pellets and spring guns

[Guest hyperion]

Hi cometa a light weight pellet will allways produce more power in a springer

than in a precharge

yet a heavy pellet will allways produce more power out of a precharge than a

spring gun I don`t know why this is it just is

aa diablo should give you about the right power to weight ratio in your gun

in 177 in 22 i would go for a light weight pellet such as a bisley lrg or accupell

hope this helps

cheers stu

[forgive my ramberling im a bit p**s*d ]

 

 

I think (though may be wrong) that it is due to how the springer and pcp work, individually, like?

 

As I understand it, it would seem to go something like this:

 

In a springer, once the trigger is pulled, the spring starts to uncoil, and this shoots the piston on it's way up the compression cylinder, which continually compresses the air stored in the cylinder. About 2/3's of the way on the piston's way along the cylinder, the pellet starts to move along the barrel, having now got enough pressure behind it to start it moving . At this stage, the spring is still uncoiling and still piling on pressure on the now moving pellet. When the spring reaches the end of it's journey (near the exhaust port) its compression is ended. But the compressed air is still expanding at this point and so the pellet gets still more pressure behind it, and as the saying goes ' a rolling stone gathers no moss'. Therefore, the pellet leaves the springer's barrel with more power. So, in a springer, the air is always expanding, like.

 

On the other hand, in a pcp, once the trigger is pulled, the top hat valve lets a measured, pre-set amount of air into the exhaust port, which in turn lets this charge of air into the breech, which again in turn instantly sets the pellet in motion on it's journeyup the barrel. Once the measured dose of air is delivered to the pellet, and the pellet starts moving, there is no more expansion to be had from the air because it has been metered out. So whereas the springer has a continual air expansion process, the pcp doesn't have that benefit.

 

I'm sure someone more knowledgable in the subject will be along to either confirm my thoughts, or point out any innaccuracies in them.

 

 

All the best,

Grim.

 

hi grim

wrong way around bud!

the air delivered to the pellet seat in a pcp is under very high pressure so is always expanding, its the expantion of air that pushes the pellet and the heavier the pellet the harder the air has to work so the more energy it imparts to the pellet!, a springer squirts the air up the barrel behind the pellet at a lower pressure!

cheers

hyper

[SteveieP 0]

I think what you need to know is:-

1) Cometa springs aren't that good. Mend it with a Titan XS from Jon Kinibbs & co next time you need a new spring. Set you back less than £20 posted.

2) Use of heavier weighted pellets will take it's toll on the spring eventually. An ideal medium weight pellet is around 15 grains e.g H&N FTT's. A bit lighter like Accupels at 14.3 grains is fine or a little heavier like AA Fields at 16 grains is still ok.

Personally I can't see a need for anything lighter or heavier than the above for a .22, 12 fpe gun.

I don't think you can whack the AA's for general compatibility with most guns & heavy enough to knock even the toughest squizzer on it's back.

[Grim Reaper 1]

hi grim

wrong way around bud!

the air delivered to the pellet seat in a pcp is under very high pressure so is always expanding, its the expantion of air that pushes the pellet and the heavier the pellet the harder the air has to work so the more energy it imparts to the pellet!, a springer squirts the air up the barrel behind the pellet at a lower pressure!

cheers

hyper

 

 

Cheers Hyper for pointing me the right way round!

 

I thought about things while reading the posts, and merely sort of started typing my thoughts onto the screen - which is why it may seem a bit funny here and there? lol

 

It would in reality look like i was wrong (or at least as you say, got it put to paper 'the wrong way round' ), but at the time, i felt that what i was writing was correct (at least it seemed that way when i was thinking it)?

 

I have no problem at all in admitting i was wrong mate - thanks again. I don't like giving wrong or misleading information out, and that was why i was waiting for someone to do what you just did.

 

 

Best regards,

Grim.

[Guest hyperion]

no worries grim!, i only know because of what ive learned from air gun world and airgunner! lol!

im pretty damn sure my info is correct but if any one knows better...............?

cheers hyper