Penetration

[Captchee]

high volocity  IMO is the majic volociy of 2200fps . give or take thats the volocity that soft lead becomes highly un stable .
  the farther way one stays from that  volocity , the more stable the lead .
 look at it as  heating up your lead pot . the hotter that pot gets , the  closer one comes to the lead becoming liquid " read as un stable .

 so lets say that a person is shooting a 45 call with a heavy load "  we cant say this  doesnt happen , how many times have we discussed abserdly high  powder charges here on this forum not to mention other forums "

 that ball , with a 120 grain charge is leaving the muzzle at over 2200 ft per second .
 the real question IMO should be , ;

At what  volocity does soft lead , once again reach and avrage hardness  that acceptable .

 then we can ask.

 At what distance does that happen so as to alow the projectile to not deform to the exstent that it effect penitration ?

 i dont have an answer for that .
 now i can say i have gotten  very acceptable penitration  with muzzle volocities  in the 1700 fps range .
  so  down to about 1000fps at 100

[Loyalist Dave]

Ok cool, makes sense and we understand the same "standard" ...2200 fps.  That's what I have always used.  The friction of the air heating the lead, plus the compression of the air mass making a point of denser air in front of the center of the projectile, and ooops their goes the bullet!

LD

[Loyalist Dave]

I've never heard of "SAE Hardness" before. I've always used the Brinell harness Number, which pure lead is 5. I know there are various hardness scales, but thats a new one to me.

That's  because I FUBAR's up my terminology
Comes from writing a post after just looking at a catalog of car tools.  Mea culpa, mea culpa, mea maxima culpa.   Doubt the Society of Automotive Engineers has anything to do with bullet hardness, except maybe on their day's off.

LD