same weight bullet Going fast V going Slow

[WhelanLad]

Hi guys, I was on a leisurely drive today from a knee specialist in the bigger town about an hour an a half away, among looking out the window for Fallow deer through the pine plantations I was also thinking in the back of my mind about the same size bullet going Faster V going slower..

the reason behind it was along the lines of say a .270Win, most blokes I know try squeeze the most FPS they can out of it, where as some other blokes (myself) happen to load their 270 "down" for whatever reason it may be, powder choice, accuracy whatever...

I was wondering if there is any/much difference out at say 400m(+) between a 130gr "corelokt" at 2800fps and one going at 3100fps.... in terms of energy.

I was kind of torn between the theory that heavy things carry more momentum out far? but with Lighter things, sometimes starting out Fast may actually slow down more dramatically to a point where the same light thing starting out a bit slower may actually meet up along the lines somewhere ??

Maybe its at ranges further than what is practical for a .270? 700-800?


Maybe I was just off with the fairies on that one??

please discuss

WL

 

[Boomer]

At 400 yards, the 3100 fps load will impact with a remaining velocity of about 2222 fps, while your 2800 fps load impacts at about 1984 fps. This is assuming 2000' elevation, 80 degrees F, and 60% humidity, which I hope is representative. The figures are from JBM for the 130 gr Sierra ProHunter, which IIRC has a similar profile to Remington's PSPCL. While the difference in impact velocities between the two loads is about 240 fps, the forces working to expand the bullets on game of equal density are similar enough not to make much difference. Both bullets will exit a fallow deer, but the slower bullet potentially will penetrate slightly deeper on a larger animal, due to slower and perhaps slightly less expansion. I'd expect both bullets to expand to about .40" The wound radius around the point of impact will be indistinguishable.

Once you get out to a half mile or so, you'll be severely limited by the available vertical adjustment in your scope, and you should be looking at a bullet that has better flight characteristics, and better low velocity terminal performance than a Remington bulk bullet.

 

[brybenn]

The reason the 270 and the 130 gr combo is popular is because of the flat trajectories and the result of hydrostatic shock when those speedy lil bullets hit. Slowing them down 300 fps at the muzzle only reduces your flatter trajectory. A deer at 400 yards likely won't ever know the difference. However the more you slow down the more elevation you need to add. A 270 is far from a big bore bullet in that it's lighter and narrower. The 270 relies on expansion to create a large wound channel where as a 458 diameter bullet uses the weight to plow thru. It doesn't need to expand to make the larger hole
I'm not saying a slower 270 load won't work. It certainly would but why have a flat fast shooter and not take advantage of its stronger points? Sounds like a 7/57 is what you need.
The lower velocity won't jelly as much meat however
The exception is if you wanted a certain bullet and it was most accurate slower speeds or limited to loads lower in the listings

I think the slower 150 gr would be better than a reduced 130 gr load for long range if the bullet is designed to open at reduced velocities
I know the heavier bullets make my steel plate bounce a lot more then lighter bullets at 400 yards

 

[H4831]

In spite of all the hype of a 130 grain bullet for the 270, I believe a 150 grain flat base spire point is a better all around bullet for the 270.
I once did a lot of testing with a 270 out to 500 yards. I was trying to get the best trajectory I could at that range, using mostly the trusted Norma 205 powder, against a couple others, as no chronograph was available at that time. I also used 2 or 3 different bullet types, in both 130 and 150 grain.
The procedure was to adjust the sighting to be 2 1/2 to 3 inches high at a hundred yards, then shoot at 500 yards with an aiming mark high enough above a piece of card board to enable the group to measured at how far below the aiming mark it was.
The best combination of 130 grain bullets were 32 inches low, while the best combination 150 grain loads were 34 inches low.
Thus, to 500 yards the 130's would be slightly better trajectory, but from 500 on the 150 grain would be best. Certainly, for hunting purposes one could consider either weight as having the same trajectory to 500. The 150 would always be better in windy conditions, so a 150 grain Nosler partition is about as it gets with a 270, and Douglas, that combination actually will kill a big game animal!

 

[Westward1]

In spite of all the hype of a 130 grain bullet for the 270, I believe a 150 grain flat base spire point is a better all around bullet for the 270.
I once did a lot of testing with a 270 out to 500 yards. I was trying to get the best trajectory I could at that range, using mostly the trusted Norma 205 powder, against a couple others, as no chronograph was available at that time. I also used 2 or 3 different bullet types, in both 130 and 150 grain.
The procedure was to adjust the sighting to be 2 1/2 to 3 inches high at a hundred yards, then shoot at 500 yards with an aiming mark high enough above a piece of card board to enable the group to measured at how far below the aiming mark it was.
The best combination of 130 grain bullets were 32 inches low, while the best combination 150 grain loads were 34 inches low.
Thus, to 500 yards the 130's would be slightly better trajectory, but from 500 on the 150 grain would be best. Certainly, for hunting purposes one could consider either weight as having the same trajectory to 500. The 150 would always be better in windy conditions, so a 150 grain Nosler partition is about as it gets with a 270, and Douglas, that combination actually will kill a big game animal!

That was my go to bullet in 270.

 

[Northman999]

I think long range target shooters figured out a long time ago that a heavier bullet with a high BC, even if it starts slower, will do better at range than a medium bullet going faster.

I'm fine with 130's in a .270 for general purpose work (150's are fine too, of course), but if I was purposely going out to hunt 400+ yards, I would go for a heavy VLD type bullet, with 150 grain being my minimum, and some of the 160 - 180 grain VLD's being more what I would be looking for. Some of the newer .277 VLS are stomping on the heels of well respected .284 VLD's, and that's saying a lot. You just need to be sure your rifle can shoot them.

Matrix bullets makes a 175 grain, .277 bullet with a .680 BC for example. Past 400 yards, this thing will turn your handloaded .270 into something altogether different than you have ever seen.

 

[sheephunter]

Heavier bullets fired at slower speeds will ultimately outperform lighter bullets fired at higher velocities but often not within practical hunting ranges. It's not momentum that causes this but the ballistic coefficient of the bullet. Heavier weight bullets have less drag in the air and decelerate more slowly than lighter bullets. When comparing identical bullets of different weights of course. A heavy bullet with a lower BC will never outperform a lighter bullet with a higher BC. As for firing the same weight bullet slower vs faster....this can be done to reduce recoil or to achieve accuracy but the faster one will always have more energy at impact regardless of range.

 

[Dogleg]

I was wondering if there is any/much difference out at say 400m(+) between a 130gr "corelokt" at 2800fps and one going at 3100fps.... in terms of energy.

Just to stick to the question, the 3100 fps load will have 1300 foot pounds of energy left, and the 2800 fps load will be at 1000. When the difference gets up to 30% like that its a little hard to ignore.

Or to look at it another way, what the slow load will do at 440 yards (400 meters) the fast one will take to 575 yards. You didn't ask; but put a boat-tail in the fast load and it'll pack the same energy out to 675 yards. When a bullet and powder choice starts makes a 270 into 235 yards more gun its time to start paying attention. That's assuming that you are ever going to shoot at those ranges, at close range where they all have plenty you are going to struggle to see a difference.