Velocity calculator

[opencountry]

I wonder if anyone remembers who posted the velocity calculator table, maybe two months ago? I worked up a new load and wanted to run the stats through the formula to determine the velocity.

Thanks in advance,
Robert

[montana charlie]

Had to put it in a compressed folder to get the forum software to accept it.
As a plain .xls file, it was rejected.

CM

[Kodiak]

http://dragonflybridge.com/cgi-bin/Muzz ... rtridge.pl

Is this it?

[opencountry]

Thank you both very much! Exactly what I was looking for.

Robert

[opencountry]

I wonder if the reason a great 100-yd. group falls apart at 200 yds. is because the supersonic velocity of the bullet drops to subsonic...? My 45-70 load starts at 1,194 fps, which is just above the speed of sound (1,115 fps). By the time it reaches the 200 yd. target it has slowed down to subsonic velocity.

Any thoughts on this?

Robert

[Lumpy Grits]

OC, some loads just do that is all.
It's like I don't worry to much what the crono sez either. The target does all the "talking" for for me.
Check you loaded rounds for bullet run-out. I keep my T.I.R @ .003" max.
Gary

[opencountry]

Yes LG,

I think it wise, if longrange shooting is in the scope of one's plans, to develop loads that shoot well out at 200, and even 300 yards if possible. There are some instances where a 100 yard group will hold good out to 200 yards and beyond, but that's not always the case I have found.

Robert

[Tasmanian Rebel]

Eight days ago on a Sunday afternoon I wanted to test some LR ammo. I got a late start and have a church not far from my 500 m firing line(they have choir practice or something at 5:00 Sunday evening) so decided to shoot some loads at 200 meters on another part of my property rather than my 500m range I usually do my testing on. The left over ammo that shot pretty well at the 1000 yd line in Phoenix shot about an 8-10 " group at the 200 m line. If it had shot that poorly at 1000 yds it would not have stayed on paper. Clearly there was a transonic issue going on. Moral of the story if you're going to shoot LR you need to be shooting at least 300 yds and 500+ yds would be even better.
Keith Lay

[opencountry]

Thanks Keith,

Point taken. Work the load for the distance(s) you'll be shooting.

Thanks,
Robert

[Brent]

Clearly there was a transonic issue going on. Moral of the story if you're going to shoot LR you need to be shooting at least 300 yds and 500+ yds would be even better.
Keith Lay

Keith, most of us shoot as long a distances as we can find. But in the end, each match is a test bed. Many of us have gone to matches with multiple loads and shot them both - just to learn how they would do.

That puts a serious crimp on anyone's advancement in the game, but that is how it goes.

Generally, I have found that loads that work well at 200 work well at 500-600. But all bets are off beyond 800 yds. There is just no substitute for the real thing.

[Lumpy Grits]

OC, Doc said what I meant to........
I always make use of the 600yd steel plate(end of range)where I shoot to "prove" a load.
To many times I had a great 100 yd load that went to hell past 200yds.
Drying out here from heavy rain this weekend.......
Gary

[Tasmanian Rebel]

Generally speaking I think you're right Brent. MOST of the time if it shoots at 200 it will shoot at 5-600. Every time I think I've got things figured out in this sport I seem to get a curve thrown my way. I have a 38-72 that is spectacularly accurate on the ram and turkey lines(It's the one you, Al, and I talked about while in the pits at Phoenix) but can't BUY a chicken or pig when shot off a bench or sticks. I tried everything at the shorter distances but figure it is something inherent (harmonic?)in the gun and not the load causing this. I've also had 45-90's that shot clean at 200 and 300 and were great shooters at 8-1000 also. The only way I know for sure now is to do the grunt work and see what happens. This being said I seem to have better luck testing a load @ 100 yds and seing what it's accuracy potential is-I presume most of my loads are still going supersonic then but again don't know until I try it.
Keith Lay

[opencountry]

I've also found this 200/500-yd. combination to work well. I had a chance to get to the shoots in Spokane, WA last summer, and the load I worked up at 200 yards worked equally well at 500. I've never tried it beyond 500, so that will be the upcoming test.

Robert

[Brent]

Keith, I'm still looking for my first rifle that is lousy at shortrange and good at longer distances. I can't quite wrap my head around this as it seems to require a prescient bullet. Someday, maybe I will be so lucky (or is that cursed?)...


Brent

[COBPTR]

It has always been hard for me to believe that if a load shoots good at 100 that it's not going to perform good at further distances.
Everytime I hear someone say, "man my load shoots great at 100, but falls apart on the ram and turkey line". I have to believe there are other more critical variables not being looked at in that situation, ie, eyes, wind, steadiness.
In this sport all of our bullets, weights, loads are within a few % of each other no matter how much we like to think we've figured something out that no one else has. Once that bullet exits the crown it's either going straight, fast enough and stabilized or not. If I shoot 1350 fps and "Joe" shoots 1220, we're both transitioning to subsonic within a very similar distance. Harmonics don't matter after the bullet leaves the barrel. Those results, however small should be seen on paper even at 100 yds.
The one that really kills me is when people say they found a load that works great for longrange but shoots bad at 100 or 200. Impossible! Unless you're shooting heat seakers.
I'm not challenging anyone on the this site but those small changes in accuracy should be able to be seen at 100yds. You're more testing your wind reading, eyesight, steadiness when you shoot at 500+. If I shoot 10 rounds and get 1/2 moa at 100yds i'm going to feel confident shooting that load at any distance, as long as I've met the minimum requirements.

Robert G