Pellet Head Size question (4.51/4.52)

[Big Dog]

I'm feeling a little bit daft asking to be honest, but could someone explain the difference and/or relative benefits between 4.51 and 4.52 .177 pellets?

I've never paid much attention to the pellets that I buy, I usually just pick up Air Arms Diablo Fields as they have always suited whatever I have been shooting. Went to get a couple of tins to tide me over this morning and was asked whether I wanted 4.51's or 4.52's. To be honest I didn't have any idea, didn't realise that there was a difference. Checked a the price tag on the bottom of a couple of old empty tins I have here at home and one says 4.51, the other 4.52.

Any help or explanations would be much appreciated.

[granville]

head size of the pellet in mils .

[Timmytree]

I'm not sure how important head size is, I've tried both sizes in the Prosport and 4.52 was best but maybe that was down to batch or die and not head size?
Realistically, no machinery could produce lead pellets to that kind of tolerance anyway. I don't think you could measure the difference either.

[gary martin]

I'm not sure how important head size is, I've tried both sizes in the Prosport and 4.52 was best but maybe that was down to batch or die and not head size?
Realistically, no machinery could produce lead pellets to that kind of tolerance anyway. I don't think you could measure the difference either.

spot on Tim, the size relates to the die size. the pellets though will vary. just try and find a batch/die number which works in your barrel.

[FPoole]

I've seen a good few tins of 4.51 AA that fit tighter in the breech than 4.52 JSB's. The inside profile of the skirt is different between AA and JSB and this is what makes some of my guns prefer one or the other. We have a guy on this side of the Atlantic that measures the heads with veneer calipers. As Timmytree says, I don't think you can measure that close with normal tools. I think he's full of it, or maybe I'm just not as good with my calipers. Forgot to mention, he claims to measure to .005mm.

[Timmytree]

I've seen a good few tins of 4.51 AA that fit tighter in the breech than 4.52 JSB's. The inside profile of the skirt is different between AA and JSB and this is what makes some of my guns prefer one or the other. We have a guy on this side of the Atlantic that measures the heads with veneer calipers. As Timmytree says, I don't think you can measure that close with normal tools. I think he's full of it, or maybe I'm just not as good with my calipers. Forgot to mention, he claims to measure to .005mm.

Maybe that extra .005 is important to his missis!

[Big Dog]

Cheers all, will stick with the 4.52's I think.