Do sized pellets foul less?

[Corvid_hunter]

I had washed a few tins of JSB 25gr Redesigned pellets and decided to size them to 5.52mm. I was surprised at the amount of swarf that came off as a result of the sizing. It got me to thinking that although not all of the swarf would be deposited it the barrel, but some of what came off the pellets must stay in the barrel. Pic of what came off of 1 tin of 200 pellets after they had been washed and then sized.

Pic of sized and unsized pellets (washed).

Looking at the pellets I would assume that sizing them would lead to increased accuracy. The recommended slug size for my barrel (.22cal Red Wolf HP) is .217" from what I have read. These pellets are .2175" after running through the sizer (if my conversion app is correct). There is an increased (uniform) bearing surface to engage the rifling from the initial chambering which should aid in accuracy. Or I could be wrong. At the very least, they should shoot as well as the ones straight from the tin. Will be lubing these ones with Pledge prior to shooting.

 

[Yo]

Pledge is good. Sizing and barrel cleaning all depends on the gun. Some matters some don't. I think weighing pellets is more important than sizing for accuracy JMHO... I weighed pellets then shot for groups over a crony and got the best groups at 50 shooting only weighed pellets which gave an es of 4fps and a sd of 1. GET THIS...Shot out of an old non regulated Theoben Rapid 20 cal shooting the now impossible to find Crosman Premiers. Sizing didn't matter according to my testing and I used the Beeman Pell sizer with the 0.2020 die. Yo!

 

[TXPlinker]

I'm guessing a lot of what you are seeing is from your sizing die scrapping lead off your pellets (look at your skirts).

 

[nervoustrig]

Generally you wouldn't want to size skirts, only the head. The skirt is deliberately a few thousandths oversized so it will conform to the bore as it is chambered, helping to ensure a good seal to minimize blow-by. It's certainly fine to experiment both ways though because you never know until you try.

Regarding the swarf (actually mold flashing), it's not being deposited in the bore. What accumulates in the bore is that which is abraded from the pellet as it is violently accelerated on its way out the door. It’s kind of an academic point but most of what gets deposited is indeed from the skirts because the pressure pulse expands it to the full groove diameter such that it takes on the distinct cog-like shape of the lands and grooves. That expansion, along with the radial forces set up by the spiral, gives it the opportunity to begin laying down lead in the inside corners of the rifling. Conversely, the head doesn’t touch the full groove diameter so it’s not as apt to leave material behind.

Instead, where you will find those little flakes is in shrouds and LDCs where they get blown into.

 

[nervoustrig]

By the way, I would say the most effective ways to reduce leading is to give the bore a proper treatment and use lubricated pellets. The bore treatment I’m referring to is polishing it (generally a one-time thing) and then thoroughly clean it and apply a hard wax. Not only will cleaning be necessary less often, it will be super easy to clean when the time eventually comes. Also, intermediate cleanings can be done with dry patches rather than breaking out the solvents and starting over so to speak.

Lubricating your pellets will help some too but likely a distant second. It’s more beneficial with slugs because of the vastly larger bearing surface.