1. The Forum Rules have undergone some minor changes and updates.  Please take the time to read them; it will only take a couple of minutes of your time. By doing so, you lessen the chance of incurring the wrath of the moderation team or making yourself look foolish to other members.

    90% of users posting adverts in the Sales forums need to be reminded to read the rules as their posts are wrong.  This is unnecessarily time-consuming and will no longer happen - if your advert doesn't follow the Sales Rules it will be deleted and you'll have to start all over again.

    To close this box once you've read it (and the Rules), click on the X in the top right-hand corner.

    Thank you.

    AGF Staff



    Dismiss Notice
  2. A reminder of one of the Forum Rules:

    'Behaviour

    Do not make inappropriate or offensive posts - including threats, harassment, swearing, prejudice, defamation, deliberate insults or name-calling, other negative remarks about this forum, its moderators and administrators or your fellow members. Even if this is just your own personal opinion, RESPECT YOUR FELLOW MEMBERS.'

    There have been changes made to our censoring software in an attempt to help with this growing problem.

    Click the X in the top-right-hand corner to dismiss this notice.
    Dismiss Notice
  3. Dear members,

    Our membership (like our country) consists of people from all walks of life; different in far more ways than can be listed here and each with a different view based on their experience of life - regardless of their colour, religion or cultural heritage. Every single person in the UK has been born of mixed race – we are a multi-coloured and multi-cultural country.

    As many of you are aware there are a handful of individuals amongst this membership that persist in making provocative, inflammatory, racist and otherwise offensive comments. This has been happening across the forum to a certain degree but is most especially prevalent in the Adult section.

    The moderation team has tried to stay on top of this, however unfortunately because of the ‘offensive’ nature of much of its content we don’t monitor the Adult section quite as much as perhaps we should. As a result much of this behaviour has gone unnoticed unless it has been reported to us. While the team always intended to take a "light touch" approach to the Adult section it would seem that some people aren’t quite adult enough to be left unmonitored after all.

    This behaviour is, and always has been against Forum Rules as well as the specific stipulations of the Adults forum and it will no longer be tolerated. We feel it's time to draw a line in the sand and as such from this point onward offenders will receive an immediate and permanent ban from the forum.

    In order for us to achieve our goal of restoring the forum to the friendly and tolerant place it once was, we ask that ALL members be mindful of the content they post and help us to stop unacceptable behaviour by using the 'Report' tool at the bottom of any offending post - the results of which can be seen only by Admin/Moderators.

    You should all receive a copy of this message by PM. 

    To close this message box, click on the 'X' in the top-right-hand corner.

    Dismiss Notice
  4. Hotmail block emails from us entering your inbox. Unless you can setup a safe sender you will not get activation emails from the forum. Please use an alternative provider or complain to Hotmail.
    Hotmail addresses include.

    @Hotmail.co.uk @Hotmail.com @outlook.com @Live.com
    Dismiss Notice
  5. Postings on Politics, Religion & Controversial Off-Topic Material

    The majority of users do not want to read about these subjects and people have left the forum as a result of it – this is after all an 'Airgun' Forum. It’s all very well to say they don’t have to read it if they don't want to, but as most of us use the ‘New Posts’ button there is no easy way to avoid it.

    All AGF staff members are in favour of people being able to discuss what they want, but we have to draw the line somewhere if it is upsetting other users. We don’t want to read about these topics either.

    IMPORTANT- The discussion of politics and religion is no longer allowed anywhere on the forum (including the Adult section).  The only exception is if it's airgun related - they must be put in the Airgun Related Politics section..

    We will not tolerate bullying or personal attacks, racism or any other offensive 'isms'. we will remove these topics from the forum, we will not give you an area where you can abuse each other. We will not hesitate to ban offenders.

    To clear this text box, click on the 'X' in the top right-hand corner.

    Dismiss Notice

Question Muzzle energy query

Discussion in 'Anything Airgun Related' started by Egg, May 24, 2014.

  1. Egg

    Egg Major Poster

    Messages:
    8,460
    Likes Received:
    13
    Location:
    Dunfermline
    OK, I'll put my hands up - I'm crap at maths so I'm throwing this out to the massive.

    If we take say 5-6 ft/lb as being the amount of KE sufficient to take a rabbit out via headshot and this 5 ft/lb is present at the point of impact when the range from muzzle to rabbit is - wait for it - 200m.

    Tricky part - pellet weight unknown.

    So, would anyone care to hazard a guess about what would the ME have been when the pellet left the gun?
     
  2. Stevie Darling

    Stevie Darling Sexual tyrannosaurus

    Messages:
    18,701
    Likes Received:
    12,492
    Location:
    St. Andrews, Jockland.
  3. oliver13

    oliver13 Donator

    Messages:
    1,149
    Likes Received:
    1
    Location:
    Lairg
    A lot more than 12ftlb's...
     
  4. terry1001

    terry1001 Major Poster

    Messages:
    9,154
    Likes Received:
    2,219
    Location:
    Ipswich
    A .22 JSB Exact Heavy travelling at 1000 fps MV will have a muzzle energy of 40 ftlbs and a retained energy of 5.95 ftlbs at 220 yards (fairly close to 200m).
    Figures coutresy of Chairgun Pro.
     
  5. warrenater

    warrenater Donator

    Messages:
    3,805
    Likes Received:
    2,173
    Location:
    Kings Lynn
    well done terry i was just about to suggest chairgun when you posted ( honest lol ) atb gary.
     
  6. terry1001

    terry1001 Major Poster

    Messages:
    9,154
    Likes Received:
    2,219
    Location:
    Ipswich
    First point of call for any ballistic type queries, the answers may not be 100% perfect but close enough for most uses. Can't believe Egg didn't try it - maybe it's a test?
     
  7. Sir Oscar

    Sir Oscar Donator

    Messages:
    338
    Likes Received:
    2
    Location:
    Oxford
    I'm crap at maths as well but here goes.
    According to chair gun your losing 98% of your energy over 200m. Sooo
    5/100=0.05x98=4.9+5=9.9@the muzzle.

    Doesn't sound right to me. :D
     
  8. Egg

    Egg Major Poster

    Messages:
    8,460
    Likes Received:
    13
    Location:
    Dunfermline
    Cheers Terry - I thought CG Pro might have been of some help but I've not installed it on my new-build yet.

    So - theoretically and using the above figures - it would be possible (with a mighty amount of holdover) to despatch a rabbit at 200m with a 40 ft/lb rifle?

    I need to make you guys aware that this is not a real life situation :)
     
  9. Stevie Darling

    Stevie Darling Sexual tyrannosaurus

    Messages:
    18,701
    Likes Received:
    12,492
    Location:
    St. Andrews, Jockland.
    What kind of energy can air rifles go up to??
     
  10. Egg

    Egg Major Poster

    Messages:
    8,460
    Likes Received:
    13
    Location:
    Dunfermline
    Pretty high - the Quackenbush Bandit .50 PCP can produce 200 ft/lb :eek:
     
  11. JD

    JD Donator

    Messages:
    7,308
    Likes Received:
    1,033
    Location:
    Dorset
    Steve, have you not seen the Bear killing .50 cal 700+ ft lbs USA Pcp's ?
     
  12. Stevie Darling

    Stevie Darling Sexual tyrannosaurus

    Messages:
    18,701
    Likes Received:
    12,492
    Location:
    St. Andrews, Jockland.
    So is there an advantage using air at that sort of power over powder burners??
     
  13. JD

    JD Donator

    Messages:
    7,308
    Likes Received:
    1,033
    Location:
    Dorset
    I would say dis-advantage with only 2 shots from a full charge.
     
  14. terry1001

    terry1001 Major Poster

    Messages:
    9,154
    Likes Received:
    2,219
    Location:
    Ipswich
    Just out of interest and in the name of scientific research, I have checked a different scenario and reckon that it is perfectly feasible given perfect conditions etc etc
    Changing to a slightly heavier RWS Eun Jin pellet (don't know if they're any good at all, this is just a feasibilty exercise) at27.8 gn and with a slightly better BC than the JSB and keeping the muzzle velocity down to 950fps to avoid going transonic we get ME of 55.70ftlbs and retained at 220 yards 9.32 ftlbs. So there's more than enough energy to do the job.
    Using a Hawke 20x mil dot reticle with the scope zeroed at 100 yards then the marks on the reticle will give ranges of up to 219 yards on the broad reticle post right at the bottom.
    Obviously zeroing at 100 yards might require long range mounts but the numbers say it could be done.
    This is one of the reasons that I like Chairgun Pro, you can look at scenarios like this in just a few minutes, it doesn't matter how realistic they are you can get an answer straight away and know whether or not your idea/thoughts are worth considering further.
     
  15. Egg

    Egg Major Poster

    Messages:
    8,460
    Likes Received:
    13
    Location:
    Dunfermline
    I've just re-installed CGP so I'll be able to tinker around with the variables again. Cheers though Terry :up:
     
  16. terry1001

    terry1001 Major Poster

    Messages:
    9,154
    Likes Received:
    2,219
    Location:
    Ipswich
    Might as well get BRC2 while you're at it, handy if you know your rifle/pellet settings.
     
  17. Jackroadkill

    Jackroadkill Donator

    Messages:
    16,784
    Likes Received:
    114
    Location:
    Drenewydd, Powys, Cymru
    The simple answer, Egg, old boy, is this: get closer or use an HMR! The time taken to do the maths, measure the wind, apply the Inverse Square Law, read the Almanac, make a brew, aim the rifle and pull the trigger could better be used stalking closer, going to the pub or having it out with keyboard warriors on the interweb.

    Oh, hang on....
     
    Last edited: May 24, 2014
  18. SteveO

    SteveO Top Poster

    Messages:
    11,080
    Likes Received:
    10,170
    Location:
    Kek
    potato...
     
  19. mattyts

    mattyts Donator

    Messages:
    6,201
    Likes Received:
    163
    Location:
    Yorkshire
    Quieter, no shells,primers or powder to worry about but with 2-4 shots per charge,its not that "portable"
     
  20. r10hunter

    r10hunter Honorary Member

    Messages:
    10,150
    Likes Received:
    4,687
    Location:
    lincoln
    It must have a trajectory like a brick also.
    Short range use only I guess??
    Cheers Andy
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice