Range Report Calculate FPS wthout chronograph

[Sako Jako]

Guys

Hand loading 6.5 x 55 ammo . I'm trying to raise my game.This guy gave me the idea http://www.youtube.com/watch?v=GsnTDzQSvxQ
My rifle is a SAKO 75 VI

Is there a program that can work out the relationship between grains of powder and fps as ball park without using a chrono?

 

[HPLLC]

Re: Calculate FPS wthout chronograph

Probably not, because the barrel bore diameter plays a role, and the program would need to account for burn rates of various powders and barrel length- it would be pretty complicated.

 

[Powder_Burns]

Re: Calculate FPS wthout chronograph

You could always make a homemade chronograph. A new one is only a hundred bucks, but if you are interested I can pull up the schematics and plans to build one. Now, this is a completely mechanical setup and its degree of accuracy isn't going to compare to like an Oehler...but it would be fun arts n crafts when you are bored...

 

[bohem]

Re: Calculate FPS wthout chronograph

QuickLoad

As Griffin said, it's complicated. I use QL and a chronograph hand in hand for a lot of work. The chrono will get you close, and QL will get you close. QL is an extremely useful tool for those that have the ability to really use it. Many people do not and it gets a bad rap sometimes on forums. The old adage is quite true "garbage in, garbage out".

 

[Sako Jako]

Re: Calculate FPS wthout chronograph

Griffin Armament thanks for getting back to me on this the reason I'm asking is lets say I find a sweet load that works really well with my SAKO and the load is lets say 39.3 grains of vihtavuori N140 which has the same burn rate as Alliant re loader 15 Im not sure how Id work out a bullet drop table with out the true fps . In fact the more I think about it a chrono would be the only way around this. Unless I could mark up a range and physically try and shoot a couple of distances and work out Bullet drop backwards.

But hey thanks for the reply.

 

[Sako Jako]

Re: Calculate FPS wthout chronograph

Powder Burns thanks man but I can you imagine the variables and the second guessing . but thanks for the reply man and hey great name .

 

[Sako Jako]

Re: Calculate FPS wthout chronograph



Bohem "The nine most terrifying words in the English language are: 'I'm from the government and I'm here to help.'" - Ronald Reagan

He gets such a bad rap sometimes but as a person living out side the states always thought he was a decent guy.

 

[buffybuster]

Re: Calculate FPS wthout chronograph

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sako Jako</div><div class="ubbcode-body">Guys

Hand loading 6.5 x 55 ammo . I'm trying to raise my game.This guy gave me the idea http://www.youtube.com/watch?v=GsnTDzQSvxQ
My rifle is a SAKO 75 VI

Is there a program that can work out the relationship between grains of powder and fps as ball park without using a chrono?
</div></div>

Do you have access to shoot to ~600m?

If so, once you have your 100m Zero, you can shoot at 400, 500 & 600m, collecting your come-ups a long the way. Once you have that and the density/altitude, you can use JBM Ballistic Calculator plug in your known variables (bullet, atmospheric conditions, scope height, etc) then put a guessitmate velocity and see what the calculated trajectory compares to your actual data. Keep adjusting the velocity until you get it as close as you can. That will get you within +/- 25fps.

 

[Ring]

Re: Calculate FPS wthout chronograph

sort of.. depends on how far you can shoot...

zero at 100y
now shoot at 400+, the further the better.
get your scope data for that distance and punch it in here under "trajectory validation"
and it will give you your FPS if you have the correct BC put in..
http://ballistics.gseven.com/