One more penetration test.

[Nomadic Pirate]

Yeah, I think to have a uniform initial board is the key,

The layering of thick carboard and thin plywood should work very well to give projectiles some resistance after blowing through the MDF  and should give a good read of further travel

[JimD]

I've never shot MDF but I use scrap 3/4 plywood to stop pellets when I am getting velocity readings on my 25 caliber Avenger.  It blows through it with the regulator set to 1500 psi.  fpe is 33 to 39 depending on the pellet weight.  Velocity goes from a little over 700 fps to over 850 depending on pellet mass.  I have a second piece behind the first and it just gets dented typically.  I will turn up the regulator eventually but I am having fun with it at the low regulator setting.  It can be raised as high as 2900 psi on this rifle. 

My main hobby is woodworking.  I don't like MDF because the dust it makes is terribly nasty.  It is not stronger than plywood, it is weaker.  It is also easily damaged by water.  The Brits talk about water resistant MDF but I've never seen it.  For shelving purposes we look at the modulus of elasticity.  Hardwood is strongest, has the highest modulus, softwood is next, then plywood, then particle board, then MDF.  I don't know however, if that translates to penetration but I tend to think it does.  If I had any laying around I would shoot it and find out.  I agree, however, that MDF will be more consistent than wood or even plywood.  Shooting it may be a good thing to do with MDF. 

[Nomadic Pirate]

Stage is set, time to start shooting 

I don't think any will but just in case I put a foam board behind the target to catch any possible pass through.

This sucker is HEAAAVY  must be 60 + pounds

[Nomadic Pirate]

All shooting done !

As expected nothing came out da back,

time to go gather some data 

[Nomadic Pirate]

Here is how the back of the MDF looks, can see that the .30 and .25 didn't make it through.

And on the immediate cardboard backing you can see some nice expansion on the Hollowpoints.

[Nomadic Pirate]

I've never shot MDF but I use scrap 3/4 plywood to stop pellets when I am getting velocity readings on my 25 caliber Avenger.  It blows through it with the regulator set to 1500 psi.  fpe is 33 to 39 depending on the pellet weight.  Velocity goes from a little over 700 fps to over 850 depending on pellet mass.  I have a second piece behind the first and it just gets dented typically.  I will turn up the regulator eventually but I am having fun with it at the low regulator setting.  It can be raised as high as 2900 psi on this rifle. 

My main hobby is woodworking.  I don't like MDF because the dust it makes is terribly nasty.  It is not stronger than plywood, it is weaker.  It is also easily damaged by water.  The Brits talk about water resistant MDF but I've never seen it.  For shelving purposes we look at the modulus of elasticity.  Hardwood is strongest, has the highest modulus, softwood is next, then plywood, then particle board, then MDF.  I don't know however, if that translates to penetration but I tend to think it does.  If I had any laying around I would shoot it and find out.  I agree, however, that MDF will be more consistent than wood or even plywood.  Shooting it may be a good thing to do with MDF. 

Well data says the opposite

My .25 and .30 Blow through quality 3/4" Birch Plywood and keep going for some time into other mediums, both didn't even make it out of the MDF

[Nomadic Pirate]

120gr Rick Merrell

[Nomadic Pirate]

148gr Matt's bullets

[Nomadic Pirate]

Predators

[Nomadic Pirate]

JSB .357

[Nomadic Pirate]

.30

[Nomadic Pirate]

.25

[Nomadic Pirate]

So only the 200gr and 190gr made it past the 1st Ply

let's go see how far they made it 

[Nomadic Pirate]

The 1st 190gr was found resting in the cardboard behind the 1st ply

[Nomadic Pirate]

the 2nd 190gr was found stuck into the 2nd ply with the 1st 200gr resting in the cardboard behind it

[Nomadic Pirate]

The other 200gr went through the 3rd Ply and was resting in the Cardboard behind it

[Nomadic Pirate]

I've never seen this kind of expansion on the 190gr bullets

this 3/4" MDF is way stronger then quality 3/4" Plywood

[JimD]

I still struggle to call MDF strong.  If you want to know why try making a shelf out of it.  But it is more dense, it weighs more per unit volume.  Maybe that is what counts for penetration.  The weight comes from all the glue holding the wood dust together.  A sheet of 3/4 plywood is about 75 lbs, a sheet of MDF (medium density) is about 90 lbs.  So perhaps the density makes it harder to penetrate. 

It appears weight of the projectile has a lot to do with penetration. 

I like testing in wet paper, ideally newsprint.  Due to availability I plan a test in glossy paper - magazines and catalogs.  I only had 4 inches for my last test and some of my 22 pellets make it through - at less than 20fpe.  I plan to use at least 6 inches to test my 25 caliber Avenger.  I'd like to have 8 inches or more. 

[Nomadic Pirate]

If that was a 3/4" Ply the high weigh bullets probably would have made it all the way.

this 3/4" MDF might not be structurally stronger but it surely is way, way harder to penetrate then quality 3/4" Birch ply

real world testing don't lie


It's to strong to make any meaningful penetration testing, from now on I will only use it as security backstop.

[Rallyshark]

Here is how the back of the MDF looks, can see that the .30 and .25 didn't make it through.

And on the immediate cardboard backing you can see some nice expansion on the Hollowpoints.

AWESOME!  I was very close on my guess   I kinda thought the .30 may not make it through, but I hedged my bets and just said the .25 wouldn't,lol!  Your results are very useful for people trying to understand real penetration.  I suspect you may get different results if you swap out the .30 and .25 with slugs.  I'm assuming you're shooting the .25 at 65 fpe, and what was the .30 at 70 or 85 fpe?  I was assuming the .30 was the 80 fpe. 

That MDF is just so dense, it'll make almost anything expand.  It takes some good power to poke through a 3/4" sheet of it.  You're making me want to get off my rear, and test my .22 and .177, while I have them set up for their high power hunting tunes...  I know they'll poke through the MDF, but the after part is what I'm curious about?

Great job on the test Manny!!!