Quoted: Here is why is wasn't a  good idea

Quoted: Quoted: Like it eh? Try shooting an M1 Garand with 168 grain Black Tip AP Ammo. If you want to only shooting 308 FMJ ammo for tactical situations, get ammo made by Hirtenberger. I thought Garands are only supposed to be fed 150 grain rounds, because higher pressures can damage the operating rod.

The M1 Garand was originally designed and its rear sights were calibrated for M1 Ammunition which had a 175 grain FMJBT bullet.

John Garand was initially concerned that the M1 wouldn't cycle properly because of the lower pressure, but it turned out to work just fine. By the way, he left the sights alone, so they are still calibrated for a 175 grain bullet.

The Army: concerned about stray bullets on rifle ranges. Swithched to M2 Ammunition with had a 150 FMJ Spitzer bullet. In the middle of WWII, the Army concerned about penetration, switched to 168 grain black tip AP Ammunition.

As an aside: the history of the 30-06 round is pretty interesting in that the original 30-03 round like its 30-40 Krag predescessor had a 220 grain round nose bullet.
When the Army modified their ammunition to a lighter spitzer round and changed the length of the neck on the 30-03 cartridge case (in 1906)  and modified the 1903 springfields for this new round.
The 30-06 was born. This new round had a 150 grain flat bottom spitzer which is what we went to War with in Europe (WWI). Lessons learned from WWI made the military concerned about the effective range of their machine gun fire, so they switched to a 175 grain FMJBT.
Until around 1940 when they reversed themselves and went back to a 150 grain round.

Then upped the bullet weight to 168 grains with a AP Steel Core.

When 7.62 NATO was adopted, in order to approximate the ballistics of the 30-06 round a little better, and to save weight, the Army switched t0 150 grain ball ammo (this would be your M80 Ammunition).

Over the years, the Army made some interesting reversals in regards to caliber for Handgun Ammunition as well, going from a 44 caliber to 45 Colt (and some cases 45 Schofield), to 38 caliber, to 45 ACP, and back down to 9mm.

Quoted: Quoted: Conservation of momentum applies and if the target is able to move it can absorb a lot of energy from the bullet.  If heavily weighted down, it doesn't move and all the momentum is contained in all the bullet fragments.  And if shooting various military bullets with more substantial cores , especially but not limited to AP cores, those cores can come back at velocities close to the impact velocity.  (Possibly even faster actually).  And uneven surfaces such as those on the weight can cause erratic and unpredictable bullet performance.   How the heck does that work? Unless physics has taken a turn for the queer in your area, how does a chunk of metal GAINS velocity after striking a surface and coming back? You are suggesting that not only it doesn't lose ANY momentum after striking metal, it somehow gets even MORE?

I was pretty curious about that one myself.

Quoted: .... and i got  small piece stuck in my hair.

Posters name seems ironic, don't it.

Any Jarheads remember pulling tagets and having the ricochets down in the butts? Aahhhh.......the good ole days.

Quoted: .30 cal has some serious power! I f'ing HATE it in the movies where they portray some monster getting hit by a rifle round and remaining unfazed. What bullshit! Battle rifles can destroy cover positions unless there's some serious steel there. A car is not enough, until you hide behind the engine block.

I watched a bullet fired from an AK-47 (7.62x39mm) go right through the engine of a Humvee, so even the engine block might not help you .

Quoted: Any Jarheads remember pulling tagets and having the ricochets down in the butts? Aahhhh.......the good ole days.

Why yes I do

Pit boss screaming: There in the *ucking pit!


Peeeeeyooowwwwwwwww

Targets down

Quoted: Quoted: Quoted: Like it eh? Try shooting an M1 Garand with 168 grain Black Tip AP Ammo. If you want to only shooting 308 FMJ ammo for tactical situations, get ammo made by Hirtenberger. I thought Garands are only supposed to be fed 150 grain rounds, because higher pressures can damage the operating rod. It's the type of powder that is used to drive the bullet that causes the problem, not the weight of the bullet.

The weight of the bullet is also an issue. Typically, though, heavy bullets and slow powders go together.

Quoted: Quoted: Quoted: Conservation of momentum applies and if the target is able to move it can absorb a lot of energy from the bullet.  If heavily weighted down, it doesn't move and all the momentum is contained in all the bullet fragments.  And if shooting various military bullets with more substantial cores , especially but not limited to AP cores, those cores can come back at velocities close to the impact velocity.  (Possibly even faster actually).  And uneven surfaces such as those on the weight can cause erratic and unpredictable bullet performance.   How the heck does that work? Unless physics has taken a turn for the queer in your area, how does a chunk of metal GAINS velocity after striking a surface and coming back? You are suggesting that not only it doesn't lose ANY momentum after striking metal, it somehow gets even MORE? I was pretty curious about that one myself.

Conservation of Momentum.  The sum of the momentums before the impact is equal to the sum of the momentums afterwards plus probably a little heat generated.  So if the bullet fragments and half stops, the other half is going to go someplace at almost twice the speed.  It's not particularly likely but it is possible.

Kind of like a baseball hitting a bat