velocity estimation?

[jeep505090]

Hey guys can some one point me in the right direction to a wesbite that i can do a ruff estimate of velocity out of my rifle? I only have access to a chrono every once in awhile and my curiousity is killing me,this is the load if it helps
175gr SMK
44.2 gr IMR4064
Federal Case
COAL 2.855
Barrel: Schneider 1/11 5P 26"

Thanks

 

[notquiteright]

Re: velocity estimation?

What would really help is zeroing the rifle at 100 yards and then shooting 300 yards. Measure bullet drop and from that all will be revealed Grasshopper.

 

[jeep505090]

Re: velocity estimation?

grasshopper doesnt have a range past 200yds..

 

[jeep505090]

Re: velocity estimation?

anybody?

 

[notquiteright]

Re: velocity estimation?

Grasshopper needs to get out and explore the world more, 300 yard ranges are not that hard to find, even in the socialist states

Now to answer your question based on the 'data' you provide-
your guess is as good as any. Reading any prior posts asking this question with just the load data would have gotten you that answer.

Good Luck

 

[gunsnjeeps]

Re: velocity estimation?

Guessing about 2670. Sierra's data is based on a Savage 26" 1 in 10 barrel. They list 2600 with 42.8 grains and increase 100 fps every 1.8 ish grains. A 200 yard zero would be 2 inches low at 100. Or 100 zero would be 4 low at 200.

 

[Tripwire]

Re: velocity estimation?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: eric0311</div><div class="ubbcode-body">I only have access to a chrono every once in awhile and my curiousity is killing me,this is the load if it helps
</div></div>

Seriously, if it's killing you that badly then pony up a little cash for a cheap chrony, as a cheap chrony will give you something a LOT closer than any "estimation" you'll ever come up with. You'll soon see the benifit of such things as knowing what EACH round's velocity is during load development, and checking future lot #'s of reloading components, etc.

Even if you do reverse engineer a generic velocity via JBM or some such, the drop data will NEVER match what you have exactly....which is why a chrono and a serious effort at rounds sent down range to confirm dope makes the only good sense........

On second thought, I think I have an old chrono around here somewhere that I don't use. If I still have it you are welcome to it, gratis....it was given to me so I have no vested "givashit". If you want it shoot me a PM and I'll take a look through my stuff. You'll need to get a tripod to put it on.....

 

[desertHK]

Re: velocity estimation?

I am guessing that you should be around 2750 fps. My AIAW with 26" 1:12 twist pushes the same projectile to 2670 fps with 43.8 grains of IMR4064

 

[jeep505090]

Re: velocity estimation?

Thanks for all the replies guys and yes i agree shelling out the cash for a good chrono is something i need to do, and thanks for the estimates deserthk and gunsnjeeps. Trip wire i will send you a pm about this chrono, thanks.

 

[flyrodder]

Re: velocity estimation?

You don't need a fancy chrono - I can read the display on mine 10 feet off the muzzle from where I sit at my portable bench. The difference in barrels can be interesting. We gave my twin sons (now 13) Savage Axis rifles in .270 last Christmas to celebrate their first (successful) mule deer hunts. (By the way - 1/2" 3-round groups at 100 yards with a $300 rifle with a 7-pound trigger still amazes me!). Even though those rifles have barrels that are 2" shorter than my Remington 700 SPS, all three rifles have muzzle velocities within 10 fps of each other, with one Savage shooting the same load as the Remington, and the other with half a grain LESS powder!

 

[jeep505090]

Re: velocity estimation?

yes barrels have alot to do with it, so do chambers as im finding out now...but none the less need hard numbers in the end