I have been checking out about pellet sizing and the affects. Has anyone tried this and did it help any in group sizing. And also if you are shooting a heavier pellet and then shoot a lighter pellet and notice a louder pop and more recoil does this mean that the pellet is too light and a heavier pellet is needed? If any onecan help i would like to make my 1000s to last as long as possible. I just did a full tune on it. The orignal assembly lacked lubricant. The entire inside was dry.

I have not tried resizing pellets, but I can tell you a couple of pointers:

PELLETS WITH LOOSE FIT
1. A pellet that fits loosely on the barrel will not create a tight seal, which will cause blow-by (the air will flow around the pellet), and because there will not be pressure in the compression chamber, the piston will slam down, reducing the life of the riffle.
2. A loosely fitted pellet can fall out of the breach when closing the barrel.
3. This kind of pellets will not engage the riffling, creating larger groups.

LIGHT PELLETS
1. Because they need less pressure to be propelled, they will not create the needed pressure in the compression chamber, causing the piston to slam down, reducing the life of the riffle (a little less worse than dry-firing).

TIGHT FITTING PELLETS
1. Will reduce the muzzle speed because of friction

Keep in mind that light pellets are intended for pistols, not magnum air rifles. Stick to premium pellets like Beeman, RWS, and other well known brands, and choose pellets of at least 7 grains.

Just my opinion

so your saying that the lightweight gamo raptor hyper velocity pellets are a no no for my powerline 1000? they bring the gun up to super sonic though (can hear the sonic crack), and groupe very well. fit a bit tight in the barrell though.

But a few things I should point out:

First, if the pellets are going supersonic, then they SHOULD not group too good; aerodynamics would make sure of this, as far as I understand.  It is possible that what you are hearing as a crack is the piston slaming into the receiver (the speed of sound at about 33 degrees, which is what we have here year round, is about 1,150 FPS; a lower temperature will increase speed).  i am not saying that it is not possible that you are going supersonic, but pellets are not designed to go that fast, so they would wobble more at supersonic speeds because of the increase in air pressure on the front of the pellet, causing inacuracy (at least theoretically).

Second, the lighter the pellet, the less the air cushion created by the resistance of the pellet to move, and thus the harder the piston slams into the receiver.  Now the piston will ALWAYS slam into the receiver, but the harder it does it, the less the rifle will last you.

Third, the lighter the pellet, the faster you will lose energy down range.  Keep in mind that energy is speed times weight.  The less weight, the less inertia you have, and the more that wind will slow the pellet down down range.  The enery you transfer to the prey you are hunting is what will kill the prey, not the speed of the pellet (two points here, though: the faster the pellet, the flatter the trajectory and thus the easier it is to aim; also, if you have over penetration and go THROUGH the target, you are not transfering all of the pellet's energy to the prey, and thus the pellet is not being efficient for killing prey).

Fourth, if the pellets fit tightly, that should create more friction with the rifling, theoretically creating a better spiral and lowering the muzzle speed because of friction.  Excess friction can create the barrel to have more lead deposits, which means you will probably have to clean your barrel more often.  BUT, having a tight fit is MOST DEFENETLY better than having a loose fit, as a loose fit will allow blow-by (when the air expelled from the power plant goes AROUND the pellet insted of getting caught behind it and proppeling the projectile forward; in other words, blow-by will make you loose power).

Now having said all that, I would just stick to the pellets that group best with your particular gun.  Just make sure that the groupings are not restricted to short ranges, in case you go hunting, the extra distance can make the difference between a hit and a miss.

Felipe

well leading the barrell is not a problem out of the pellets, they are not leed. they are a bit harder than lead so they penetrate more. over penetration has not been a problem yet and groups are still acceptable out to about 50 yards with them. at 25 yards in my mostly unmoded gun they stay under an inch.(takes some time cause the trigger sux, but very repeatable) kinda expensive though. i am almost positive they are sonic cracks (only fools are positive) it is the same sound you get when you switch from subsonic 22 lr match grade ammo to hyper velocity ammo. maybe i can get a friend here at work to let me borrow a cam corder and post up a sound clip. as far as grouping they group the best followed pretty closely by the walmart cheapo copperhead pointed hunting pellets. i will continue to shoot the raptors out of my gun as they have proved very accurate and sufficient to kill coon sized game, and will let you all know of any ill effects. thanks for the input.

Adam,

I was reading online that someone (unknown author) tested resizing pellets, and the accuracy of his gun improved significant.

I think it is worth taking a closer look at this, as it seems the results are very favorable.  Just got to make sure the size is right for you gun...

Here's a transcript of the text (the original you can find at http://www.charliedatuna.com/airgun_docs/Pellet%20Sizing.doc)

Author unknown

Presented by Charlie

 

One night while shooting some of the cheap, nasty Industry .177 pellets I noticed shots were scattering all around the bullseye of the target. The gun I was using at the time has always shot very accurately in previous sessions and the only difference was the brand of pellet being used. So I dug out the venire (micrometer) and measured the skirts on several pellets! Whoa! They ranged all over the place and some were actually oval.

So I grabbed a piece of steel and drilled a .182" hole in it, hit it with a countersink to give it a bit of a smooth chamfer/lead and began pressing the pellets through it. After 10 or so pellets I gave them a try. Voila! The shot groups became much tighter and very acceptable. Even the gun sounded better...no longer wheezing on some pellets and sneezing on others.

After that I decided that a swage is pretty much a necessity for true accuracy. The folks at the gun club who shoot in competitions use a swage religiously (and a scale too) so this gave some credibility to their actions.

So I took a piece of 2" x 2" x 1/4" wall square tubing about 4" long and drilled a series of holes spaced evenly along one face: .177", .180", .182" and .185" in diameters. Again I used a countersink to chamfer each hole as a lead in. As a tool to press the pellets through I took a 1/8" hardened pin and soldered it into a 3/16" roll pin. Anything with a blunt end will work though...just so long as it fits inside the pellet skirt.

The reason for the different sized holes is that some guns behave differently than others with a given pellet skirt size. I wanted some variation available so I could determine which size shot best with which gun. I don't have any "results" as yet other than it appears that the .185" swage hole seems to work very well with my B-4-2 and KL-3B while the .180" hole seems to work best with both my Daisy 840's.

The swage block/tool worked so well with .177 caliber guns that I flipped the block and drilled holes for the .22 caliber guns: .221", .228" and .234" in diameters. I have no tangible results from those diameters as yet other than I did shoot some .228" in the B-4-2 and the results seemed as good as with the .234" hole in terms of accuracy at 30 feet. I have yet to chrony different skirt diameters though.

 

Thanks….Charlie