and I was disappointed.  I took some 35lb plates from my weight set, that have about a 1 1/2" thick area towards the center, and shot them at 100yd.  The first bullet went in about 80% of the way and we found the steel core close by.  The second went about 90% in and the steel core was fused with the plate.  The third we shot at the thin 1/2" area of the plate and we blew off a 10lb chunk of iron.

My question is why didnt the api get through the 1 1/2" iron?  Is that typical?  The load was 225gr wc860 so it shouldve had plenty of umph.

Try it with a SLAP round and post results

^Not a good idea if you have a brake or suppressor from what I've read and heard.

I'm not 100% sure on this since I'm not a ballistics expert or know enough about the AP and API rounds. I'd think standard AP might go through thicker steel that API would. With API, you have to cut down on the size of the steel core to make room for the incendiary portion.

I haven't had a chance to shoot any steel targets yet. I should be able to in a couple weeks though. AP will be shot for sure. Not sure about API yet. It will be up to the range owners since it is surrounded by woods. They let me shoot tracer rounds out of my AR last Spring since it rained the day prior. It was dry in the Fall though.

So, had you read up on the penetration characteristics before hand?





Also, what is your barrel length, as IIRC most data regarding penetration is based around firing from an M2 barrel.

http://www.docstoc.com/docs/document-preview.aspx?doc_id=33283805





Hard to read but it looks like the specs call for penetration of 7/8" of steel by the core or entire bullet at 100 yards, but that's out of an M2 with a MV of 2900 FPS.
So...  sounds like it was performing somewhat within expected parameters.




 

I havent clocked the api but the ball ammo I loaded comes in at 2800 fps.  It penetrated around an inch so I guess it did its job, maybe I just had it hyped up in my head more than I should have.  Thanks for the info.

Lower two were the 50 api, the divot middle left was the 338 lapua (barely made a divot), and when we shot the "thin" part of the plate with the 50 it blew the top off.

Pic of an api core fused to the plate:

Would be interested to hear how AP black-tip compares to API against your steel weight. I'm sure it has a bit more penetration potential over API, but how much more? So far I have only had one steel plate stop AP. That was an .8" thick of some very hard steel plate. Not sure of the exact steel grade but it is dam hard. I've had 1.0" mild steel plate punched through like butter by AP. Must be lower grade steel.

Where can I get the black tip AP bullets?  I can find the ball and API's, but the 700gr AP's seem to be hard to get ahold of.

Survivalops.com is one place I can think of. 50bmgsupply.com is another. You can check freedommunitions.com once in a while. They are out right now.

M2 AP is 1" at 100 yards, API/APIT is 7/8" at 100 yards.  Raufoss even less.

....which is why the .50 caliber isn't an anti-tank gun, as portrayed by the gun-banners.

Because of the gun-banners, and the fact that I had never shot an API before, I was sure it was going through all 3" of steel plates I had lined up.  Maybe I just need to stuff another 40-50gr of powder in there? ;-)

You need to know the hardness of the steel before judgeing penetration and was it hanging or jammed in the ground. . I have a piece of "mild" 1 1/4" steel plate with a hole threw it. Shot with api @ 100 yards. I used a 1" blind flange that it only made a divit in. My 3/8" AR500 targets have just a mark about the same as a 556 ss109 round.

That looks like cast iron. Again it has alot to do with what your shooting at. The 50 isnt the  hole maker tv makes it out to be

all though, it might not be the hole maker per say. I believe that its enough to damage a engine in a hummer if given a shot at it. Or any other vehicle for that matter. And if  I could get a clear shot at an Abraham battle tanks turbine engine. I am sure we could make mince meat of it. Dont have to penetrate a tanks armor. Just disable its engine is all that one needs to do.

The only thing I trust to stop a bad tank is a good tank ha!

I'm going to pick up some of the black tips and retest this...

Good to know, but I'll leave the tank hunting to guys like my little brother who's flying F-18s. =)

Iv'e been buying AP from SurvivalOps in Oregon but do note slow shipping and spotty communications. Also try TMI50BMG, Tactical Manufacturing Inc. which is the factory for SurvivalOps. They usually have AP in stock.

In a SHTF scenario, any bad guys rolling up your driveway will start having the worst day of their lives once the .50 comes out to play. Most scumbags won't have a tank but would still feel pretty confident using a car or a tree for cover. The trouble is a car, large tree, cinderblock wall or any other manner of cover that would be effective against small arms fire won't mean squat against a 50. "Browning 50BMG, turning cover into concealment since 1921"

Back to shooting steel. As mentioned in previous posts. The length of barrel and quality of steel will greatly influence how much penetration is achieved. Assuming a 32" barrel, shooting full up AP black-tip, mild steel plate up to 1.5" thick would be at risk. I would have assumed that a 1.5" cast iron weight would yield to API but this experiment cast some doubt on that notion. That new Hardox steel, 500, 600 series is some tough stuff. I don't think any .50 cal is going to penetrate an inch of that stuff, even using AP. So I'm wondering if that chunk of .8" heavy ass plate I bought at the local metal yard is Hardox? It stopped an AP round shot from a 30" barreled Barrett 99.

You sure it was API? When I hit steel with API it leaves a flash burn mark on entrance.

.... and AP cores don't usually deform at all, just loose their jackets.  Here are some M2/AP at 1k yards on a 5/8" mild steel target.

That is wicked looking...

Here is a API i cut open. Just a fyi pic.

API just won't penetrate as far as 690 gr. black tipped AP. They both in my supply have the same size and weight penetrator. Maybe the incendiary going off slows the penetration? A piece of steel that the AP was barely getting through the API was staying in with about half the penetrator sticking out. A heavier piece of steel that the impact won't throw the steel helps penetrate deeper. A 690 AP will easily penetrate a 1 1/2" block of cold roll or hot roll steel. I'd done it and seen it done on 1 1/2" blocks.

Here's a video of an API hitting 2.5 inches of steel. Go to the 9:03 mark.

As others have said, Cast is usually a little harder than steel. More brittle, but harder.

http://www.makeitfrom.com/compare-materials/?A=Grey-Cast-Iron&B=mild-carbon-steel