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maximum distance


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#16 pianoman

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Posted 19 March 2011 - 08:40 pm

@ pianoman, what's the retained energy in sub 12ftlb at 100yrd's and what cal are you using? http://www.thehuntinglife.com/forums/pub...

sub .12 ft/lb .22 Garfield.

I don't know what the retained kinetic energy is at these ranges but, it's plenty more than enough as the shot hits from a plunging angle and gravity takes an effect. A chrono and balistic putty will give an accurate measure. I've never measured it with a .22 air rifle pellet but done plenty of calibre-effect testing with .300, .303, .308 7.62mm and .50 ammunition in extreme range shooting during my service years. A hit from a plunging round carries far more destructive kinetic power than the same calibre round hitting from shorter ranges using flatter trajectories. Taking this as a principle I've only really scratched the surface of applying it to air rifle shooting.

I think air rifle arms manufacturers have the technological means to produce far more efficient pellets, barrels and cylinders for a next-generation of air rifle that will enable a degree of greater range accuracy control by more skilled shooters more consistently. But it would mean perhaps charging prices into several thousands of pounds and that's just not financially viable. Not when an FAC and a good .22 or .17HMR rimfire can be bought for a few hundred pounds.

As things stand, I've found 12ft/lb air rifles and pellets in both major calibres now, are capable but, I must stress, ARE NOT CONSISTENTLY capable, of accurate field shooting to 200 yards. If they got those inconsistencies ironed out, it could be amazing what the humble old air rifle's performance could be made capable of.

The main problem however is that the average 11.5 ft/lb output at the muszzle is not enough to counter variances in the wind. You need absolutely not a breath of wind when shooting a target at these extremes.

#17 matt_hooks

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Posted 19 March 2011 - 08:54 pm

i thought they went up first an then dropped


Not quite.

The pellet begins to drop FROM THE LINE OF THE BARREL as soon as it's fired.

Your air rifles scope is at an angle to the barrel, to compensate for the pellet drop. It is set at an angle such that your pellets trajectory passes through the line of sight of the scope twice. This is necessary because the pellet starts out below the line of sight, then passes through the line of sight on the way up, and then drops through the line of sight again on the way down.

The second point where the arc of the pellet intersects with the direct line of sight of the scope is where we would normally put the zero point. (Well actually, we choose where the second point of intersection is by setting our zero point.)

The pellet travels in a straight line from the end of the barrel initially, if only momentarily. Then the acceleration due to gravity causes the well known "parabolic trajectory" to develop.

Hope that makes sense.

#18 andyfr1968

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Posted 19 March 2011 - 09:04 pm


i thought they went up first an then dropped


Not quite.

The pellet begins to drop FROM THE LINE OF THE BARREL as soon as it's fired.

Your air rifles scope is at an angle to the barrel, to compensate for the pellet drop. It is set at an angle such that your pellets trajectory passes through the line of sight of the scope twice. This is necessary because the pellet starts out below the line of sight, then passes through the line of sight on the way up, and then drops through the line of sight again on the way down.

The second point where the arc of the pellet intersects with the direct line of sight of the scope is where we would normally put the zero point. (Well actually, we choose where the second point of intersection is by setting our zero point.)

The pellet travels in a straight line from the end of the barrel initially, if only momentarily. Then the acceleration due to gravity causes the well known "parabolic trajectory" to develop.

Hope that makes sense.


:hmm: I've never really given this much thought before as like Fry, I always thought the same. Up then down....

Surely if the POI is on the same horizontal plane as line of sight, the projectile must first go up at a slight angle as it's leaving the barrel an inch and a half (give or take) below LOS....?

Edit... So it really depends on the angle the shot is being taken.

Edited by andyfr1968, 19 March 2011 - 09:06 pm.


#19 pianoman

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Posted 20 March 2011 - 12:08 am

Everything is determined by the angle we shoot from. :thumbs: What happens Andy is that, everytime you aim your rifle, you are viewing your target either through a lens or an open sight which is invariably mounted above the bore centreline of your rifle's barrel. The shot itself flies straight and true from the barrel then, as it begins to fall with depleting energy, and increasing gravity, it describes a downward curve flightpath till it hits the ground. Viewing through a scope, your eye is actually following a straight line of sight in a gentle, downward angle (a closing bearing angle) which bisects through the pellet's (or bullet's) downcurve of flight. What we are actually doing when we shoot through any kind of sight system, is tilting the rifle back a little and just high of true horizontal, so that, indeed, it would appear we are shooting with a rising and falling curved or arcing flight path.

Basically, our gentle downward view-line through the scope is being brought a little more true-paralell and the barrel has been gently raised in the process.

Our sighting system, be it a scope or diopter, open sights is now controlling the amount of tiltback and left/right windage play so that, hey presto! Our line of sight and line of shot coincide accurately at the target.

I swear I can hear grannies sucking eggs here! :thumbs:

Edited by pianoman, 20 March 2011 - 12:15 am.


#20 Rake aboot

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Posted 20 March 2011 - 12:57 am

They only go up first if thats where the barrel is pointed ,,!!lol
When the barrel is level they drop straight away. To aim at a point in the distance, you have to aim slightly above it and allow the pellet to "arc" towards it and come down to hit it. "trajectory" its called.
If you fire a pellet level, and drop a penny next to the barrel at exactly the same time, they will hit the ground at exactley the same time (this goes for all bullets, 50 cal included lol)
Gravity works for all projectiles regardless of weight or speed. To counteract this you have to "aim up" and allow the pellet to arc towards the target.
Because a pellet can travel 100 or so mtrs in a second,then if you compensate for drop, then you could hit a target out at these distances

Hope this explians a bit

ATB

#21 secretagentmole

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Posted 20 March 2011 - 08:54 am

Ah ha! Light dawns, slowly. So to hit centre at 30 metres you are aiming up, so the pellet drops back down, and the first zero point in that happening is at approx 10 metres (going in .22 here)... I get it now :signthankspin: :signthankspin: :signthankspin:

#22 clubshot

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Posted 20 March 2011 - 12:05 pm

@ Lea Valley - We have a Plinking Range with Reset Targets out to 60 Metres

A .177 can reset Targets at these Distances

A .22 can not as fall rate @ distance and angle will not reset Targets

Yes I do Shoot most Calibres - Mostly .177 for Range - As All Shot Sub 12FP

BOB/R

#23 matchbox

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Posted 20 March 2011 - 10:12 pm

So did I! The parabolic trajectory and all that, hang on, ah found it!

Trajectory etc explained!

It was discussed at length on this thread!

Hi i have an old webley raider two shot it hits a smarty at 40 yards
You can hit rabbits a 30 yards this is my chosen distance as you can sit at the rabbits holes rats in the barn or sheds night and day with lights no problem lots of them :gunsmilie:

#24 andyfr1968

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Posted 21 March 2011 - 01:48 am

It's a right load of old bollox this whole 'maximum distance' thing :icon_eek:

Mine won't be the same as the next man and his probably won't be the same as your's.

It is, quite simply, whatever range you can reliably put a least 80% of your shots within a group of about an inch.

I do a lot of standing shots and when I'm doing that, mine's no more than 30 yards. If I'm sitting I can go out a little further and I've only very recently started shooting prone and I'm not sure yet what my maximum is from this position.

If you can't do better than an inch at ten yards, then that's your maximum. If you're really very good and can do that a LOT further out then...... :thumbs:

Cheers.

#25 zini

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Posted 21 March 2011 - 06:52 am

True Andy mate.

Thats something I try to convey to people that your max distance is different from each shooting position and in different weather condition.

I will always try to support before I shoot if possible because its the most stable way but if not and im unsupported my accuracy gets 90 % worse.

Si

Edited by zini, 21 March 2011 - 06:53 am.


#26 hw97k

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Posted 21 March 2011 - 08:43 pm

it was more of a question if the ultra was up to it,having heard of a lot of under powered ones ,and not who was shooting it.it seems if you ask a question somebody takes over and the subject originally asked goes by the way side, but never the less entertaining.

#27 andyfr1968

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Posted 21 March 2011 - 10:02 pm

it was more of a question if the ultra was up to it,having heard of a lot of under powered ones ,and not who was shooting it.it seems if you ask a question somebody takes over and the subject originally asked goes by the way side, but never the less entertaining.


:laugh: It did go a bit off track, didn't it.

The Ultra's a very good gun but if you're worried about a lack of power then the only answer is to have it chronoed.

#28 fry

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Posted 21 March 2011 - 10:14 pm

it was more of a question if the ultra was up to it,having heard of a lot of under powered ones ,and not who was shooting it.it seems if you ask a question somebody takes over and the subject originally asked goes by the way side, but never the less entertaining.

yup sometimes the first answer by a non expert can be the best an easiest to get your head round :whistling:

#29 hw97k

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Posted 22 March 2011 - 08:11 pm


it was more of a question if the ultra was up to it,having heard of a lot of under powered ones ,and not who was shooting it.it seems if you ask a question somebody takes over and the subject originally asked goes by the way side, but never the less entertaining.

yup sometimes the first answer by a non expert can be the best an easiest to get your head round http://www.thehuntinglife.com/forums/pub...
,ive never heard of an airgun expert before.i know the lads on here have years of experiance between them but i doubt if they call themselves experts.they are unbelivibly helpfull to a novice such as i mate and one day with out being patronising ill be an expert. :boogie:

#30 fry

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Posted 22 March 2011 - 10:24 pm



it was more of a question if the ultra was up to it,having heard of a lot of under powered ones ,and not who was shooting it.it seems if you ask a question somebody takes over and the subject originally asked goes by the way side, but never the less entertaining.

yup sometimes the first answer by a non expert can be the best an easiest to get your head round http://www.thehuntinglife.com/forums/pub...
,ive never heard of an airgun expert before.i know the lads on here have years of experiance between them but i doubt if they call themselves experts.they are unbelivibly helpfull to a novice such as i mate and one day with out being patronising ill be an expert. http://www.thehuntinglife.com/forums/pub...
trust me mate there are a few fellas postin on this thread that are proper experts not just in airguns but ballistics and feild craft too! myself on the other hand am a beginner but i shoot within my limits (40 yards)and put bunnys in the bag more often than not. i have learnt shed loads from them in the last year :thumbs: which is roughly how long i have had my aa 410.


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