Thursday, April 14, 2011

The Thousand Yard Conspiracy - Part 5: "The Understudy" - The Low Dollar Lightweight Layout

So, about 18 months ago, as part of my Thousand Yard Conspiracy series, I wrote a post about how to get into long range shooting on the (relatively) cheap.

In that piece, one of the recommendations I made, was grabbing a relatively low cost factory rifle, and converting it to long range use.

Around the same time, I managed to run across a late 80s or early 90s production Winchester model 70 featherweight, push feed, 26" barrel, blind mag, synthetic stock, in .300wm (I think it's actually an early production black shadow from the serial number); with just a few rounds through it (the previous owner only shot it twice, once for sighting, once on a successful elk hunt; less than a box of ammo through it).

Basically that gun, but blind box, and a "W" in the checkering.

Of course, the 70 featherweight, at under 8lbs and with a pencil barrel; isn't exactly the ideal platform to build a long range rifle on. It IS however a great platform for a mountain rifle (what the featherweight series was made for).

Now, I'm still halfway through my thousand yard gun build (I've got most of the pieces, just haven't done the barrel, the optics, and of course, the final assembly) and I need a practice rifle. Plus, I plan on hunting next year, and I need a hunting rifle... and I now live in the Idaho mountains...

And of course, the kicker on the featherweight, was that I snagged it for $300 (a new one would be about $800, though they don't do the featherweight long action in synthetic anymore, and a new one would be a CRF action).

For $300... what the hell, why not.

When it came time for boomershoot last year, and it became clear I wasn't going to finish my 1000 yard gun any time soon, I decided it was buildup time for "the understudy".

From the beginning what I decided I wanted, was to improve the accuracy and precision of the rifle, the ergonomics and shooting feel, and make it a good practice gun for my long range shooting; while keeping it light weight for dragging it around in the mountains, and preserving the budget for my bug custom.

Keeping in mind that budget constraint, that meant no rebarrel, a low cost optic, and a low cost stock.

So, I started acquiring parts as I could, on sale, special, or in good shape used.

Step one was to find a new stock. The Winchester factory synthetic stock was, frankly, crap. No pillars, no bedding block, nothing but plastic... no thanks. No way to tighten an action down properly without risk of warping.

I knew I wanted either a pillar bed, or a bedding block stock; and later Winchester synthetic featherweight guns used a McMillan stock.

Unfortunately, that stock runs about $500, and that was beyond the budget of this gun. H-S Precision also has a full length bedding block stock for this gun, but I won't do business with them anymore.

I was just about ready to go with a Bell and Carlson Carbelite, for about $200; when I found a Hogue overmold pillar bed stock on clearance for $79, and snagged it:

Yes, I could have grabbed the full bed model for another $100; but remember, this is a budget build, and the difference between pillar bedding in a stable reinforced synthetic stock, and a full bedding block, is going to be nearly negligible. If I was going to spend any real money on the stock, I'd spend the $500 on a McMillan. Plus, the full block stock is about half a pound heavier.

Now, all the stocks I was considering are cut for the hinged plate mag bottom metal; and this gun was a blind box. I hate blind box guns for field use though. If your bolt ever jams, you need to disassemble the entire gun to unload it. Although a blind box gun can be stiffer than a mag gun, in this case, with no bottom metal, just a three screw attachment to the action, and a plastic triggerguard; that is definitely not the case. It is lighter than a steel bottom metal with internal box though.

I looked at a couple different internal mag bottom metal solutions; and that was a strong option, but they were all going to cost me at least $200, and be quite heavy (all the ones I found for the long action Model 70 were steel, not aluminum). A new detachable box mag bottom metal wouldn't run much more than that; and even with the mag in them, they're not too much heavier than the steel bottom metals as they're aluminum. So I decided to go with a box mag.

The default choice most make is Badger, but the model 70 long action bottom metal from them is about $350 with a magazine, and is usually backordered.

I decided instead to go with CDI precision:

They're a small shop out of Florida that does really good work; and shipped me a bottom metal and AI .300wm magazine for $290, in a week. I think they're every bit as good as Badger, a little bit lighter, a fair bit cheaper, and quite responsive.

Now poking through that bottom metal is the second most important part of the gun as far as accuracy,  the trigger.

The factory trigger isn't awful. It's about a six pound weight, but should be easily adjustable (the Model 70 is one of the easiest triggers on the planet to adjust weight on) down to 4lbs.

Unfortunately, it's got a fair bit of creep, and a slightly uneven feel. Rather than try to stone the trigger into something good, there are plenty of drop in triggers already set to the weight I want (1.5-3 pounds), and with a crisp, creep free, even break.

Normally I'd buy a Jewell and be done with it, but again, the budget on this build is a little low, as they run about $250.

You can get a rifle Basix trigger for the Model 70 for about $80; but I found a considerably better Timney on sale for $90 and grabbed it immediately:

The final critical element of a shooting system, is an aiming system; and as this is a long range shooting system, that means a decent scope and mounts. 

 As it happens, another great deal came my way:

The BlackDiamonds are the same optics and adjusters as their XTR line, but with low profile target knobs with screw down o-ring covers, rather than tactical turrets (and the 8-32x in particular has 1/8moa adjustments instead of 1/4moa... both a plus and minus there). It's even got a mildot reticle with a drop scale out to 700 meters on .300wm (same as in the xtr).

I've made no secret of the fact that I consider Burris's high end scopes the best value in midrange optics, with excellent optical performance, great toughness, and the best warranty in the business (lifetime, no questions asked).

The best part though, was the price. MSRP on the thing is $1350, but you can frequently get it online for around $850. I got this one, new in the box, never been mounted, with sunshade and butler creek covers, for $450.

Now normally I wouldn't go for an 8-32x given that I prefer a scope with a minimum exit pupil over 2mm. Anything lower than 2.5mm or so and you lose sharpness, so for a 50mm objective I prefer something more like a 5-20x or a 6-24x. 

But for the price I got... 

Nothing says I need to turn the knob past 24x... and besides at 32x on a bright sunshiny day, I can spot the holes better.

Also, at 21 ounces, it's a bit of a heavy SOB, but still lighter than a Nightforce (36oz for the comparable model), and you don't get good long range optics and light weight at the same time. 

So, how to mount it up?

As I said, the 8-32x has 1/8moa elevation adjustments. That's a great thing for precision at long range; a 1/8moa click means each click is only 1.31" at 1000 yards instead of the normal 2.62". Unfortunately it also means that unlike similar 30mm tube scopes, it's only got a 39moa elevation adjustment range (at least that what the documentation says. I actually measured 42moa in clicks; but that's not unusual).

That's not exactly a small range (some 25mm scopes have as little as 20moa), but it's not a lot for a gun that I want to shoot at 700 yards (in comparison, most tactical scopes have over 80moa adjustment... many over 100moa, and one I know of has 170moa adjustment).

Depending on bullet weight and design, and the velocity of the load from the rifle, .300 winmag runs anywhere from about a 25moa drop, to about a 40moa drop, at 1000 yards. That means, in order to leave a full range of adjustment for bullet drop compensation at all reasonable ranges, I need to mount on a 20moa canted rail.

Normally, the neutral set point of a scope (the point where if the optical center of the scope were mounted on the bore axis the crosshairs would line up with a laser shot down the bore) is somewhere near the middle of a scopes elevation adjustment range. This allows for the scope to adjust to a wide variety of zero ranges, mounting heights and positions etc... Then, you need to compensate for the offset of the centerline of the scope from the centerline of the bore. Finally, you need to compensate for the rise or drop of the bullet at your zero'd distance.

In a normal hunting scope, you're lucky if you have half the scopes adjustment range left once you're zeroed; though in some scopes there is deliberately more drop compensation than rise compensation (especially with tactical scopes, and other scopes designed for long range shooting).

A 20moa rail will hopefully put a 25/200 yard battlesight zero (with this sight offset, a 0moa adjustment from the neutral setpoint of the scope should intersect the ballistic arc of the bullet at 25 yards, and 200 yards. This is the battlesight zero) close to the very bottom of the adjustment range... preferably within 1/2 turn up or less; and a 300 yard zero (where I like to zero a 1000 yard gun. About a 2.5moa drop from 0/0, using the loading I plan on) to less than another 1/2 turn up or so (this scope runs 7moa elevation per turn, with six turns of total elevation available). That should let me dial in any range from 25 to 1000 yards, down to less than the mechanical accuracy of the rifle, within the full adjustment range of the scope.

Actually, presuming I get the results I expect from the load I want to use, I should be seeing something like 15moa drop at 700 yards, and 25moa drop at 1000; so presuming 200 yard zero was within 15moa of the bottom of the range, I could get away without a 20moa rail; but why take the chance? 

The rifle came with a pair of Weaver bases, but I want a full, one pice, Picatinny rail. A full rail will be stronger, more precise, and more versatile; and with a detachable box magazine system, theres little disadvantage (with a blind magazine you want a 2 piece, to give you more clearance under the scope to load and unload).

If I had unlimited budget, I'd just buy a badger 20moa rail, and badger tactical rings (you can probably get away with medium rings, but I'm going to go fo high to give a little extra clearance to the rail). Unfortunately, that would run around $300... nearly as much as I paid for the rifle itself; and weigh almost a pound altogether. 

Thankfully, EGW makes a perfectly acceptable 20moa rail, and it sells for $40:

Would I run these on a 1000 yard gun? absolutely not. Am I reasonably certain they're going to hold zero for this gun? Absolutely.

Now, do I expect 1moa performance from this gun at 700 yards... Well, it'd be nice, but with the factory featherweight barrel, I doubt it. I've only shot the thing out to 300 yards, and it gave me a 4" group with the nasty stock, mediocre trigger, crap glass, crap mounts... so with the upgrades, maybe maybe not. I think it'll do better than 2moa, maybe better than 1.5moa.

I've also grabbed one of those barrel resonator donuts to try out. Some guns they work great on, some not. We'll see.

But either way, I'm pretty damned happy with the state of the gun. The new stock is great, the new scope is great, the new trigger is great... if it shoots at 1.5moa or better at 400 yards I'll be happy. If it does it at 700 I'll be thrilled.

And of course, what I'm really thrilled about, is the price:
  • Base gun - $300
  • Stock - $80
  • Bottom metal - $290
  • Trigger - $90
  • Scope - $450
  • Rail - $40
  • Rings - $40

  • Total rifle - $760
  • Total optics and mounts - $540
  • Total system -  $1300
Given that a factory rifle of similar quality with a detachable box mag, would run me at least $1250, and a scope for it another $850 for the same scope new... or $1600 for the nightforce I'd probably buy if I was spending that much anyway...

Or to put it another way, for the same money I'd be getting say, a Howa 1500 with a Vortex 4-16x50. Not a bad solution for the money certainly, but I'd rather the mag, trigger, and scope I've got.

So moneywise, not bad at all.

Hell, at that money, I don't mind throwing the factory barrel away and spending $400 on a really nice Krieger... AFTER boomershoot.

Now I just hope it's under 9.5lbs. With that big scope on there, that might be a pipe dream.

Next post on this topic, well go over the actual build process and pictures (and I'll weigh the thing).