Best Lube for Pellet Trap?

I have a trap for shooting pellet guns in my basement that I bought about 15 or 20 years ago. It's a nicely finished oak box, and inside is a
spring loaded vertical galvanized steel plate. I'm not sure what sort of spring they use behind the plate, it may just be foam rubber. The pellets flatten against the plate & fall down inside the trap.
I have been practicing a lot lately, trying to get my scores back up to where they were when I was a lot younger. I'm shooting a Steyr LP50 5- shot compressed air pistol, which has a muzzle velocity of ~ 525 feet per sec. I think this is a bit hotter than the older CO2 match pistols, at least it makes a more authoritative "clank" when the pellets hit.
I don't know if the galvanizing is worn off, or if it's just the higher velocity, but the pellets have started sticking to the plate. A thin layer of oil stops this for a while, but evaporates and/or gets shot off fairly quickly. Right now, I've applied some waxy stick lube for metal working (Boelube) on the theory that at least it won't evaporate. The stick lube is relatively clean to apply, but I don't know how long it's going to last. If this wears off too fast, I may try a grease next.
I'm thinking an "extreme pressure" lube might be best, but I figured folks here might have some more specific ideas.
Any suggestions?
Thanks!
Doug White
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Doug White wrote:

How about changing the plate out with some polished stainless. OR sand it a bit and paint it with graphite based paint.
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I thought about stainless. I took the thing off the wall, and took a much closer look. I found several interesting things:
1) The existing plate appears to be just flat (or it was, see below), with no bends at the edges. It's a bit hard to measure, but using a bent paper clip as a hook, I estimate the thickness to be somewhere between 50 & 60 mils. It looks like I should be able to replace it with a polished SS sheet without too much trouble.
2) The plate is bulged out in the center by about a 16th of an inch. It doesn't appear to be lead build up. Somehow the constant hammering with pellets has made the metal expand outward. I'm a bit baffled as to the mechanism for this, it's like a reverse dent. The surface is also rough, but that may just be residual bits of lead sticking to it.
3) The plate IS backed with foam rubber. That may have stiffened up over time, contributing to a harder impact & agravating the sticking problem. If I repalce the plate, I'll have to try to come up with a good repalcement for the foam. It may be tricky to get the right stiffness, given what may be available locally, and that my only sample is thoroughly aged. There is a really good foam place in Boston that may be able to come up with a close match.
I'm trying to practice every day, so I'm loathe to tear it apart at this time. My club's indoor range is being rebuilt, so at the moment my basement is the only place I have to shoot. I'm in New England, and outdoors isn't an option this time of year. Once the club's indoor range is operational, I can open my trap up & have more time to rebuild it properly. I may need to experiment with the foam, and I have some adhesive-backed sound absorbing rubber sheet that I could put on the back of the plate to quiet the "clank".
Even with a SS plate, I think an occasional lubing might be a good idea, so the original question still stands.
Doug White
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wrote:

Doug, might it be easier to boil up some bullet lube and coat your pellets in that instead of trying to keep the target slick?
-- Not merely an absence of noise, Real Silence begins when a reasonable being withdraws from the noise in order to find peace and order in his inner sanctuary. -- Peter Minard
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You have to be careful with many lubes around high pressure air, and I'm not wild about gunking up my expensive air pistol with excess lube. A tiny dab on the nose would suffice, but lubing 60 pellets a night would get tiresome pretty fast. Waxing the trap once before each session seems to help a lot.
It occured to me that part of the problem is that I shoot 10 or 20 shots per target, and that means (especially now that I'm getting better), a lot of pellets are going through pre-existing holes. I shoot target "wad cutter" pellets, so with a fresh target, the pellets nose is nicely covered with a disk of paper, and can't stick. Once I've chewed up the center of the target, I'll bet the ones that are sticking are going though pre-existing holes, or close enough that there isn't a significant paper buffer on the nose. The trap was originally intended for air rifle, where one shot per bull is the norm.
In air pistol matches, they only shoot a couple shots max per target to avoid scoring problems with pellets going through the same hole. For practice, schleping back & forth every 2 or 3 shots gets time consuming, and good targets aren't exactly cheap. They use special paper so it doesn't tear & the holes made are crisp. I've been meaning to develop an automatic remote controlled target changer for some time now, but that will take a while.
I think a new stainless plate and softer fresh foam will help a lot. McMaster has 410 SS sheet in 12" squares, and polyurethane foam in three stiffnesses. I'm pretty sure the shop at work has a shear that can trim the SS sheet for me. If I start with a good waxing before each session, I should be good for another 20 years.
Doug White
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    [ ... ]

    Hmm ... target paper feels a lot like old yellow TeleType roll paper, except perhaps a bit thicker. If you can get some rolls, cut off a few squares and try them in place of the target material and see how they do.
    You might want to make a motorized roll to pull paper off a source roll, and wind it up on a destination roll, or perhaps to simply pull off a source roll, pull a known count of turns on pinch rollers, and then run a cutter across below the pinch rollers to leave a pile of perforated paper targets.
    You'll need some way to protect the mechanism from stray pellets, especially the pinch rollers.
    As for the printed target -- set up a slide projector with an image of a target on a slide and project it on the paper. Perhaps have a solenoid close the shutter while the paper is in transist, so you don't shoot at a stationary image on a moving paper background. :-)
    To get the image to project in the right shape - take the photo of a good target from the position where the projector will sit, so the perspective distortion from the photo will cancel the perspective distortion in the projected image.
    Enjoy,         DoN.
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wrote:

Folks are constantly trying to find a good substitute for target paper. The teletype stuff is a new idea, but may be hard to come by in quantity. Some people use cheap US targets & paint the back with dilute glue to prevent tearing. Baking or microwaving them also helps.

They used to do something like this for big matches. They had a moving "backer" that would slowly scroll behind the scoring target. They would fire 5 or 10 shots per target and use the backer to sort out if multiple shots went through the same hole. This was used for 50 meter free pistol at the Olympic level, where guys are good enough to make it an issue. Now the scoring is all done electronically, but it's filthy expensive to set up a full range. I think there are only a couple in the US with all the hardware.

Interesting ideas.
I was thinking about making something that could be produced in sufficient quantities that it could be used for matches, which requires that it handle regulation targets. Ideally, you would be able to load 62 targets (one shot per target for major competitions + 2 sighter targets) into a hopper. I need to study the innards of my laser printer to see how it picks up & feeds one sheet at a time. The targets should be simpler, in that they are thicker & stiffer. To keep the changer simple & low power, a bin on top could drop them down into firing position, and then drop them into a hopper below the pellet trap.
Doug White
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    [ ... ]

    The impact of the pellets makes the plate a little thinner, causing the area of impact to enlarge. Repeat this long enough, and you have the center of the plate larger than the room for it in the rest of the plate, so it is just a matter of luck whether it will bulge towards or away from the shooter, but it *will* bulge some direction, so the extra size can be accommodated.
    Enjoy,         DoN.
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Someone else suggested that it may be like a sheet metal shrinking hammer in reverse. Because the pellets flatten when they hit, if they are also sticking, the flattening action may be slowly expanding the surface of the metal. That might preferentially make the dome form outward, instead of simply denting in the direction of the pellet impacts.
Doug White
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The same sort of surface expansion takes place with careless sandblasting of sheet steel. With a high air pressure and the nozzle too close to the sheetmetal, the surface begins expanding, while the "back" side does not, causing the surface to raise.
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The problem with a heavier plate is that it won't allow the foam backer to absorb any energy. Ideally, the plate should be as thin & light as possible so the energy goes into the foam, and not into deforming the pellet. A harder, stiffer plate should help, so stainless is a step in the right direction compared to the original galvanized steel (probably A653 or similar). If I use 410, which is easy to shear to size, I could get then it hardened. I don't mind replacing the plate (or just flipping it over before it gets too deformed) every 10 years or so.
It occurs to me that replacing the foam with "temperpedic" foam that soaks up energy better than springy foam should help a lot. A hydraulic damper system would also work well, but is a bit overkill. There is another trap someone used to make that just had light steel springs behind the plate, with no energy damping at all. They were very noisey, and tended to bounce the flattened pellets back out onto the floor.
Doug White
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Doug White wrote:

Well, isn't "pellets ... sticking" sort of an indicator of how accurate your shot was? How do you measure the distance from the bulls-eye if the pellet just falls off?
Thanks, Rich
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That's what the paper target in front of the plate is for...
Doug White
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Doug White wrote:

Ah.
Never mind. ;-)
Cheers! Rich
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I doubt if extreme pressure lube would help. Better a oil that will wick back to a spot where a pellet has hit and removed the lube. So maybe something like ATF and some wax. The wax will hold some ATF so there is some ATF to wick back.
Dan
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PAM cooking spray?
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Doug, I think the 1st problem is the design. The back plate should be angled at 45 degrees. and the bottom of the box should be sand. The backing plate should be hardened and then 40 to 60 Shore "A" rubber should be glued to the rear side for sound damping. On the current design, the sticking is caused by the rough pock marked surface. Sand it smooth and the sticking will go away. The reverse dent is caused by metal stretching created when the backing plate deforms upon repeated impacts. It is the same principle that the English wheel uses to bell sheet metal.
The best design of a pellet stop would allow you to reuse the pellets. To do this, use a whole series of hanging ropes in a contiguous row backed by several other rows offset by 1/2 the rope diameter. three rows will do it. Behind that, use a 1\2" thick sheet of rubber and of course, no noise. Steve

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I agree. I think the expansion of the pellet as it flattens is stretching the surface of the metal, causing it to swell outward. The roughness of the plate now makes it worse.

We had a trap when I was a kid that used strips of denim & inner tube hanging down. It was a pretty big boxy affair, much bigger than my sprung plate trap. Reusing pellets for match practice isn't very practical. Even if you trap a pellet with no deformation, the skirt has already been swaged down to fit the bore & rifling. We could occasionally find pellets that weren't too banged up in the denim trap, but they never shot as well as fresh ones. We didn't mind running them through our cheapo Benjamin pump rifle, but they picked up enough dust & dirt that I wouldn't want to cycle them through an expensive match pistol. I just collect them & give them to reloaders at my club.
Doug White
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I've never see one with just a vertical plate. You'll get spatter above a pretty low velocity, penetration with the high-end guns. The one I use that I bought from Beeman's many years ago uses "ballistic putty"(Duxseal) in a wood box with a cardboard face. You could do the same with a loaf of Duxseal in a cardboard box. The ones they use for matches use a square edged steel funnel going into a pellet catcher. Noisy, but works.
Stan
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snipped-for-privacy@prolynx.com wrote in

When it was new, it worked quite well. The foam absorbed enough of the energy that the pellets didn't spatter and it soaked up a lot of the noise as well. It's not meant for high velocity hunting rifles. I'm going to be curious to compare the pellet deformation before & after installing fresh foam.
I know a number of folks who use the putty traps. The problem is that they get clogged up pretty fast if you practice a lot. I'm going through a 500 pellet tin every week & a half at this point. The pellets rapidly pile up & need to be pried out & the putty massaged back into place.
The conical or angled baffle traps work OK, but they tend to be a bit deeper. Mine is just 4" thick & hangs nicely on the wall.
Doug White
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