Range Report Light vs heavy bullets

[pitdog85]

The following 2 statements have been bugging me a bit.

1. A lighter bullet travelling faster spends less time in the wind so therefore should drift less that a heavier higher bc bullet going slower.

2. A certain bullet is too heavy for a certain case to take advantage of a higher bc heavier bullet.

I know frank has said that he like lighter bullets traveling faster however he is speaking from a PRS type view where someone might have to shoot unknown distances and from compromised positions here a lighter Bullet travelling faster could be an advantage.

My thoughts are for prone shooting at known distances. Why is it that in f class the guys shooting 308 are usually shooting heavy 200g+ bullets because they are better in the wind.

it seems that if a heavier higher bc bullet is pushed to an equivalent pressure/muzzle energy the heavier bullet will drift less every time. Don't ballistic calculators allow for the time the bullet is spending in flight? Ie so even though the heavier bullet is slower and spending more time in the wind it drifts less??

An example is the 6.5x47l let's say someone is running a 123eld bullet at 2900fps the equivalent velocity based on muzzle energy for a 147 eld is 2652fps. The 147 eld despite going much slower still has less wind drift at all distances and the advantage grows the further you get. This is assuming similar accuracy can be gained from both bullets at the equivalent pressure/muzzle energy. If someone says well you can run the 123 at 3000fps at x pressure well shouldn't you be able to run your 147at a higher velocity also to match that pressure/muzzle energy??

So why is it said that for example a 147 eld is too heavy for a 6.5x47l or a 215g too heavy for a 308. The ballistics for known distance shooters seems to favour the heavier higher bc bullet going slower despite the extra time it spends in the wind?

What am I missing here?

Thanks

 

[Gohring65]

People get caught up in the high BC numbers. Some just see high BC and think it’s the best choice. But running a lighter faster bullet often give up very little in drift and is flatter out to all but the extreme ranges. 1000 yards and under, I’ll take a sleek lighter bullet with a acceptable BC over lobbing a slow bullet any day.

 

[Dan Warner]

One certainly has to have enough velocity to see the difference/advantage. The simple answer is the time of flight. The longer its in the air traveling to its target, the more it can and will be affected by the elements it travels through. Flatter trajectory (higher BC) and increased velocity reduce TOF significantly.

 

[CJS-6.5]

Something to think about, is time of flight to different distances. So a lighter bullet bleeds off speed faster. A 123 going 2900 at the muzzle, vs a 140 going 2700 will get to medium range faster, and thus be affected less by wind out to say 600 yards. However the 140 is still charging along well at 1000, where the 123 is now just putting. So a lighter bullet will beat wind better up close, and a heavier one farther out. Assuming the caliber remains the same, and the bc to weight ratio is the same.

 

[Gohring65]

Here’s some numbers I put together the other day regarding a bullet I may try in 6.5 Creed.
My current load is the 140 RDF
Calculated BC .690 (G1)
2700 fps.
1000 yard data;
10 mph 90 degree wind.
8.5 mils up
1.8 mils drift.

New load consideration,
121 grain Lehigh
BC .538 (G1)
3100 fps
1000 yard data.
Up 6.9 mils
Drift 2.0.
The faster 121 grain load smokes the 140 in trajectory and only gives up 2 tenths to wind in this particular scenario. Some may be able to shove the 140 faster but theoretically they could shove the 121 faster as well. If I’m engaging targets out to 1000 yards I’m picking the lighter faster option.

 

[CJS-6.5]

Lighter bullets recoil less too. I'd be surprised if a 6.5 creed can get a 121 grn bullet to 3100 fps though.

 

[Gohring65]

Yea that number is hypothetical.
I shove a 130 hybrid at 3000 fps
Hex coated.
I figured the 121 mono was good for another 100 fps.

 

[408w]

The Creedmoor can do it. I tested with 120g eld’s 45.3g of rl-17 went 3205fps

Check out the Warne tool/flatline bullet website for load data on 121g bullets

 

[CJS-6.5]

Cool. I'll have to give the light bullets a whirl.

 

[surgeon260]

I prefer to send heavy, high BC bullets as fast as possible.

 

[47guy]

Lighter bullets recoil less too. I'd be surprised if a 6.5 creed can get a 121 grn bullet to 3100 fps though.

im shooting 123g lapuas out of a 26" 6.5x47 at 3025 and this is not a hot load

 

[47guy]

Cool. I'll have to give the light bullets a whirl.

try the 123g lapuas...nice BC good price and youll easily get 3050fps outta your creed

 

[pitdog85]

One certainly has to have enough velocity to see the difference/advantage. The simple answer is the time of flight. The longer its in the air traveling to its target, the more it can and will be affected by the elements it travels through. Flatter trajectory (higher BC) and increased velocity reduce TOF significantly.

Dan this is what confuses me are the ballistic calculators not allowing for this fact? Because like in the examples I gave (not talking about your solids which is a different beast) a 123g bullet when pushed to x pressure/muzzle energy is beaten by a 147g bullet when pushed to the same pressure/muzzle energy at all distances in the wind. That includes distances from 300 yards and out its not much but it is better?? So if the calculators are not allowing for this factor that the heavier bullet is spending more time in the wind more time of flight then are the drift number jbm and 4DOF showing me wrong??

Something to think about, is time of flight to different distances. So a lighter bullet bleeds off speed faster. A 123 going 2900 at the muzzle, vs a 140 going 2700 will get to medium range faster, and thus be affected less by wind out to say 600 yards. However the 140 is still charging along well at 1000, where the 123 is now just putting. So a lighter bullet will beat wind better up close, and a heavier one farther out. Assuming the caliber remains the same, and the bc to weight ratio is the same.

This is what I'm saying run the numbers of a 123 vs a 147 with the same muzzle energy figure and the calculator will show that even at 600 yards the heavier bullet is drifting less than the 123. You are saying the lighter bullet will beat the heavier bullet up close however this is not the case based on ballistics calcs unless you are pushing the 123 harder. Not trying to argue here just stating I have run these numbers many times and it always results in less drift from heavier bullets.

I also bring this back to the f class guys they are shooting in some cases up to 230 bergers in the 308 however most stop at 215 and from all reports the only reason some don't go to 230 is because of recoil making it difficult to hold together for a 20 shot string. If it wasn't for recoil they would be using the 230 for wind drift despite low muzzle velocity.

 

[408w]

Here is my data: 121 flatline vs 140 Berger vld. 200 yard zero...

Flatline 121g
500- 5.5 moa
750- 11.75 moa
1000- 19 moa

Berger 140vld
500yd -7.5 moa
750yd -15.75moa
1000yd -27moa

 

[MarkLeupold]

Here is my data: 121 flatline vs 140 Berger vld. 200 yard zero...

Flatline 121g
500- 5.5 moa
750- 11.75 moa
1000- 19 moa

Berger 140vld
500yd -7.5 moa
750yd -15.75moa
1000yd -27moa

I don't think solids can be included here. They hold all the advantages. They can achieve an equal or higher BC at a lower weight, which allows you to push them faster. Higher BC and more muzzle velocity is always going to win.

In the spirit of the argument, I've always heard that a higher BC bullet pushed to the same velocity is going to drop less and drift less than a lower BC bullet, which intuitively makes sense. The problem is where does BC make up for muzzle velocity or vice versa.

I've seen the lighter bullet (155 gr) win in my 308 in drop and drift inside 800, but I may not have been pushing the heavier bullets (175 gr) to their full potential.

 

[pitdog85]

I don't think solids can be included here. They hold all the advantages. They can achieve an equal or higher BC at a lower weight, which allows you to push them faster. Higher BC and more muzzle velocity is always going to win.

Yup I already stated this is not comparable to solids. I'm comparing a similar designed bullet in different weight class eg a 123 ELD M or 130 ELD M vs a 147ELD M pushed to equivalent muzzle energy/pressure. My question is are the calculators wrong? Because the statement the faster bullet spends less time in the wind therefore should have less impact from the environment etc but the JBM and 4 DOF don't support this?

 

[dk17hmr]

Depends when the higher BC slower bullet takes over.


I recently shot an elk with a 300gr SMK from my 338 muzzle velocity 2670fps wasn’t really impressed with the results (killed the elk just not what I was hoping for). I worked up a load quickly with the 10 shot method using the Hornady 230gr eldx, I spent 10 rounds with the charge I decided on getting chrono numbers and dope....at 2980fps the 230gr according to Kestrel doesn’t give anything up to the 300gr until 1100ish yards with a 15mph full value but the 230 is still 1.2 mils flatter and takes .1 second less time to get there. After 1100 yards the 300 has the advantage in the wind.

The 300 starts out with more energy as well, around 200 foot pounds more

Your theory might be tougher to prove because your bullets are very close in mass.

 

[pitdog85]

Depends when the higher BC slower bullet takes over.


I recently shot an elk with a 300gr SMK from my 338 muzzle velocity 2670fps wasn’t really impressed with the results (killed the elk just not what I was hoping for). I worked up a load quickly with the 10 shot method using the Hornady 230gr eldx, I spent 10 rounds with the charge I decided on getting chrono numbers and dope....at 2980fps the 230gr according to Kestrel doesn’t give anything up to the 300gr until 1100ish yards with a 15mph full value but the 230 is still 1.2 mils flatter and takes .1 second less time to get there. After 1100 yards the 300 has the advantage in the wind.

The 300 starts out with more energy as well, around 200 foot pounds more

Your theory might be tougher to prove because your bullets are very close in mass.

I'm not familiar with .338 bullets but guessing maybe the form factor (ie bc relative to weight) of the .230eld x is much better than the 300g smk? Hard to get a form factor on sierra bullets as they don't list G7. If the form factor was the same/similar ie if there was a 300g eld x that was a scaled up version of the 230g with similar form factor than I would think that your results would be different if both bullets were pushed to the same pressure/energy.

 

[308pirate]

Yup I already stated this is not comparable to solids. I'm comparing a similar designed bullet in different weight class eg a 123 ELD M or 130 ELD M vs a 147ELD M pushed to equivalent muzzle energy/pressure. My question is are the calculators wrong? Because the statement the faster bullet spends less time in the wind therefore should have less impact from the environment etc but the JBM and 4 DOF don't support this?

First, stop thinking about equivalent muzzle energy/pressure. Neither term exists in any external ballistics equation. Muzzle velocity is the only parameter that matters in that regard.

Second, ballistic calculators take TOF into account, otherwise your dope out of them would be useless. The statement that "faster bullets spend less time in the wind, affected less" ignores things like changing BC as bullets slow and probably a whole lot of other subtleties that a good ballistics program already takes into account.

Is Bryan Litz wrong? Are Hornady's ballisticians wrong? Probable but not likely. I'll take their work over idle internet chitchat.

 

[Dan Warner]

I'll just leave this here for those that might want to reduce TOF. New bullet released today!

https://warner-tool.com/collections/flat-line-projectiles/products/flatline-6mm-88gr

 

[pitdog85]

First, stop thinking about equivalent muzzle energy/pressure. Neither term exists in any external ballistics equation. Muzzle velocity is the only parameter that matters in that regard.

Without pressure measuring devices adjusting velocity until 2 bullets show the same muzzle energy is a way of an apples and apples comparison between 2 bullets. Litz also has a formula for this that shows if for example bullet a weighing 130g going at x velocity what the equivalent velocity would be for bullet b that weighs 150g for example. If you use his formulas it does the exact same thing as matching up the muzzle energy vs velocity of 2 different bullets I prefer to go to JBM and adjust muzzle velocity to muzzle energy when comparing 23 bullets as its quicker for me than looking up litz formula to do the same thing.


Second, ballistic calculators take TOF into account, otherwise your dope out of them would be useless. The statement that "faster bullets spend less time in the wind, affected less" ignores things like changing BC as bullets slow and probably a whole lot of other subtleties that a good ballistics program already takes into account.

You mustn't have read my statements as I'm agreeing with litz and 4DOF I believe the calculators are correct and am saying why are there people on this site still saying the light bullet has less time of flight so therefore less drift etc?? Unless someone can point out why litz and hornady are wrong doesn't seem anybody has.


Is Bryan Litz wrong? Are Hornady's ballisticians wrong? Probable but not likely. I'll take their work over idle internet chitchat.

I agree 100%

 

[spaniel]

If all you are thinking about is time of flight, your thoughts on the topic are far too simplistic.

 

[pitdog85]

I found this when searching for this topic this is exactly what I was trying to say but put into better words. This was posted by laurie from Great Britain who is a very well respected in F class shooting both in GB and the US. This can also be applied to the 6.5x47L example I gave comparing a 123 to a 147. The F class guys get what I'm saying I will leave it at that.

Take two bullets of different weights but with a shared form factor in a calibre, ie they exhibit the same drag relationship to the G-whatever reference projectile.

Then give them equivalent MVs. And how do we know what they are? They're MVs that produce the same ME values. To take an FTR example comparing the 155.5gn Berger .308 to a 200gn model. If the 155.5's MV is 3,100 fps MV that's 3,319 ft/lb ME. To achieve that same ME with the 200gn model, the MV is 2,733.5 fps and so that's the ballistic equivalent and is normally achievable within the same pressures, changing powder grades as needed.

Then run the pair through a ballistics program. You'll find the heavier bullet outperforms the lighter one in terms of wind drift. If you want to try it for yourself and we stick to 30-cal models, Berger's 175gn OTM Tactical and Sierra's 210gn MK have near identical form factor values (1.002 v 1.000), ie in ballistic / drag terms they match the G7 reference. Let's give the 175 an MV of 2,800 fps which is 3,047 ft/lb ME. The 210 needs an MV of 2,556 fps to match that. Their G7 BCs are 0.263 and 0.316 respectively. (Form factor and BC values from Bryan Litz's Ballistic Performance of Rifle Bullets third edition.)

The 0.263 BC 175 @ 2,800 fps MV moves 88.12 inches in the classic 10 mph crosswind at 1,000 yards.
The 0.316 BC 210 @ 2,556 fps MV moves 78.95 inches, a 10% reduction.

Another gain for the heavier model is terminal velocity. The 210 is calculated to have a retained velocity of 1,343 fps at 1,000 yards against the 175's 1,308, so in this 308 Win type example, the 210 just stays above transonic speeds while the 175 slips into them.

On trajectory shape, the 175 shoots a bit flatter with an MRT of ~118 inches against ~125 for the 210. The latter will also produce significantly more torque and recoil in any given weight rifle.

As the heavier' model's downsides are more recoil and a higher trajectory, tactical competitors and varmints shooter might prefer lighter bullets and accept a bit more wind drift, while the BR and prone competitor in known-distance shooting will go for less windage every time.

I was surprised the first time I did this using a couple of different weight thirties with near identical Litz G7 form factors and redid the sums several times convinced I had to be doing something wrong. 'Common sense' says that if the drag curve based form factors are the same and MVs are equivalent, then the bullets should behave in the wind the same way at say 1,000 yards. I eventually contacted Bryan who confirmed my findings - the heavier model of a pair with identical drag factors always outperforms the lighter in this (wind) respect.

 

[spaniel]

I eventually contacted Bryan who confirmed my findings - the heavier model of a pair with identical drag factors always outperforms the lighter in this (wind) respect.

Drag factors being equal, this is a simple concept called inertia. A heavier object will not be moved as much by a given force as a lighter object, all else being equal.

At the end of the day, long range shooters shooting known distance use heavy for caliber bullets because a better BC gives less drift. Light bullets become useful a) at shorter distances where their speed advantage actually makes them better in the wind, or b) when ranges are not known and a flatter trajectory combatting range estimation errors starts to come into the equation vs simply minimizing wind drift.

 

[pitdog85]

[QUOTE
At the end of the day, long range shooters shooting known distance use heavy for caliber bullets because a better BC gives less drift. Light bullets become useful a) at shorter distances where their speed advantage actually makes them better in the wind.[/QUOTE]

If you run the numbers you will see this is wrong as well. Go to jbm have one coloum in mrads and one in cm, although scopes mostly only dial to .1mrad the advantage is still there if you use a column in cm you will see that with a 100 yard zero the heavier bullet already has less wind drift at 200 and grows all the way out so the lighter bullet when compared equally does not have less drift at closer distances. Run the numbers I gave yourself in JBM 123 at 2900 vs 147 at 2652 put a column in cm and see.

 

[MarkLeupold]

I found this when searching for this topic this is exactly what I was trying to say but put into better words. This was posted by laurie from Great Britain who is a very well respected in F class shooting both in GB and the US. This can also be applied to the 6.5x47L example I gave comparing a 123 to a 147. The F class guys get what I'm saying I will leave it at that.

Take two bullets of different weights but with a shared form factor in a calibre, ie they exhibit the same drag relationship to the G-whatever reference projectile.

Then give them equivalent MVs. And how do we know what they are? They're MVs that produce the same ME values. To take an FTR example comparing the 155.5gn Berger .308 to a 200gn model. If the 155.5's MV is 3,100 fps MV that's 3,319 ft/lb ME. To achieve that same ME with the 200gn model, the MV is 2,733.5 fps and so that's the ballistic equivalent and is normally achievable within the same pressures, changing powder grades as needed.

Then run the pair through a ballistics program. You'll find the heavier bullet outperforms the lighter one in terms of wind drift. If you want to try it for yourself and we stick to 30-cal models, Berger's 175gn OTM Tactical and Sierra's 210gn MK have near identical form factor values (1.002 v 1.000), ie in ballistic / drag terms they match the G7 reference. Let's give the 175 an MV of 2,800 fps which is 3,047 ft/lb ME. The 210 needs an MV of 2,556 fps to match that. Their G7 BCs are 0.263 and 0.316 respectively. (Form factor and BC values from Bryan Litz's Ballistic Performance of Rifle Bullets third edition.)

The 0.263 BC 175 @ 2,800 fps MV moves 88.12 inches in the classic 10 mph crosswind at 1,000 yards.
The 0.316 BC 210 @ 2,556 fps MV moves 78.95 inches, a 10% reduction.

Another gain for the heavier model is terminal velocity. The 210 is calculated to have a retained velocity of 1,343 fps at 1,000 yards against the 175's 1,308, so in this 308 Win type example, the 210 just stays above transonic speeds while the 175 slips into them.

On trajectory shape, the 175 shoots a bit flatter with an MRT of ~118 inches against ~125 for the 210. The latter will also produce significantly more torque and recoil in any given weight rifle.

As the heavier' model's downsides are more recoil and a higher trajectory, tactical competitors and varmints shooter might prefer lighter bullets and accept a bit more wind drift, while the BR and prone competitor in known-distance shooting will go for less windage every time.

I was surprised the first time I did this using a couple of different weight thirties with near identical Litz G7 form factors and redid the sums several times convinced I had to be doing something wrong. 'Common sense' says that if the drag curve based form factors are the same and MVs are equivalent, then the bullets should behave in the wind the same way at say 1,000 yards. I eventually contacted Bryan who confirmed my findings - the heavier model of a pair with identical drag factors always outperforms the lighter in this (wind) respect.

So, this is a very good write-up on the subject and does a lot to explain what's happening. What exactly are you trying to solve by answering this nagging question of yours? What is the goal we're shooting for here?

 

[CJS-6.5]

The goal is the goal. Most little kids found out about the wind not affecting heavier stuff by throwing rocks. 3 ball bearings. Same weight ratio. .5, 1, 1.5 inch. Climb tower. Drop them to see if school books are right. School books wrong. Why wrong? Windy day. That why. Wind blow smaller ball more, smaller ball have to go farther. Speed same. Longer time. School books not have wind factor. So why? Because exterior area of projectile that wind can push on is not following total area of projectile. So that gives us our ratio difference.

Layman's terms.

 

[CJS-6.5]

The goal is the goal. Most little kids found out about the wind not affecting heavier stuff by throwing rocks. 3 ball bearings. Same weight ratio. .5, 1, 1.5 inch. Climb tower. Drop them to see if school books are right. School books wrong. Why wrong? Windy day. That why. Wind blow smaller ball more, smaller ball have to go farther. Speed same. Longer time. School books not have wind factor. So why? Because exterior area of projectile that wind can push on is not following total area of projectile. So that gives us our ratio difference.

Layman's terms.

This was all just made up, btw. Just trying to provide a simple false answer for those looking for one.

 

[pitdog85]

So, this is a very good write-up on the subject and does a lot to explain what's happening. What exactly are you trying to solve by answering this nagging question of yours? What is the goal we're shooting for here?

I don't know really I guess it bugs me that I see this information such as the lighter bullet will drift less at closer distances etc when they are not really apples and apples comparison. Or the statement such and such bullet is too heavy for a certain case ie a 215g is too heavy for a .308 or a 147 is too heavy for a 6.5x47l.

Anyway I mostly shoot 123 scenars, 130vld and 139 scenar out of my 6.5x47l I will try the 147 when I can get them for the right price.

 

[fvalmostthere]

You can only compare what your gun will allow and every gun is different. I recently tested the 123 scenars, 130 ar hybrids and the 140 hybrids out of my 26in creed. I didn't push them to the max but ended up with quality loads for each. I got the 123's going 3046, the 130's 2915 and the 140's 2830. Plug that into a ballistic calculator: 10mph 90 deg wind

123 scenar: 3046fps (44.4gr H4350)
500yards - 2.4mil elevation & .8mil wind
1000yards - 7.5mil elevation & 2mil wind

130 hybrid: 2915fps (43.5gr H4350)
500yards - 2.6mil elevation &.8mil wind
1000yards - 8mil elevation & 2 mil wind

140 hybrids: 2830fps (42.8gr H4350)
500yards - 2.7 elevation & .8mil wind
1000yards - 8.2 elevation & 1.8mil wind

For me the .2mil edge in wind at 1000 wasn't enough for me to lose .7 in elevation and pay $10 more a box when I can even find the 140's. I am in the northeast so most of our matches are inside 1000 anyways and as you can see they are the same wind wise out to 500 and the 123's win in elevation. This may not be the same for everyone, maybe you can get the 130's or 140's going faster to make them work better for you, this is just what I found. In my case lighter and faster was he way to go.

 

[Diver160651]

I am getting the same 123 scenar: 3046fps (44.5gr H4350) 3045 in a 24" Bartl Barrel with Prime Brass..
it still ends up being a 6mph gun to 800

 

[Lowlight]

External Ballistics is only one side of the equation,

You have to consider the internal side of things because that has a bearing on the accuracy. The longer it stays in the bore, the more chance your fundamentals will affect the results from shot to shot.

The recoil which was noted above is part of it, and then you add in the shooters skill to maintain that consistency from shot to shot combined with the longer dwell time in the barrel.

Everything is Time, TOF, Lock Time, Time In Bore, start adding them up and it points to why guys are going lighter bullets, at faster speeds with heavier rifles to succeed on the competition side of things.

None of this is linear

 

[Deleted member 113831]

I don't know really I guess it bugs me that I see this information such as the lighter bullet will drift less at closer distances etc when they are not really apples and apples comparison. Or the statement such and such bullet is too heavy for a certain case ie a 215g is too heavy for a .308 or a 147 is too heavy for a 6.5x47l.

Anyway I mostly shoot 123 scenars, 130vld and 139 scenar out of my 6.5x47l I will try the 147 when I can get them for the right price.

A couple of things:

There is a difference between "Ballistic Coefficient" and "Drag Coefficient". Drag Coefficient is a bullets shape, while Ballistic Coefficient takes into account a bullets shape, weight, and caliber. So, you are correct that two bullets with the same shape and started at the same speed are not equal.

A bullets drift is a function of it's "lag time", not purely it's TOF or velocity. "Lag time" is the difference between a bullets actual TOF vs. it's theoretical TOF in a vacuum. So, it is a calculation that takes into account both ballistic coefficient AND muzzle velocity. At some point, you can run a bullet with a high drag coefficient so slow that a bullet with a lesser drag coefficient does better in the wind.

 

[Diver160651]

^ that’s why guys like Chad Dixon for fun chase the 4,000 FPS load

 

[Lowlight]

Don’t forget too, the Practical side.

Advertised BCs are usually 300 yard averages, shot at a specific speed. Increase the speed and the BC goes up, lose muzzle velocity and it goes down.

When people take the published BC yet lower the velocity the drift still looks good. But the reality is the BC will go down so the drift will actually rise.

It’s why you need to shoot it vs just plugging data into a solver without making real world adjustments, those small .2 wind differences can actually move in favor of the lighter bullet especially if the heavy is going slow.

 

[Deleted member 113831]

Don’t forget too, the Practical side.

Advertised BCs are usually 300 yard averages, shot at a specific speed. Increase the speed and the BC goes up, lose muzzle velocity and it goes down.

When people take the published BC yet lower the velocity the drift still looks good. But the reality is the BC will go down so the drift will actually rise.

It’s why you need to shoot it vs just plugging data into a solver without making real world adjustments, those small .2 wind differences can actually move in favor of the lighter bullet especially if the heavy is going slow.

As you have alluded to before, the benefit of an increased danger space can offset a correspondingly small reduction in wind drift resistance. If I can gain a mil or more at 1K and only give up 1mph in wind, I'll take that trade all day long.

 

[Holliday]

This thread is well timed for me. I am just moving to the 6.5 cm and trying to decide what to shoot. I don’t compete and mostly shoot steel out to 1200 yards here in windy Wyoming. The 147-M have had my eye for the high BC but this thread has me rethinking that. I’ll be shooting a 24 “ 1-8 twist.

 

[Kadams1563]

I too have been thinking about a new bullet but do not want to pay for solids or anything else expensive. I have about 800 rounds of 140ELD down range and thought about a lighter bullet. I have no clue what to look for though.

For not competing and shooting out to 1200 yards I would think the 147 would be the way to go. Although I have shot that far plenty of times with the 140 eld.

Running a 24" barrel though and a 147 might not get you all the speed required.

 

[47guy]

I too have been thinking about a new bullet but do not want to pay for solids or anything else expensive. I have about 800 rounds of 140ELD down range and thought about a lighter bullet. I have no clue what to look for though.

For not competing and shooting out to 1200 yards I would think the 147 would be the way to go. Although I have shot that far plenty of times with the 140 eld.

Running a 24" barrel though and a 147 might not get you all the speed required.

This thread is well timed for me. I am just moving to the 6.5 cm and trying to decide what to shoot. I don’t compete and mostly shoot steel out to 1200 yards here in windy Wyoming. The 147-M have had my eye for the high BC but this thread has me rethinking that. I’ll be shooting a 24 “ 1-8 twist.

123g lapuas or 130g bullets like the Berger hybrids or the ELDMs any of those will get done what you want to do.

You guys should be able to easily get over 3100 with the 123s and 3050 with the 130s out of a 24” barrel in those creeds.

I am 3025 easy with a 6.5x47 and the 123s and my 2 barrels prior I was running 130s at 3000 out of a 24” barrel.

I have gone back to the 140g hybrids for the rest of this season and beganing of next as an experiment.

Try the 123s they are easy to find priced right if you buy by the 1000 and very easy to load for.

 

[Holliday]

123g lapuas or 130g bullets like the Berger hybrids or the ELDMs any of those will get done what you want to do.

You guys should be able to easily get over 3100 with the 123s and 3050 with the 130s out of a 24” barrel in those creeds.

I am 3025 easy with a 6.5x47 and the 123s and my 2 barrels prior I was running 130s at 3000 out of a 24” barrel.

I have gone back to the 140g hybrids for the rest of this season and beganing of next as an experiment.

Try the 123s they are easy to find priced right if you buy by the 1000 and very easy to load for.

I dont think I will go that light but I have been concidering the 140 Berger Hybrids as a compromise. I also am hoping to keep things reasonble pressure wise, so as to maximize barrel life too. My .308 I was running pretty ”warm”......

 

[47guy]

I dont think I will go that light but I have been concidering the 140 Berger Hybrids as a compromise. I also am hoping to keep things reasonble pressure wise, so as to maximize barrel life too. My .308 I was running pretty ”warm”......

the 140g hybrids are fantastic bullets...and if your going with the heavies take a look at the 140g ELDMs and the 142g SMKs they are great bullets as well.

as far as maximizing barrel life goes...shooting a lower/slower charge is not going to net you huge gains in barrel life...what kills barrels is heat...so if your just an average shooter that shoots a few times a month and shoots 4-5 rounds and lets the barrel cool your barrel will last longer than my barrels do...how much longer i think depends more on your accuracy expectation.

and like Rob1 says...why drive a top fuel dragster if your going to run pump gas in it!

 

[Seymour Fish]

The following 2 statements have been bugging me a bit.

1. A lighter bullet travelling faster spends less time in the wind so therefore should drift less that a heavier higher bc bullet going slower.

2. A certain bullet is too heavy for a certain case to take advantage of a higher bc heavier bullet.

I know frank has said that he like lighter bullets traveling faster however he is speaking from a PRS type view where someone might have to shoot unknown distances and from compromised positions here a lighter Bullet travelling faster could be an advantage.

My thoughts are for prone shooting at known distances. Why is it that in f class the guys shooting 308 are usually shooting heavy 200g+ bullets because they are better in the wind.

it seems that if a heavier higher bc bullet is pushed to an equivalent pressure/muzzle energy the heavier bullet will drift less every time. Don't ballistic calculators allow for the time the bullet is spending in flight? Ie so even though the heavier bullet is slower and spending more time in the wind it drifts less??

An example is the 6.5x47l let's say someone is running a 123eld bullet at 2900fps the equivalent velocity based on muzzle energy for a 147 eld is 2652fps. The 147 eld despite going much slower still has less wind drift at all distances and the advantage grows the further you get. This is assuming similar accuracy can be gained from both bullets at the equivalent pressure/muzzle energy. If someone says well you can run the 123 at 3000fps at x pressure well shouldn't you be able to run your 147at a higher velocity also to match that pressure/muzzle energy??

So why is it said that for example a 147 eld is too heavy for a 6.5x47l or a 215g too heavy for a 308. The ballistics for known distance shooters seems to favour the heavier higher bc bullet going slower despite the extra time it spends in the wind?

What am I missing here?

Thanks

Depending on the circumstances, shootability may be much more critical than a few inches of extra wind drift

 

[Greg Langelius *]

My shooting opportunities beyond 300m are becoming very sparse.

I am developing 28" barrel 260 loads for two very diverse bullets, the 95gr V-Max and the 143 ELD-X.

The 143 load will be to get a zero and work up a drop chart for what if, and the 95 will be for a flat as heck 300yd and under load that has so little drop it can be shot on the fly. Hard to estimate an MV for the 95, but it's clear it'll be over 3000fps, and may be as fast as 3400fps.

At 4350-ish ft ASL, this could get weird, and drift could be even weirder.

The 143 will complement a 1400yd LRF I've been sorting out. The main problem is keeping it steady enough all the way out there. I may be needing a tripod, badly.

The main thing I'm finding is that Frank's right; charts say a lot of things, but targets tell it as true as it gets. Until you shoot it, you're basically just reading fiction.

Greg

 

[Twitchy]

I've played with light vs heavy in a few different calibers. The chart below is my personal experience using 123g SMKs vs 143g ELD-Xs in my 18" 6.5. In cases like this, pick which ever has the best groups and stick with it.