RedBeard’s Curious Life

After using my .22 rifle and AR-15 for a while, I got the itch for long-range precision shooting. The .22 cartridge is only accurate to 100 yards, and .223 is accurate to about 600 yards, although my AR-15 isn’t super-accurate. Drawing inspiration from movies and games, I wanted a rifle that could reach out to 1000 yards or more; for a bullet to remain accurate at long range, it must maintain supersonic speed because the transition to subsonic randomly and significantly destabilizes a bullet. Military snipers have used the M21, M24, and M110 to great success, and all of those rifles fire the .308 cartridge which is known to maintain supersonic speed beyond 1000 yards. The M24 is a bolt-action rifle, which is a design well regarded for its accuracy, whereas semi-auto actions like the M21 and M110 are typically regarded as good but not great. I wanted to have an M24 of my own, capable of hitting a dinner plate at 1000 yards.

The key to accuracy is consistency, in both the rifle and the ammunition used, not to mention the marksman. The ammunition must provide a uniform bullet weight and velocity from one round to another, since any variation will cause a change in the trajectory and thus the impact point at distance. The rifle must propel and release the bullet the same way every time, which means the barrel cannot vibrate or bend much, the action must be immobile, and the scope must stay in perfect alignment; basically, the rifle must be solid and relatively heavy. The stock must not push on the barrel at the front, which means that the barrel and stock must actually be joined no farther forward than the chamber, and that the stock must be rigid forward of that point; typically this is achieved by “bedding” the stock with fiberglass or aluminum. The trigger must be crisp with a relatively light resistance to avoid any destabilizing motion when firing. Long-range accuracy typically means using a heavier projectile that will keep its momentum when fighting against wind resistance, and M118LR is the standard military sniper ammunition, sporting a 175-grain boat-tail hollow-point bullet. Accuracy is typically measured in inches or MOA, which are roughly equivalent at 100 yards, and 1 MOA is considered good for a long-range rifle, and 0.5 MOA is considered excellent; anything better is extraordinary. Hitting a dinner plate at 1000 yards calls for 1 MOA accuracy.

The M24 is a custom-made rifle, built on the Remington 700 long-action platform, with a custom barrel and stock along with a fancy Leupold Mark 4 scope. The rifle alone can actually be bought, for a mere $3685, and the complete sniper weapon system is only $8970; this is somewhat beyond my budget for a long-range rifle, but I felt that I could get something almost as good for considerably less money. The M24 is built with a special barrel which has 5 grooves (instead of the usual 6) and rifling tuned specifically for the M118LR cartridge, at 1 full rotation per 11.25 inches. This same barrel rifling can be purchased on a commercial Remington 700 rifle called the “5-R mil-spec”, which retails for about $1100. I was highly tempted, but that was still a bit rich for my blood, and I already had a couple of Remington firearms that hadn’t quite been perfect, so I continued to look for deals on something similar. I came across a decent deal on a lightly-used but well-reputed Savage rifle fitted with an aftermarket stock that should improve accuracy; I decided to buy it, for about $700.

The specific model is the Savage 10FP, which comes standard with a 24″ heavy-profile .308 barrel with a 1:10″ twist rate, a 4-round internal magazine, a user-adjustable trigger, and a somewhat flimsy stock. The copy I bought had already been fitted with a more solid aftermarket stock, the Bell & Carlson Medalist, which is aluminum-bedded for rigidity and has a free-floating barrel channel. The stock has a couple of front sling swivels, which can be used for attaching a sling or a bipod, and I had the intention of attaching a Harris bipod, similar to the ones used on the M24. The bipod is designed for slightly rounded stocks, and the stock has a flat forend, which allows the bipod to yaw slightly; not a serious problem, and Harris even makes an adapter for flat forends, but it doesn’t offer much improvement. The Harris bipod I bought allows for swivel or tilt, meaning you can tip the rifle sideways to get the scope sights level with the horizon; the adjustment knob for this is notoriously difficult to lock down, so I attached a small handle that gives enough leverage to lock the swivel feature solidly; the swivel is of limited use anyway, I would recommend saving money and getting the non-swiveling model.

For optics, I wanted a scope that could scale from 100 to 1000 yards. This caused me more trouble than I had anticipated, as the bullet-drop for a 175-grain .308 at 100 yards is practically nothing but at 1000 yards it’s about 30 feet, which translates to an angular difference of 30+ MOA (minutes of arc). The implication here is that after allowing some give for mounting imprecision, the scope needs about 40 MOA of adjustment; since the consistency of a scope’s zero tends to decrease towards the edges of adjustment, it’s typically best to avoid those extremes, especially if windage adjustments may be needed, so the desirable adjustment range is more like 60 MOA in one direction. You will not find a scope with that degree of adjustment for less than $1000, but if you mount the scope pointed down by 20 MOA or so and then adjust up by 20 MOA to hit 100 yards and down by 10-15 MOA for 1000 yards, the scope only needs about +/- 30 MOA adjustment, which is still somewhat hard to find. The rifle’s previous owner had attached a 20 MOA scope rail, so I was in luck. I finally found an affordable scope with a fixed magnification of 10x but with an adjustment range of +/- 40 MOA: the Bushnell Elite 3200 10×40mm. This is the same scope that Barrett includes with some of their .50 BMG rifle packages, so I had a feeling it would be a solid buy. I attached it to the scope rail with Burris Xtreme Low rings.

After assembling the rifle with its accessories, I took a few photos before heading to the range. Here’s a full frontal, and here’s a close-up of the Savage AccuTrigger. The AccuTrigger uses a safety device like those found on Glock handguns, which allows the user to adjust the trigger resistance down to about 2 lbs for high target precision. I took my rifle to the range in Issaquah, where they have 25, 50, and 100-yard shooting positions, with the hope of seeing some consistent 1-MOA performance. The 100 yard distance is a pretty long way if you’re accustomed to indoor ranges and handguns: my target in this photo is the white dot in the middle. My first trip was spent mainly trying to dial in the scope, which I did first by roughly bore-sighting the scope by peering through the barrel with the bolt removed. I finally got around to shooting some groups at 100 yards that actually hit close to the mark, and one of them recorded an amazing 0.5 inch 3-shot group.

Not convinced that the half-inch group wasn’t a fluke, I made another trip with a variety of ammunition to try and test the accuracy I could get with each. The test subjects were: Federal Gold Medal Match .308 175 grain, Black Hills .308 Match 175 grain, and American Ballistics M118LR which also uses a 175-grain bullet. I shot 10 rounds of each, in 5-shot groups, switching ammo types after each group. In the following photos, each target was used for only one type of ammo, with the first group in the top left and the second group in the bottom right. My half-inch group had been shot using the Federal ammo, and I was hopeful to repeat that feat so I started with 5 shots of the Federal GMM, to the result of a wide-open 2-inch group. I followed that group with some Black Hills, to see a fairly tight clustering with a high flyer making it about 1.5″ overall. My third group was with the ABT M118LR, which showed a relatively open 1.75″ group. All of the groups were clustered a bit to the right of the aiming point, so I adjusted the scope left by 8 clicks, or 2 MOA. I then did another group with each of the ammo types in the same order, aiming at the bottom-right target spots. The Federal ammo produced another open group, although a bit smaller at 1.5″, and the ABT ammo had similar improvement, closing its group to just over 1.1″ with a high flyer. The Black Hills ammo demonstrated another tight cluster, producing the only group under 1″ of the whole trip (my last 2 shots in this group were actually hurried because the range master was about to call a cease fire). My overall conclusion is that my rifle works best with the Black Hills .308 Match 175gr, which is actually in the middle of the pack for cost, at just over $1.50 per round; long-range accuracy is certainly not a cheap hobby!

I’m honestly a little disappointed that my more-rigorous accuracy experiment didn’t demonstrate any half-inch groups, but I was only hoping for 1″ groups on my budget. I have heard that a break-in process can be used to enhance the accuracy of a rifle, but this is quite a time-consuming process which involves cleaning the barrel between every single shot for 10+ shots, then between every other shot for 20+ shots, then between every five or ten shots for 50+ shots. The idea is that the first bullet through a clean barrel will hit a few imperfections and wear them down as the bullet passes, but that following bullets will only wear down the fouling left behind by the previous bullet. Cleaning between each shot allows the bullets to slowly polish the bore and fully smooth out any imperfections. I’ll have to give it a try when I have several hours free at a range that doesn’t mind cleaning on the firing line. I also realize that my personal shooting accuracy is probably not at its peak, although I did try my best to provide a stable sandbag platform for the rifle and to pull the trigger with maximum smoothness and consistency. I feel that I was able to keep the rifle within at most 0.2 MOA of the same target location for each shot, but if you have some good accuracy tips then please send them my way.

Overall, I’m pleased with the performance of the Savage 10FP considering the money I spent, and time will tell whether I will feel the need for something beyond the capabilities of this rifle. I can’t help but wonder if a few hundred dollars more spent on the Remington 5R could have got me twice the accuracy.