Which type and calibre of Air Arms pneumatic

[Ultrastu]

It's due mainly to the the shape the pellet deforms into as its fired or more precisely when the blast of air hits the skirt of the pellet .

So take a .177 exact it has a pretty thin skirt that obturates on firing the amount and pressure and duration of the air blast will deform it more or less .A high pressure short duration blast (springer with short barrel ) will blow the lead skirt deeper into the lands of the barrel and deform it by ballooning the skirt outwards .this ballooning of the skirt is more aerodynamic that the straight skirt that the unfired pellet has .or one that is fired from a low pressure long duration air blast from a pcp (longer barrel).

 

The shape of the skirt has a significant effect on the drag /bc of the pellet .look at my example above .

Think of the areodynamic of a car .the ones with a sloped off tail are better than ones with a vertical cut off .the front head /shape is only part of the equasion .

[Walker570]

Wind drift .... you eventually learn to read it if you shoot enough. Don't want to sound like a smart Alec, but you cannot beat experience and that comes from learning what your rifle does in various wind strengths. I shoot a TX200HV in 177 and on a windy day I will do a couple of test shots, one across the wind and one with the wind, which gives me some idea as to what I am contending with. BC will help but nothing like being able to read it. This last couple of weeks have been windy and I have had a number of 35-40yrd shots at magpies at all angles and one in particular at 35yrds across at 45 degs, I gave it a good five inches ... tend not to use the dots ... and the Maggie fell stone dead off the gate. Very satisfying. This was with JSB Exact 8.44gr pellets as recommended by the guys at Solware. The rifle and pellets shoot far better than I am capable of.

[bruno22rf]

So a PCP fires a smaller pellet than a Springer? - struggling to believe that. Lets take an AA TX200 and an S410 - both barrels are made by mr Walther and, chances are, the same deep borer and rifling tool are used on many rifles that AA produce. To say that the PCP causes less "Ballooning" of the skirt is akin to saying that the pellet never reaches the maximum diameter determined by the outer dia. of the barrel - i.e. the height of the lands produced by the rifling tool in relation to the actual bore size - this would have a serious effect on accuracy surely? yet the potential PCP 's accuracy is beyond question. If we were to accept that a springer does indeed increase the skirt size of the pellet then the BC changes by definition as being larger and is no longer relative to the PCP's projectile?

[Ultrastu]

Bruno mate .you have slightly miss under stood me .

The pellet size is the same that cant change .but if you retrieve a pellet that has been caught gently ie at distance into say a large box of rags so there is no impact damage .you can see the shape of the pellet as it left the barrel .

A springers are usually shorter in the skirt and it balloon outwards .So the straight side now take on a curved shape .A pcps less so .

Obviously a short barreld pcp running at high power can also balloon the skirt as its hit with a higher pressure blast .

 

This isn't something im making up its well known facts .and explains why many people often feel their springer hit harder than thier pcps .even though they are both sub 12 guns .

I have a fair few springers and pcps and can attest to this effect .

[bruno22rf]

I must be thick cos I'm just not getting it...you are saying that you have a PCP and a Springer firing the same pellet, at the same velocity, and you can tell that the Springer is hitting a Bunny harder than the PCP? Aside this is the idea that a Spring gun reaches a higher pressure in the chamber than a PCP when typical pressures, according to my limited research, seem to quote around the 2000 psi mark - a PCP charged to 200 bar is nearer 3000psi, as well as having the capacity to far exceed the volume of air in comparison to a Spring gun. Power is Volume multiplies by pressure in our case so where is the PCP losing all it's power?

[Mice!]

Got to laugh, I was expecting a "how great AA are" thread and its turned into a science lesson, point shoot enjoy, learn how your rifle behaves with different pellets or find one that covers all the bases accu pell for me in .22 not as flat shooting as .177 I know but I've mostly shot rabbit rat squirrel over the years, and .177 are too small and fidly for my liking.

[Guest]

Ha ha. I have to agree with Mice. I switched from 177 to 22 years ago for the same reason, and like Bruno's experience. Nothing wrong with 22.

[Hendrix's rifle]

Can't help on the air arms side of things but I've always used a 22 Springer and have taken many many jackdaws, crows, rabbit's, squirrels and rats over the last 10 years using it. If I had the choice of either rifle in .177 or .22, I'd go 22 and learn your holdover values. That way it doesn't make a difference because if you know how far to hold over it's dead anyway! Don't think it will know what pellet hit it.

[manton]

One point I forgot to mention and I wonder if it would have any effect on calibre choice is this . The model i am interested in is a 30 foot pound F.A.C. model .

[jacko53]

I am thinking about buying my first pneumatic after many years of using springers. I favour Air Arms but cannot decide between a 410 or a 510 . I also cannot decide between .177 or .22 Most of my shooting is informal target with some vermin control . I would very much value members opinions on these matters.

Go for the s510 as it is a real nice gun, I have one and I love it and the shot is top, right on the button each time.

[Ultrastu]

Well thats easy .if your going fac at 30 fpe .Then its a .22

But there is also .fac .177 at 16 - 18 fpe or .25 at around 40 fpe .