The reason why you are using a heavier bullet but have less energy is simply math. Energy = mass X velocity. Even though you have a heavier projectile that is outweighed by a greater percentage of drop in velocity and thats why the difference drop in energy. You've got a bullet thats about 13% heavier but you have 20% less velocity.

There are lots of factors on what kills when talking energy, etc. Lets take a Utah mule deer for example. The general rule of thumb for a rifle is about 1000 ft-lbs to cleanly kill a deer (Debateable). So you should be more concerned about energy than velocity. But you also have to take into account bullet construction, weight, and caliber. If your bullet is to light it will shatter on impact with bone regardless of energy and the result is usually a long tracking job. Heck even a bullet thats too heavy can be a bad thing. I've seen them pass cleanly through an animal with almost no expansion. Bullet construction is also important because of the same reason. You want a quality bullet that shoots accurately but holds together well once impacting an animal and retain its energy after impact. You need the right caliber to make a big enough hole and retain its energy after impact.

Never used a .254 so I can't help you with your rifle choice. Good luck.

[ This Message was edited by: rather_be_huntin on 2004-01-15 15:05 ]

Well, I'll start with the fact that I have never even seen an Antelope or a wild hog in person but I do own a 257Roberts and a 270win. I have killed deer with both though I have more experience with the 270. My dad, however, used a 257Roberts for 30years off and on and killed more deer with it than most guns will ever see. For antelope, I don't think you can go wrong with either one. I hesitate on giving advise on wild hogs though because the only knowlege i have of them is what i have read. I think the 270 would be more than fine but if you go with the 257Roberts I would stick with either the Federal 120gr Nosler Partitions or the Hornady Light Magnum 117gr. Interlocts.

Welcome aboard Utah.

what kills, energy or velocity?

Neither. Blood loss and/or organ failure definitely do though. :smile:

Anyway, luckily you don't get to choose between energy and velocity because they are not independent variables (because bullet mass is usually fixed).

Usually when folks are talking about killing power the things that come into play are:

- Velocity (v)
- Mass (m)
- Diameter of bullet (d)

From these variables you can calculate kinetic energy (m * v^2)/2 and momentum (m * v). When I think about killing power I try to look at mass, velocity, and there derived values of momentum and kinetic energy.

Bullet integrity is important and dependent on mass, but is hard to quantify, imo. Practical experience and the experience of others is about the only way I've found to measure bullet effectiveness.

I have used 80 and 100 grain 243 bullets on antelope in the conditions you describe, without issue. Keep in mind "speed goats" are pretty small.

I have no experience with hogs.

[ This Message was edited by: bitmasher on 2004-01-15 22:13 ]

Utah...I've matched up your ballistic numbers with Remington's 130 grain Accutip and the 150 Soft Point Core-lokt (This is basically a round nose). The main reason for velocity and energy loss here is not so much weight as it is SHAPE. If you see the ballistic coefficient listed on the top, you'll notice that the 150 grain bullet has a very low ballistic coefficient. This means that the round nose is more affected by air resistance. The higher the number, the less affect air resistance has on it. This means that the accutip (BC=.441) will lose less velocity over distance than the soft point (BC=.261). A good place to see the difference is http://www.federalcartridge.com. There are two 150 grain loads in Federal Classic. A 150 HI Shok RN and a 150 Speer Grand Slam. The Grand Slam is a slim, pointed bullet, whereas the round nose has a large lead tip. Use the compare feature, and you'll see that they both leave the barrel at exactly the same velocity/energy, but due to air resistance, the RN really drops off. It is a large difference once you get out past 100 yards. Hope this helps.
-MV

Wanted to thank everyone who replied. The formulas will be extremely helpful as I learn to calculate different values for different loads. I'm very aware that what works flawlessly on the drawing board has a mysterious way of acting slightly different in the real world, but I feel I have a good starting point with the help you've all given.

This seems like a really good board and I hope to have more to contribute in the future.

Thanks again for taking the time to read through my post and reply with remarkably clear answers.

Utah

Hey... Don't go rifle buying yet! I have shot both. I use a .270. I love the .257. It is an awesome Pronghorn rifle. The problem with pigs (and there's a few...), Is that they range in weight from around 100 pound young adults to 400 pound monsters. You probably won’t see any 400 pounders, but I shot a 280 and a 220 in central California two years ago and let me tell you. They are a rough group. .257 will take 150 pound pigs (average size) up out to 250 yards without much problem with a well placed shot. But: they are always in bad shooting spots – next to brush or near cover; they have an armor like coat of skin and hard fat on them (that deer do not have); they have hard muscle; they are physically strong; they are extra ornery when shot (as is to be expected); they have tusks and can use them to eviscerate you if you surprise a wounded animal or an animal that you just stumble on; they don’t leave a big blood trail due to the armor. What I’m saying is that many folks think a 30-06 or .308 is the minimum for big hogs. They are wrong, but not far off. My cousin has shot several with a 6.5x55. He is a an excellent shot and even more important an excellent judge of when to shoot. As I said, I love the .257, but I think if you are buying one rifle for prongs and pigs, then you’ll want the .270. By the way, will you folks who keep talking about bore size read up on sectional density? It will explain why narrow bullets that are thought by the magnum crowd to be ‘small’ like .243, .270 and 6.5x55 kill animals so effectively. Chuck Hawks.com is a good place to start. Now, I need to go clean my 30-378 Weatherby, I’ve got a big Javalina hunt coming up…

The only state that I have hunted prairie goat in is Nevada. I prefered the 270 with 130gr Speer BT's, because they seem to beat the wind and are still rather easy to shoot.

As far as pigs. I've hunted the Hunter Ligget reservation in California. Most of the pigs that I've seen are good eatin size. 200 lbs more or less. There's a Standard gas station in King City, on I-5, that has pictures of some of the pigs that have come out of that area. There are some big mean looking hogs in those pictures. I don't recall exactly, but some of those hogs in the pictures were in the 500 lb. weight class. Most of the guys, that I know, that have hunted that area use there deer rifles. A 270 with a heavy, well constructed bullet would be a good choice. I prefered a 30-06 with 180's. I wouldn't recommend the 257 Roberts on the pigs. Would probably just piss off one of those big boys. Although, I knew some hunters that used 357 and 44 mag revolvers behind dogs.

Hunter Ligget is a military reservation. No side arms of any kind are allowed on the reservation. So, you won't be able to carry a pistol for back up if you head there. There is an area north by Eureka that use to have a lot of pigs. I don't know how the area is now. The 270 would be the best round of the two for either of those areas.