The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Hunting African Big Game Hunting Bullet test.Go | New | Find | Notify | Tools | Reply | |
| Bullet test. | Login/Join |
| one of us |
I am contemplating performing a load versus deformation test on jacketed bullets (could do monolithics too, but don't see the need). I know I will test the 570gr Woodleigh SP and the 600 gr Woodleigh PPSP (both 0.51" bullets). Probably will also do the 0.416", Speer 350 gr and the 9.3mm Speer 270 gr, and just for fun the 200 gr Sierra GK. Anyone have any bullets they would like to have tested? If so I will test them as well if I have them. The test will be conducted using a calibrated tension/compression machine (the same machine used to determine the tensile and/or compressive strength of steel, aluminum, brass, bronze, etc). This approach will eliminate all variables common with less scientific tests, and provide the actual elastic and plastic curves for the bullets tested under known loads. I will also post the results of the testing if anyone is interested in knowing them. Should realistically have results in the next month or two. I consider this a first step in determining the penetration characteristics of my favorite jacketed soft points. ASS_CLOWN I will post this on the reloading forum as well. | ||
|
one of us |
How about testing the 200 gr Barnes Triple Shock? CFA *If you are not hunting in Africa you are planning to hunt in Africa* | |||
|
One of Us |
I am curious. How do you plan on fixturing these bullets in your testor? Can you also test coupons taken from various parts of the bullet (Ie. Jacket and Core coupons) to determine their mechanical properties? | |||
|
| one of us |
TheBigGuy, Good questions! No I cannot test coupons of the jacket and core, they are too small. I was going to rely on popular myth that the jacket was 90/10 and the core 95% or higher lead. Then use the published material properties. With regard to fixture design. I have some ideas, but would like to hear what you may have in mind, as my idea is anything but "simple". ASS_CLOWN | |||
|
| One of Us |
AC, Perhaps the manufacturer could be convinced to cast coupons for you to test? (Probably not) I was only invisioning a fixture which could test the ultimate shear strength of the bullet. It would be comprised of two plates each with a relatively tight silouette of the bullet shape cut out. Then you would place the bullet in the silouette between both plates. By applying force to one plate and holding the other static attempt to shear thru the bullet. It would be dependent on the capacity of you testor if you can shear the bullet straight thru with this arrangement. By obtaining the ultimate shear strength in this matter I feel you would have an accurate measure as to the frangibility of the bullet. | |||
|
| one of us |
This test will have very little to do with the properties of a bullet traveling super-sonic. | |||
|
| one of us |
Walker, Why do you say that? The bullet's mechanical properties are the same regardless of speed. Besides that, no hunting bullet is ever travelling super-sonic when it it penetrating an animal. For clarification, the purpose of these tests is not to estimate the path the bullet will take during penetration. These tests are simply building block in determining the expansion / time relationship which occurs during penetration. TheBigGuy, I could do as you suggest, but the fixturing would be tricky as well as specific to each and every bullet style tested. Since bullets are compressed during penetration I was planning on doing a compression test. The hard part is duplicating, in steel, the hydraulic forces at work on the exposed lead tip of the bullet. I have some ideas to simulates (read estimate) this effect, but nothing that would be exact. There will definitely be a learning curve. Further, I am investigating impact testing of the bullet. I can calculate rather easily the mean penetration force and penetration duration, IF the bullet is contained within the target. With these values I can estimate an initial impact load. Anyway, the compression test and impact tests are what I am currently planning on doing. I will definitely give your shear idea serious consideration. I fear that, due to the necesity for bullet specific fixturing, I would only be able to test a very small number of individual bullet "styles". ASS_CLOWN | |||
|
| One of Us |
What about instead of machining out a bullet shaped pocket in the plates you machine out a rectangular pocket. Then you can cast the bullet in a rectangular shaped billet and install that into the plate fixture. The casting material should be something with known mechanical properties (or you could test a pure billet to determine this) Maybe a phenolic or perhaps a two part epoxy would do the trick. That would eliminate the need for different fixture plates per bullet. You should be able to extract the actual shear values of the bullet from your knowledge of the pure billet properties. This same methodology may work with your other tests as well. The only effect I am aware of on the properties of a super-sonic piece of metal is related to temperature. I don't think the bullet through friction with air will be above the melting point for any of it's constituent metals. Is there more to this? I don't know. | |||
|
| one of us |
I can't think of a single hunting round that impacts at less than super-sonic speed. And impact dynamics are different from compression dynamics. Ask any structural engineer. | |||
|
| one of us |
Walker, Valid points. I intend on conducting both Impact and Compression tests in the lab. I also intend on correlating, to the best of my ability, these test results with expansion characteristics exhibited by bullets recovered from animals. ASS_CLOWN | |||
|
| One of Us |
If you eliminate quite a few pistol driven projectiles it would be a short list. Are you a structural engineer Walker? Please share with us the reasoning that the mechanical properties of a bullet will not be useful in comparing predicted bullet performance. This is what this thread is about not the difference between compression and impact dynamics. And yes I realize there is a difference. | |||
|
| one of us |
No I'm not a structurat engineer. I'm a professional firefighter. My knowledge of structural strengths comes from "Building Construction For the Fire Service." That's a college textbook for fire science. It covers loads. Static and impact loading, compression strength, tensil strength, shear strength, and torsional loading and strenght. Torsional loading is one factor that a spinning bullet will encounter upon contact with a target. I don't see haw AssClown can incorportae torsional stress into his tests. It will be interesting to see though if the compression test results have any corolation to the impact tests results. By the way, it was impact loads that brought down the WTC Towers. They were designed to hold all that weight up in a station load, but could do the same job when the load became an impact load. | |||
|
| one of us |
A friend of mine just got back from using the 200 TSX on various game in the Cammeroon, including Lord Derby Eland. He could not have been happier with their performance. Remember, forgivness is easier to get than permission. | |||
|
| One of Us |
Fair answer Walker, I am a Mechanical Engineer have been degreed since 1989. These same tests AC is proposing I have done on various materials (composites included) in my career. These material properties gleaned from composite structures in particular are extremely useful in predicting impact behaviour most especially when graphed. This load vs deformation graph AC proposes would follow exactly the same form as the stress vs strain graph. In fact the stress vs strain chart could be extrapolated from the load vs deflection curve. The area under the stress vs strain curve is a parameter known as "Toughness". Materials with a higher toughness can take more impact abuse. | |||
|
| one of us |
Well an update. So far have tested three bullets in compression and impact. Bullets are" 150 gr Remington Corelokt - .308" 174 gr Hornady Interlock - 0.311" 250 gr Nosler Ballistic Tip - 0.366" The compression and impact deformation shapes are identical for all practical purposes. Furthermore, with specific regard to the 0.308" and 0.311", the deformation shapes are very similar to that exhibited by bullets shot at steel plates (long range ~ 500 yards). Unfortunately the shapes are NOTHING like what is encountered in soft target penetration. I am currently working on a few fixture design, which should do a fairly descent job of simulating hydraulic force distribution across the bullet's point geometry (while using steel). The first fixture prototype proved promising with the Nosler BT 0.366". ASS_CLOWN | |||
|
| One of Us |
Just a thought. Bullets get hot during deformation. How hot, I don't know. If you re-set bowling pins, you notice those bumps where a bullet is resting under the far side plastic coating are hot. That's about as close a guess as I can give you on the temperature. I don't expect they get hot enough that it affects the properties of the jacket at all, or else the bullets would melt through the Surlyn coating on the far side of the bowling pin. Maybe they get hot enough to affect the mechanical properties of lead. H. C. | |||
|
| one of us |
Henry, You are right. I have been hit by two bullets, a 25ACP that was a ricochet [sp], hit me in the leg, and a part of a 44 mag bullet that ricocheted [sp] off of steel and hit me in the chest. Both were HOT!!!VERY HOT!!! DOUBLE RIFLE SHOOTERS SOCIETY | |||
|
One of Us |
btt Mike Legistine actu quod scripsi? Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.  What I have learned on AR, since 2001: 1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken. 2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps. 3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges. 4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down. 5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine. 6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle. 7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions. 8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA. 9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not. 10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact. 11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores. 12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence. 13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances. | |||
|
| Powered by Social Strata |
 | Please Wait. Your request is being processed... |
|
Visit our on-line store for AR Memorabilia