Looks nice. As for spinning. I don't know. Wouldn't it depend on the weight of the target also? How much does it weigh. Let us know how it works. If it works well how bout some building plans.
October 6, 2004, 04:35 PM
I'll weigh it and reply. The quarter and snuff can is there for scale.
October 6, 2004, 04:44 PM
Middle target weighs 11 lbs
October 6, 2004, 04:45 PM
I couldn't tell that was a quarter. I thought it was a hole in the center with a piece of tape over it so you could tell if you hit dead center.
October 6, 2004, 04:47 PM
11 pounds....dunno if it will swing, but it will most certainly RING! and I'm sure it'll sway a bit too at the very least.
Shooting metal gongs and plates is fun! :D
October 6, 2004, 04:49 PM
Cool! A couple of comments...
If you make the side frame wood instead of the nice aluminum tubing, it'll be cheaper to replace when you shoot it up. Also, it looks like there is nothing to keep the targets from moving along the bar when they start spinning. You may need to add some stops.
October 6, 2004, 04:57 PM
Only 11 pounds? The first time you hit it, it will go flying like 100 feet.
Hey, it works like that on people in the movies... :D
October 6, 2004, 04:59 PM
Good idea on the uprights. The target arms are riding on an axle and have metal conduit(pipe) between the swing arms. A little hard to see from those pics.
October 6, 2004, 05:30 PM
Looks really nice and engineered, but I don't think you will like fixing it when someone accidentally hits parts that are not supposed to be hit! Have fun!
October 6, 2004, 05:37 PM
We're curious about the parts taking hits that weren't designed to be hit.
It's the frame that I have doubts about. The whole assembly takes down for transport so I'm hoping the parts will replace easily.
Of course the best case is--don't shoot nothing but the plates.
October 6, 2004, 05:46 PM
Hit with a .45, it will not spin. It will fly clean off the stand and disappear over the horizon. :p
October 6, 2004, 06:17 PM
What weight steel? Thickness of the plate? Hardness? Original intent of the manufacture? Is it relatively mild steel or hard?
I think I would keep it ONLY for pistol calibers.
October 6, 2004, 06:22 PM
I have not seen swinging target arms made out of bar stock. Usually, its, a captured cylinder or pipe with the bar stock welded to it.
A lot of the weight of the plates are on the inside hole of the bar stock, and you need to spread the load more than it currently is. I think you are going to see a lot of wear and tear in this area of the frame.
Any other shade-tree engineering critiques out there? :D
October 6, 2004, 07:21 PM
Doing a quick check on google, the first good hit I had for "45 acp ballistics 25 yards" was for Winchester Ranger 230-grain. They gave 407.2 ft-lbs of energy.
We'll call that 552.1 joules.
If the center target weighs 11 lbs, that's 4.99 kg.
Using 9.805m/(s^2) for gravity, it would take 48.927 joules to lift the target a full meter.
So if you smack that center plate and it rotates away just enough that it comes to a dead stop at top dead center, you've lifted the center of mass a certain amount. Just for fun let's say 20cm. One-fifth of a meter times 48.927 joules equals only 9.79 joules.
Compared to the 552 joules the round has at that distance, there's no comparison.
The only question is exactly how much of the energy will be deposited on target. When the bullet glances off (and it will) much of that energy will keep going elsewhere. But even a tenth of the energy transferred would be enough to spin it.
October 6, 2004, 07:23 PM
Having built/repaired lots of "pepper poppers" for IPSC shooting over the years, here is my observations:
1. a .45 will cause the plates you created to swing, but not enough to spin around the axis. HOWEVER--if support stand is not sandbagged, or spiked down FIRMLY, the first impact WILL knock the stand over, while it rings the plate. The stand needs to be secured from movement to be useful for more than one shot. We bag AND spike our poppers.
2. the plate should be AT LEAST 3/8 inch thick, and hardened for decent durability. If it's mild steel, 1/2 inch thickness or more would be better for durability (See below for details).
3. DON'T use anything more powerful than a centerfire pistol on this type of plate. Virtually ANY centerfire rifle will drill right through these plates.
4. Repeated hits with centerfire pistol WILL start to make the plates concave in the impact zone. This is not necessarily bad, but MAY lead to ricochet problems as it progresses. Be forewarned.
5. Don't shoot at these type of targets from any closer than about 10 yards. Ricochet problems get significant any closer up.
October 6, 2004, 07:27 PM
I made something similar to that however much more crude. I used that same metal conduit pipe. My .40S&W put a hole through it first time. I think I was able to fire a total of 50 rounds before the whole contraption was toast.
To make something like this work, I think your tubing needs to be solid. Something like rebar. Keep us posted, hope it functions better than mine did.
October 6, 2004, 08:36 PM
i would go ahead and make the welds solid all the way around the swinging arm, the welds will be the first thing to go...
the supports will get hit, the spinners will be bent all to hell, but it will be fun...:D
October 6, 2004, 09:04 PM
I'd maybe come out about four inches forward with two arms attached to the uprights. To these attach a piece of 2" angle iron across so that the outside corner face the shooter and the two angled legs make a nice cover for the axle. I don't think they will spin, so that won't be an issue stopping the spin.
Biggest problem I see when working with IPSC steel is welds failing. From here yours look nice, more never hurt. Most home makers weld pretty cold, probably because they don't have a stick burner that runs on 440 and can handle serious juice. I'd try to get as much penetration as possible without turning the plate front red so that it loses temper. Or if you are really creative like me, torch pre-heat your welds, burn them in there really darn good, get everything nice and red, and then quench the front face with motor oil. Caution, I have done this, you will have a big fire, but fire is fun right?
October 6, 2004, 09:56 PM
I made somethign similiar to that a few years back in Welding class. Used 3/8" scrap steel, and it has held up well to .22. They can't make it spin, and mine are about 3 or 4 pounds.
October 6, 2004, 10:19 PM
Mega, I can come over with my 8mm with the Turk steel-cored surplus to "test" your contraption.:D If it stands up to it, we will declare it good.
Where in AR are you located, anyway?
October 7, 2004, 12:06 AM
A) you need to welt irons across the support in the back, and to the plate, that will help keep the welds from snapping from a far off center hit.
B) you will be lucky to get 45 degrees of rotation from a .45ACP
October 7, 2004, 10:41 AM
Friday is range day so we'll take some video and stills and report back.
The target arms were turned at an angle and sharpened at the front to shear a round if it got too high. Of course this makes the surface area of the arm at the axle small increasing wobble and wear at that point.
Also, we thought about the cross gusset on the targets after the fact and we'll see how that holds up. Failure testing is fun.:D
October 7, 2004, 12:27 PM
megcatia, what are the plates made out of? They appear to be stainless. Anything less than 3/8 inch hardened plate (ar400 or ar500) may not last very long.(see BigBlueEyedDevils post above)
My experiances with target steel.
Mild Steel. 1/4" through 1" OK for rimfire targets,
Centerfire blows through it like a drill.
T1 Steel 3/8" Great for Rimfire Targets, 22RF does not make a mark.
Centerfire goes through it so fast at 175 yards that it
doesn't even swing.
AR400 5/8" and 7/8" This is REALLY good stuff. 300 WBY knocks
the paint off and makes a very small crater at 175 yards.
Beleive it or not, at 175 yards, a .17 Rem does more damage
than the 300 WBY. At 25 yards(minimun CF rifle distance) .223
FMJ makes a very small crater.
AR500 3/8" for swinging targets and 5/8" or thicker for static targets.
I could not find any of this locally, but my research tells me
THIS IS THE STUFF
I made mine using the "modular concept" Anything that can/will inadvertantly get shot can be easily replaced. Any areas that are very likely to get shot should be "faced" with hardened plate. I made my plates with holes in them for bolts. The bolts allow me to easily replace the support chains/arms when needed.
Give us a range report and let us know how it hold up and don't forget the pics.:D
October 7, 2004, 12:39 PM
I imagine that tank will be VERY reactive when a 45 hits it!:what:
Oh-----you meant the square swingers..................yeah - I guess that will be fun too 9 though not as much):neener:
October 7, 2004, 11:06 PM
Sorry, it won't even move much. You won't even notice the movement. Just the way it is. For swinging around the axle, you will have to counterbalance. For instance, we shoot shotgun targets of a similar build in matches, and even a full 12 ga won't make it go around. Will move it more though.
October 8, 2004, 10:11 AM
It looks like it's going to rain us out today. Maybe we'll get to try it out next week. My new CZ 40 will just have to wait I guess. :(
October 8, 2004, 03:55 PM
If it were me, I'd move that tank with the haz mat tag before shooting your target :D
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