Building new ELR rifle some input: 300win VS 338 (ULTRA MAG, EDGE)

[cypriss32]

I am looking to build a new ELR rifle. Dedicated for 1k plus shooting. This is my first rifle tailored around shooting extremely heavy and high BC bullets. I have had both of these rifles in the past and due to unforscene events I was forced to SELL all of my rifles. I am getting back into shooting after a few years again and have acquired almost everything I had back. My current stable is:
R&D 30-06, 25" 1-10tw oby barrel, B&C M40 stock, PT&G BDL floor plate, USO 3.2-17x Ergo (longer range hunting rifle)
GAP 243 1-7.75 Bartlien 26", HDMR (target comp rifle)
DPMS AR10 SASS build 3.5-15x NF F1

I have 2 other rem actions sitting around that are short action. One is a WSM bolt face, one is a 308 B/F (6.5 SAUM and other IDK). Now my question is this: 300win mag or 338 class.
I have a remington long action mag bolt face, and will be using a AICS 1.5 Long Action stock. Will the 230gr Bullets out the 300win be able to be fed in the AICS mags. The 338 Ultra seems the best 338 bang for the buck. Is it worth it to move to the 338 class for the heavier bullets? I can ONLY build one of them. What do you guys in the ELR section think?

 

[Bigwheels]

Check out this thread.
http://www.snipershide.com/shooting/elr-beyond-1000-yards/192501-230gr-hybrid-target.html
And this one too.
http://www.snipershide.com/shooting/elr-beyond-1000-yards/139141-300wm-past-mile.html

 

[Lowlight]

Get a left hand twist barrel...

 

[milo 2.0]

Get a left hand twist barrel...

Care to elaborate as to why?

 

[Jaxdialation]

Care to elaborate as to why?

I think this was a tease

 

[Aimsmall55]

I built a .300 win mag with a 30" Broughton 5c 1:10 on a trued 700 action. Had it throated very long. I'm pushing the 230 OTMS at around 2975 to 3,000 fps with Retumbo. Very accurate load and is gtg next to a .338 Lapua pushing a 300 grain smk out to 1500 yards or so. The 230 targets are even better ballistically but are a bit pickier on seating depth. Running those at 2960 fps or so.
Here's a 5 shot group with the 230 OTM

 

[BirdEyes]

I think this was a tease

Because of the left hand generator rule. Does away with the need for VJJ's Cornholio 3000 to compensate for coriolis. The thread describing that is elsewhere.

 

[cypriss32]

Will the 230s fit in AICS mags?

 

[Lowlight]

Here is an explanation, and not from me, as it appears people want to hear from others on the subject, not taking the word of the messaged.

Modern Practical Ballistics -- Arthur J Pesja

His background:

Aerospace Scientist for over 25 years

Worked on the Titan II ICBM, the THOR Missile @ Honeywell he worked on the Apollo project

Assistant Professor of Mathematics & Mechanics at the US Naval Academy at Annapolis

Also won a Distinguished Flying Cross in WWII as a B29 Pilot

So in Chapter 13 pages 112 & 113 he explains the effects of gyroscopic drift and Coriolis where he ends his two short paragraphs saying:

The effects of gyroscopic drift is difficult to analyze precisely because many variables are involved. Drift Tables, which have been determined mainly from well-controlled Army and Navy tests, indicate that gyroscopic drift is roughly double that of Coriolis drift, and thus also negligible for most purposes. It is interesting to note that that with counterclockwise or Left-Hand Twist barreled rifling, gyroscopic drift is to left in the Northern Hemisphere and more than cancels the effect of Coriolis Drift.

This is he words, not mine, so reading this, I would say, if you are building a dedicated ELR rifle to be used primarily in the Northern Hemisphere, you would be better served using a left hand twist barrel over your conventional right hand model. Because we have things like drift, both SD & CE, would it not be smarter to cancel out as much of the effect as possible before the bullet leaves the bore ?

Seems to me someone looking to tackle this, would agree as opposed to compounding drifts on top of any other variables, including wind, shooters, etc.

 

[Bigwheels]

I'd like a fin stabilized sabot in a smooth bore. Works for tanks...

 

[Jaxdialation]

I'd like a fin stabilized sabot in a smooth bore. Works for tanks...

Better solution! I shoot all over the world, including polar regions. Franks idea was a bit limiting.
The other thing that worries me is night shooting when the moons gravitational influence comes into
play ELR.

 

[JC Steel]

Well if I should go with a Left Hand twist for the typically righty, should I actually go back to the right hand twist since I am left handed...something for me to think about huh?

I went with a 338 Edge, 30.5" Inch Benchmark Barrel, AMU contour to keep the weight up where I wanted it. I also shoot the 300 Grain Berger Hybrids at 2875 FPS. Good luck keeping a 30 cal bullet up with that....

Although I have seen first hand what Bigwheels does with a 300WM. So I cant dispute that, but still the 338 edge is the clear winner in the fight.

 

[bodywerks]

Yep, can't argue with BC...

PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg