Light or Heavy Bullet Choice

This may sound like a dumb question but what are some of the benefits of using a heavier bullet? Obviously it will hit an animal harder but ballisticly what are the advantages of a heavier bullet?

I am handloading 140 gr AMAX's for my 6.5 Creedmoor. My buddy is giving me crap telling me to get a lighter bullet because they shoot flatter. I ran a quick ballistics calculator and the 120 AMAX's do fly a bit flatter but not much.

What are some advantages using a heavier bullet?

Since a heavier bullet generally has a higher BC, it will at some point downrange overtake a lighter bullet in terms of trajectory and retained energy. The question becomes whether or not you're going to shoot at distances long enough for any of that to matter. And as to the "energy" concept...well, save that one for another day.

It all depends on what you're trying to do. So what do you want to do. The only thing I can add to what river said is a higher BC generally will have less wind drift.

Tell your buddy to leave you alone.

140 A-max means 6.5mm. 400 yards, and in, it will drop just a tad less than a 130 or 120 gr, but when we get out past that the 140 gr will hold up way better than a 120. Ballistic coefficient is the ability to mauntain velocity, and as RR stated, if you ran a drag race of a 120 gr against a 140 gr, the 120 gr will pull out ahead early, but the 140 gr will pass it down range.

The 140 gr will have less wind drift along the way as well.

A 140 gr @ 2800 MV will make a barrel last longer than a 130 gr @ 2950 MV. Wind drift for both is the same, the 140 being a heavier projectile has more retained energy down range.

I've talked about this a couple of times, but will do so again. I shoot a 260 mostly these days, having parked my 270 in the safe. The first 260 I bought had a 16.5 inch barrel, which didn't push along the 120 grainers as fast as I'd like, so after a year or two with that bullet, I moved to the 100 grain version of that same bullet (Nosler BT). I wanted ballistics similar to the 270, because after 30ish years with the 270, those ballistics were ingrained in my hunting/thinking. I found that the 100 grainer worked just fine, and I've used it for 2 years now on coyotes, pigs, and deer. My conclusion at this point is that the 100 grainer is fine for deer but the 120 grainer knocked em down noticeably faster, even though it was moving a little slower. The difference isn't large enough to make me move back to the 120's, but I probably eventually will go back to the larger bullet. If I can make a guess, the 140's might be even a little better on deer or larger animals, but do you really need better? It's your call. As for me, I went with the very familiar flatter trajectory of the smaller bullet. That allows thinking about trajectory to be uncomplicated at 400 yards or less.

Rifling twist will affect what weight of bullet your rifle can stabilize.
Also, each rifle is different. Your rifle might shoot most accurately with a medium load of ABC powder, 140 gr bullets made by Hornady and Remington primers. Your buddy might get better groups with a max load of XYZ powder, 120gr bullets from Speer, and CCI primers.

Clear concise provable information - and not just Opinions - like this is sometimes hard to find, when less experienced folks clutter the conversations with "My Grandaddy said" stuff.

New better boolitz, powders & primers have changed the time worn "Rules" from even as recent as 10-15 years ago. Even us Old Dogs can learn sumthin...IF we pay attention and keep up.
Ron

It's really a good question. I discuss this with shooters all the time. Take a look at the chart below. It is a 123 A-max @ 2980 fps and a 140 A-max at 2800 fps. These speeds are a realistic amount for the 6.5 CM.

Let's look at each column.

Velocity- The speed of the 123 at 1000 yards has slowed to less than than the 140. The 140 began to surpass it at about 700 yards. But you can see the 123 loses velocity faster than the 140 does. This has to do with BC. The higher the BC, the less it loses it's velocity, and increases it's effective range. The "effective range" is generally defined when the bullet goes transonic, or below the speed of sound. But, the 140 A-max will transition well through the transonic, and will maintain true flight past this, which will increase it's actual effective range.

Energy- The 140 has more energy on target than the 123 does throughout it's entire flight. The combination of high BC, and increased weight allow this.

Elevation- This is one that most shooters get hung up on. The 123 is flatter than the 140, even at 1000 yards. Even at 500 yards, the difference is less than 5 inches. If you are dialing your elevation into a scope, this is easily accounted for by an extra .1 mil or .25 moa or so. I do not look at the elevation as my main deciding factor when comparing bullets. (I look at the wind drift). It's easy to know where your bullet is with elevation. Once you know your rifle and ammo, it is very repeatable.

Wind drift- Immediately the 140 A-max will have less wind drift than the 123 will. At 1K yards in a 10 mph wind, the 140 has 8" less wind drift than the 123. This is where most shooters will miss. The BC on the 123 is actually pretty good, and does not show a significant difference in all areas.

So, your bullet choice can be based on what factors are most important to you. I generally like heavy for caliber bullets for the added BC and added energy on target. But there's nothing wrong with a 123 for hunting close in game, say under 300-400 yards. The 6.5mm has very good bullets with high BC's, and will not show a large difference between the 123 and 140 A-max. But other calibers, like a .308 will.

123 A-max @ 2980 fps
Range Velocity Energy Elev Wind
(yards) (ft/sec) (ft-lbs) (inches) (inches)
0 2980 2425.3 --- ---
100 2793.1 2130.6 0 0.59
200 2614 1866.1 -2.71 2.42
300 2442.4 1629.1 -10.52 5.6
400 2278 1417.2 -24.17 10.28
500 2119.7 1227 -44.53 16.6
600 1967.4 1057.1 -72.64 24.74
700 1822.2 906.8 -109.75 34.92
800 1684.8 775.2 -157.35 47.35
900 1555.6 660.9 -217.23 62.26
1000 1436.2 563.3 -291.51 79.9

140 A-max @ 2800
Range Velocity Energy Elev Wind
(yards) (ft/sec) (ft-lbs) (inches) (inches)
0 2800 2437.1 --- ---
100 2647.1 2178.2 0 0.54
200 2498.5 1940.5 -3.22 2.22
300 2354.5 1723.3 -12.01 5.14
400 2215.4 1525.6 -27.08 9.41
500 2081.4 1346.7 -49.24 15.15
600 1952.2 1184.7 -79.44 22.49
700 1826.8 1037.3 -118.78 31.6
800 1705.1 903.7 -168.55 42.67
900 1587.2 783.1 -230.3 55.92
1000 1473.3 674.8 -305.89 71.6

I like to use the bullet weights the round was designed for-at least within a reasonable range. For example, a .30-06 will shoot bullets from 110 to 220 grains, but I would keep it in the 165-180 grain range for that caliber.

The newer well-constructed bullets do allow for lighter bullets with similar performance to a little heavier bullet. But I still like the heavier bullets within the normal design ranges of any given caliber. More weight (within reason) is always better IMO.

6 in 1/2 dozen in the other.... Run the ballistics on both.... Then compare them and then you will go I should just stop stressing

I shoot 129 to 140 grain bullets in mine. Those bullet weights also tend to be the most common. I've ran 129 SST, 139 Lupa, 140 amax, 130 vld...... POI under 400 is pretty close on all. To the point they are almost interchanable in my rifle

Just to try and make sure I am understanding what is being put down:

129 nosler: target/hunting below 300-400yds, more wind drift than the 140s, about the same POI as a 140 elevation wise.
140 Amax: target/hunting to 1k yds, about the same POI as 129.

Now for a couple of questions:

129 & 140, What size game out to what distance? I am just curious to what these bullets can do in capable hands, not necessarily my hands.
140 Berger/Hybrid: What's the difference between the Berger and Amax? Use, experience, etc.
160: Where do these fit into the equation or do they?

I'm trying to figure out what ammo to go with in a 6.5 Creedmore with a 1:8 twist, 26" barrel, No suppressor.

The Bergers have a higher BC than the A-max. They're also a dime per bullet more expensive. My experience with them has been find the right powder charge then adjust seating depth. The A-max was less work to make it shoot.

A 6.5 Creedmoor with a 140 A-max even with the lands (as long as it still fits in the mag) will shoot right around 42.0 gr of H-4350. Mine shoots at 42.4 and a good friend's shoots at 42.3, we could swap ammo and still be sub-MOA.

That's a lot of questions with some long answers. Basically, it boils down to performance. The higher the BC, the less drop and less wind drift. When comparing 1 cartridge (like the 6.5mm CM in this case) and comparing bullets in that cartridge, there is generally a break even point. For example, take the 338 Lapua. Most shooters want to compare the 250 Sierra Matchking (SMK) to the 300 grain SMK. They want to know which one is better. I ask what will be the primary use or distance you will be shooting. The 250 SMK is flatter and has about the same wind drift as the 300 SMK out to 700 yards. At about 700 yards, the 300 SMK will have less wind drift and begin to shoot flatter out past 700. So, the break even point is about 700. So when they say they want to shoot out to 1K and beyond, the 300 SMK will perform better than the 250 SMK. Inside of 700-800 yards, the 250 SMK is a good choice. Every caliber will have a break even point when comparing different bullets. And it generally works out to be about 700 yards for most rounds anyway. If you plan to shoot inside of 500 yards, the lighter bullets may be what you want for the added speed and flatter shooting.

Also keep in mind "flatter" doesnt really matter. Take my 6.5 Creedmoor against my 7mm-08, both shooting A-maxes, 140 gr in the 6.5mm and 162 gr in the 7mm.

The 7mm has a higher BC but has a much lower MV due to a shortened barrel. At 600 yards the correction for the 6.5mm is 3.6 Mil, for the 7mm it is 3.9 Mil. Big deal! I have to dial in three more tenths on the elevation turret.

You need to let the rifle decide. Both of my x47 barrels hated the 140 amax. I mean like 1.0-1.5 moa on average.

However, they both loved 123 scenars, 123 amax's, and 130 jlk's.

BC doesn't mean squat if the round doesn't start out accurate to begin with.

Just buy 100 of each bullet you want to try. Do a little load development. Shoot all the good loads at distance.
You will start to see what is working and what isn't.

^^^^^^^^THIS^^^^^^^^^

if you aren't shooting over 400 yards then shoot what the gun likes. If you are shooting over 400 yards then shoot what the gun likes. If the gun isn't finicky then shoot what you like. If you aren't shooting over 400 yards, you will always have enough energy to kill a whitetail size animal(assuming you are 100+ grains on the bullet in this caliber). There are a lot of details involved with the trajectory of each bullet. What matters is that you know the trajectory of the bullet you are shooting and no other. Just remember the buffalo hunters shot buffalo with a 45-70 past 1000 yards. Did the bullet shoot flat? NO Did the bullet shoot fast? NO Did the hunter know the trajectory of his bullet? YES

I agree with that-within limitations.
When I buy a rifle for a specific hunting use, I have a narrow range of bullet types and weight ranges I have in mind for that specific rifle. If it likes one of those, I keep it. If it doesn't, it goes. Sometimes you get lucky and get a rifle that shoots almost anything pretty well. So far, I have only had one that just didn't like any of my choices.

I am handicapped since I don't reload though. Reloaders have many more options and can usually find a load that works for their purposes.

The first 6.5mn I had, I tuned a 130 VLD to shoot terrific. 500 bullets later I switched over to 140 gr A-maxes and they shot terrific as well. I decide what bullet the rifle is going to shoot, not the rifle. If you've got the twist rate to stabilize X weight of bullet then work up the load until it shoots.

What loads and powders did you try with the 140? I find it hard that a x47 would not like a 140 A-max.

Thank y'all so much for your help! This makes a lot more sense. I can see how dialing for elevation is not a big deal. The numbers don't lie, if your shooting long range it looks like you just need more bullet, especially when it comes to the wind.

Reloading is a lot of fun, but man there are so many variables. This weekend I shot the 129 SST's and the 140 AMAX. The rifle shot both great but I like the 140 AMAX's a lot because the high BC and extra weight.

I'll be coming out to take that class with you soon Fireman!

Ballistic coefficients aside, I feel like heavy for caliber bullets perform better on game than do light ones.

I'm ready! The 140 A-max is probably the most shot bullet on my range.

I agree. Most of the guys with a huge amount of hunting experience (not saying I am one of those) agree as well. All else being equal, more bullet is always better.

I will say that I will go up in caliber if the bullet is too heavy for caliber beyond what it is designed for though. For example, I with a 200+ grain bullet I would go up in caliber to a .338 rather than push one out of a .30-06.

Two x47 barrels actually.

Both 8 twist. A shilen and a bartlein. The shilen was the better of the two barrels.

Tried H4350, Varget, and an oddball 4320. Tried a few loads with RL17 as well.

Neither one of those barrels liked the 140 amax or 142 SMK.

The 140 hybrid wasn't out when I had my shilen, but I did send a few rounds with the bartlein. They shot well, but the barrel was on it's last leg at over 4k rounds.

To me this is debatable as well. What do you mean by hit harder? Sure the heavier bullet may have more energy than the lighter one, but if both expand the same and pass through they both lost the same amount of energy in the animal. I feel like heavier for caliber bullets tend to hold together and penetrate better for deeper wounds and hopfull exit and blood trail if it is needed. Lighter bullets likely give more shock thought which will appear to me as hitting an animal harder. Some of that depends on the construction of the bullet as well.

...Back in my horse tradin' days on the side while I was repping, I'd picked up 3-4K of Speer 270 150's out of the $3-400's I'd spent at $2-$3's a box cleaning out a dealer that was going Out of the Speer bullet Bidnizz...and went "whaada I'm gonna do with all those 150's now?? " when I unpacked the Suburban...and learned about ventilating BOTH sides of the critter was mo bettah than not and breaking BOTH shoulders at the same time to anchor the fresh meat on the OUTSIDE of the prickly pear and huisatch thicket where all the buzztails lived on that lease...Just Sayin ...Heavy for caliber WORKS Best in that circumstance....and carry more energy at distance too, generally speaking.
Ron

...Back in my horse tradin' days on the side while I was repping, I'd picked up 3-4K of Speer 270 150's out of the $3-400's I'd spent at $2-$3's a box cleaning out a dealer that was going Out of the Speer bullet Bidnizz...and went "whaada I'm gonna do with all those 150's now?? " when I unpacked the Suburban...and learned about ventilating BOTH sides of the critter was mo bettah than not and breaking BOTH shoulders at the same time to anchor the fresh meat on the OUTSIDE of the prickly pear and huisatch thicket where all the buzztails lived on that lease...Just Sayin ...Heavy for caliber WORKS Best in that circumstance....and carry more energy at distance too, generally speaking.
Ron

What Wiley says is, of course, correct. Still, there is a trade off that should be considered. Trajectory (flatter trajectory) of the bullet will matter to many hunters, even if it doesn't matter to the turret crankers. And I think that trajectory/MV matters to a large percentage of us, based on the posts I read in this forum. Bullets and cars...and the need for speed. It's part of our 'maleness'.

Good points.