.17hmr help - ballistics calculator

[Ozzy Fudd]

sorry guys can i cross check some figures for the 17hmr if possible?

 

muzzle velocity is 2530 fps (federal vshok), bullet weight is 17, zero range 100 yards, and ballistic coefficient (as per chuck hawks HERE) is .123, scope height (measured from middle of scope tube to middle of bore) is approx 2"

 

so the figures im getting are

 

50yd +00.13"

100yd 00.00"

150yd -03.30"

200yd -11.14"

250yd -25.40"

300yd -48.24"

 

does this sound right? sorry ballistics calculator is doing my head in, and havnt had the chance to go out and do a full test at different ranges :blink:

Edited April 27, 2010 by Ozzy Fudd

[Vermincinerator]

Exbal gives the following:

 

50yd +0.10"

100yd 0.00"

150yd 2.60"

200yd 8.60"

250yd 19.40"

300yd 36.50"

 

Quite a bit of difference.

 

Ian.

[mikee]

Exbal gives the following:

 

50yd +0.10"

100yd 0.00"

150yd 2.60"

200yd 8.60"

250yd 19.40"

300yd 36.50"

 

Quite a bit of difference.

 

Ian.

 

pretty much the same as the Hawke BRC programme

 

mikee

[harv]

hornady v max 17 gr., .123 B.C. www.hornady.com

 

Range (yards) Muzzle 50 100 200 300 400 500

Velocity (fps) 2550 2208 1893 1366 1048 899

Energy (ft.-lb.) 245 184 135 70 41 30

trajectory (100 yd. zero) -1.5 0.0 -8.6 -36.3 -93.7 -188.7

Come Up in MOA -1.5 0.0 4.1 11.6 22.4 36.0

 

ozzy,

no wonder you never hit anything :thumbs:

Edited April 27, 2010 by harv

[Ozzy Fudd]

 

ive been sticking to a max range of 150 yards til i got the stock extender and stuff through, got it all last week so ill be getting a few hundred rounds on saturday morning and going out to play

 

think i need a new ballistics calculator then, any good (free) ones to download? :thumbs:

[wymberley]

Hi, Based on your spec. given, yep, go along with everyone else. But by playing with the Federal figures it may just be that that BC is suspect as by extrapolating the Federal info it appears that what you are actually getting is what (ish) you should. This would mean that the BC is somewhat less than that given.

Cheers

[Beardo]

good software (and free)

http://www.hawkeoptics.com/brc/index.php

 

http://www.handloads.com/calc/

 

and whilst not free, it's very good...

http://www.exteriorballistics.com/I6suite/index.cfm

[Ozzy Fudd]

thanks nick, ill get that tonight

 

wymberley i thought the bc might have been off, that chuck hawks link in the first post shows the .17bc as being .123, yet .22lr is rated as being .1!! or it could be my ballistics calculator

 

ill play about with it tonight and look at the alternatives and see what figures i can get

 

thanks everyone :thumbs:

[harv]

The figures I got were using the b.c. you quoted so looks right given the similarities in drop on the different calculators apart from yours :thumbs:

Hornady developed the .17 in conjunction with marlin which you use,theyll be over the moon you've blown years of research out the water

[wymberley]

thanks nick, ill get that tonight

 

wymberley i thought the bc might have been off, that chuck hawks link in the first post shows the .17bc as being .123, yet .22lr is rated as being .1!! or it could be my ballistics calculator

 

ill play about with it tonight and look at the alternatives and see what figures i can get

 

thanks everyone :thumbs:

Hi, The problem is we have several unknown variables. There are two 'v shock' rounds, a Speer (hp) and Hornady V max. Can't find the info on the former, but Hornady give a BC of 0.125 (just for info, your estimate for that of 22lr can be a bit low, eg, Eley is about 0.138). Can't find either, the sight height for the Federal tables as this may be 1.5" My Sierra programme is usually quite good for extrapolating rimfire ballistics (all of us came up with the same figures, give or take) but this one has, I'm afraid, got me beat. I think, as always, the best answer is to suck it and see in the field.

Good luck

Cheers,

Phil

[hyflier]

Errrmmmm,

 

What happens to the trajectory if you zero at 50m? The 50m range when you look at a graph shows the bullet at the highest point of trajectory, so everything beyond that is downhill?

 

I'm confused :thumbs:

[harv]

Given any zeroing distance the trajectory will be Downhill from that point,the bullet will always fall at the same rate but the drop will read differently at the same increments depending what you zero at :thumbs:

[Beardo]

Errrmmmm,

 

What happens to the trajectory if you zero at 50m? The 50m range when you look at a graph shows the bullet at the highest point of trajectory, so everything beyond that is downhill?

 

I'm confused :thumbs:

 

that'll be the second zero point (downward travel of arc) at 50 yards - a first zero point of 45 yards (roughly) will give 100 yards zero

[MC]

I have often wondered do people actually use all this information?

 

I don't and all my shooting is done in the field, if I want to know what the drop is at 200 yards then I will put a target out at 200 yards and shoot it The difference from the POA and POI is the drop surely. If using mildots or similar you can hold of the POA and then see what the holdover should be at that range. It doesn't take long to get the hang of it and it saves all this faffing around with technical jargon.

 

Even with my Full bore target rifle I have elevation settings for each range but that is all worked out from using a zero target set at a specific distance (72' 7") So from a 300 yard zero I know what elevation will get me somewhere near the centre of the target at 500, 600, 900 and 1000 yards.

[Ozzy Fudd]

Hi, The problem is we have several unknown variables. There are two 'v shock' rounds, a Speer (hp) and Hornady V max. Can't find the info on the former, but Hornady give a BC of 0.125 (just for info, your estimate for that of 22lr can be a bit low, eg, Eley is about 0.138). Can't find either, the sight height for the Federal tables as this may be 1.5" My Sierra programme is usually quite good for extrapolating rimfire ballistics (all of us came up with the same figures, give or take) but this one has, I'm afraid, got me beat. I think, as always, the best answer is to suck it and see in the field.

Good luck

Cheers,

Phil

 

sorry mate, its the federal v shok, dont know any more info. heres part of the table i was using for the bc, its from chuck hawks

 

Cartridge (Wb@MV) Bullet BC 100 yds. 200 yds. MRT@yds. MPBR (yds.)

.17 HMR (17 SP at 2550) .123 +1.5" -5.5" 1.5"@100 165

.204 Ruger (33 BT at 4225) .185 +1.1" +1.0" 1.5"@150 275

.22 LR (40 HP at 1255) .100 -3.0" -40.9" 1.5"@45 90

.22 WMR (40 HP at 1910) .100 +0.5" -19.0" 1.5"@65 123

.222 Rem. (50 Sp at 3140) .220 +1.4" -0.4" 1.5"@118 222

.223 Rem. (45 Sp at 3550) .167 +1.4" +0.2" 1.5"@130 235

.223 Rem. (55 SP at 3240) .235 +1.4" +/- 0" 1.5"@120 230

 

personally i thought the bc of a .22lr would have been about 0.14, so the 17hmr should have been about 0.2, ill have a play with it later on and see if i can get the figures closer to what's been posted

 

 

I have often wondered do people actually use all this information?

 

I don't and all my shooting is done in the field, if I want to know what the drop is at 200 yards then I will put a target out at 200 yards and shoot it The difference from the POA and POI is the drop surely. If using mildots or similar you can hold of the POA and then see what the holdover should be at that range. It doesn't take long to get the hang of it and it saves all this faffing around with technical jargon.

 

Even with my Full bore target rifle I have elevation settings for each range but that is all worked out from using a zero target set at a specific distance (72' 7") So from a 300 yard zero I know what elevation will get me somewhere near the centre of the target at 500, 600, 900 and 1000 yards.

 

mc, are you talking about the ballistics calculator or the poa, etc? if its the calculator the reason im faffing about with all this technical jargon is i havnt had the chance to stick a load of targets out at different ranges yet, and i know from previous experience with a .22lr at longer range that its easy to waste 20 or 30 rounds (and do a good bit of walking in between) before youve even hit the target, never mind hitting the bull now ive got the info i can set the targets out at different ranges and have a good idea where the rounds will hit, then its just the fine tuning and learning the mil's :thumbs:

[MC]

I meant the ballistic software.

[Ozzy Fudd]

ok, well then there you go

[wymberley]

Ozzy, hi,

Yep, Federal are using 1.5" sight height. The Sierra programme duplicates the Federal, rather sparse, table on their web-site therefore the extrapolation will be valid. As said, the figures that we all gave are, within a whisper, the same and are valid. This relates to the V-max bullet (the Speer has an inferior BC). Chuck (no pun intended, well perhaps a little one) that other info in the bin. If you need to fill in any gaps in the distances given and your calculator can't do it, just sing out.

Cheers

[Ozzy Fudd]

cheers mate will do

[Dekers]

Your figures do seem to drop off abit quicker then others, which I tend to believe more, although I have never checked my HMR past 300 yards!

 

One thing I noticed...your 2" scope height, do you actually have a VERY big objective or is there a big gap between scope and barrel, even with a 56mm Objective you can usually manage 1.5"

[Ozzy Fudd]

combination of both tbh, theres a bit of a gap (1/4") but its slightly under 2" height, i just rounded it up to that for simplicity. as long as i have the rough figures then i can fine tune it on targets

 

ps downloaded the hawke ballistics calculator tonight, the figures its giving seem to be a bit more accurate; ill be heading out this weekend so ill hopefully get a bit of testing done