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Discussion in 'Sub9 and Sub2000 Rifles' started by Dulcimer1, Jan 19, 2018.
Anyone tried the Liberty Civil Defense 9mm in the Sub 2000? Just wondering what you thought.
I have this in 40, and 45. I won't buy it in 9. For anything. I am thinking it just isn't enough mass. My "neighbor" did this test. It might be ok shooting a coyote. A deer? Probably not. A Human? Probably not.
It seems that this bullet is marketing to the camp that "more velocity means more energy deposit", since velocity is squared when calculating energy. In theory, if you fired a needle at light speed it should obliterate anything, right?
I'm of the camp where momentum is the more important factor. The faster you can push a heavier bullet, the better. A 124 or 147 wins in my book. I wouldn't even consider a 50 grain bullet.
Federal hst is what you want
Then I stumbled on this video tonight.
I'm late to this thread but still have questions. I have not tried the Liberty 9mm. I'm still researching.
I did come across this video tonight.
The wind noise is terrible but once you start looking at the muscle damage to the ribs and shoulder roast I think it would suffice as a defensive cartridge. I hear 5" of damage is to be expected. Understanding that those 5" of damage is fragmented. Any doctors, nurses, EMT's out there that have treated gunshot victims care to elaborate?
Gusfinley could you give the equation of more velocity equals more energy deposit? I'd like to check that out and study it.
I was discussing something similar to this with a co worker today and we wondered if damage from higher velocity bullets were similar to the military using rail guns and damage on the objects they were targeting. They are slinging an object out there really fast and relying on that velocity to do the damage to their targets. I think they are using depleted Ur as the material of choice (very dense) so they do have significant mass they are hurling through the air, unlike the light weight 50 grain Liberty's.
One final thought. Has anyone recorded any velocities coming out of a sub 2000? Would think it would have to be higher than the 3.5" barrel of a pistol.
Someday I will check the velocities of several carbines. 45, 40, 9. I have some Buffalo Bore .40 155gr +P to try.
We all know (I hope) that the 3" pistols some are so fond of carrying have less muzzle velocty than 5" but longer barrels have limited velocities.
I have not chronographed any ammo from the Sub2000 but recall from earlier tests on other pistol carbines that there was a point in barrel length that the muzzle velocity reached maximum and longer barrels slowed muzzle velocity. Not sure where that sweet spot may be and it will be dependent on what specific ammo is being fired. +P being (intuitively) benefiting from barrel length vs Bubba's Reloads with sketchy powder.
One experiment done several years ago used a mechanical mounted barrel and receiver and started out with a barrel of "X"-length. Data acquired and then the barrel was cut back in (unremembered) increments gathering data. Again, all ammo dependent.
16" barrels seem to be about optimal for wringing the most FPS out of the 9mm.
Pistol caliber carbines need adequate penetration not velocity. 5" of fragment damage is not enough to reach vitals on most humans. Yes they might bleed out, after they just smashed your face in.
12"-14" (give or take a few) is where you need to be to consistently hit vitals on a wide range of humans.
How many people do you know that are 14" thick? The base continues on in the testing. If a 36gr .22 can kill? Real world results is hard to get unless you shoot a goat in a leather jacket. Shoot a piggy in the gristle plate.
I've been looking at Liberty for a while.
Sorry, but I have no doubt concerning this round's ability to incapacitate.
If it were more widely available, I'd have a nice stock of it.
Sportsman's Guide had it for $13.99 a box. Really cheap. Out of stock. I guess you could sign up for an alert.
Locally we have lots of it in all the calibers except 40. That goes quick. 45 a close second.
Very interesting read, I have attached a couple of pics of some 44 Special ammo that i bought years ago at a show as they were an oddity to me. they were made by PMC and have a hollow copper bullet that has a hard plastic base. I do know that these will just zing right through a cast iron stove without trouble.I don't know if these would be along similar lines or not.
When I ran .45 acp 78 grain Liberty through my 16" Mechtech I hit 2255 fps on the chronograph (880.85 Ft-Lbs muzzle energy). The 43 grain flat base continued to the second gallon milk jug with everything else remaining in the first. Impressive for blowing stuff up but I think I would rather have an expanded HST or Barnes TAC-XPD hitting the recommended 12-18" in ballistics gel.
Quite a few. Add in the high chance of the shot being at an angle and plus the thickness of clothing and 5" is no where near adequate
These bullets go through hard things. Drywall/multiple layers. Hitting squishy is when they scatter.
It's simple: Energy = mass x velocity x velocity ( think of the famous e = mc^2 )
So, an increase in velocity contributes more to an increase in energy because it shows up twice in the equation (simplest way to think about it). Increasing mass will increase energy, but only if velocity is relatively unaffected- and not by as much as an increase in velocity.
Warning - Now for the Nerd Stuff:
I tried to figure out for a while the physics equivalent of what we would call "Stopping Power" and determined that it must not be merely energy deposit, but must also be the effect of that energy.
I believe that Impulse is the physics equivalent to stopping power. It is a quantity that is difficult to calculate, but can be simplified and approximated as ( and therefore tested as ) "change in momentum".
Take these excerpts from wikipedia's article on Impulse (Physics):
Again we are not talking about energy here, but momentum. Which uses the equation: Momentum = velocity x mass.
So you can increase momentum by either increasing velocity or mass. This fits more of what we have to do when designing a load since we have finite spaces and pressures within to work.
So yes, while you could deposit a ton of energy by ramming a moped into a semi-truck at 200 miles per hour, how much damage would it do compared to a half-ton pickup travelling at 75 miles per hour?
Although, in the end the physiological affects of a gunshot wound contribute most to incapacitation- There is no calculation that can accommodate for that. A well-placed shot is what matters most. The load you choose to place that shot will only increase your chances of successful incapacitation, and since we're relying a lot on luck, the hope is that your load of choice might make a not-so-well placed shot count a little ( or a lot ) more.