Cornish lad Posted May 13 Report Share Posted May 13 Hi ,would anybody know what the Ballistic profile is for H&N 18.13 pellets in .22 ?? Not the coefficients,it’s for putting in the ballistic calculator asking for the G number ?? To enter in the menu can find just about all other info but not a G number thanks in advance 🤔 Quote Link to comment Share on other sites More sharing options...
wymberley Posted May 13 Report Share Posted May 13 This is a guess and not a particularly educated one at that. Is 'G' also known as the 'Form Factor'? If so, then the answer is 1.38. If it helps, what info are you after as I can run it through my Sierra Suite programme which permits me to enter the BC of choice? Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted May 13 Author Report Share Posted May 13 Hi ,thanks going to try and get the pulsar ballistic calculator on my scope but asked for the ballistic profile of the pellet saying which G profile is the pellet G__ havent a clue is it G1 or others just tried looking on H&N site but tells you everything but what this is H&N 18.13 in .22 pellets would be great if you could find it thank you Quote Link to comment Share on other sites More sharing options...
wymberley Posted May 13 Report Share Posted May 13 1 hour ago, Cornish lad said: Hi ,thanks going to try and get the pulsar ballistic calculator on my scope but asked for the ballistic profile of the pellet saying which G profile is the pellet G__ havent a clue is it G1 or others just tried looking on H&N site but tells you everything but what this is H&N 18.13 in .22 pellets would be great if you could find it thank you I'm getting the deja vu feeling that we've been here before way back. It boiled down to a difference in terminology. In my ignorance I don't even know if airgun pellets have a G number. I'm afraid I can't remember the specific details now but have got a feeling that what the programme/calculator was asking for was actually the BC but was termed something like the form factor which it was decided had given a nonsensical answer. Using the BC put things right. If you wish, give me your velocity, zero range and sight height for the pellet I'll run Infinity so you can compare things - my leaving the same BC for the same velocity boundary will make very little difference. Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted May 13 Author Report Share Posted May 13 Looking at the pulsar ballistic calculator app to put into my c50 following down through the details required asks for BC then the G rateing in the next Box down ,I know the BC that’s on the tin of pellets and on a site elsewhere but no mention of this G rate you might be correct in that you don’t need it ?? Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted May 13 Report Share Posted May 13 The g number is the drag profile .ie the shape of the projectile. G1 is basically a bullet shape .ogive head flat base think .22lr . Ga is pellet shape . Waisted skirt . With dome head . Very different through the air due to the turbulence off the rear . Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted May 13 Author Report Share Posted May 13 Nice 1 thank you very much ,so complicated when you have no idea what it means really appreciate it cheers Quote Link to comment Share on other sites More sharing options...
scarecrow243 Posted May 14 Report Share Posted May 14 On 13/05/2024 at 12:00, Cornish lad said: Hi ,would anybody know what the Ballistic profile is for H&N 18.13 pellets in .22 ?? Not the coefficients,it’s for putting in the ballistic calculator asking for the G number ?? To enter in the menu can find just about all other info but not a G number thanks in advance 🤔 H&N Baracuda 18 18.13 grn B.C. is 0.029 Quote Link to comment Share on other sites More sharing options...
villaman Posted May 16 Report Share Posted May 16 G1 Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted May 16 Author Report Share Posted May 16 Bit more confused ultastu says Ga and now G1 !!!! Anyone confirm please Quote Link to comment Share on other sites More sharing options...
scarecrow243 Posted May 16 Report Share Posted May 16 air gun pellets are G1 used in many scope ballistic calculators Quote Link to comment Share on other sites More sharing options...
Kev1gun Posted May 17 Report Share Posted May 17 If GA isn't listed on your PulsarC50 use G1 instead, it makes very little difference Quote Link to comment Share on other sites More sharing options...
Ultrastu Posted May 17 Report Share Posted May 17 Waisted diabolo airgun pellets definitely ga . G1 is for a flat base projectile so a slug would come under that . Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted May 17 Author Report Share Posted May 17 O have another question to ask of anybody regarding my muzzle velocity had to buy chronograph to try and get the muzzle velocity and set up.in.my shed air arms s510 fac ,says fill power supposed to be 32 ft.lbs anyway fully charged.set chronograph 40 cm.fro..end of barrel.fired 6.HN 18.13.pellets.and it.registerd 6 diffrent fbs ??do I take a average. To.get the velocity ,Rifle shoots.Brillantly but.just surprised. How in consistent the Readings were please be kind I've never.done.anything like this.before so a bit.Dim regarding. This technology??? Quote Link to comment Share on other sites More sharing options...
scarecrow243 Posted May 18 Report Share Posted May 18 i use the fx chrono the speeds and ft1lbs will be different if you do not weigh the pellets so you have a batch that are the same weight then your speed and ft1lbs will be very close Quote Link to comment Share on other sites More sharing options...
wymberley Posted May 18 Report Share Posted May 18 1 hour ago, scarecrow243 said: i use the fx chrono the speeds and ft1lbs will be different if you do not weigh the pellets so you have a batch that are the same weight then your speed and ft1lbs will be very close Because I'm back on airguns after many decades, would it be fair to say by 'close' you mean consistent? Quote Link to comment Share on other sites More sharing options...
scarecrow243 Posted May 18 Report Share Posted May 18 Hi say you have weighed some pellets so they are say 18 grns your speed is 750 fps power is say 24ft1lbs thru the chrono you may get ie 750 750 751 750 749 etc the same goes for the ft1lbs there will always be a slight variation i get this with my regulated stealth .25 using jsb hades 26.54 grn speed 870 fps 44.6 ft1lbs i hope this helps Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted August 10 Author Report Share Posted August 10 Hi wonder if anyone could help a mate of mine out he’s trying to work out his muzzle velocity his fps is 924 we don’t know how to convert this to fts would be grateful if anyone could help two old **** cheers Quote Link to comment Share on other sites More sharing options...
Stonepark Posted August 10 Report Share Posted August 10 (edited) 1 hour ago, Cornish lad said: Hi wonder if anyone could help a mate of mine out he’s trying to work out his muzzle velocity his fps is 924 we don’t know how to convert this to fts would be grateful if anyone could help two old **** cheers If 20.06gr H&N FTT, 924 gives 38ftlbs On the H&N page is a ballistic calculator bottom right, not great as no tables but gives an idea https://www.hn-sport.de/en/air-gun-hunting/field-target-trophy-25 Edited August 10 by Stonepark Quote Link to comment Share on other sites More sharing options...
wymberley Posted August 10 Report Share Posted August 10 3 hours ago, Cornish lad said: Hi wonder if anyone could help a mate of mine out he’s trying to work out his muzzle velocity his fps is 924 we don’t know how to convert this to fts would be grateful if anyone could help two old **** cheers Velocity times Velocity (ft/sec) divided by 450436 (a constant) times projectile weight (grains) equals energy (ftlbs). so:- Using Stoneparks's figures: 924 x 924 divided by 450436 x 20.06 = 38 Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted August 11 Author Report Share Posted August 11 Would anybody know what the ballistic coefficient of HN ,.22. 21.14 pellets might be ?? Quote Link to comment Share on other sites More sharing options...
wymberley Posted August 11 Report Share Posted August 11 1 hour ago, Cornish lad said: Would anybody know what the ballistic coefficient of HN ,.22. 21.14 pellets might be ?? There are several of that weight averaging 0.033 Quote Link to comment Share on other sites More sharing options...
Cornish lad Posted August 11 Author Report Share Posted August 11 Nice thank you Quote Link to comment Share on other sites More sharing options...
Savhmr Posted August 29 Report Share Posted August 29 For anyone wanting to calculate ME from a chrono reading, you can use the simple equation below: M/E (lbs-ft)= mV2/2g Usually expressed in imperial for the purposes of airguns so: m = mass in lbs (gr/7000 as there are 7000 grains in 1 lb) V = velocity in ft/sec g = acceleration due to gravity = 32.2 ft/s/s approx so simplify "2g" by 64.4 I simply use an Xl spreadsheet when testing new pellets which runs a macro to convert each pellet type MV to lbs-ft result. Quote Link to comment Share on other sites More sharing options...
wymberley Posted August 29 Report Share Posted August 29 2 hours ago, Savhmr said: For anyone wanting to calculate ME from a chrono reading, you can use the simple equation below: M/E (lbs-ft)= mV2/2g Usually expressed in imperial for the purposes of airguns so: m = mass in lbs (gr/7000 as there are 7000 grains in 1 lb) V = velocity in ft/sec g = acceleration due to gravity = 32.2 ft/s/s approx so simplify "2g" by 64.4 I simply use an Xl spreadsheet when testing new pellets which runs a macro to convert each pellet type MV to lbs-ft result. or: 7000 x 64.4 (or precisely 32.174 x2) =450436 Quote Link to comment Share on other sites More sharing options...
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