quote:

Originally posted by Pieter die 4de:


Energy is a misleading statistic at best. Driving up the velocity and hence its energy value becomes self destructive with frangible lead-core bullets - it shatters and penetration suffers, but it makes a mess where it dinintegrates and often do not reach the vitals.

A 120 gr TSX bullet in a 260 Rem or 6.5x55 Swede is much better than a 140 gr Soft bullet that is not bonded - but this is not recognised by those that make the laws. Once a bullet loses a major percentage of its weight on impact, it loses its momentum too that must be driving the bullet forward.

Pieter

Don't think I agree with that when it comes to medium velocity cartridges like the 260 REM or the 6.5x55. A 140 grain soft bullet will do good damage and penetrate well into the vitals from any angle at reasonable impact velocities and usually kill extremely fast. If you were talking about the 26 Nosler or 264 Win Mag, a TTSX makes more sense. It's just not needed or more effective at moderate velocity.

The last major overhual of the caliber/rifle classification was made for outruling old and unsafe blackpowder rifles( m1867(remington rollingblock 12,7*44rimfire). The common m96 6,5*55 became the minimum for biggame. (1950?)
Sence 1950 we have got several new huntable speices as:wildboar, roedeer, lynx, fallow deer mouflon, reddeer/elk, bear, beaver and no adaptation is done in caliber classification.
I dont want any changes because if the rules in bullet weight change then the greens would get new ammunition in trying to ban leadbullets.

quote:

A 140 grain soft bullet will do good damage and penetrate well into the vitals from any angle at reasonable impact velocities and usually kill extremely fast.

The Remington Core-lokt load of 140 gr is doing 2,650 fps im my 260 Rem and the bullet breaks up on Impala, and I have stopped using them. I now use 120 gr TSX bullets which work better for me and I do not have to fear angling shots.

The Core-Lokt Ultra bullets are bonded bullets and they should be better, but I have not tried them as we do not get it on our shelves.

Pieter

Jeffe,
Whatcha been smoking?

Just ain't that much difference with my chronograph!!

I have owned and shot the .280 and the several different forms of the same including the 7x64, all were great calibers and all did the same on game as far as I could tell..

My favorite and the only one that's lasted around my casa has been the wonderful little 7x57 Mauser, its damn hard to beat even on some of the bigger stuff..

quote:

Originally posted by Pieter die 4de:

quote:

A 140 grain soft bullet will do good damage and penetrate well into the vitals from any angle at reasonable impact velocities and usually kill extremely fast.

The Remington Core-lokt load of 140 gr is doing 2,650 fps im my 260 Rem and the bullet breaks up on Impala, and I have stopped using them. I now use 120 gr TSX bullets which work better for me and I do not have to fear angling shots.

The Core-Lokt Ultra bullets are bonded bullets and they should be better, but I have not tried them as we do not get it on our shelves.

Pieter

Having confidence in your rifle and load is extremely important. Sounds like you have a winner. Welcome to the forum.

quote:

Originally posted by Pieter die 4de:

The 7mm Shooting Times Westerner popped up in the 1980s, a super seven on full-length 8mm Rem. Mag. brass. At 3,325 fps, the STW's 140-grain bullet flies 150 fps faster than the 7mm Remington Magnum round. Predictably, the difference narrows downrange, because the faster a bullet, the greater the drag. More drag means a higher rate of deceleration, all else equal. At 500 yards the 7mm STW is only about 110 fps ahead of the 7mm Rem. Mag. But the STW is not the last word in speed. Remington's rimless, full-length 7mm Ultra Mag. and the 7mm Dakota (on a shortened .404 Jeffery case) have upstaged it by 100 fps. John Lazzeroni's 7mm Firebird offers even more horsepower.

Pieter

This second paragraph isn't quite true. If you put in the numbers of a STW shooting a 140 grain bullet at 3225 and a 7mm RM shooting same bullet at 3175. At 500 yards the STW will have 72% (2335 fps) of it's original velocity remaining and the 7mm RM will only have 69% (2215 fps). So your theory of a faster bullet loosing velocity faster doesn't quite hold up.

At 1000 yards the STW still has 46.4% of it's original velocity and the 7mm RM has 45.8%. So the gap does appear to narrow, but it never really happens. At 500 yard and 1000 yards the STW is nearly 6% faster than the 7mm RM where as it's only 1.5% faster at the muzzle.

This is because if you use the same bullet with the same BC the slower bullet slows down faster. This is due to the fact that drag has more time to work on the slow bullet over the same distance. I don't think for the 6% velocity at 500 & 1000 yards the STW is a worthwhile pursuit. Hell I have a hard time liking anything 7'm make mine .270 Win.

I've been using the STWs for right around 25 years, and the velocities we've come to expect are 3500 fps with 140 Ballistic-tips. 3200 is easy with 160 Accubonds, which I use in 3 of them.

quote:

Originally posted by taylorce1:

This second paragraph isn't quite true. If you put in the numbers of a STW shooting a 140 grain bullet at 3225
and a 7mm RM shooting same bullet at 3175. At 500 yards the STW will have 72% (2335 fps) of it's original velocity
remaining and the 7mm RM will only have 69% (2215 fps). So your theory of a faster bullet loosing velocity faster
doesn't quite hold up.

interesting,
Im going to go check the rate of deceleration of 7mmRUM vs 280rem....at close range from muzzle to 100yd,
..and will get back to the forum...

Answer:

7mmRUM 3225mv (vs) 280rem 2775mv (vs) 7mm/08 2600mv...[160 NP]

100yd: RUM retains 93.4%, 280rem 93.1%, 7mm/08 92.8%

Percentage of retained velocity is going to depend a lot more on the bullets used than the cartridge it is launched from. The Sierra 165 gr GameKing has a slightly lower BC above 2500fps than below while the 175gr Matchking has a slightly higher BC above 2500
than below.

Compare the same bullets in the cartridges and with one choice the STW will have better retention and with another choice the 7 Remington Magnum will. It ain't much and is really of no consequence to the target and is more a consequence of the projectile choice than the cartridge case used.

Jerry Liles

quote:

Originally posted by Jerry Liles:
Percentage of retained velocity is going to depend a lot more on the bullets used than the cartridge it is launched from. The Sierra 165 gr GameKing has a slightly lower BC above 2500fps than below while the 175gr Matchking has a slightly higher BC above 2500
than below.

Compare the same bullets in the cartridges and with one choice the STW will have better retention and with another choice the 7 Remington Magnum will. It ain't much and is really of no consequence to the target and is more a consequence of the projectile choice than the cartridge case used.

Jerry Liles

I agree, not all bullets are created equal. However, I'm betting the faster bullet even if it has a slightly lower BC above 2500 fps will in the end remain faster all the way across the board.

Trax, FYI I used a 140 grain NBT in my figures and the OP's numbers. I used what he posted for velocities because I have neither rifles, and didn't want to look up any data. I've tried the 7-08, .280 Rem, .280 GNR, and the 7mm RM and I still prefer my .270 Win.

Biggest problem with the .280 is underloaded factory ammo and anemic loading data. I load the .280 using .270 data. 3000fps with the 150 nosler and 2900fps with its 160 gr. cousin, turns this caliber into a different animal altogether.

I will throw in on the side of the 7MM Rem Mag. There have been some pretty solid big game hunters who hunted all over the world for about every species with a 7mmRM and a 375 in various rifles.

If I personally knew what I know today then I could have saved myself a lot of money and time both by just buying a 7mm Weatherby back in the 1980s instead of the 300 Weatherby Mag back then. That lead me to ultimately retool to the Sakos and finally to the Winchesters. The 7mm Laredo and the 7mm Extreme Weather are both among my favorites today.

I truly could have gotten all of the medium game hunting done in between with a 7mm Weatherby and a Dale Goens built 280. But I didn't know what I know today. I didn't yet know that a few fps or a few hundredths of an inch were (not) going to make a difference.

Then I might not have had the chance to get walloped by 338s, 378s, and things over .40 bore.

quote:

Originally posted by Stoneybroke:
Biggest problem with the .280 is underloaded factory ammo and anemic loading data. I load the .280 using .270 data. 3000fps with the 150 nosler and 2900fps with its 160 gr. cousin, turns this caliber into a different animal altogether.

Horse shieat

quote:

Originally posted by taylorce1:

quote:

Originally posted by Jerry Liles:
Percentage of retained velocity is going to depend a lot more on the bullets used than the cartridge it is launched from. The Sierra 165 gr GameKing has a slightly lower BC above 2500fps than below while the 175gr Matchking has a slightly higher BC above 2500
than below.

Compare the same bullets in the cartridges and with one choice the STW will have better retention and with another choice the 7 Remington Magnum will. It ain't much and is really of no consequence to the target and is more a consequence of the projectile choice than the cartridge case used.

Jerry Liles

I agree, not all bullets are created equal. However, I'm betting the faster bullet even if it has a slightly lower BC above 2500 fps will in the end remain faster all the way across the board.

Trax, FYI I used a 140 grain NBT in my figures and the OP's numbers. I used what he posted for velocities because I have neither rifles, and didn't want to look up any data. I've tried the 7-08, .280 Rem, .280 GNR, and the 7mm RM and I still prefer my .270 Win.

Taylorce1:

You are incorrect; drag is a function of velocity. Here is the general equation:

FD=(1/2)PU^2(CoefD)

where FD is the force of drag, P is the density of air, u is velocity, and CoefD is essentially the ballistic coefficient.

In identical bullets in identical atmospheric conditions, we can eliminate all terms except velocity, which is squared.

A bullet at a higher velocity but a lower BC would definitely lose velocity much faster.

quote:

A bullet at a higher velocity but a lower BC would definitely lose velocity much faster.

Yes, it is all about drag. You can feel the drag by sticking you hand out of the car at say 25 mpu and then again at 100 mpu, and you will feel the difference.

Pieter

quote:

Originally posted by taylorce1:

quote:

Originally posted by Pieter die 4de:

The 7mm Shooting Times Westerner popped up in the 1980s, a super seven on full-length 8mm Rem. Mag. brass. At 3,325 fps, the STW's 140-grain bullet flies 150 fps faster than the 7mm Remington Magnum round. Predictably, the difference narrows downrange, because the faster a bullet, the greater the drag. More drag means a higher rate of deceleration, all else equal. At 500 yards the 7mm STW is only about 110 fps ahead of the 7mm Rem. Mag. But the STW is not the last word in speed. Remington's rimless, full-length 7mm Ultra Mag. and the 7mm Dakota (on a shortened .404 Jeffery case) have upstaged it by 100 fps. John Lazzeroni's 7mm Firebird offers even more horsepower.

Pieter

This second paragraph isn't quite true. If you put in the numbers of a STW shooting a 140 grain bullet at 3225 and a 7mm RM shooting same bullet at 3175. At 500 yards the STW will have 72% (2335 fps) of it's original velocity remaining and the 7mm RM will only have 69% (2215 fps). So your theory of a faster bullet loosing velocity faster doesn't quite hold up.

At 1000 yards the STW still has 46.4% of it's original velocity and the 7mm RM has 45.8%. So the gap does appear to narrow, but it never really happens. At 500 yard and 1000 yards the STW is nearly 6% faster than the 7mm RM where as it's only 1.5% faster at the muzzle.

This is because if you use the same bullet with the same BC the slower bullet slows down faster. This is due to the fact that drag has more time to work on the slow bullet over the same distance. I don't think for the 6% velocity at 500 & 1000 yards the STW is a worthwhile pursuit. Hell I have a hard time liking anything 7'm make mine .270 Win.

I thought about this tonight while I was riding my bike. I ride an 8 mile loop, where the first 4 miles is generally downhill and the return uphill. I did two loops tonight before it got dark.

Going downhill, I can pedal my ass off and fly, but the faster I go, the more the wind resistance. So I wondered if I just layoff a bit, might I have more energy when I ride uphill?

Here is the final nail in the coffin of your "the faster a projectile travels the less velocity it loses theory": if you were correct, the faster you drive, the higher the gas mileage. Do you really think that is true?

I read the article. Good discussion I shoot a .280 Rem and have taken a lot of plains game and elk, about 25 animals in total. I tried the 7 mag, loud and kicks hard, but shoots great. Went back to my .280. Tried .270, .300 RUM and .264 women - still liked the .280 better for me.

Great discussion for change BTW. You guys are a lot smarter than I thought on ballistics and stuff. Thanks for staying civil!

The problem in comparing calibers is paper ballistics which in my opine don't mean a hell of a lot unless your writing a nice story for a magazine..I still cannot tell from shooting big game any difference in the field between the 7x57, 280, 7-08, 270, 30-06 and 7 mag, the 9.3x62, 9.3x64, .338, 358, and the list goes on and on. The only difference, and its so minor in the field, that it cannot hold water is the flatness of trajectory that is often quoted, but in reality is is never much more than 6 inches and I'm allowing for room to argue over that as its usually about 2 or 3 inches, then add it to field shooting and its crap shoot!! We have reached a saturation point I fear! The only reason the subject exists is "what would we have to discuss without it"

quote:

Originally posted by Atkinson:
The problem in comparing calibers is paper ballistics which in my opine don't mean a hell of a lot unless your writing a nice story for a magazine..I still cannot tell from shooting big game any difference in the field between the 7x57, 280, 7-08, 270, 30-06 and 7 mag, the 9.3x62, 9.3x64, .338, 358, and the list goes on and on. The only difference, and its so minor in the field, that it cannot hold water is the flatness of trajectory that is often quoted, but in reality is is never much more than 6 inches and I'm allowing for room to argue over that as its usually about 2 or 3 inches, then add it to field shooting and its crap shoot!! We have reached a saturation point I fear! The only reason the subject exists is "what would we have to discuss without it"

With a rangefinder, velocity is not an issue at all. Flat trajectory is appealing to those who want a "max point blank zero" but they generally don't realize having a bullet fly as high as 4 inches above your point of aim is recipe for disaster.

quote:

Originally posted by AnotherAZWriter:

Taylorce1:

You are incorrect; drag is a function of velocity. Here is the general equation:

FD=(1/2)PU^2(CoefD)

where FD is the force of drag, P is the density of air, u is velocity, and CoefD is essentially the ballistic coefficient.

In identical bullets in identical atmospheric conditions, we can eliminate all terms except velocity, which is squared.

A bullet at a higher velocity but a lower BC would definitely lose velocity much faster.

You are correct a higher velocity bullet with lower BC would loose velocity faster. I never said it wouldn't or didn't intend to. What I meant was regardless of the bullet used as long as the bullets are equal BC the faster one will maintain speed the longest.

What the OP fails to come to grips with regardless of speed if the BC is the same the bullets loose speed the same rate. The drag ratio is pretty much the same, the faster bullet will travel further and the slower bullet will never match speeds over any distance.

Yes, there might be more drag on a bullet leaving the barrel at 3200 fps vs. one at 3000 fps. However is the atmospheric conditions are the same when the faster bullet reaches 3000 fps it has the exact same drag as the other at 3000 fps MV. It just happens further from the muzzle than the slower bullet.

quote:

Originally posted by dogcat:
I read the article. Good discussion I shoot a .280 Rem and have taken a lot of plains game and elk, about 25 animals in total. I tried the 7 mag, loud and kicks hard, but shoots great. Went back to my .280. Tried .270, .300 RUM and .264 women - still liked the .280 better for me.

Great discussion for change BTW. You guys are a lot smarter than I thought on ballistics and stuff. Thanks for staying civil!

I would be on that page too especially if I had a custom rifle built from somebody like Mark Penrod. It would most likely be a 280 and it would be my medium hunting rifle other than I almost have to have a 270 in my safe too.

.[/QUOTE]
With a rangefinder, velocity is not an issue at all. Flat trajectory is appealing to those who want a "max point blank zero" but they generally don't realize having a bullet fly as high as 4 inches above your point of aim is recipe for disaster.[/QUOTE]

There's a lot of people who have been doing just that for a long time without disaster. It probably isn't much of a system for a bush hunter who when confronted with a 200 yard shot for the first time in his life thinks it must be time to hold on its backbone and shoots over, but not everyone fits in that category. There's more than one way to skin a cat, and there's plenty of guys that can put a 400 yard MPBR to good use.

I like a rangefinder, subtension reticles, yardage marked turrets, MOA turrets and stock charts, iphone apps and my G7 with built in ballistic solutions just as much as the next guy, but with the exception of very long hunting ranges I don't think I've made a whole lot of progress from when I just plastered an STWs crosshairs in the middle of some luck-less mammal on this side of a quarter section and pulled the trigger. My turret scopes on hunting rifles are carried dialed for MPBR even though they are zeroed for 100.

Excellent thread ,thanks to you all.jc

7mm in carious cartridges have served me well on game up to and including elk, wildebeest and zebra. If I'm going for bigger game than that I'm using either my 9.3x62 or an old 375 H&H.

quote:

Originally posted by Dogleg:
.

With a rangefinder, velocity is not an issue at all. Flat trajectory is appealing to those who want a "max point blank zero" but they generally don't realize having a bullet fly as high as 4 inches above your point of aim is recipe for disaster.[/QUOTE]

There's a lot of people who have been doing just that for a long time without disaster. It probably isn't much of a system for a bush hunter who when confronted with a 200 yard shot for the first time in his life thinks it must be time to hold on its backbone and shoots over, but not everyone fits in that category. There's more than one way to skin a cat, and there's plenty of guys that can put a 400 yard MPBR to good use.

I like a rangefinder, subtension reticles, yardage marked turrets, MOA turrets and stock charts, iphone apps and my G7 with built in ballistic solutions just as much as the next guy, but with the exception of very long hunting ranges I don't think I've made a whole lot of progress from when I just plastered an STWs crosshairs in the middle of some luck-less mammal on this side of a quarter section and pulled the trigger. My turret scopes on hunting rifles are carried dialed for MPBR even though they are zeroed for 100.[/QUOTE]

Dogleg:

I have to disagree on this one. If your MPBR puts you four inches high at say 180 yards, you must shoot 2 inch groups before you risk missing a five inch vital area. The problem IME is that most animals within 180 yards are somewhat aware something is not right (at least in open terrain like antelope hunting). You cannot often take a shot from a rock solid position, which means perhaps that 1 inch group your rifle can shoot at 180 yards (just a hair over 1/2 MOA) becomes 3 inches. Now your group is 4 inches, which when laid over a five inch vital area would be deadly - except said group is now centered four inches high which means nearly 50% of your shots will be higher than 5 inches.

The same math applies in reverse when the animal is at the far end of your MBPR, only now it is worse. If your bullet is four inches low, you have to shoot 1/2 MOA groups in the field or you risk missing. Four inch groups in the field (MOA) mean you have some bullets striking as low as 6 inches. That is a miss.

I prefer a 200 yard zero. Few people can tell the difference between 300 and 400 yards, or 400 and 500, so they are going to use a rangefinder anyway, relegating the concept of MPBR rather moot. At that point you use your BDC or crank the knobs.

I used to use MPBR, but its usefulness has been vastly overestimated since rangefinders first came out. I don't like my maximum trajectory ordinate to be higher than 2 inches on my zero.

Do you really believe the vital area of a big game animal is 5"?

quote:

Originally posted by Dogleg:
Do you really believe the vital area of a big game animal is 5"?

No, 10 inches is my reference. But that means you can't be lower than 5 inches high or low or you risk missing. Bullets don't shoot one hole groups; half will be above the center of impact and half will be below. The amount above or below is function of the abilities of you and your rifle.

The same math applies to windage error at long range. Wind error effectively shifts your zero left or right; group size in the field further compounds the issue.

The only real bad ting about this thread is that it has me at Jarrett's site reading up on the 280 AI and the 284 Jarrett. Here I was getting pretty happy with my 7MM RM and now this . . . .

A 7mmRemMag and 160 AB's @ 3100fps (71.5g Retumbo) is a hard combination to beat for open country hunting, IMO. Although I've been fiddling with CDS dials the past few years, a +3" @ 100yds zero has served my needs very well since 1971.

One can get into trouble with a 4" high setting unless he is aware and it has had time to sink in, I say this in agreement with Ariz. in that more game is missed by over shooting than undershooting.

However, for the last 60 or so years at the advise of Jack O'Connor I still sight my rifles in 3 inche high at 100 yards, that's 4" high at 200 yards and spot on at 275 or 300 depending on the caliber..I also always check my shooting at 100, 200 and 300 and even 400 and 500 if the range allows it..there may be some difference from gun to gun..

Having done this for many years, I'm automatic with it..I have only owned a range finder for about six months, it seems to work, its just that I have yet to remember I have it when game is spotted..I seem to judge range pretty well and my zero is normally on target. I aim AT the animal unless its way out yonder then I get a little sky between my cross hair and the back of the deer, if I miss he was too damn far to shoot at anyway. Its been a long time since I shot over anything but on rare occasions I have shot low with my sky shot...It just happens even though I know better, and I have seen more game wounded by long range shooting than any other way..I really try to not shoot over 300 yards, I can almost always get closer by at least a 100 yards.

As far as I know, there still isn't any law against those using the MPBR method from also using a rangefinder. Bullet hits a bit high at 200 and you have time to think about it? Aim a bit lower. It isn't any different than the guy with a 200 yard zero creeping below center on a 100 yard coyote or magpie. Also what does the guy with a 300 and 400 yard crosshair do when the deer shows up at 350? He's bound to aim a bit high with 300 hashmark, or low with the 400 depending on his nature. I wonder how he got so smart when the duplex/MPBR guy is too dumb to do the same at 200 or 300? I wonder if he's also smart enough to at least start moving his crosshairs to the windy side of the vitals?

Whether you like subtention reticles (I do too BTW, but more for 400-600 yard hold points than to avoid shooting over at powderburn range.)a MPBR technique, a knowledge of your duplex reticle for rangefinding and an alternate hold-point, a knowledge of your game's size and some different hold-points for different ranges or even a blend of techniques your system is still going to depend rather heavily on knowing what you're doing. For that there are no short-cuts.

Can a person shoot over a game animal while using the MPBR method? Sure. Can another use the wrong cross-hair and shoot over/under? Yep, seen that too. Ever see an F-Class shooter make his windage adjustment backwards? That's always good for a laugh. Its almost as much fun as watching someone boresight during a match because he got lost in his turret. Actually if you see someone doing that it means that it isn't the first time it happened to him.

There are many ways to skin a cat. Some have small advantages for some things and some people. All can be screwed up if you try, or don't try hard enough. I like subtention reticles, and I also like dial yardage knobs and when push comes to shove and the distance gets long I'll take MOA turrets above everything. As much as I like everything, with the amount of things that can be done wrong with any system there is still a place for the do nothing, aim at the middle until its too far to shoot at MPBR. When you do nothing, there's less to do wrong.