6.5 Creedmoor bust'n Welds

demolitionman

demolitionman

Send’r Bud
Full Member
Minuteman
Feb 26, 2013
1,366
645
Midwest
#1
Thought you all might get a kick out of this. I tried building some steel targets in the past and just blew through them like butter so I had to go back to the bone yard and get some heavier duty steel. I torched some bolts off an old Loader bucket's digger edge (its some super hard stuff) thinking I would just cut it up and weld it together to make an indestructible target that I wouldn't blow through with 22-250, 223, or 6.5 creed.

So I cut the bucket edge down, welded her together really hot, tons of penetration, and used a cobalt bit to drill through the top plate to allow hanging it with some 3/16th cable. Simple enough, done deal. I got this one done right, or so I thought....



On the 6th round the welds let go, and it wasn't from bad welding. The welds were still in tact mostly and pulled off the plate edges with them! The back weld ran the entire length of the two pieces, the front I welded a 1"bead every 3 inches.







I consider this a success, because this metal didn't dent at all at with my 6.5. I just gotta figure out how to mate the two together. I think maybe more metal prep before welding. Hmmmm......
 
#2
What you call tons of penetration is better described as minimal. If the process was mig, know that visually, you can't tell anything about penetration. Find someone with a DC arc welder and all should be well. common 7118 should be plenty strong enough and use complete welds on both front and back. penetration means that if you cut it apart, the base metal and welds look homogenous. Depending on the thickness of the plate and the capabilities of your welding machine, multiple passes will be necessary to complete the welds. Good Luck
 
#3
farrier said:
What you call tons of penetration is better described as minimal. If the process was mig, know that visually, you can't tell anything about penetration. Find someone with a DC arc welder and all should be well. common 7118 should be plenty strong enough and use complete welds on both front and back. penetration means that if you cut it apart, the base metal and welds look homogenous. Depending on the thickness of the plate and the capabilities of your welding machine, multiple passes will be necessary to complete the welds. Good Luck
Click to expand...
Ill hit it with an arc instead and see how that goes. This was mig'd with the welder at its max. I thought it would work, boy was I ever wrong!
 
#5
Ya that was weak welds, like qkieler said you need to bevel the metal at least a 1/4 of the thickness of the material being welded and fill it in completely with multiple passed while it is still hot. A lot of energy is being released onto that steel, especially at shorter distances.
 
#6
Demo-man,
Those cutting edges you're using are some type of AR plate, and may require being heated up to take a weld. And yes you can weld ar plate.
For the cartridges you mentioned it may be fine, but heavier faster bullets could break the weld.
 
#7
As alluded to prior,,,, it doesn't matter what 'wonder-metal' that you're working with,,, the plate-s will be no stronger than the weld itself. This includes the weld filler-rod makeup.

Facetiously speaking, two diamonds welded together with a steel rod, are no stronger than the steel in the rod. It'll still break apart. You may want to look at making two individual targets, and reducing your target size.

The key thing to remember though, is that the getting out and shooting it, is the fun part. Prove me wrong, I dare's ya! ;)
 
#9
You may be able to find small drop pieces from a local machine shop or fab shop. Most suppliers will sell you a whole sheet but it was around $1k for 1/4" or 3/8" in a 4'x8' sheet.
 
#10
AR 500 plate isn't cheap - we've put up dozens of targets from it.

Using what you have, it appears as though the plate is tough enough, you are going to have to get full penetration welds to hold it, WITHOUT heating it, because that will soften the heat treat that makes AR500 what it is. Ok to cut it with plasma cutter, doesn't heat the plate that much if you quick. When you weld it, use DC setting, the 7118 rod is a good choice, or any hi tensile low hydrogen rod you have available. Use the plasma to cut a quick 45 degree edge prep, and weld it in no more than 1-2 inch long passes, skip around to minimize heat build up. You'll need at least a couple passes to make a full weld profile.

The risk, as was stated above, is that the weld is the weakest point. You may need to cover the weld with a 3rd piece, welded on the top and bottom edges, that will minimize the weld available to be hit by the bullet.

Having bought LOTS of that high dollar plate, I wish you the best in making that scrap work. Remember to not shoot this stuff up close though, jackets can and do come back sometimes.
 
#14
Demo-man,
You can find ar plate at places that sell steel or iron. Welding shops may have remnants from jobs they will let go reasonably. If any place has to order it, you're probably not going to get much of a deal. Around here with the mining industry, ar plate is common, and buying rems makes for some cheap and easy targets. Your local, I'm not sure.

For your edges, make sure you plug the holes with grade 8 bolts or fill in with rod, I'd hate to see you loose your confidence because your shooting through them!
 
#15
Another problem that you will run into is, "Harmonics". The thing is, as stated above, if you weld the plate cold, the leading edge, were the plate meets the weld, becomes Tempered, to a point of some brittleness. The metal is strong on a structural stand point but not flex or harmonically. When this occurs, the harmonics of the bullet impact will eventually brake at that point. Being this is the entire center of the plate, were most impacts hit, you'll be fighting this battle a lot. Of course the ultimate problem solver is a heat treat cycle, but then again not everyone has an oven that'll go to that temp, nor have an Argon hook up.

I think you would have better luck with taking a 3rd piece of the same metal, and attaching it to the back, overlaying the center point of the 2 plates. Then weld the edges of the overlaying plate entirely. 360 degrees of weld around it, plus the original weld in the center. It will still eventually brake, but last 5x longer. Also get rid of the cable, use some type of thick rubber or conveyer belt material. Believe it not, those 2 will absorb a lot of the harmonics, and vibration.

I've used the cutting edge of heavy equipment lots of time to make my targets as well. It helps having a father who owns a grading business, for supplies. The best loaders to get the plates off of are Dozers. Some of these plates are 10-12" wide. Another good part of the loader that is good is on a Cat 963 front end loader. The plates in between the teeth, AKA wear pads, are 10"x 12"X 3/4" thick with square hole already at the corners. I've even used the track sections before. Just take them apart, turn them around, hang them, and shoot away.
 
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#16
I know it's fun to build things on your own and I do it all the time. You've save a good amount of money already by making a good target stand. If you want a good target that will definitely last and the money goes to a good cause, look up JC Steel Targets. Jake is on here often. A 12"x12" AR500 target will cost you $61.75 shipped to your door, and that includes the flat $18 shipping fee, so you could add several more targets to the order and not pay more shipping. I'm very happy with the targets I've bought from them and part of the money goes to a youth ranch.

Washington Steel targets
 
#18
demolitionman said:
Ill hit it with an arc instead and see how that goes. This was mig'd with the welder at its max. I thought it would work, boy was I ever wrong!
Click to expand...

Was this done with a consumer type wire welder? Looking at the beads they aint much to speak of, very little penetration. Butting two edges together and skip welding isnt going to work well in this circumstance. Cant not tell the thickness of the plate but looks like 3/8" or possibly 1/2". If you dont have enough voltage the base plate is going to soak it up(heat) like a sponge and penetration will suffer.

Using the proper preparation, (beveling both sides or spacing the plates where a 100% weld can be achieved) filler rod/wire, pre and post heating, shielding gas and technique will go along way in the weld holding up to repeated stress.

If you are limited on a relatively low powered machine like a short circuit 140A using .030" wire I would definitely suggest some preheating. Welding some gussets (90 degrees to the weldment) on the back side, something like 1/4"x 2" flatbar on edge or something heavier will also help.
 
#19
I cleaned it up, rewelded it together, placed a 1 1/2 wide piece of bucket edge all the way across the weld center, I'm about to send some Bergers at it in an hour or two. I'm excited to see how it goes. Deflection and richochet(sp?) will be more erratic but thankfully I'm not shooting near anything.

I ended up mig'n with an SP175 again because the big miller buzz welder is at a jobsite argh!
 
#20
If you cut the plate out of a bucket, it is ar400 or ar500,or some other type of wear plate, either way it is hard shit, and you need to step up on the rods, either 8018 or 9018. If you only have a mig, buy some dual shield wire like e71t and have at it, run it hot and flat with a slight pull and you will be good to go
 
#21
Some of the prices for AR 500 are Wacko, Wideners reloading sells AR 500 targets all day -cheap give them a look. I just saw their 16.5 inch x 9inch x1/2 AR-500 targets, $73.00 each, $69.00 each for three or more and 3 ship for flat rate of $16.00. Demolitionman, thanks for the post, and showing up your work, I'm interested in how your fix works-more photos please, sounds like you not only have the skills to use the "big equipment" but access to it too! Hope you make a series of targets and share with this group, I love this DIY board, some really talented people on here, Demolitionman being one of them.
 
#23
30 degree bevel both sides, throw a 3/32 land on it, get and SMAW (Stick) weld it with a 6010 for the root and finish it out with 7018 rods, GMAW(Mig) sucks for fusion and penetration unless your machine can pulse or pulse spray...
 
#24
not sure if someone else has mentioned it but anytime you heat steel you change it characteristics. so what once was a hard steel is now brittle where the heat was applied. that's what looks like happened. the weld didn't break in the weld but instead broke off the base metal. you can correct this by retempering the steel, but even then I doubt you'll get it back to its original hardness. your best bet would be to find a piece in the size you want and go from there.
 
#25
demolitionman said:
...where is a good place to buy ar500 plate?
Click to expand...

I have bought quite a few plates from Jake at JCSteel targets. So far, I haven't found a better price, and he ships via USPS flat rate for around $18-20 to get around 70 pounds of targets into one box.

Although the flat rate shipping works out really well for me, I don't think the local postal clerks are too keen on having to carry the packages I get from Jake.
 
#26
there was very little penetration on that weld... like whats been mentioned before....grind down a 45 on each welding surface....arc weld the shit out of it (7118 should work just fine)rose bud it and continous pass shuld work just fine....

if it were me... id do ^^^^ + a back brace and some angle iron over the front weld so in case a of a direct strike to the weld it will deflect it off but you will see the impact
 
#29
Talvey nailed it a few posts up. If you're gonna wirefeed plate of this type, use something like dual shield. If you run uphill, you shouldnt have to bevel. Remember fellas, position has a very significant effect on penetration. When you positively need to burn the f#ck out of something with mig or stick, go uphill. With a mig, a flux cored electrode like dual shield is the ticket for going uphill.
 
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#31
6010 is a brittle rod. I would use a chrome rod like 9018-b9 for my filler and cap. I would bevel both sides top and bottom amd run one side then grind back into it on the other and finish your fill and cap. Take your time like everyone else has said to keep your composition the same. Your heat affected zone is going to be what will break apart not your weld. If you have some type of insulation wrap the plate when you are done to allow it to cool slow so you don't make it anymore brittle then you have to. Chrome is extremely hard but if you don't cool it slow it will crack just like any hard metal. Be patient. You will probably be farther ahead by purchasing a target from jc steel targets or another low priced supplier. The rod your going to need is going to cost about what a target will from them. If you use 7018 as your filler rod the weld is going to be as soft as carbon steel and when you shoot it, it will smoke through it like a standard carbon steel plate.
 
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