bladeracer wrote:Very interesting post on FB I just saw.
https://www.facebook.com/groups/Reloading101/permalink/2180066548894270/
He's reloading .17HMR in an AR15 trying to shoot 1000yds with it.
If anybody is FB-disabled I'll screenshot and post the thread in here.
in2anity wrote:bladeracer wrote:Very interesting post on FB I just saw.
https://www.facebook.com/groups/Reloading101/permalink/2180066548894270/
He's reloading .17HMR in an AR15 trying to shoot 1000yds with it.
If anybody is FB-disabled I'll screenshot and post the thread in here.
Has to be a piss-take doesn’t it?
No1_49er wrote:No. It's true. It's on FB.
Wombat wrote:But it is on a closed group, even if you are on FB.
in2anity wrote:Reckon it’s feasible? I mean what happens to 20gr pills crossing the barriers?
bladeracer wrote:Quick calc with Hornady's 25gn VMax (BC of .230). If he can launch it at 3700fps it stays supersonic to 750yds.
To be supersonic at 1000yds though requires 5200fps.
If he can make a 35gn bullet with a BC of .300, he only needs to launch it at 4000fps to stay supersonic at 1000yds.
in2anity wrote:Reckon he’d have enough case to fit a heavier pill AND anywhere close to the amount of powder to launch it that quick? What about the strength of the action? And twist rate? Wonder what powder he’s considering - lil’gun?
SCJ429 wrote:The transonic buffeting can start at well over 1200 fps, sounds like a big ask but looks like they are having fun trying. Nice project.
bladeracer wrote:Quick calc with Hornady's 25gn VMax (BC of .230). If he can launch it at 3700fps it stays supersonic to 750yds.
To be supersonic at 1000yds though requires 5200fps.
If he can make a 35gn bullet with a BC of .300, he only needs to launch it at 4000fps to stay supersonic at 1000yds.
Cooper wrote:bladeracer wrote:Quick calc with Hornady's 25gn VMax (BC of .230). If he can launch it at 3700fps it stays supersonic to 750yds.
To be supersonic at 1000yds though requires 5200fps.
If he can make a 35gn bullet with a BC of .300, he only needs to launch it at 4000fps to stay supersonic at 1000yds.
Surely you'd need a 17 hornet to launch a 25gr projectile that fast? And a 17 Remingtom or something to get a 35gr to 4000fps
Gwion wrote:My 223 wallaby rifle with 50gn bullets is capable of 1" groups and smaller at 300yd on a day with good even wind. I can even keep it around the 5 ring at 600yds when everything goes right. The slightest variation in wind can tripple that group size. Any serious gusting or mid range fluctuations just blow it all over the place out at 600yd, which is it's absolute limit for supersonic impact. This is a 50gn bullet with a higher BC that the .17 35gn bullet, leaving the barrel at 3150fps (short barrel).
The 'typical' groups these guys are claiming just screams horse doodoo.
If they can do that, they should be unbeatable at world champ fclass or other precision shoots with their shooting skill, mirical working gunsmith, flawless reloading and divine wind reading.....
sungazer wrote:I think they are going to be shooting on "That Day" the overcast inverted weather system with no wind. Again I don't think the first round hit is such a big deal once you have your rifle dope. If it is a reasonable rifle results should be repeatable from one session to the next all thing considered.
bladeracer wrote:Gwion wrote:My 223 wallaby rifle with 50gn bullets is capable of 1" groups and smaller at 300yd on a day with good even wind. I can even keep it around the 5 ring at 600yds when everything goes right. The slightest variation in wind can tripple that group size. Any serious gusting or mid range fluctuations just blow it all over the place out at 600yd, which is it's absolute limit for supersonic impact. This is a 50gn bullet with a higher BC that the .17 35gn bullet, leaving the barrel at 3150fps (short barrel).
The 'typical' groups these guys are claiming just screams horse doodoo.
If they can do that, they should be unbeatable at world champ fclass or other precision shoots with their shooting skill, mirical working gunsmith, flawless reloading and divine wind reading.....
I agree about the accuracy side of it, but I think the practicality is that the shot is certainly possible.
I had a look at the trajectory of the Hornady .17HMR 20gn VMAX load at 2550fps. BC is only .125 compared to the .230 of the 25gn bullet. The calculator gives it barely more than 2000yd maximum potential range, and is virtually falling vertically by 2100yds. At about 1500yds it is is falling at 45-degrees. And, for a 1000yd zero, the bullet reaches 18.6m above LoS at 600yds, shooting up at an angle of two-degrees, requiring a +3500mm (117MoA) 100m zero. It is already subsonic by 260yds, and under 500fps at 100yds.
Now consider, Mark & Sam have done .22LR at 900yds...https://www.youtube.com/watch?v=Fg808TYc2Ao..although not a cold-bore hit. If they'd used a 48"-square target instead of the 24" they would've hit it with very good consistency, even in that wind. I don't know what their "group size" would've been, but probably sub-5MoA?
sungazer wrote:Blade what calculator are you using. I tried JBM and got really different results, I then thought of trying Hornady Site if they had something specific for the 17HMR as it was one of their projectiles they only had a pretty basic calculator but it was close to the JBM results.