18" vs 20" velocity

[jluna575]

All things being equal at 800 yards, sea level, 59*...all the basic starter info from JBM Ballistics. Those difference between those numbers gets smaller the higher in elevation you are.

	Range	Drop	Drop	Windage	Windage	Velocity	Mach	Energy	Time	Lead	Lead
	(yd)	(in)	(MOA)	(in)	(MOA)	(ft/s)	(none)	(ft•lbs)	(s)	(in)	(MOA)
2450 FPS	800	-256.6	-30.6	68.1	8.1	1258.7	1.127	432.6	1.364	240.1	28.7
2500 FPS	800	-244.6	-29.2	65.9	7.9	1294.5	1.159	457.6	1.332	234.4	28

It may or may not be worth chasing faster FPS than factory. I try to at least match it, but often the accuracy node is below factory ammo speeds.

Thank you for breaking this down. It definitely puts it in perspective. All of my shooting is in New Mexico, the elevations range from 4500-7000 ft above sea level.

[Kswhitetails]

It's a balance, 2400 fps has over a half moa more wind drift at 1000yards than 2500. Yes, both will get there, but unless the 2400 groups 0.5moa smaller, 2500fps is the better load.

E=MC(squared). In this equation the number squared = KING - period.

But, if your limited by that 100 FPS, then sure, it makes sense. It does not however, make sense to discuss this in that extreme if this is the case. Get the extra length, out to 20 inches, you gain a consistent increase. If you're really worried about the 1/2 moa... then what is there to discuss? Get the 20.

Again, i find myself wondering what we're talking about. It seems the OP wants to shoot steel at 800. 2200 gets that done, handily. It requires more elevation and wind than 2500. Duh? I'm missing something important, I just KNOW it...

Lilja, Shillen, JP, PF, among others make top notch barrels. That 18 inch GB is the best deal going for what you wind up with, and will tag steel all day long at 800, or 1000, as proven by members far and wide. (Ok maybe not the GB barrel, yet, but 18s all day long)You're likely to see higher velocities from the EE rifling in that GB barrel too. You're going to want the performance of a good barrel at that kind of distance. IMHO...

[grayfox]

^^ +1 Kansas......... except I think you meant E=1/2*m*v(squared).

(Unless there's some U235 in the bullet... lol!)

[NugginFutz]

^^ +1 Kansas......... except I think you meant E=1/2*m*v(squared).

(Unless there's some U235 in the bullet... lol!)

LOL - beat me to it. We're not dealing with Plasma pulse rifles, firing photons.

KE = M/2 * V^2

Momentum, on the other hand is expressed as P = MV, where P=momentum.

[StoneHendge]

LOL - beat me to it. We're not dealing with Plasma pulse rifles, firing photons.

KE = M/2 * V^2

Momentum, on the other hand is expressed as P = MV, where P=momentum.

Bearing in mind that energy can be transferred to a target in the form of heat

[Kswhitetails]

No, guys. No.

It's all so relative, it's pointless to argue.

Seriously, the exponential expansion of this thread's scope is getting rather close to escape velocity. We need resolution in our perspectives!

[NugginFutz]

This is on the wall where I used to work...

148d7c3ba8f2e984dddda412dbfcad7b.jpg

The things we did with simple photons were the stuff of dreams. This included shooting down UAV's, blowing up 120mm Mortar rounds while in flight, disabling and burning up fast boats and, my personal favorite, shooting down a missile off the coast of California with a laser mounted in a Jumbo Jet.

[grayfox]

Yeah, where is that plasma-green pulse rifle thingy that Arnold was shooting in "Eraser", when we need it????
ROTFL

[grayfox]

...My work was all based on the E=mc^2, 200MEV/fission stuff.
Boy was that fun!!!

.........
O NO, Admiral Kirk,,,THE REACTOR IS CRITICAL!!!!!!!!! (Voyage to the Bottom of the Sea). (again, rotfl!!!)

[grayfox]

Sorry, kinda got carried away........

[Kswhitetails]

This is on the wall where I used to work...

[ATTACH=CONFIG]10660[/ATTACH]

The things we did with simple photons were the stuff of dreams. This included shooting down UAV's, blowing up 120mm Mortar rounds while in flight, disabling and burning up fast boats and, my personal favorite, shooting down a missile off the coast of California with a laser mounted in a Jumbo Jet.

Didn’t I see him movie one time where you guys use that thing to pop house full of popcorn? And don’t play it off, I know it was you.

[Sticks]

Didn’t I see him movie one time where you guys use that thing to pop house full of popcorn? And don’t play it off, I know it was you.

ROTFLMAO

[diddlyv]

All things being equal at 800 yards, sea level, 59*...all the basic starter info from JBM Ballistics. Those difference between those numbers gets smaller the higher in elevation you are.

	Range	Drop	Drop	Windage	Windage	Velocity	Mach	Energy	Time	Lead	Lead
	(yd)	(in)	(MOA)	(in)	(MOA)	(ft/s)	(none)	(ft•lbs)	(s)	(in)	(MOA)
2450 FPS	800	-256.6	-30.6	68.1	8.1	1258.7	1.127	432.6	1.364	240.1	28.7
2500 FPS	800	-244.6	-29.2	65.9	7.9	1294.5	1.159	457.6	1.332	234.4	28

It may or may not be worth chasing faster FPS than factory. I try to at least match it, but often the accuracy node is below factory ammo speeds.

What am I missing here, dont understand the Lead Columns, or at least don't know what target speed is assumed in the calculation

[Sticks]

What am I missing here, dont understand the Lead Columns, or at least don't know what target speed is assumed in the calculation

It is just pulling a sample set of velocities at 800 yards to show that the difference between 2450 and 2500 velocities is negligible - READ, not that big a deal. Only 12 inches of drop, and more importantly, 3 inches of wind drift. So if 2450 is working, and one is still trying to get something at 2500, it is a lot of work to pick up 3" of drift in a full value cross wind at 800 yards.

[JASmith]