Learned a few things about my Trail NP today...

[Makincheez]

1) The GRT III trigger is a huge improvement! I had to turn the adjustment screw in nearly 1 full turn to get it close to where I wanted but it is so much better now. It was nearly unshootable with the trigger it came with; had to have been 8-10lbs and creepy as heck. Seriously.

2) Trying some pellets at 10m (got about 800 rounds through it before today) it really doesn't like CPHPs nor the 13.42grn JSBs. It throws these JSBs about 3" low and group looks like it came from a shotgun. CPHPs just look like a shotgun blast; just all over the place.

3) It seems to like Beeman Ram Points, H&N wadcutters , and the FTS well enough. They all group about the same for me and POI is about the same. Can cover a group of 5 shots of any of these with a nickel.

4) It just loves the JSB 18.1s. 5 shots in one ragged hole about 1" above target. Can't quite get my head around how a lighter pellet goes 3" low and a heavier pellet goes 1" high but that's what I get.

5) This is not an easy gun to shoot accurately, for me at least. After about 2.5hrs shooting NP I grabbed my R1 (.20) and promptly stacked Beeman Crow Mags into the same hole and then JSB Exacts with the same results. And here I always thought the R1 was kind of tough to shoot accurately.........

[yote300wsm]

The NP's tend to like the heavier stuff. my NP loves 18 JSB's. 18g Crow Mags are close second. The JSB's hold the edge for the long range stuff. If I had to pick one, the JSB's would be my one pellet. My TF99 likes them too. My NP hates the sand bags. Try kneeling and resting it up against a tree or other "field positions". Hold it loose and just let it rock.

[Makincheez]

I was shooting from bags and tried shooting "loose"; basically just my hand between the forestock and the bag, my thumb firm around the pistol grip, light against my shoulder. I seemed to do a little better with the forearm on the bag and my hand resting over the barrel pivot area. There is potential there; I can put 2 or 3 into the same hole and the other couple of shots open the group. I'll keep plugging away but that's part of the fun isn't it? Thanks for the advice yote

[Frank]

I asked BB (Tom Gaylord) one time about a heavier pellet shooting higher. He had an answer for it. It is not unusual. It was something about the pellet moving slower and being in the barrel longer. Maybe someone else can fill that in as I cannot find the full answer now....

[eddielee70]

http://www.arld1.com/rifledynamicssmaller.html

[Progun]

Frank is right. It's not unusual for heavier pellets to strike higher than lighter ones even though the velocity will be lower with the heavier pellet. It all has to do with barrel harmonics and where the barrel is actually pointing(due to vibration/harmonics signature) when the pellet exits the barrel, There is an illustration that demonstrates this process somewhere either in our archieves or another site. Perhaps someone will chime in with a link to it.

[eddielee70]

only for short distance will a heavier pellet have a higher POI on spring rifles.  longer distance with higher fps still wins in higher POI.

[squirrelsniper]

i've heard that with a high velocity air rifle after a pellet leaves the barrel it drops down first, then goes higher, then drops down again. when i have my spingers zeroed in at 15 yards and then take it outside and shoot at 25 yards the pellet hits about 1 1/2 inches high, and at about 35 yards its right on. kinda weird, maybe thats why the heavier pellets are hitting higher. because since they're heavier they aren't traveling as fast, so it doesnt drop as much in the beginning of travel or something.. shooting barracudas out of my trail xl i get the same results that you are talking about. but don't take my word for it, because for all i know i could be talking outta my ^&*  

[Frank]

The problem I have with heavier pellets is that they do shoot higher or at least a different POI. As most of my .22 pellets are in the 14.5 gr range. Then when I do want to shoot, say, a 18+ gr  pellets the POI is off from the scope setting of my lighter pellets. Sometimes makes it  hard to choose the best pellet.

[Makincheez]

Squirrel, I think you're talking about something different but still true. Line of sight through the scope is straight. Pellet trajectory crosses line of sight twice. That's why you can sight in at 10yds, be an inch high at say 28yds, and on again at 35.

What you guys are saying about barrel harmonics make s some sense. The barrel will whip some and time in the barrel and how tight it fits would I suppose affect how much. I just never expected to see a 4" vertical POI spread at 10m due to this. That's the kind of stuff that makes this so fun, at least for me. Thanks for the insights guys!

[stacycfi]

Frank is right. It's not unusual for heavier pellets to strike higher than lighter ones even though the velocity will be lower with the heavier pellet. It all has to do with barrel harmonics and where the barrel is actually pointing(due to vibration/harmonics signature) when the pellet exits the barrel, There is an illustration that demonstrates this process somewhere either in our archieves or another site. Perhaps someone will chime in with a link to it.

.

When I was growing up we could sometimes "tune" a bad powder burner by turning down the barrell 1/2" at a time to
get a better harmonics for the loads we were using.  Sometimes the crown was the reason but we checked that
first.

[squirrelsniper]

ohh ok thanks makincheez!  

[bluzjamer]

Anyone try one of those barrel resonators?

[eddielee70]

Squirrel, these two links will explain POI relative to distance for you.

http://www.arld1.com/trajectory.html

http://www.arld1.com/trajectorydynamic.html

heavy pellets vs lighter pellets are

http://www.arld1.com/rifledynamicssmaller.html

you can learn alot from this home page.  I got most of my questions answered here.

http://www.arld1.com/

[Kirk B]

I agree that this is not the easiest gun to shoot. I have about 1000 pellets through mine and I'm still trying to figure out how to get sub 1" groups from 10 yds consistently on the bench. I tried resting gun in hand and hand on the bag, supporting the rear in different ways (not resting the stock on anything). I've tried every conceiveable hold on the pistol grip and I'm still getting lots of fliers.

One thing I did find that seemed to help a little was to not put any pressure on the thumb when pulling the trigger. I say pulling rather than squeezing because I was doing just that - essentially pulling the gun straight back into my shoulder with the pressure on the trigger and the three fingers on the grip. I'm not pulling it in real tight, just enough to tighten up my wobble around the target. Even then I had to practically "will" the pellet into the target (I guess you'd call that follow through  ).

This has been a little frustrating for me because I'm not that good at the other shooting positions yet. I'm working on that but in the meantime, I figured sighting in the gun and hitting the x from the bench at that distance should be a no-brainer. So far it's been more challenging than that.

Cheez, it's funny you mention that your gun doesn't like CPHP's but does like the JSB 18.1's. Mine's the opposite. It's real bad with the JSB's and not too bad with the 14.3 gr CPHP's. It likes RWS Superdomes about the same. I've yet to try the FTT's or Baracuda Match pellets which everyone seems to like but that's going to have to wait until after I tear this thing down for a seal, deburr, etc...

Keep us posted with your experiences with the NP.