Guest Posted November 20, 2017 Report Share Posted November 20, 2017 I've seen it mentioned a couple of times on the forum. I can't see the point of fac .177 rather than .22 but I am open to the pros and cons. Discuss! Quote Link to comment Share on other sites More sharing options...
manthing Posted November 20, 2017 Report Share Posted November 20, 2017 From what I've read you want to try and avoid the pellet getting supersonic (1100f/s depending on altitude and temperature) as it can cause the pellet to become unstable. A 177 doesn't need to get that much more speed to go supersonic. Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 20, 2017 Report Share Posted November 20, 2017 I feel I'm pretty qualified to answer most of your questions on this subject . But first , any fac gun requires to be a solution to a problem . So say your problem is squirrels high up trees .or crows nesting 50 yds high up a tree. The solution ? Shot gun .? Possibly too loud..possibly ..too far for the pattern . A .17hmr .? .22 lr. ? .308 .? Dont be silly . So maybe a .25 fac air .? Well that would be effective but what about the fallout ? Too risky. .22 air .16 grn pellet on the head ? Again too risky . How about a 8.4 grn .177pellet falling out the sky with less energy than a hailstone .? Much reduced risk .though it's still there a bit. Fac air has its place .its all about having a need and filling it with the most suitable gun. I have fac .177. 22 and .25 And use them all differently . None is ."better " the others . "For rabbits" I hear u say Well I have perms where I'm close to houses.and the .177 is a much safer prospect over the .25 and .22 The trajectories are basically the same and they all kill rabbits well .accuracy is great for them all .but the .25 goes a bit further and bucks the wind a bit better . Quote Link to comment Share on other sites More sharing options...
Mice! Posted November 20, 2017 Report Share Posted November 20, 2017 You should have said, read all the other posts where you have already written this, I've read in a few places now of folk saying there using fac .177 air. Now just to make it interesting i said I would put this up and forgot, December 1992 Airgun World. How is this for different thinking Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 20, 2017 Report Share Posted November 20, 2017 It is different thinking, wind drift is ,broadly speaking , related to the bc of a projectile .the size of the pellet has little to do with it . Quote Link to comment Share on other sites More sharing options...
Mice! Posted November 20, 2017 Report Share Posted November 20, 2017 I re read it a few weeks ago and thought everyone seems to say that .25 is less affected by wind than the .177, but that article says different?? it will niggle at you now so look forward to the results in a few weeks ?? Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 20, 2017 Report Share Posted November 20, 2017 Its often thought that a .177 due to its smaller side profile compared to the larger pellets has less side wind acting on it. But wind never blows on the side of a pellet in flight .air only passes over the front of the pellet from directly infront of it . Quote Link to comment Share on other sites More sharing options...
Mice! Posted November 20, 2017 Report Share Posted November 20, 2017 The cross wind must have some effect otherwise you wouldn't need to aim off to allow for the wind? Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 20, 2017 Report Share Posted November 20, 2017 Oh it has an effect .ofcourse. but it doesn't blow on the side of the pellet .only air passes over the front .towards the rear of the pellet . Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 20, 2017 Report Share Posted November 20, 2017 Think of a plane flying in the sky with a cross wind .and the piolet wants to head in a straight line to the airport .he angles his plane slightly nose first into the wind .ie if the cross wind blows from the right his nose points slightly right into the wind .the combined speed of the wind over the planes nose is from the say 400 mph forward momentum and the 30 mph side wind .as you see the 400 mph of the plane creates a much much bigger vector of force on the nose of the plane compared to the slow cross wind relative to the earth .a gun projectile flies faster than this plane and so the side vector is a smaller percentage of the force .but like the plane it will naturally tip into and face the combined wind (force ) head on .as the skirt of the pellet (like a weather vien) makes it do this . Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 20, 2017 Report Share Posted November 20, 2017 So just like the plane, although the pellet is pointing slightly into the wind from the right it moves with the wind and the poi is to the left of the poa. The problem with shooting in the wind is that because the pellet is facing slightly one way but travelling slightly in the opposite direction this can destabilise the pellet over extended ranges and is one of the reasons that groups open up as opposed to grouping well, but just to one side ..spinning a pellet in the barrel has the effect of stabilizing the pellet.and what this means is that the pellet will want to stay pointing in exactly the direction it was shot .ie forward .not left right up or down .this stabilization can have a negative effect at long range as all the out side forces are pushing it different ways and the spin acts against them but also at odds against the direction of travel . For very long range shooting a slower spin rate is often better as it allows the pellet head to follow the natural line of trajectory. Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 20, 2017 Report Share Posted November 20, 2017 So trying to get back on track a bit . Take a .177 at 900 fps bc.0.021 A .22 at 900 fps bc.0.029 And a .25 at 900 fps bc .0.035 Typical med weight pellets from jsb Over 50 yds the .177 displaces nearly twice that of the .25 in a cross wind . With the .22 between them . The .25 gets to the target faster than the .22 and .177 as the better bc means it retains its velocity better over distance .hence it spends less time in the flow of moving air and hence displaces to the side less . Quote Link to comment Share on other sites More sharing options...
Mice! Posted November 20, 2017 Report Share Posted November 20, 2017 Cheers Stu, always interesting. come on Dc what's your thoughts? You thinking of a fac in a different flavour? Quote Link to comment Share on other sites More sharing options...
Fisheruk Posted November 20, 2017 Report Share Posted November 20, 2017 I use an FAC .22 in the States and you can hear the supersonic crack. Very accurate and amazing the way you can take Squirrels easily out of tree tops at 60 metres. Quote Link to comment Share on other sites More sharing options...
Guest Posted November 21, 2017 Report Share Posted November 21, 2017 So scratching my head now but I still cant see any particular benefit of .177 fac over .22. It seems like a very specialist calibre at fac - the .22 being a good all-rounder. Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 21, 2017 Report Share Posted November 21, 2017 That is about right .if going for 1 fac air only .then you would be best served with a .22 running between 25 - 30 for. Jack of all trades master of none .. You want long distance bunnies with plenty of safe back stops.? Get a .25 cal at 45 fpe . You want elevated shots and less than ideal back stops (obviously within reason) then .177 .22 runs the middle ground. Personally i don't take elevated shots with my .22 unless I can see the treetrunk behind the quarry . Oh I run my fac .177 at 16 fpe .and .22 at 23 fpe. And .25 at 45 fpe. The .25 cal also being a specialist calibre .ie safe rabbits. = might as well have a .22lr.....almost. Quote Link to comment Share on other sites More sharing options...
Guest Posted November 21, 2017 Report Share Posted November 21, 2017 I am a mostly rabbit man. Elevated shots only taken with sub 12ftlb. So 22 fac has its place when the 22lr would not be safe. The 177 is best left at sub 12 for my needs. Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 21, 2017 Report Share Posted November 21, 2017 Fair enough If you already have a .22lr .there is little point in stepping on its toes with a .25 cal ..a .177 sub 12 is perfect for close stuff .yep id go with the .22 fac air too if I were u . Just don't expect to be able to shoot rabbits at 80 + yds or with anywhere body shots. My .25 needs head or heart shots Quote Link to comment Share on other sites More sharing options...
Walker570 Posted November 21, 2017 Report Share Posted November 21, 2017 Excellent advice. You can have a Plus 1 on your school report Stu Having just purchased this AA200 .22 with the facility to upgrade to plus/over 12ft your advice is first class. I was aiming to raise up to around 20fpe for those squirrels that sneak out just over the 40yrd marker. Quote Link to comment Share on other sites More sharing options...
suburban shooter Posted November 21, 2017 Report Share Posted November 21, 2017 A cross- wind doesn't just affect the pointy end of a jumbo jet surely ? Like the Coriolis force in water there must be an effect on the plane from the large body of air . Fast pellets are affected less than slow ones as there is less time for the force to be applied. Same speed pellets of differing size and mass I don't know but this is the most interesting bit. Quote Link to comment Share on other sites More sharing options...
Walker570 Posted November 21, 2017 Report Share Posted November 21, 2017 I can see the 22 pellets bend through 10 power on my scope. Made the most of it today in a 12mph wind across the shed roof, I could see that pellet bend about 2 inches in 30yrds prior to it hitting the barn pigeons. Haven't a clue what part of the pellet was effected but seeing the first miss by 2 inches was not good news for 9 barn pigeons which followed. Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 21, 2017 Report Share Posted November 21, 2017 33 minutes ago, suburban shooter said: A cross- wind doesn't just affect the pointy end of a jumbo jet surely ? Like the Coriolis force in water there must be an effect on the plane from the large body of air . Fast pellets are affected less than slow ones as there is less time for the force to be applied. Same speed pellets of differing size and mass I don't know but this is the most interesting bit. At first it seems counter intuitive. Surely the cross wind blows on the side of the plane ?? No it doesn't . Not a bit .Not even slightly .all the " wind " , see air flow .is from front to back from the nose to the tail . If the plane slows to such a slow speed as to be the same as the velocity as the cross wind then to go forward towards the airport destination the plane would fly at 45 degree to the cross wind /airport .this would mean the resultant wind direction would be over the nose to the tail .So same as above . So can see planes approaching this effect when landing in a heavy wind and being a small light (slow speed ) aircraft . Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 21, 2017 Report Share Posted November 21, 2017 Plane coming to land in a strong cross wind . Has to aim into the wind so the air flows over its wings .if it didn't it would fall out of the sky Plane coming to land in a strong cross wind . Has to aim into the wind so the air flows over its wings .if it didn't it would fall out of the sky The direction of travel is directly along the runway Quote Link to comment Share on other sites More sharing options...
suburban shooter Posted November 21, 2017 Report Share Posted November 21, 2017 Yes understand how big 200 tonne big planes can fly better than light weight crisp packet but there must be some wind force against side of plane even if just pushing against overflow from lift over wings. But your explanation does correlate with fact that Crossman Powapell deflects less than Accupell which is same weight and speed. However I have said before that I feel that the .177 version ( 7.9g) is deflected less than the 14.3g .22 version. Are you sure that .177 is same ballistic co efficient to .22 version of the same pellet ? Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted November 21, 2017 Report Share Posted November 21, 2017 Chairgun has the bc of a .22 powerpells at 0.025 and an accupell at 0.026. So no discernable difference . (Your gun though could make the difference. And shoot the powerpells with a higher bc .the above values are just averages of many tests . The .177 bc of an accupell is 0. 021 according to cg. So where the higher bc of the .22 means that the pellet retains its velocity better it still takes longer to get to target . We should always remember that a deflection due to wind near to the muzzle will be greater than the same wind force on the pellet if it were received further down range . Quote Link to comment Share on other sites More sharing options...
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