camnbo

My son wants to test for a school project the penetration of 30-06 vs .270. I'm gonna make a fixture to hold serial pieces of 1/4 in plywood about an inch apart to shoot through. How many pieces of 1/4 inch do y'all think I need to stop the rounds. I'm thinking 10 or so should do it.

tomanyboats

I dont think your going to have near enough..

cphilip

In everywhere besides Alabama he'd be kicked out of school.

I'd day about 4 - 5 inches at say 100 yards. You could see if you could use something else. I think here is a recipe online for a fake ballistic gel.

hybrid

I would think 10 would be plenty depending on the bullet being used. Ballistics tipped bullets should start fragmenting after the first couple of boards. I would be more worried about trying to keep those fragments contained somewhat. What distance are you shooting? My bet is on the .270 having more penetration.

I just went back and reread 1/4" plywood. Better get more.

NCummins

I'd use 1/2"" plywood. I'm not sure how many you'll need, but I'd say 5 would be a good starting point.
Make sure to use the same bullet weight, heavier bullet means more penetration, which I'm sure you knew already.

NO WAKE

I did something similar with my son several years ago but using 12 ga vs 20 ga slugs. I stacked cinder blocks up to make columns then layed 2"x 8" boards on top of them horizontally. We collected one gallon milk jugs for quite a while before this project. Filled the jugs with water and lined them up along the 2"x 8" boards with the jugs touching.

I stacked the cinder blocks 4 or 5 high to get a good line of sight across the top. Set up my shooting bench approx. 15' back from the first jug. We stuck an orange dot on the first jug for an aiming point. My son then tested (shot) the 20 ga three times into the jugs. After each shot we found out how many jugs the slug penetrated. We replaced the damaged jugs after each shot. We duplicated the process using the 12 ga.

Pretty cool project! Of course we have access to lots of farm ground here so setting it up in an empty field with empty woods for a back stop was no problem.

I know this doesn't answer your question but thought it might give you another medium in which to shoot.

The cool thing was we recovered all the slugs from each shot. They ended up inside the last jug which it penetrated.

We were surprised at how few jugs were penetrated! I think initially I lined up 25 jugs. They only penetrated the first 5 or 6.

Good Luck! And of course......enjoy the time with your son!!!

camnbo

I'm thinking 30-40 yds so we are safe but can make a good shot. I'm gonna have the ply in a long box to keep things contained. I don't know if this is gonna work but it's gonna be fun.

ryan darrow

Nah. I did a project in college where we had two ARs, one with bull barrel and one with standard. Hooked thermocouples and strain gauges to a data acquisition system and studied the difference in barrel heating and expansion between the two. Got an A!

NCummins

Milk jugs would be a better medium than plywood, plywood isn't uniform and one knot will skew your results.

camnbo

Thanks. Y'all are giving me good ideas. I think I'm gonna but something between the plywood pieces.

cphilip

Ok... and OK! At least in College. Then again, in my day we had our Shotguns hanging in back window of our Pickups in the school parking lot. And that was in Florida.

And probably here in SC too....

arbogb06

We've used phone books as well. One would think a rifle round would easily pass through a thick phone book...... Wrong.

The phone book idea would allow you to see how many pages the bullet actually penetrated giving you data to the nearest thousandth or however thick a phone book page is. If you use milk jugs with water both bullets could end up in the same jug not showing any difference when one bullet may have just pierced that jug while the other easily penetrated but could not make a pass through.

I would do several tests. Shoot phone books, milk jugs with water, plywood and an aluminum plate.... This will give you a lot of data and show the clear winner.

BlueRudy

You need material with higher density than ply wood.
I would clamp news papers or magazines between two pieces of ply board.
I would guess 8" to 12" of material pressed tightly will do the trick.

icthruu74

Somewhere I've seen a setup that uses gallon zip-lock bags filled with water. I think it was Field & Stream.

Make sure you use bullets of similar construction and SD - a 110grn .270 varmint load won't be the same as a 180grn 30-06 Partition or A-frame.

Just a guess but I'd think both with good bullets will pass thru 4" of plywood. Might check out box o' truth to see if they have anything that might help.

BlueRudy

So we're gonna need Jesus to coma along and take care of the water bags for us?

Barnacled

Montrose phonebook is pretty thin.

chad13

Maybe try to build a box where you can put sand between the layers of plywood.

jlipsky14

http://m.wikihow.com/Make-Ballistics-Gel

I would personally make ballistics gelatin. It simulates the density of soft tissue. You can either buy it pre made which is expensive or you can make your own. And that would be a cool little project of its own.

If you have ever watched the show mythbusters it is the same stuff they use when testing projectile penetration.

Mythbusters Ballistics Gel: http://youtu.be/023Ho--XPtsurl]

icthruu74

You betcha!

Took me 30 seconds to notice that and edit it, but Rudy was right there to catch if for me!

chad13

More importantly post the results here