To those that know

[ram1000]

Is there any reason the newer Xtreme Penetrator/Controlled Chaos bullets would not be the best choice for hunting with a 10mm?  Even for bear protection it seems you would want these over anything else- that is if you only carry a 10mm.

[sqlbullet]

Two words....Sectional Density.

The heaviest bullet they have for 10mm is the 140 grain extreme penetrator.  The other .400 designs (200 gr and 215 gr) are for muzzle loader and would not leave much room for powder once loaded in a 10mm.

A 140 grain bullet in 10mm is not going to penetrate as well as a 200 grain bullet, no matter how fancy the nose is.  For bear or boar you are better off with a wfn hard cast bullet in 200 grain or heavier.

[ram1000]

Two words....Sectional Density.

The heaviest bullet they have for 10mm is the 140 grain extreme penetrator.  The other .400 designs (200 gr and 215 gr) are for muzzle loader and would not leave much room for powder once loaded in a 10mm.

A 140 grain bullet in 10mm is not going to penetrate as well as a 200 grain bullet, no matter how fancy the nose is.  For bear or boar you are better off with a wfn hard cast bullet in 200 grain or heavier.

I have some 220 grain hard cast BB I think but the solid brass/copper bullets seemed to be the answer.  I don't know what sectional density is but I'll take your word for it...Thanks

[sqlbullet]

Sectional density is the measure of mass for diameter.

Think of it like this....Would you rather have a 95 lb blond or 300 lb line backer stamp on your foot with stiletto heals?

In terminal ballistics, light, high velocity rounds dump a lot of energy very fast.  This makes for nasty but relatively shallow wounds.  Works fine on humans becuase we are relatively shallow creatures with relatively flimsy bones.

A bear on the other hand, is not a shallow creature and does not have flimsy bones.  So, a 140 grain solid, even at high velocity, doesn't have the momentum to drive through.  It is going to dump more energy into the target, but it does that by deccelerating quickly due to it's light weight.

Comparing a 140 grain @1550 fps, which is a hot load only attainable from a 6" gun even from Underwood, to a 200 grain hard cast at 1250 fps, which is a standard 10mm load from a 5" barrel, we find the 200 grain, while trailing in muzzle energy by 8% (693 to 746) , dominates in momentum by 12% (35 to 31).

[pasky2112]

In an 'armored car vs. locomotive engine', even if both are going only 10mph, which one would you prefer to be in at collision?

If "best choice" assumes successful penetration, usually to the CNS of the target, for purposes of stopping it on the spot from running/charging, the conventional wisdom ballistically is hard +heavy +fast increases probability of success. Ideally, some controlled expansion thrown in for increased wound channel diameter is a desired attribute as long as it doesn't diminish the primary required attributes. In light of that, as sqlbullet correctly described, for boar/bear type targets, the 200/220gn hard cast loaded reasonably hot...~1300-1100 fps, respectively is recommended and any 140g is just going to get you in a bad spot, barring some remote chance sequence of events. ( heard the..."killed a T-Rex with a .22 short" story?)

@sqlbullet  greetings...long time  quick question on your Sectional Density reply.  Apologies if it's OT
Are you describing sectional density as inertia + considering the construct of the projectile? First thing comes to mind is 5.56 xm855 LAP (hardened steel core 'penetrator') vs. a std. 62g .224 designed for 5.56/.223. All else considered equal, the 62g LAP penetrates further than a 62g ball. Just curious how sectional density factors into this scenario.

[sqlbullet]

In this case I am not really considering bullet construction.  Reason being the huge discrepancy between a 140 grain solid versus a 200 grain WFN hard cast.  When you increase the mass by almost 50% construction becomes an afterthought.

That said, within the scope of similar bullet weights, yes, construction can make a difference.  If I were selecting a 135-150 grain 10mm round for high penetration, the xtreme penetrator would be on the short list.

[Pinsnscrews]

Xtreme Chaos? Hell No!

Xtreme Penetrator? Maybe

If I could not use Lead in an area and was limited to only Copper projectiles, I would take the Xtreme Penetrator without a second thought. If I had other options, a Heavy, Non-Expanding WFN bullet would be my first choice.

Here is why, the Xtreme Penetrator's gimmick frontal area is not so much a gimmick, as it is the laws of physics. The Frontal Area of the .400 Xtreme Penetrator is very small. Total surface area of that configured cross is probably the same as a 22LR nose. But instead of having 30-35gr of mass pushing that frontal area along after initial impact, it has 140gr. So a more accurate comparison would be,  a 190lb MMA heavyweight woman in stlletos TRYING to punch it through your foot vs a 300lb linebacker in Cowboy Boots. Both are going to ruin your day, but you might not bleed out from the linebacker...

TNOutdoors got OVER 32 Inches of Ballistics Gel Penetration from the 115gr 9mm at 1250fps...cutting that in half to account for the higher denisty of the bear musculature, and this is still in excess of 16 Inches of penetration. Add in the fact the Xtreme Penetrator does not deform on impact, it doesn't lose energy from the deformation process.

I would still like to see another 20+ grains added to the weight of the .400 as a 10mm component though.