BULLET NOSE SLUMP OR MISALIGNMENT

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mdeland
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BULLET NOSE SLUMP OR MISALIGNMENT

Post by mdeland »

I still have my doubts about bullet noses setting back unevenly to one side or the other from ignition inertia assuming they were actually coaxial with the bore when fired. No question they set back but as no one can actually see it happening to the side and then assume it did not happen from misalignment or at impact on recovered bullets seems a bit of a stretch.
Oh Gadd, the bullet did not do as the others so it must be lateral bullet slump,Yup sure enough see how that nose is bent off to one side and the engraving is longer on one side than the other, in this recovered bullet.
Land engravement longer on one side or the other......... surely that proves the notion! Well maybe but that can also be explained by out of coaxial alignment when using finger seated bullets or impact distortion.
I wonder if the same thing would happen if the problem bullet were to be seated with a crimp.
Seems to me that these tapered bullets could quite easily get out of coaxial alignment when finger seated into the case and then inserted into the chamber.
I'm wondering if such a problem plagues Schutzen shooters who mechanically seat bullets into the barrel throat a head of charged cases?
Kicking some thoughts around!
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desert deuce
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by desert deuce »

RESULTS, RESULTS, RESULTS, what matters is results.

What does the rifle operator do to obtain the least vertical dispersion at whatever distance fired with a black powder cartridge rifle? That is the goal ?

If so here are some of the options, swage primer pockets, weigh charges, weigh bullets, weigh primers, deburr flash holes in brass, turn the inside of case necks, breech seat bullets, size bullets, don't size bullets, size the case, don't size the case, compress the powder, don't compress the powder, new bullet lube, etc, etc. etc.

And, when none of that obtains the desired result in ultimate frustration the rifle operator may try different alloys.
Does this one slump, no that is not slump, what is slump, there is no such thing, whatever.............

So what matters ultimately is still the results. Can we agree that what works may vary from rifle to rifle? For instance, a standard chambered 45-90 with a 16 twist barrel, firing a cast grease groove bullet 1.44" long.
Cast up 30 bullets each of whatever alloy 1-30, 1-25, 1-20, 1-16, 1-14, 1-12, 1-10, as you so desire. Load them seated .0040" into the rifling with .105 compression of 1.5 Swiss and fire each load starting with the 1-30 on a target at 800 yards. Next day the 1-25, next day 1-20 and so on. Keep record of each 30 shot string. Go with the alloy that gives the best group. In other words, let the target make this decision. In all three of my long range 45-90's I use 1-16 alloy because it gives the best groups from 800 yards on out and I have no idea whether there is nose slump or not. Dave Gullo uses 1-20 in his 1-18 twist 45-90 and it shoots very well. I doubt he knows whether or not he gets nose slump. He does get good groups though and that is what matters.
Sometimes you get the chicken, and sometimes you get the feathers!
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desert deuce
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by desert deuce »

And, as always.

The real felon in the long range accuracy trial is hard barrel fouling. Fouling control is critical to success. That too varies somewhat from individual rifle to rifle and is very dependent on environmental conditions.
Sometimes you get the chicken, and sometimes you get the feathers!
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Kodiak
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by Kodiak »

Checking bullet run-out as loads are developed doesn't hurt either.

Jim
I don't always shoot well, but when I do there isn't any reason.
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Distant Thunder
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by Distant Thunder »

Shooting a well fitting bore diameter paper patched bullet that is seated as much as possible up in the rifling eliminates the alignment question and 16:1 hardness got rid of my unexplained fliers whether it was nose slumping or whatever. Don't care, I just go with what works in my rifle.

I don't stick with something that doesn't improve the results on target very long and I don't give up very easy on what has improved the results on target. 95% of my weeding out process is at matches so the results I get matter. If it works it goes to the next match, if it doesn't work it probably doesn't. If it hurts it sure as hell doesn't go! I don't spend any time sitting around questioning the things that have worked and I don't spend any time trying to determine why something didn't work, I just accept the good as good and the bad as bad and move on.

After 20+ years I'm still refining the whole process and that is what I love about this game. I can hardly wait 'til next year when I get to apply all the new things I learned this year. When the learning stops I'll probably get bored and move on to something else, but I know that it won't ever stop if I don't. On to the next match! :D :D :D
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mdeland
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by mdeland »

The trouble with observing a cause and effect without knowing for sure what actually has happened often gives rise to false conclusion and pour solution in remedy. If a grease bullet deforms I want to know when and why it happened and a solution found for that bullet type.
A switch to another bullet type has not answered the question at hand only diverted the answer , in my opinion.
If a stronger alloy eliminates the deformity the bullet may still be out of align but better able to cope with inertia with out deforming. If alignment is the remedy then both alloys would almost certainly produce better accuracy.
If one thinks about it why would a perfectly coaxial seated bullet have any reason to set back unevenly even if the alloy used is soft and the nose unsupported. The exact same amount of inertia is applied to the whole surface area of the ogive and nose which presumably is cast of evenly mixed alloy having the same strength and is uniformly radial in shape and free of voids.
Under this criterion, bullet nose so called "side slump" should be nearly impossible to produce, I would think.
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by Kurt »

mdeland wrote:
Under this criterion, bullet nose so called "side slump" should be nearly impossible to produce, I would think.
Your wrong on this Mike.
This is all I will say about this..........Kurt
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Distant Thunder
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by Distant Thunder »

It was back in early 2009 when I first started to seriously experiment with paper patched bullets in my Shiloh.45-90 with the goal of becoming the first shooter to win at Lodi, WI using paper patched.

I was lucky in a number of ways, I had a rifle that turned out to really shoot well with paper patched. I had the good fortune to become acquainted with Brent Danielson who was all in on the idea of an elliptical nose bullet being the best choice for long range shooting. Although I have taken some liberties with Brent's original prolate design, sorry Brent! In all my paper patched shooting this basic elliptical design has proven to be very accurate out to 1000 yards.

I was also lucky enough to have machines and enough skill with them to be able to produce my own molds, which has allowed me to experiment with the bullet length, diameter, and exact nose profile in an effort to find the best paper patched bullet for MY rifle.

Once I had that first mold made and a couple different kinds of useable paper I began to load and shoot a lot. I tried everything I knew of or had heard of that would possibly give me the accuracy I felt I needed to win with paper patched bullets.

Like I said the rifle was a big part in the good results early on and the encouragement to continue. Right out of the gate it produced 5-shot groups at my backyard 200-yard range that were under 3" ctc. This was using my grease groove alloy of 20:1. As I tested papers, primers, seating depth, compression, patch length..... and on, and on, I would occasionally get one in five that would be an inch or more out of the tight grouping of the other four. These were still usually under 2 MOA so I didn't get to concerned at first. The outliers continued. I felt I needed to just eliminate them and I would be where I wanted to be.

Everyone knows that the original Sharps Rifle Co. recommended 16-1 alloy with paper patched bullets intended for the target range. So I tested 16-1 against 20-1 with 10-shot groups at 200 yards. The interesting thing is when I went to 10 shots instead of just 5 my groups with 20-1 got bigger, almost twice as big. The same exact loads with 16-1 didn't increase much at all, there where just more holes in the same small area.

The question here seems to be whether the increase in group size with the 20-1 was the result of micro-imperfections in my cast bullets or some miniscule misalignment caused by the slightly more shrinkage that 20-1 may have given me? My answer is, "Never asked, don't know, don't care!".

In process of developing my paper patched loads there are many, many things I tested and some of them improved the results on the targets and some of them had the opposite result. The whys and wherefores just don't interest me all that much, in part because the pursuit of those answers would only distract me from my goal, which is to shoot the very best paper patched loads I can at any give time.

16-1 was one of those things that improved MY results on target, there are many others. If someone wants to dig into the nitty gritty of what the actual cause is I'll be happy to wait for the results of that in depth probe. My good shooting years are some limited so I'll just go with what works. You all do whatever makes you happy.
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mdeland
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by mdeland »

I had the excellent pictures of your bullets in mind when I wrote this Kurt and I very well could be wrong about the reason for it's occurrence but the slump thing makes no sense to me unless the bullet is out of alignment to begin with.
Also I've looked at a good many snow bullets I've picked up myself and never had any confidence that they are in the same physical shape they flew in. Some of them were pretty banged up, bent and distorted.
mdeland
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by mdeland »

DT are you lathe boring your molds or making up cherry's? The smaller calibers are much easier with Cherry's. I need to make several PP molds in various calibers I shoot. One in .303 British.
I usually buy smaller caliber blocks at gun shows and bore them out but have also made them of mild steel but then you have to make the sprue plate, alignment pins and cut vent lines.
Used molds or mold blanks are a lot less work!
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Distant Thunder
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by Distant Thunder »

Mike,
I cut my mold cavities in a machining center and that works pretty well most of the time. I have used existing molds and also have made my own blocks which is a lot of work as you say.

The bullet I use in my Hepburn now is the same mold I used for my .45-90 Sharps starting in 2009 and has been the most successful long range paper patched bullet I've shot. It is cut in a set of Lyman blocks. I have another mold I cut in a set of RCBS blocks that is identical except for the length and it shoots as well, but I have greater confidence in the Lyman one.

My .40-65 paper patched bullet is cast from a set of RCBS blocks that I inserted to allow for the new cavity. I cut dovetails into the blocks to remove the original .50 caliber cavity. I then fitted a set of cast iron dovetail inserts to the blocks and cut the new cavity. The idea rattled around in my head for a while before I decided to give it a try and it worked better than I expected. It's a great .40 caliber mold now and cast very well. It was a lot less work than making a new set of blocks.

The new blocks I make from a fine grain cast iron, but it's a lot of work just to make the blocks and I still have to cut the cavity, which may or may not work out.

I have also bought uncut mold blocks from RCBS and Lee then cut my own cavities into them, but they cost as much as a finished mold.

Jim
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mdeland
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by mdeland »

How do you shape your nose forming tool? Quarter profile?
Neat idea about the dove tail inserts, I have never thought of that and believe it an excellent notion.
Speaking of dovetail inserts I once saw a Rolling block bushed to a small diameter firing pin with a dove tail block. It was the slickest bushing idea I had ever seen on one and worked perfectly. I'll use both of those dovetail ideas one day.
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Distant Thunder
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by Distant Thunder »

Because it's CNC I just program the nose profile I want and use the appropriate ball mill to cut that profile. Paper patched are fairly easy, grease groove are another story altogether. I have modified the nose profile on existing cavities to better suit my needs also. It can be a real bugger indicating in the original cavity, many are as true as you might think.
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mdeland
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by mdeland »

Oh. I see. I have to turn a nose shaping tool for use in my manual lathe, the profile of the bullet nose desired then section it down to quarter profile ,harden and relieve cutting face. Probably the hardest part of making a mold.
I talked to Brooks one time about figuring out alloy shrinkage when cavity cutting and I think I remember him saying all of his are based on 25 to 1.
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Kodiak
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Re: BULLET NOSE SLUMP OR MISALIGNMENT

Post by Kodiak »

While we're on the "nose" subject, is there a bullet seating guide/punch that fits the .45 cal. money bullet nose profile, for my Redding seating-die?

So far this is a subject worth reading again.

Jim
I don't always shoot well, but when I do there isn't any reason.
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