Range estimation error .338 Lapua vs. .375 Chey

m1a convert

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I know that the flatter a cartridge shoots the more room for range estimation error you have without it killing you. (think .223 vs .44 mag at 200 yards)

I know that you still try to range as precisely as you can. But, how much additional "fudge factor" do you get with a .375 over a .338 at ranges from like 1200-1600 yards by going to a .375? (I know it depends on target size as well)

Is it enough to be significant, or at that range have you not really bought yourself much by going with a .375 Cheytac?
 

bohem

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Re: Range estimation error .338 Lapua vs. .375 Chey

I wouldn't attempt to tell you a direct answer, but a method to think about it and get some reasonable ideas would to be put both loads into the JBM calculator and plot the drop in inches from 1200-1600 next to each other on an excel spreadsheet.
 

doc76251

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Re: Range estimation error .338 Lapua vs. .375 Chey

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: m1a convert</div><div class="ubbcode-body">Is it enough to be significant, or at that range have you not really bought yourself much by going with a .375 Cheytac? </div></div>

The answer is ALOT!!!!

The term you are looking for is "danger space".

The 375/408 is in a whole 'nother realm from the 338LM. IIRC from 0 to 1K holding the top of an "E" shilouette you would not fall off the bottom. Zero at 1K for MAXFLEX, Much to be said for that.

Cheers,

Doc
 

Dogtown

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Re: Range estimation error .338 Lapua vs. .375 Chey

Exactly, you don't need anywhere near as much elevation at longer distances with the 375/408 compared to the .338LM. In fact, you're taking a .338LM to the absolute limit, having the round impact at quite an angle, when you take it to 2000 yards, for example. With a 375/408 you've still got about 800 yards of supersonic range at that distance, so your trajectory is flatter and your maximum ordinate lower - environmental conditions permitting.
 

djd

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Re: Range estimation error .338 Lapua vs. .375 Chey

As Doc stated above. The answer to your question is to reseach the term "Danger Space". Once you understand it, you can compare on your own easily. It will tell you just how bad you can screw up the range estimate and still be somewhere on target.

Here is the definition that we teach here:

Danger space is a horizontal measurement expressed in yards or meters. As the projectile goes past the Maximum Ordinate and travels downward toward impact with the ground (ignoring the target), danger space measurement begins at the point where the bullet is equal to the top (height) of the target and continues to when the bullet impacts the ground.

We also purposely put this function into our ABC computer. It's good info to know, same as knowing your max. ord., time of fight, impact velocity, etc. etc.

Dave
 

Dogtown

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Re: Range estimation error .338 Lapua vs. .375 Chey

DangerSpace.jpg


Nevermind the aesthetics, what Dave is talking about is the amount of allowable range estimation error to still result in a hit. In this diagram, the angle of the red trajectory allows very little deviation from the trajectory to hit the target. The blue one however has more elevation variation that will result in an impact. Of course, target profile plays a bit of a part in this, but generally it's a factor in extreme range shooting as the high angles of impact that often result from such long shots leave very little allowable error in range estimation. This is why a 375/408 will beat a .338LM at extreme range.
 

Dogtown

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Re: Range estimation error .338 Lapua vs. .375 Chey

Thanks...that was the point I was trying to make. The sad part is that I'm a professional artist
wink.gif
 

Louis Corkern

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Re: Range estimation error .338 Lapua vs. .375 Chey

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dogtown</div><div class="ubbcode-body">Thanks...that was the point I was trying to make. The sad part is that I'm a professional artist
wink.gif
</div></div>

Can we get a Speed Racer or Mummy version of that drawing LOL.