Pellet sizing

[stu64]

I've just bought a lovely new air arms S410F carbine and its certainly an accurate gun. while I was buying it I picked up a tin of air arms diabolo pellets 4.52mm. I then got some webley accupell and some jsb exact 4.51mm. After some paper bashing I really couldn't say one pellet grouped better than the other, all were excellent and certainly the gun and pellets were better than me. I don't know why but it occured to me to measure pellet head, so with digital calipers in hand i set to work. accupell don't actually give a head size but mine were very consistent at 4.48/4.49mm. the exacts labelled as 4.51 were actually 4.49, and the aa diabolo labelled at 4.52 were actually 4.49/4.50.

I then went on to measure some h&n field target trophy in .22 I've had for years that none of my guns like. labelled as 5.53mm they actually measured up at 5.55/5.56. I then measured some jsb exact in 5.50, 5.51 and 5.52 and they all measured the same at 5.48/5.49.  Has anyone else measured pellets? what did you come up with? as far as I can see unless you are buying hand sorted match ammo, what it says on the label may wrong. I will add the all the pellets were very consistent in there measured size. In the end I suppose it doesn't matter whats on the tin, its whats on the target that matters. Weighing them is another story.....

 

[ditchman]

you can get really anal about pellet quality...i did..................and still am...............couple of years ago i made a "pellet sizer" and posted it up on thye forum.......

[Whitebridges]

The truly anal airgunner will possess some resizers and a set of scales. If you make a call to invest i hope this shows up in the guns groups. 

 

[Ultrastu]

You will probably find that the skirt size has more effect on the the pellets performance than the head size .

The skirt is responsible for sealing the bore from air blow past . (Obturation into the bore ) 

Its also the last bit to leave the barrel and stablises it in the bore .

The skirt is also responsible for the turbulance of air flow off the back of the pellet in flight and the shape it takes on in the barrel makes a huge difference to this . (Some skirts balloon out massivley .creating different results in stability ,bc , yaw , momentum of angle and finally accuracy )

Check your skirt size mate .

I found years ago that you can change the skirt diameter of a pellet (up or down ) and effect groups size massivley  

Depending on gun can pellet etc .

Edited April 30, 2019 by Ultrastu

[stu64]

1 minute ago, Ultrastu said:

You will probably find that the skirt size has more effect on the the pellets performance than the head size .

The skirt is responsible for sealing the bore from air blow past . (Obturation into the bore ) 

Its also the last bit to leave the barrel and stablises it in the bore .

The skirt is also responsible for the turbulance of air flow off the back of the pellet in flight and the shape it takes on in the barrel makes a huge difference to this . (Some skirts balloon out massivley .creating different results in stability ,bc , yaw , momentum of angle and finally accuracy )

Check your skirt size mate .

I found years ago that you can change the skirt diameter of a pellet (up or down ) and effect groups size massivley  

Depending on gun can pellet etc .

Yes I totally agree with you but the size on the tin is head size isn't it. 

[ditchman]

7 minutes ago, stu64 said:

Yes I totally agree with you but the size on the tin is head size isn't it. 

yes it is....................but you meauser them with a micrometer...........you wont get 2 the same size........

[Ultrastu]

Just now, stu64 said:

Yes I totally agree with you but the size on the tin is head size isn't it. 

Yes it is .

For what its worth. 

 

And that might be why some manufacturers  dont put it on the tin .

 

[stu64]

👍😄

[Mice!]

read a few times about people using pellet resizers, and i imagine the FT guys weigh and measure every pellet.

Like Ditchy says i would measure with a micrometer if you want to be accurate, just be gentle.

it does show though why your guns didn't like the H&N.

[Ultrastu]

Problem with a pellet sizer  (say 4.52 mm ) 

Is that the pellet head might be 4.49 mm (not going to make it bigger )and the skirt around 4.7 mm which when its gone through a sizer will now be 4.52 mm .and not ideal for sealing (obturation) in the bore. 

Besides if you push a pellet into a barrel it gets sized to perfection at that point .

I dont see the point in pellet sizers personally .especially in pcps .

There could be slight argument in a springer .just .

[Mr.C]

Personally I filter all my pellets by rolling individually between my fingers followed by a visual check. 

By that I mean I take one out the tin and if the skirt doesn't look round it doesn't go in the barrel.

I've more chance of wobbling out of a free stander or being winded out of 35mm at 40yds than getting a flier.

AA diabolo 4.52.

Having said that those die 42's are very good 😉 

[bruno22rf]

stu64 - repeat your measuring tests after holding your pellets in your hand for a minute - totally different size. If you are going to be so anal as to measure pellets then it should be done at a standard temperature.

[stu64]

I suppose where I was going with the post was to show that the labels h+n and jsb put on the bottom of the tins is a load of twaddle. I'm not into measuring and weighing pellets normally- i test pellets to see what works down range and leave it at that. The pellets I measured were all off the same shelf and  measured at the same time so no temp variation there. If I got into HFT I might take it more seriously. I guess a better title for the post would have been pellet size and not pellet sizing 😄

[wobbly bob 2]

On 30/04/2019 at 21:26, Ultrastu said:

 

I dont see the point in pellet sizers personally .especially in pcps .

I've tried them for pellets in my HW100 and the results on paper at an indoor range were a quite a bit worse than pellets straight from the tin.

[bruno22rf]

You may be missing my point stu64 - bring the temp of the pellets up to exactly 20c before measuring them - pretty sure that 20 degrees is the standard temp when measuring metal.

[stu64]

2 hours ago, bruno22rf said:

You may be missing my point stu64 - bring the temp of the pellets up to exactly 20c before measuring them - pretty sure that 20 degrees is the standard temp when measuring metal.

I didn't know that 👍 every day's a schoolday 😤

[zx10mike]

i'll go against the grain and say that i have tried sizing and weight sorting and see no real benefit . i often paper punch out to 100 yards in an fac wolf and can honestly say i can't find a way to cull flyers without going down the slug route.i also find reading the wind is way more of a problem than flyers.as said earlier on here earlier visual ispection probably is the best route.but all that said i'm watching the thread to see if i can learn a new trick.

 

[figgy]

I've also weighed measured sorted and lubed, could not find any difference worth bothering with. Only thing I'd look for is if shooting comps weigh them and check for damage. The odd pellet would be heavy or light by a good amount.

Tried shooting all the pellets with lightly damaged skirts and they all shot fine, crushed ones got binned. Tried shooting some bent skirts into water, heads got bent out shape on impact but the skirts all opened out and had rifling marks.

Biggest factor I found was in my old Springer days I never cleaned a barrel ever,never had accuracy issues.

Modern PCP, I tried not cleaning and seeing if it would shot through the fouling and become accurate when it got to its own level of fouling. Where it won't get any more fouled up and no it wouldn't shoot straight. Cleaned and shot a few to sort the barrel and back to accurate. Soon as it goes off I clean it.

Edited May 7, 2019 by figgy