One more penetration test.

[steveoh]

Is it me, or does it look like this bullet hit base first?

Okay, I did a quick and dirty test today.  I'm sorry I didn't do as good of a job as Manny did on the documentation I didn't take a ton of pictures of each layer, and probably forgot to take some pics I should have, because I was short on time.  It was starting to rain when I did the shots, I promise I can shoot better, haha.  I had planned on doing more shots with different weights, especially in .22, but the weather said no.  I basically did a shot, adjusted the HS, did another, etc... 

The target was clamped together, but I only had two clamps large enough to grip the thickness.  I don't know how that may have affected the consistency of penetration.  Given the time constraint, I literally ripped through some pieces of cardboard and ply as fast as I could to roughly match the piece of MDF I had. I did make sure and shoot where I knew all layers were present.  The target consisted of:
3/4" MDF
9 layers of cardboard
1/4" plywood
4 layers of cardboard
1/4" plywood
4 layers of cardboard
1/4" plywood

The results pretty much matched the power levels used.  I tested the .177 from 45.5 fpe to 54.9 fpe.  I tested the .22 at 72.8 fpe and 80.5 fpe    Obviously, the .22 was the penetration leader, but the .177 wasn't too bad either.  Below is the run down of penetration and details.

(1) NSA 20.5 grain .177 slug @ 1000 fps
      -Went through 3/4 MDF, and was stuck in 2nd layer of cardboard
(2) Griffin 24 grain .177 slug @ 975 fps
     -Went through 3/4 MDF, and was stuck in 4th layer of cardboard
(3) Griffin 24 grain .177 slug @ 1000 fps
     -Went through 3/4 MDF, and was stuck in 9th layer of carboard
(4) Griffin 24 grain .177 slug @ 1015 fps
     -Went through 3/4 MDF, 9 layers of cardboard, and was stuck in 1rst 1/4 plywood
(5) NSA 31.2 grain .22 slug
     -Went through 3/4 MDF, 9 layers of cardboard, 1rst 1/4 plywood, and stuck in 2nd layer of cardboard
(6) Cast 35.2 grain .22 slug
     -Went through 3/4 MDF, 9 layers of carboard, 1rst 1/4 plywood, 4 layers cardboard, 2nd layer of 1/4 plywood, and stuck
       in 2nd layer of cardboard. 

I didn't do the best science here   It does, at least, give some idea of penetration differences and slug destruction.  Note those nice grooves in the .177 slugs from the new Alfa Precision 14.6" twist barrel

[Rallyshark]

The bullet is sitting nose down, and may have done a little tumble on the last board it went through.  It is also a cup base, so looks are deceiving.

[JimD]

I got another squirrel this morning (actually two but one was with the car).  So I did my penetration test on it's body.  At least 3 of the 4 pellets I shot into it at 20 yards went through.  So pellets that went through 1 1/4 inch thick MDF piece and into but not through the second went through the squirrel - at least most of the time. 

I also know from prior experience that my little 177 that only buried the pellet in the first 1/4 inch piece didn't make it through a squirrel shoulder.

So my opinion is penetration through 1/4 inch of MDF, at the distance you want to hunt, is a good test for small game.  If it only goes through and doesn't bury itself in the second you may not be able to go through a squirrel but hopefully it will make it to the vitals.