grooves is fine, the SIZE of the grooves may need to be changed as they determine how much lube is carried. Comparing a bullet to a football is not quite correct. The bullet ALWAYS rotates around the center of mass - that doesn't mean it rotates around the geometric center. If the center of mass is NOT in direct line with the force vector, 'wobble' is introduced, which happens immediately leaving the muzzle and can only get worse. Can't put 'english' on a bullet.

[btroj]

Bullets going to sleep is certainly believed in by many bench rest shooters and high power competitors.

[MT Gianni]

Lube 5 bullets with lube only on 1/2 of their side and use the hardest lube that you can find. Orient them in your bbl if you wish. Lube 15 boolits fully. Shoot 10 to lube purge, then compare your groups of five. I do n ot see it making much of a difference @ 25 yards or less but could believe it would mean a lot @100-200 yards.