.177 f.a.c.

[dr_nick]

Has anyone tried an F.A.C. .177? I have a slot on my ticket and I could send my s410 to ben taylor. The idea of a 10g 177 pellet at 930fps sounds like a good hunting tool. It should shoot flat right out to 65 yards (acording to my software) with plenty of energy still left.

[bunny_blaster]

i think that once a .177 pellet goes over 20 ft/lbs it breaks the sound barrier and u get the sonic crack. .22 on the other hand can go up to 30ft/lbs without becoming sonic.

 

cheers

ben

[king ratcatcher]

I would have a .22 if i was going onto FAC deffonatly

[henry d]

i think that once a .177 pellet goes over 20 ft/lbs it breaks the sound barrier and u get the sonic crack. .22 on the other hand can go up to 30ft/lbs without becoming sonic.

 

cheers

ben

Don`t think ask............any,and I mean any,object that exceeds 330m/s(if my O level physics is still correct) will then break the speed of sound and can only be moderated.

So if dr nick sends a pellet of .177/.22/.25/.50...........whatever @ 930fps then it will never break the sound barrier,it is not dependant on calibre just pellet velocity.

[roblade]

Don`t think ask............any,and I mean any,object that exceeds 330m/s(if my O level physics is still correct) will then break the speed of sound and can only be moderated.

So if dr nick sends a pellet of .177/.22/.25/.50...........whatever @ 930fps then it will never break the sound barrier,it is not dependant on calibre just pellet velocity.

 

which for those of you that still prefer a pint when you go down the pub, is roughly equal to 1138fps.

 

as for having a .177 fac i personaly i would prefere a slightly harder hitting .22, a .22 running around 24f/lbs is going to be pretty damn flat, with a nominal amount of hold over out to 75 yards.

 

all i can say is try one before you part with you money and take up a very important slot on your FAC, just look at how many .177 fac rifles have been sold, i think that fact alone should be enough for you.

 

If your talking fac and different calibers you should be going up the scale rather than down, have a look at a high power .25 or even consider the super high power stalker rifles .50 cal running 3,000 flbs (or was it 300?)

 

ROB

[kdubya]

as for having a .177 fac i personaly i would prefere a slightly harder hitting .22, a .22 running around 24f/lbs is going to be pretty damn flat, with a nominal amount of hold over out to 75 yards.

 

 

using something like an aa fields @ 24lbs and say with a zero of 45 yards the drop will be 6" @75yards

not exactly flat, even worse with 21 g bismags I am running one gun @40lbs with aa 16g fields its doing around 1060 fps so no where close to the 1116 fps "boom" speed and even that needs calculated hold over from 60 yards mind you anything between 12 and 60 is a simple point and aim at a bunnies head

cheers KW

[roblade]

using something like an aa fields @ 24lbs and say with a zero of 45 yards the drop will be 6" @75yards

not exactly flat, even worse with 21 g bismags

cheers KW

 

oh i really hate you sometimes LOL

 

The point i was trying to make was an FAC .22 would be able to get a lot flatter and more manageable. I mean compare it to the 30" hold over required for a standard rifle and i would say it was pretty damn flat LOL

 

WARNING THIS POST COULD MELT YOUR BRAIN!!!!!

 

to give you a comparision, it has been aleged that no PCP rifle can push a pellet beyond 1130fps (the sound barrier) due to variouse physical reasons, im not starting this up as a debate on that matter, just using it as a refernce point). but lets take this statement as true.

 

a standard .177 runs around 800fps so increase that velocity up to 1100 is onyl an increase of about 300fps (or 37% increase in velocity) which would give us a MAXIMUM power of 28flbs which is an increase of approx 250%

 

now for the .22 this runs a little slower at around 600fps so is able to increase a lot more in velocity to reach 1100fps an increase of 83% on velocity which measn the power its capable of would be around 62flbs!!!!by my calculations that is an increase in power of around 520%!!!!!!

 

with the .25 being an even higher power level.

 

to give you an idea of the number of shots you would get, im sure you know how many your rifle does and in comparision to the standard .22 it does approx 30% less. a 24flb S410 will give around 24 consistant shots so 30% from that is less than 20 shots, now even for the fields that is a pretty low number. Yes i know it wont be exactly 30% less shots becasue its a high powered version, but you get the idea.

 

just curiouse but you say "it should have pleanty of energy left at 65 yards" just how much energy do you need out to that distance?

 

Like i said check the sale sections or phone up a few gun shops and see what they would offer you for a .177 FAC S410, im will to bet its a lot less than the .22 version, remember once on ticket always on ticket (and yes i do know there are exceptions to this rule as well LOL)

 

ROB

[lurcherboy]

Don`t think ask............any,and I mean any,object that exceeds 330m/s(if my O level physics is still correct) will then break the speed of sound and can only be moderated.

So if dr nick sends a pellet of .177/.22/.25/.50...........whatever @ 930fps then it will never break the sound barrier,it is not dependant on calibre just pellet velocity.

 

which for those of you that still prefer a pint when you go down the pub, is roughly equal to 1138fps.

 

as for having a .177 fac i personaly i would prefere a slightly harder hitting .22, a .22 running around 24f/lbs is going to be pretty damn flat, with a nominal amount of hold over out to 75 yards.

 

all i can say is try one before you part with you money and take up a very important slot on your FAC, just look at how many .177 fac rifles have been sold, i think that fact alone should be enough for you.

 

If your talking fac and different calibers you should be going up the scale rather than down, have a look at a high power .25 or even consider the super high power stalker rifles .50 cal running 3,000 flbs (or was it 300?)

 

ROB

 

 

Dr Nick, I assume you are a 'real' doctor so take heed of roblades post.

 

He does it and knows whats what.

 

 

 

LB

[roblade]

Dr Nick, I assume you are a 'real' doctor so take heed of roblades post.

 

He does it and knows whats what.

 

 

 

LB

 

now i have put a reply up while you were typign that, say that without laughing LOL i think i melted my brain doign that one :'(

 

ROB

[kdubya]

speed of sound at sea level = 1 116.43701 feet per second just to clear that one up?

 

cheers KW

[deadeye ive]

What was left of my shrunken by alcohol brain as now melted .........Thanks Rob

 

Ouote From Air Arms site

 

The S410 Xtra is the highest powered gun in the Air Arms range. Producing 28-30ftlb (38-40joules) in .22 there is plenty of power for most air rifle applications. Depending on the pellet used velocities of 1000ft/sec in .22 (5.5mm) and 1100ft/sec in .177 (4.5mm).

 

You'll get less shots per charge with the lighter pellet Dr Nick ...........Go .22 with a 16 grn'r as mentioned previously for flat shooting

[P03]

speed of sound at sea level = 1 116.43701 feet per second just to clear that one up?

 

cheers KW

To absolutely accurate the speed of sound at sea level is 1116.447835 with an atmospheric pressure of 1013.25 mb.

 

As I've said before......MEEEEE!.. ...pedantic!!

[pin]

If we are being pedantic, pressure has little to do with the speed of sound (in air), however temperature does.

 

At 15C at sea level its about 340m/s

At 35000 feet (about -57C) it drops to 295m/s

[P03]

If we are being pedantic, pressure has little to do with the speed of sound (in air), however temperature does.

 

At 15C at sea level its about 340m/s

At 35000 feet (about -57C) it drops to 295m/s

Au contrare Pin. The transmission of sound is all about the movement of molecules, the higher the pressure, the denser the air, the faster sound travels.

[dr_nick]

What a can of worms that question opened up.

 

I do have a fairly good idea of the physics behind pellets at fac levels.

 

Basically if you go beyond 900fps you start to get problems with turbulence which gets worse the closer you get to the speed of sound. Anything going through the sound barrier gets buffeted badly which kills accuracy. It’s the transition that is the problem. You can actually push a pellet faster than the speed of sound but it will very quickly decelerate and pass through the sound barrier which is bad. Don’t forget by the time the pellet leaves the barrel it would already be travelling at its maximum velocity, it does not continue to accelerate (once you stop pushing something it stops accelerating, trust me on this). This is why you don’t get the problem with centerfire velocities since they do not decelerate below the speed of sound until they hit something or travel beyond a couple of thousand yards or more depending on the calibre but are already going super sonic before they leave the barrel. To summarise the velocity above 900fps an up to the speed of sound gets more and more hostile the closer you get. Pellets are not deigned to go super sonic as they do not have the right shape to do so efficiently (they also start to melt in the barrel which is another problem).

 

Now a standard .177 pellet is usually around 7 and a bit grains, which at 12ftlbs = 800fps which is all sorts of good.

 

However when you crank this up to 20ftlbs it goes way beyond the 900fps sweet spot. So you have to bring the velocity down to around 900 fps. You can do this by increasing the pellet weight, for this level 10 grains works well and gives the 930fps which is sweet.

 

So now the physics is sorted out, what about the real world. From your answers I take it that it is not a popular option and would not be worth the money which is sad but not unexpected.

[kdubya]

If we are being pedantic, pressure has little to do with the speed of sound (in air), however temperature does.

 

At 15C at sea level its about 340m/s

At 35000 feet (about -57C) it drops to 295m/s

Au contrare Pin. The transmission of sound is all about the movement of molecules, the higher the pressure, the denser the air, the faster sound travels.

 

WRONG? temp is the variable factor with the sound of speed?

 

ie Air pressure and air density are proportional to each other at the same temp?

meaning that the speed of sound in AIR depends on the density of air AND the density of air depends on the TEMPERATURE

so at the same temp the speed of sound on a mountain peak will be the same as the speed of sound at sea level

cheers kw

[Evilv]

Has anyone tried an F.A.C. .177? I have a slot on my ticket and I could send my s410 to ben taylor. The idea of a 10g 177 pellet at 930fps sounds like a good hunting tool. It should shoot flat right out to 65 yards (acording to my software) with plenty of energy still left.

 

If you have a FAC, why stick with 'air'?

 

I just bought a CZ425 standard and stuck an old silencer on it. It is quieter with 1085fps 120 ft pound Eley hollow point Subs than any of my airguns (strange but true) but makes a very mighty 'SMACK' when it hits the bunny. They don't even twitch. I took out four in a group one after another last night at 55 yards and they didn't spook at all. As for the result - small entry hole one side, empty head cavity the size of a 20p piece the other. Very humane and effectively point and shoot between 20 and 60 yards.

 

What's more the gun onl cost £230.

[P03]

If we are being pedantic, pressure has little to do with the speed of sound (in air), however temperature does.

 

At 15C at sea level its about 340m/s

At 35000 feet (about -57C) it drops to 295m/s

Au contrare Pin. The transmission of sound is all about the movement of molecules, the higher the pressure, the denser the air, the faster sound travels.

 

WRONG? temp is the variable factor with the sound of speed?

 

ie Air pressure and air density are proportional to each other at the same temp?

meaning that the speed of sound in AIR depends on the density of air AND the density of air depends on the TEMPERATURE

so at the same temp the speed of sound on a mountain peak will be the same as the speed of sound at sea level

cheers kw

Explain to me then, why sound travels 25 times faster through water than it does through air. Is it perhaps because water is 25 times denser than air regardless of temperature? I grant you that, in air, temperature does have an effect, but only as it effects the barometric pressure of the air and therefore the density. The reason temperature drops at height is because as the air becomes less dense it loses its ability to retain heat. The fact that the speed of sound in a vacuum, regardless of temperture, is 0 is proof of this. In space, and in the confines of your own mind, no-one can here you scream

P03 (Aerospace Engineer)

 

Edited to add - PS don't you just love the way these threads go off on tangents

[kdubya]

simple really!

 

Sound is a type of longitudinal, mechanical wave. They need a medium to propagate and will not travel through a vacuum. Sound travels at different speed in different media. The speed of sound is determined by the density (Ï) and compressibility (β) of the medium. Density is the amount of material in a given volume, and compressibility is a meaasure of how much a substance could be compacted for a given pressure. The denser and the more compressible, the faster the sound waves would travel. Therefore, the speed of sound is about four times faster in water than in air. The speed of sound in a medium can be determined by the equation …

 

v = (βÏ)-1/2

 

Where …

 

v is the speed of sound,

β is the bulk modulus of elasticity, and

Ï (rho) is the density.

 

The speed of sound can also be affected by temperature. Sound waves tend to travel faster at higher temperatures. I have found different values for the speed of sound in water in different sources. They range from 1450 to 1498 meters per second in distilled water and 1531 m/s in sea water at room temperatures (20 to 25 °

cheers KW

[Dave-G]

Quote:

v is the speed of sound,

β is the bulk modulus of elasticity, and

Ï (rho) is the density.

 

Aw this is hurting my lil ol brain

 

So would you recommend BT'ing the .177 that he already has? :(

[hawkeye]

Has anyone tried an F.A.C. .177? I have a slot on my ticket and I could send my s410 to ben taylor. The idea of a 10g 177 pellet at 930fps sounds like a good hunting tool. It should shoot flat right out to 65 yards (acording to my software) with plenty of energy still left.

 

If you have a FAC, why stick with 'air'?

 

I just bought a CZ425 standard and stuck an old silencer on it. It is quieter with 1085fps 120 ft pound Eley hollow point Subs than any of my airguns (strange but true) but makes a very mighty 'SMACK' when it hits the bunny. They don't even twitch. I took out four in a group one after another last night at 55 yards and they didn't spook at all. As for the result - small entry hole one side, empty head cavity the size of a 20p piece the other. Very humane and effectively point and shoot between 20 and 60 yards.

 

What's more the gun onl cost £230.

 

 

Have you checked the Eley doing 120ftlb on a cronno i use Eley myself and through my cronno they only do 90ftlbs and the speed is 1000fps that was the average of 5 shots.

[dr_nick]

Has anyone tried an F.A.C. .177? I have a slot on my ticket and I could send my s410 to ben taylor. The idea of a 10g 177 pellet at 930fps sounds like a good hunting tool. It should shoot flat right out to 65 yards (acording to my software) with plenty of energy still left.

 

If you have a FAC, why stick with 'air'?

 

I just bought a CZ425 standard and stuck an old silencer on it. It is quieter with 1085fps 120 ft pound Eley hollow point Subs than any of my airguns (strange but true) but makes a very mighty 'SMACK' when it hits the bunny. They don't even twitch. I took out four in a group one after another last night at 55 yards and they didn't spook at all. As for the result - small entry hole one side, empty head cavity the size of a 20p piece the other. Very humane and effectively point and shoot between 20 and 60 yards.

 

What's more the gun onl cost £230.

 

Yup already got one, I still like airguns though and have always wanted an f.a.c. one. Though as a hunting tool .22 rf and 177 hmr would be more fun.

[Evilv]

Has anyone tried an F.A.C. .177? I have a slot on my ticket and I could send my s410 to ben taylor. The idea of a 10g 177 pellet at 930fps sounds like a good hunting tool. It should shoot flat right out to 65 yards (acording to my software) with plenty of energy still left.

 

If you have a FAC, why stick with 'air'?

 

I just bought a CZ425 standard and stuck an old silencer on it. It is quieter with 1085fps 120 ft pound Eley hollow point Subs than any of my airguns (strange but true) but makes a very mighty 'SMACK' when it hits the bunny. They don't even twitch. I took out four in a group one after another last night at 55 yards and they didn't spook at all. As for the result - small entry hole one side, empty head cavity the size of a 20p piece the other. Very humane and effectively point and shoot between 20 and 60 yards.

 

What's more the gun onl cost £230.

 

 

Have you checked the Eley doing 120ftlb on a cronno i use Eley myself and through my cronno they only do 90ftlbs and the speed is 1000fps that was the average of 5 shots.

 

No, I don't have one. Is the chrono accurate? I'd have thought that the manufacturer's data would have to be accurate, but I can't dispute your figures.

 

Whatever its actual energy and velocity, it surely does turn those rabbit heads inside out though.

 

Maybe I'll try some empiracle drop tests to work out the velocity the poor man's way. I can measure the drop from say forty to seventy yards and check on the POI curve of chairgun to see what the velocity is. That itself begs questions like whether Chairgun itself is accurate though. The method did work with a known power 11.7ft pound air rifle though.

[Evilv]

Yup already got one, I still like airguns though and have always wanted an f.a.c. one. Though as a hunting tool .22 rf and 177 hmr would be more fun.

 

In answer to the original question, since with a FAC airgun your velocity can be anything that is feasible, I'd go for a heavier calibre rather than lighter one. With standard 12 ft pound rifles, I think the flatter trajectory would make a .177 easier to use in the field where it would make judging distance a bit less critical.

 

I have a fac air slot on my ticket too, but I'm wondering whether I should bother now. I only hunt with my rifles so the CZ seems much preferrable.

[dr_nick]

 

Yup already got one, I still like airguns though and have always wanted an f.a.c. one. Though as a hunting tool .22 rf and 177 hmr would be more fun.

 

In answer to the original question, since with a FAC airgun your velocity can be anything that is feasible, I'd go for a heavier calibre rather than lighter one. With standard 12 ft pound rifles, I think the flatter trajectory would make a .177 easier to use in the field where it would make judging distance a bit less critical.

 

I have a fac air slot on my ticket too, but I'm wondering whether I should bother now. I only hunt with my rifles so the CZ seems much preferrable.

 

I have been told that they will let you shoot fac air guns more places than other guns. From my FO's point of view he didn't seem to care about airguns at all.