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Old November 10, 2002, 07:39 PM   #1
Coltdriver
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Join Date: March 2, 2001
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17 HMR Trajectory Questions

This is a question for some of you ballistics/ammo gurus.

If you sight a .17 HMR rifle in to hit a target at 100 yards what is the trajectory like???

Assume that the elevation of the rifle is 0, can you describe the arc of the bullet to say that at 25 yards the elevation (relative to the starting point) is this, at fifty yards the elevation is this, at 75 yards the elevation is this and at 100 yards the elevation of the target is this.

Can you do the same exercise for 200 yards with the same round and give elevations every 25yards??

You can see that I am trying to come to an understanding of about how high or low I should hold my point of aim given different distances.

Is it possible to predict the behavior of a cartridge like this or does it all become platform dependant??

Thanks in advance
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Old November 10, 2002, 08:49 PM   #2
bad_dad_brad
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The .17 HMR shoots pretty flat to 100 yards. It drops off 10 inches at 200 yards. That is an improvement over a .22LR (5/6 inches at 100) and .22mag (2 inches at 100). Bullet drop is not the big problem with this little fella within 100 yards. It's wind. Any fair amount of wind and that tiny little 17 grain bullet is all over the place.

I have a Marlin .17 HMR bolt action rifle. Within 100 yards I think it is a pretty good improvement over a .22 on small game. Nothing bigger than a prairie dog. Just look at the thing. It is really tiny and light. I mean, there is so much you can do according to the laws of physics. After 200 yards there is so little energy left in that little projectile that you might as well throw a rock.

The .17 HMR is currently all the rage, but I predict in a few years, even though it will still be around, it will pretty much be forgotten. New cartridges are like new fishing lures. Not meant to catch fish, but fisherman. Guilty as charged!
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Old November 10, 2002, 10:40 PM   #3
Coltdriver
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I have often said that in order to catch a fish a lure must first catch a fisherman.

That being said I got caught by a .17 the other day.

Are you saying that if you dial in your scope to hit a target at 100 yards that the bullet will fall an additional 10 inches at 200 yards??

Any idea, if you dial in to hit a target at 100 yards where the bullet is at 50 yards??
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Old November 11, 2002, 06:23 PM   #4
bad_dad_brad
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Congrats on your purchase.

There is no bullet drop for a .17 HMR in the first 100 yards, at least that is what the charts say - shoots flat to 100 yards and then the bullet starts to lose energy pretty fast and will drop from flat to 10 inches lower at point of impact in the next 100 yards. At 50 yards or 100 there is no drop off. So zero your scope at 100 yards. If you are going to shoot anything further you will need a scope a whole lot better than mine (4X28 Weaver Rimfire) with range finding marks and or good adjustment knobs with precise click stops.

Look at this site and you will find a chart that answers your question about bullet drop off for the .17 HMR from 100 to 200 yards:

http://www.cctrap.com/~varmint/ashot.htm#Clicks

Personally, I have never attempted anything over 100 yards with the .17 because I don't think the bullet is that effective past that. Check this out.

http://www.cctrap.com/~varmint/17hmr.htm

This fellow claims he took some ground squirrels at 300 yards. Check out his scope - pretty sophisticated outfit.

Your questions about scope zeroing, range, distance, bullet drop, etc. are pretty much out of my league of expertise. I generally shoot at distances where bullet drop is not a factor and don't use a scope that often and so you might ask that question to TFLers more experienced. What they can tell you would apply to any type of ammo.
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Old November 11, 2002, 08:22 PM   #5
Chuck Dye
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Join Date: June 28, 2002
Location: Oregon-The wet side.
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Go to

http://www.norma.cc/htm_files/javapagee.htm

and

https://gateway.hornady.com/cgi-bin/....html&cart_id=

Using Hornady's velocity chart and the Oehler Ballistic Explorer, I get a calculated ballistic coefficient of 0.1251.

On the Norma page, go to the "Define your own bullet" option. Plug the bullet weight, 17gr, and the B.C. into the definition boxes, then slide the other variables around. It is fun!
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Gee, I'd love to see your data!
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