# Ballistics Question



## Bruce Glover (Feb 22, 2007)

I am a long time deer hunter but just now trying to understand longer range shooting. I currently shoot a 270 WSM Savage and I love it. Most of my shooting is less than 200 yds. When I compare specs of my gun to 308 or 6.5 Creedmore, my rifle shoots much flatter with slightly less wind drift.
Why do so many shooters use a 308 or 6.5 Creedmore for long range shooting when there is so much more drop in trajectory at least out to 400 yds? Why wouldn't the flatter shooting 270 WSM or 300 WSM make a better long range gun out past the 400 yds distances? I wonder if my 270 bullets begin to wobble at the longer ranges and significantly lose accuracy.
I notice that the 6.5 Creed has a better ballistic coefficient than the 270WSM or 300WSM but not the 308. At what distance does the faster and flatter shooting 270WSM/300WSM gun become a less efficient rifle?
Any information or directions to the information would be greatly appreciated.


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## 223AI (May 7, 2012)

Bruce - 

The simple answer to the question of the WSM's vs the 6.5's/308's is this: Is the "juice" worth the squeeze... In this case, the downside to a WSM is simply that of more recoil, increased component cost, Lack of good long range bullets (270 wsm only) comparative to other calibers, and shortened barrel life comparative to the alternatives that you mentioned.

Shooting "flatter" at distance doesn't matter much to long range guys, because 90% of the time, the distance is constant or known. It's the wind that most are worried about, and the wsm's are not that far off of the 6.5 creed/6.5x47L/etc until you get close to 1k and beyond. What small gain you have in wind drift, you are giving up with all of the "negatives" associated with a WSM...barrel life included.

The 308, in my opinion, is simply there because it's the most common round. It does nothing particularly well (except barrel life), but does everything somewhat "ok". I'd never shoot one unless I was forced to. I stomp on my 308, ballistically speaking, with my 223ai sending pointed 82 bergers at 3010 (standard 223 at 2900)...it's simply better at everything but downrange energy. 

Hope this helps.


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## Jungle_Jim (Nov 16, 2007)

223AI is right. I would add that most off the shelf bullets available in 270 wsm ( I have one) have a low ballistic coeffecient. If you compare the high velocity low BC bullets in a 270 wsm to the lower velocity high BC bullets in a 308 you will find that as the range increases, the slower more efficient bullet begins to catch up and at some point is going faster than the magnum. (you can fix this by reloading with high BC bullets)

Your question: " At what distance does the faster and flatter shooting 270WSM/300WSM gun become a less efficient rifle? "

The answer is it dependant on the bullet. If you fire a 308 and a 270 wsm bullet and each have the same BC the 270 will be more efficient and have more velocity at any distance.

If you want a long range 270 wsm. load it up with some 160 grain berger or sierra bullets and voila you now have one 

Jim


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## Rmm (Jun 7, 2013)

You would. have to shoot your gun at distance to see how the accuracy holds up. One of the keys to long distance shooting is a small extreme spread in the velocity of a load. An accurate load at short range may open up at extreme ranges. At 1000 yards even flat shooting magnums with good bullets will have around 200 inches of drop with a 200 yard zero. Knowing the yardage and having a drop chart for the load is critical. There are many good ballistic apps and websites you can look at. Berger bullets has one that is easy to use on their website. You can enter the ballistic coefficient of your bullet, muzzle velocity and a few other things and get drop and drift out to 2000 yards or so.


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## 223AI (May 7, 2012)

Rmm said:


> You would. have to shoot your gun at distance to see how the accuracy holds up. One of the keys to long distance shooting is a small extreme spread in the velocity of a load. An accurate load at short range may open up at extreme ranges. At 1000 yards even flat shooting magnums with good bullets will have around 200 inches of drop with a 200 yard zero. Knowing the yardage and having a drop chart for the load is critical. There are many good ballistic apps and websites you can look at. Berger bullets has one that is easy to use on their website. You can enter the ballistic coefficient of your bullet, muzzle velocity and a few other things and get drop and drift out to 2000 yards or so.


Those ballistic calculators are good at giving you a general idea of what the bullet is doing, but you'll only be somewhat accurate. A multitude of factors some into play at distance.

To make sure your hit probability increases at distance, you need to also measure correct density altitude, make sure your sight height is calculated appropriately, measure the wind speed and direction, and keep an eye out on what the mirage is doing downrange. Higher BC bullets coupled with higher velocity gives you more wiggle room...which is where your 300wsm would shine.


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## artys_only (Mar 29, 2005)

F


Jungle_Jim said:


> 223AI is right. I would add that most off the shelf bullets available in 270 wsm ( I have one) have a low ballistic coeffecient. If you compare the high velocity low BC bullets in a 270 wsm to the lower velocity high BC bullets in a 308 you will find that as the range increases, the slower more efficient bullet begins to catch up and at some point is going faster than the magnum. (you can fix this by reloading with high BC bullets)
> 
> Your question: " At what distance does the faster and flatter shooting 270WSM/300WSM gun become a less efficient rifle? "
> 
> ...


^^^*^ this !ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½

John burns who was one of the first one taking long range shoots , I can remember who he working with to build and sell long range guns shot a bull elk on film @ 1005 yards with a plane old 270 with a high BC bullet , if you utube it you could take a look , just make sure what ever you do you know exactly what your gun does , at that range with the conditions you are in. I enjoy long range hunting and shooting , but hate seeing people shoot and lose animals at long range because they never practiced or really know what there gun does , great info above.


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## Rmm (Jun 7, 2013)

223AI said:


> Those ballistic calculators are good at giving you a general idea of what the bullet is doing, but you'll only be somewhat accurate. A multitude of factors some into play at distance.
> 
> To make sure your hit probability increases at distance, you need to also measure correct density altitude, make sure your sight height is calculated appropriately, measure the wind speed and direction, and keep an eye out on what the mirage is doing downrange. Higher BC bullets coupled with higher velocity gives you more wiggle room...which is where your 300wsm would shine.


All true. I was giving the berger website as a place to compare bullets and get an idea of how different bullets perform at long range. Even after developing a load here in Texas I will shoot it quite a bit in colorado to verify the data used for the drops before hunting. I use a kestrel with a ballistic app and a g7 rangefinder. It usually takes some tweaking to get them dialed in. Shooting long range is fun whether it is hunting or targets or just plinking. What length and twist do you use on the 223 ackley?


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## Bruce Glover (Feb 22, 2007)

Wow thanks for all the info guys. There's a lot of knowledge here. I'll try the Berger or Sierra in 160 grn and see how they shoot.


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## [email protected] (Jun 25, 2005)

I don't understand why people shoot long range with a .308 either and why it's so popular for long range since it's a slow bullet and has a lot more drop than other calibers. I think the 7mm bullet at high speeds is a great long range caliber and a lot of the guys that hunt at very long ranges use the 7mm lrm round which is has great performance. If I were to buy a long range hunting rifle today it wold be a Gunwerks 7mm LRM. With all the new calibers coming out today the .30-06 and .308 are almost obsolete kind of in my book. You can get something so much better performing now with not much downside. .270 wsm is a great round, I have one and love it. It's like taking a good thing, the .270, and making it better haha.


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## Sgrem (Oct 5, 2005)

The OP is talking about 400yds which is not particlary hard with most any rifle...even with a 30-30....people put too much emphasis on all this ballistics....yes it matters....no you probably can't make a difference with ballistic tables in texas out to 400 yds.

700+ is a different discussion. ....larger game is a different discussion....much more room for error.....most will never and should never take aim at that distance anyway.

Take a steel target. Place it in front of your truck....walk backwards till you are comfy shooting at it. That is your effective range on animals too.


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## andre3k (Dec 3, 2012)

I can't speak on the hunting aspect but in long range competition 308 does just fine. Its not the fastest or has the flattest trajectory but its an affordable round to reload, I can find all the surplus brass I want, its not hard on barrels, I can easily find good components. All of these new high pressure, high velocity rounds can be killer on the throat of a barrel. No issue if you hunt and aren't putting many rounds down range but it becomes one when you are shooting matches twice a month plus practice rounds and you can shoot out a barrel in one season, i.e. 6.5x284. Its nice shooting the same round that the military uses because components are that much more available and cheaper so 223 and 308 will always have a place in my safe.


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## spurgersalty (Jun 29, 2010)

sgrem said:


> The OP is talking about 400yds which is not particlary hard with most any rifle...even with a 30-30....people put too much emphasis on all this ballistics....yes it matters....no you probably can't make a difference with ballistic tables in texas out to 400 yds.
> 
> 700+ is a different discussion. ....larger game is a different discussion....much more room for error.....most will never and should never take aim at that distance anyway.
> 
> Take a steel target. Place it in front of your truck....walk backwards till you are comfy shooting at it. That is your effective range on animals too.


:rotfl:
That last paragraph nails it. Great example! But, which truck should I use


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## Lezz Go (Jun 27, 2006)

IMHO, nothing beats trigger time and learning to call the wind really well out past 300 yards. Just my .02


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## T-roy66 (Dec 6, 2013)

*Berger Bullets*

Bruce
I have a Remington 700 xcr in 270WSM. I shot Barnes 110 grain hollow points last year. During the summer I worked up a load for the Berger 150 grain VLD hunting bullets. They shoot less than 1" at 100 yards. I shot a wide 8 pointer opening weekend at 240 yards. The bullet preformed perfectly. It look like someone took a bucket of blood and tossed it down the trail that the deer ran down. He only made it about 20 yards.i have chronographed this load at around 2850 fps. I am extremely satisfied with the Berger bullets. Good hunting.


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## Pocketfisherman (May 30, 2005)

The big draw of the 6.5 Gredel at long ranges is that the bullet is still supersonic at 1000 yard match ranges. When a bullet slows from supersonic to subsonic, its' own shockwave passes it and disrupts the bullet's stability in the process. It is not a big disruption, but it is there and it does affect accuracy. Also, the cartridge has the case shape of the efficient burning short magnums, but still retains a long neck. The latter is important when seating long bullets commonly used for longer ranges as they won't intrude as much on the powder volume you can put into the case.

For 308 the largest factor I think is that it is one of the allowed calibers in service rifle matches. As a result, there a huge influx of ex military shooters moving into civilian and law enforcement that still prefer the caliber since there is so much data for it regarding bullet types, powders, and performance at long ranges. It's been used at 1000 yards in competitions since the early 1950's.


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## Jungle_Jim (Nov 16, 2007)

Pocketfisherman said:


> The big draw of the 6.5 Gredel at long ranges is that the bullet is still supersonic at 1000 yard match ranges. When a bullet slows from supersonic to subsonic, its' own shockwave passes it and disrupts the bullet's stability in the process. It is not a big disruption, but it is there and it does affect accuracy. Also, the cartridge has the case shape of the efficient burning short magnums, but still retains a long neck. The latter is important when seating long bullets commonly used for longer ranges as they won't intrude as much on the powder volume you can put into the case.
> 
> For 308 the largest factor I think is that it is one of the allowed calibers in service rifle matches. As a result, there a huge influx of ex military shooters moving into civilian and law enforcement that still prefer the caliber since there is so much data for it regarding bullet types, powders, and performance at long ranges. It's been used at 1000 yards in competitions since the early 1950's.


100% correct


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## Ernest (May 21, 2004)

No. 

The Grendel is not a truly effective 1000 yard round. Sure, it can do it, but it does not do it particularly well. 

The Grendel does NOT have the shape of short mags. That's backwards. Its based upon the 7.62x39 which then was made into the 220 Russian. The 220 Russian has been used for years as the basis for PPC rounds. The 6 PPC was introduced in something like 1975. The short mags are knock offs of the 220 Russian/PPC rounds. 

The Grendel does not have a long neck. The shoulder is blown forward, and the neck is shorter than the 6PPC. 

The primary restriction on the use of long bullets is the mag length restrictions, not the neck length. Loaded to max mag length, long bullets are deep into the case. But, even if it had a longer neck and was not subject to mag length restrictions, there is simply not enough powder space to run the super high BC 6.5 140's at the necessary speed. Thus, the development of the 6mmAR and the 6AR Turbo. 

Service Rifle/Civilian Marksmanship Comps are dominated by AR based weapons, not .308's. While the .308's displaced the 30-06 in the M-14/M1A1 platform, the M-14/M1A1 is not competitive with the AR platform. And, in the AR platform, there are far better rounds than a .308.


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## Jungle_Jim (Nov 16, 2007)

nevermind


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## Sgrem (Oct 5, 2005)

Again....I will say....most put too much emphasis on ballistics of the round....

Most people are not truly effective 1000 yard marksman ....

Hunting....HUNTING to me means getting closer than 1000 yards....take ethical shots on game people.


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## Jungle_Jim (Nov 16, 2007)

sgrem said:


> Again....I will say....most put too much emphasis on ballistics of the round....
> 
> Most people are not truly effective 1000 yard marksman ....
> 
> Hunting....HUNTING to me means getting closer than 1000 yards....take ethical shots on game people.


Yep, most people can't even find a game animal at 1000k yards. I shoot to about 500 with a 300 rum on deer and hogs but any further and wind plays hell with it.


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## rundm (Dec 1, 2012)

Lezz Go said:


> IMHO, nothing beats trigger time and learning to call the wind really well out past 300 yards. Just my .02


What he said. Learning to dope the wind is paramount in long range shooting. You can cheat it by getting long bullets with high coefficients and speed but you still need to be able to dope the wind. If you reload, you can run 155 lapuas with a 27 inch barrel or so from a 308 and stack shots up at 1000 yards. You still have to practice at it. I wouldn't shoot the 308 at game near that far though.


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