tumbling pellets, diagnosis?

Tyro · Post by **Tyro** » Wed Jan 31, 2007 11:00 am

Hello Everyone:

I hope that this question hasn't been addressed repeatedly, but my searches haven't turned-up anything.

I'm very new to AP, shooting a 747, and am tearing gaping irregularly shaped holes in the target. Unfortunately I don't have a chronograph to determine their velocity, but by the fact that I can't see the pellet and by the sound of the impact, I don't think that this is the issue.

The targets are the NRA Nat.Target Co. series, I haven't seen this with my other guns.

The 747 is adjusted properly, has sufficient lube, and has been cleaned repeatedly. The bore and crown appear fine.

The tearing is less pronounced with longer pellets. Pellet weight doesn't seem to have an affect, though the pellets that I've tested only deviate by a few grains.

The tearing increases w/ the distance from the bull, close shots tend to be cleaner but they're still ragged.

Is it possible that my technique is influencing the rotation of the pellets?

any advice will be appreciated!

Richard H · Post by **Richard H** » Wed Jan 31, 2007 11:12 am

No it has more to do with crappy targets and low velocity, the further away you move by the time the pellet gets to the paper its going slower.

You can put some masking tape on the back of the target that should help you make cleeaner holes ( not acceptable for competition but ok for fun),

Tyro · Post by **Tyro** » Wed Jan 31, 2007 11:34 am

what's a typical velocity for a 747? Will I damage the action if I adjust the stroke engagement to a distance beyond the prescribed range?

just to be clear, by tumbling I mean that it's evident that some pellets have rotated such that they're oriented laterally when they strike the target.

Are 747's known for this issue?

Fred · Post by **Fred** » Wed Jan 31, 2007 12:09 pm

Trust us, it's almost certainly the targets. Before you do anything to your gun, order a batch of Edelman targets from our host, and see what your gun does with one of those. If you still see a problem, then you might want to consider alterations to the gun.

HTH,
FredB

jrmcdaniel · Post by **jrmcdaniel** » Wed Jan 31, 2007 1:27 pm

National switched paper sources about a year ago. While they have never made great airgun targets, the newer paper was horrible for airguns. If you must use National targets, I suggest spraying the backs with clear lacquer -- when dried, pellets will punch fairly clean holes. Otherwise, as suggested above, switch to using Kruger or Edelmann targets (I don't like Cibles are a bit better than Nationals, but not nearly as good as Kruger or Edelmann (must be North American paper).

Joe

GaryBF · Post by **GaryBF** » Wed Jan 31, 2007 2:21 pm

Tyro,
I agree with the others that target paper quality will have some effect on the appearance of the holes. From what you wrote however, this sounds like it may be something else. At what distance are you shooting? Specifically what pellet style and weight are you using? For that gun I think you should be using light (0.5g) diabolo (wadcutter) pellets. You said "longer" pellets showed less tearing. Perhaps the pellets you are using aren't stabilizing because they are too heavy, the wrong shape, or the distance is too great. Is this gun new to you, so it has always done this, or is this a new problem? Give us some more information and maybe we can help you figure this out.

pgfaini · Post by **pgfaini** » Wed Jan 31, 2007 5:49 pm

I had trouble with my last lot of American Target Co. targets. I would get tears the dia. of the pellet about 1/2" to 5/8" long. They were all horizontal. This was probably the orientation of the target paper's fibers. Is this the type of tears you're getting?
Try shooting into a sheet of corregated cardboard, and see if your pellets are striking head on, or tumbling. If striking head on, the near side of the cardboard will have a round hole, even if the back side of the hole is a bit ragged. If the pellets are tumbling, they will strike the cardboard on their side or at an angle, and the irregular hole will show this.

Paul

Tyro · Post by **Tyro** » Wed Jan 31, 2007 8:45 pm

Thanks for all of the responses!

I've performed a few tests which seem to confirm that the paper is the culprit. For the first series I'd rolled a fresh sheet of duct seal, and shot into this directly, w/o an intervening paper layer. All of the embedded pellets were more or less correct in their orientation - none demonstrated the degree of rotation that I'd assumed was occuring in flight. Subsequently I'd shot into a single layer of corregated cardboard, per pgfaini's suggestion - these shots printed correctly as well.

The size and geometry of the holes had lead me to assume that the target was being struck by the broad side of the pellet. The holes often look like a rough cut-out of a diablo. The pellets found underneath, embedded in the duct seal, are sidelong as well.

I hadn't considered that the paper surface is sufficiently elastic that it can absorb the oncoming pellet and cause it to rotate before breaking the surface. The phenomena that I'd half too cleverly assumed was due to drag stabilization, was probably just due to differences in weight.

I'll try one of the target stocks recommended.

Gary: This has been occurring w/ JSB Schaks & Diablos for air pistol, Beeman H&N's, & Crosman Super Match. I've had the pistol for a few weeks, probably put 700 rounds through it and have noticed this problem from the start. But then I've always been shooting the same targets.

Thanks for all the help!