New Project Rifle

[mempilot]

My last project is almost complete and has proven to be a very tight shooter. This rifle started out as a Remington 700 Milspec 5R 308 and was mounted in an Accuracy International Stage 2.0 and topped with Leupold Mk-IV base, rings, and LR/T 4.5-14x50 with M1's and TMR. After shooting her for a few months now, I'm ready to send the bolt out for a tactical knob install and then all metal is headed to Walter for a Black-T finish.

That project left me with an unused HS Precision stock to start my next build on. The goal is an @ 10 lb back country hunting rifle capable of sub-1/2 MOA. After much contemplation, I've decided on the 300 WSM cartridge and will stay with the 5R rifling that seems to love the 168 Barnes TS and 175 SMKs. I want the barrel to be short(er) and light weight, but I don't want to compromise in the accuracy. I've decided to order a cut blank rifled in 5R from Rock Creek and then send it off to Advanced Barrel Systems to be cut, contoured, and wrapped in carbon fiber. After reading a few articles and testimonials about their work, and specifically a write up on a light weight hunter in 300 WSM that they did, I knew this was the way to go. My original plan was a heavy palma contour, but fluted to reduce some weight and maintain rigidity. Now that the carbon wrap has peaked my interest, I've decided to go that route.

My question is this: I'm thinking about a 20" barrel vs a 22 or 24" to reduce weight marginally and make a more compact stick. I don't think the reduced length is going to impact MV enough to decrease accuracy much at hunting ranges. I'll probably take the MKIV off the AIREM700 5R 308 and put it on this rifle, replacing it with a Night Force on the long range shooter.

What do you guys think about a 20" barrel on this new project?

The stock for the new rifle:

 

[nicholst55]

Re: New Project Rifle

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MEMPILOT</div><div class="ubbcode-body"> I don't think the reduced length is going to impact MV enough to decrease accuracy much at hunting ranges.

What do you guys think about a 20" barrel on this new project?</div></div>

Reduced muzzle velocity has no effect on accuracy (within realistic limits). My question is this - not having the ballistics tables handy to do a side-by-side comparison, will a 20" .300 WSM give you a significant velocity increase over a .308 or .30-06? Will you merely be burning more powder in more expensive brass to achieve essentially the same thing?

 

[mempilot]

Re: New Project Rifle

Granted the accuracy will not be affected much at short to medium hunting ranges; however, barrel and BC staying constant, the longer range drop of from a 300 WSM cartridge is substantially less than the 308 at longer ranges to my recollection. I'm guessing this is due to @ 60 grain of powder in the WSM cartridge vs @ 40 grain of powder for the 308 Win cartridge producing a higher velocity (just rough numbers for conversation sake). My initial thought, based on the desire to reduce weight but maintain comparable ballistics to the 308 Win, was to bump up the powder by using the short magnum casing, but benefit from the reduced weight of the shorter barrel. Therefore, I figured I get a comparable shooter, but out of a shorter and much lighter barrel. I'm not too concerned about the increase in powder or brass price, unless the barrel proves too short to effectively burn the powder. I guess the question would be, what would the opinions be on the shortest barrel length that could effectively be used with the 175 grain SMK and a WSM cartridge? If this is 24", then I'm back to square one on cartridge choice, but could still reduce weight through carbon wrapping.

Thanks for your thoughts on the matter.