Trajectory question 270WSM what is it close to?

blinddog

blinddog

New member
I have a savage in 270 WSM it has a Simmons 3-9 x40 varible scope on it and is a tack driver at 100 yards. But I want to put a bit more glass on it. I have been looking at the ATN day light scopes with a much larger objective I think the one I looked at wa s6-24 x60 objective diameter it has a range finder and BDC built in to it but like most BDC's you have to put the caliber specific cam on it. It comes with cams in .223 .270 .308 7mmMag 30.36 and 300 win mag.
I think the WSM has a trajectory btween the 270 win and the 7mm MAg but I am not sure can anyone clear this up? I am not fully sold on the ATM as yet. I have seen some bad but unspecific things about them on other boards. ANy opinion about the ATM profesional series scopes is appreciated also.
The one I was thinking about is a 30 MM tube with a 60MM objective 6-24 LU I think is the model. Any how thanks
 
I am sorry I was looking at scopes on the web and asked that question because i thought that since the WSM is so new maybe it has aflatter trajectory than the 270 Win. Then I thought to look in vol 2 of the Hornady manuals I just got
a couple months ago. /ubbthreads/images/graemlins/angry-smiley-055.gif Guess what? The same bullet at the same speed has the same drop. BC on 270 bullets is the same and surprisingly the velocity of the WSM and the old 270 Win is (you guessed it) the same. while the charges are a bit differant and powder selection is also. More powders work with the old 270 than are sugested for the WSM.
So again I am sorrry for the brain fart. /ubbthreads/images/graemlins/smiliesmack.gif I must be getting old, I know this stuff, or at least I used to think I did. /ubbthreads/images/graemlins/smiliesmack.gif /ubbthreads/images/graemlins/confused1.gif
 
my 270 will shoot a 130 grain ballistic tip 3000 fps. i was getting 3250-3280 with the same bullet from my wsm. thats over a chrony.
 
Blinddog- I do think a .270 WSM pushes bullets closer to 7mm mag speeds. I think there might be a misprint in that volume 2 manual. One example I looked up is .270 Win 150gr. factory loads vary from roughly 2700 - 3000 fps,, .270WSM Winchester 150gr. PP at 3150fps, and 7mm mag Winchester 150gr. PP at 3130 fps. I think you were right on in the beginning. Ryan
 
Blinddog

You didn't mention what you are using the gun for. But I'd opt for a better scope than the ATN. Look at perhaps a Bushnell 4200 4 X 16. A very bright scope at a far price. The low end of this variable will still let you hunt close in the timber. The high will bring game in as much as you need and you won't have much mirage problems usless it's really hot and the thing is when that happen you're probably going to be shooting at 10 or 12 power.
 
Right now i am useing this rifle for just about everything I don't use my 45-70 for in other words any thing smaller than deer. I live in Ks and the marage is just about as bad as it was when I lived in AZ. Like I said I am still looking,The atn look good because i have a vision problem so i need the largest objective and exit pupil I can get. I will look into Bushnel and Louies as well. The only comment I have gotten on the ATN was "another tactical nightmare"no explination of why, thats why I asked
Ryan Any bullet of the same caliber(diameter) with the same BC and the same velocity has the same trajectory.
I used a loading manual from Hornady the newest one out it is two volumes the first is load data, the second volume is ballistic data. When you hand load as long as I have somtimes you forget the basics. Look on the load data and you get several bit of info besides the amount and type powder. BC and Sectional density are also listed. Ballistic Coefficient is a number that helps to determine the flight path of a particular bullet at a specific vels.
So knowing that all I need to do is make sure when I load my 270WSM I load it to a specific vel not exceeding the 270 winchester in that bullet wt. It is pretty easy since I also found that the WSM loads to the same vels as the 270 Win. with the same bullets. So the trajectory is the same.
Now knowing that,I can load for any vels. I want with in the parameters of the WSM pressure limits.
Refreashing my knowledge of the WSM line I have found that the Magnum appelation is a misnomer Rightly they should be Winchester Short Cartridge But I am sure marketing had a lot to say about that. Since while the case is shorter than the 270 Winchester, the powder used and the fatter column has a more efficient burning ratio, or as it is known expansion ratio. The burn is faster taking advantage of the slightly longer barrel so the pressure is accieved a bit faster. So shorter fatter case gives the same vels with the same bullet I do not know how the 300 WSM compairs to the 300 Win MAg as I just haven't had the time to research it yet. I have looked into the 240 WSSM as I am planning on puttiing togeather an AR varment rifle with one of DiTechs uppers when I have the cash saved up.
 
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With equal (close) sectional density bullets the 270 wsm is a little faster and shoots a little flatter than a 7mm Remmag. With a high balistic coefficient 130 gr bullet its trajectory is close to a 22-250 with 55gr bullets.
 
BD,
The 270 WSM has easily + 200fps greater potential over the 270 WIN. BC for BC, The 270 Whizzum is flatter than the 7MM Remmy. Why not take advantage of it? I'm getting just under 3300 fps, chrono'd, with 130 NBT's.
/ubbthreads/images/graemlins/grinning-smiley-003.gif
F1
 
stay away from the atn scopes.i bought one of them never did get the thing to do right.atn brushed me off.they have the worst customer service i have ever seen.for the money i would go with the burris.way better scope.
 


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