Pellet/airsoft barrels

[jackssmirkingrevenge]

Almost all of them are larger than the nominal diameter, otherwise they don't bite the rifling and fall though the barrel. Some brands like JSB give you the option of different sizes in increments of 0.01mm to suit your particular barrel.

[Ragnarok]

Some brands like JSB give you the option of different sizes in increments of 0.01mm to suit your particular barrel.

That's actually a rather laughable concept. Have you ever put some vernier calipers across any pellets?

I have, and the results were...

Crosman Premier lites, .177" - Measurements are taken at two points 90 degrees to each other, which relate between the skirt and head measurements.

All pellets are from Die #1 and the same batch on 13 Nov 2007

Pellet 1: H 4.48/4.48 S 4.59/4.59
Pellet 2: H 4.46/4.47 S 4.54/4.59
Pellet 3: H 4.47/4.47 S 4.59/4.56
Pellet 4: H 4.47/4.47 S 4.58/4.55
Pellet 5: H 4.47/4.46 S 4.36/4.63 (Visibly warped skirt)
Pellet 6: H 4.47/4.47 S 4.59/4.60
Pellet 7: H 4.47/4.47 S 4.56/4.59
Pellet 8: H 4.47/4.48 S 4.57/4.57
Pellet 9: H 4.46/4.47 S 4.58/4.60
Pellet 10: H 4.45/4.47 S 4.55/4.61

Premiers aren't a bad brand of pellet, but as you can see, they're not perfect to the hundredth of a millimetre - even though it's the same batch and die.
They can't be selling pellets accurate to the hundredth of the millimetre, because the standard deviation on the production is too large.

It came up on AirgunBBS here: http://www.airgunbbs.com/forums/showthread.php?t=289835
(I'm Skoll on there BTW)

In general with most brands, the head is roughly the published size, take a couple of hundredths of a mm, and the skirt is about 0.1-0.2mm bigger than that.
The skirts are designed to be pressed into the bore anyway to get the right fit, so in any case, the head size is the most important factor in whether it will fit the bore neatly.

Almost all of them are larger than the nominal diameter, otherwise they don't bite the rifling and fall though the barrel.

Actually, despite being quoted as a 4.5mm barrel, pellets I've recovered intact after firing show the choke on my TX is only about 4.45mm, so there aren't really any worries about the pellet not biting into the rifling.

[jackssmirkingrevenge]

I tried several brands of 0.22 pellets in a true 5.5mm I/D brass tube, all of them had to be swaged down - rather forcibly - to fit.

[ghostman01]

hmmm, ill try to get my hands on some .22 pellets from my cous then ill measure that brand with my vernier and try to find some 5.5mm aluminium around the place or even hydraulic pipe, This page might help with sizes and stuff

[jackssmirkingrevenge]

I like going for 6mm barrels, it gives you the option of shooting airsoft BBs too.

[ghostman01]

Yeah but i cant get my hands on any 6mm bb's lol will this .21 fit .22 pellet heads ? or will the skirt and the head not fit ?