"Only accurate rifles are interesting." - Col. Townsend Whelen
Unless you know a rifle is accurate from the bench, how can you be sure it shoots well in the field? Hitting the bullseye is a play on the law of averages. The more accurate a rifle is, the closer to the point of aim it places its bullets, the better odds one has of predicting where the next shot will land. Only when we are certain the rifle is capable can we draw any meaningful conclusions about our personal ability, including shooting from field positions.
What level is acceptable? A rifle designed for 300 yard shooting should be capable at a minimum of placing three shots in a 1.5" group at 100 yards, measured from the center of the most distant bullet holes. Most folks these days strive to move that standard closer to 1-inch (minute of angle). With a bit of tuning, however, 3/4" - 1/2" at 100 is a reasonable goal for smaller caliber rifles, say .308 and under, when fired from a solid rest.
Back before I started monkeying with a large number of rifles, I approached every rifle as if it was capable of MOA, all I needed to do was find the right load. As I was to discover this was not always the case. Over the years I've found genuinely accurate rifles usually shoot any good load acceptably well, others wouldn't shoot anything much under a couple inches. Accurate rifles can be enhanced a bit by testing various loads to see if it has a preference, when inaccurate rifles shoot a small group it is usually by accident, the law of averages at play. Shooting a couple more groups will often expose this. Therefore we must not fool ourselves by shooting one good group and declaring our task complete, we must confirm our results by repeating them at least a couple more times.
Then there is the matter of the shape of the group. I’ve seen rifles that would place several shots relatively close together in a line, however from end to end the line of holes was unacceptably long. (When a rifle is stringing its shots like this with a number of loads the usual culprit is the stock bedding.)
So how do we go about improving accuracy? We do it through the systematic elimination of variables (components) that may be interfering by fixing or replacing them with commonly known cures.
For the sake of this discussion we'll assume our goal is to shoot five shot groups at 100 yards under an inch consistently. We pull our rifle out of the case, check every screw for proper tension and check our scope for parallax (see below). If we have a torque wrench, we loosen the takedown screws slightly and re-torque (if we haven't done so already), making sure to tighten the front screw last so any stress goes to the rear of the receiver, not to the barrel region.
You can easily check the parallax on any scope by setting it in a solid rest on the target and without touching it, move your head from side-to-side while observing the relationship of the crosshairs on the bull at the yardage you will be shooting. In a scope that has the wrong parallax setting the reticle will appear to move relative to the target when your eye moves. Obviously this will affect where the bullet goes, your groups may open to the degree the crosshairs appear to move.
If your scope has an adjustable objective or side focus, this is simple to correct. Adjust the dial until there is no parallax paying no attention to what the graduations on the dial state, they are often estimates. If the scope has no such adjustments, or the internals are bad, the only solution is to send it back to the factory for adjustment. Most scopes are set at the factory to be parallax-free at 100 or 150 yards, so there will always be some small amount noticeable at other yardages. You can minimize its effects by being sure your eye is always at the center of the field, at the same spot shot after shot, because parallax comes into play when your eye is off-center. If you are experiencing occasional flyers, outliers from an otherwise good group, this may be the cause.
Even during break-in, we can learn something about the gun. Bearing in mind a new barrel often won't begin shooting to its best potential for a while, we zero the scope and immediately start shooting for groups. Placing the rifle on a SOLID REST (sandbags, bipod or lead-sled) we may find it helpful to dry-fire a few times, getting a feel for our technique and this particular trigger, calling our shots by taking note of the position of the crosshairs on the target when the firing pin fell.
Notice the "solid rest" part, if your gun is wobbling all over the place on the bench one can never be sure of its accuracy. Holding the rifle as loosely as possible while still able to maintain control over recoil is the best method to reduce human error, remember we are trying to learn about the rifle at this point, not the shooter. There's plenty of time for practice once your rifle is dialed in.
Satisfied that we can keep the reticle on target at the right moment, we have at some live rounds. If the rifle has not yet been sighted, we start at 25 yards to be sure we are on the paper. If we are sure it'll be on the paper, we move to 100 yards for some accuracy testing. Bear in mind that because we are testing different loads we are not overly concerned with zero at this point, however zeroing the rifle with one of the chosen loads ( 2" high or whatever) may tell us what to expect if we have to switch loads in the field, after all we are here to learn something about the rifle that will be at the center of some very expensive hunts.
For example, we may discover our '06 shoots 180's and 165's of the same brand to the same point of impact. We may find it shoots two or three different loads the same, this info will be very handy when the airline loses our ammo or we are hunting various size game on the same hunt. Or we may discover we must re-zero when changing loads at all. The point is predictability.
If it all shoots around an inch we can think about going home once the barrel break-in is complete. It is not a bad idea to have another shooter shoot a couple groups to verify our results. If at least one or two of those loads didn't pass muster but one did, we must fire a couple groups with the good load to see if its consistent. If it's not, or if it won't shoot the preferred bullet well, we have some work to do.
It never hurts at this point to mount a different scope. I've found a couple, though rare instances where the scope was bad. This is most often caused by unsatisfactory internal adjustments and can only be corrected by sending the scope to the factory for evaluation.
Having eliminated the easy stuff like bad loads (tested several) loose screws and copper-fouled bores we now turn our attention to other components, in this order:
- Stocks and / or bedding;
We do this in the order of experience as well as expense. If you have a stock that it suitable for an epoxy bedding job you may find $20 worth of epoxy solves the problem, I've see it happen a lot and it's definitely worth a shot. Epoxy will adhere to wood, fiberglass or aluminum. Should you be the unfortunate owner of a stock that epoxy won't adhere to (plastic) now would be a good time to start shopping for a new one. We constantly get reports from the field that the simple replacement of the stock was indeed the cure to any and all of the inaccuracy ills. Only rarely is one required to progress further. If you want a realtively inexpensive stock that is certain to eliminate any and all bedding issues, check-out Stocky's $200 LRC Accublock® stocks - if you don't bed, bolt it into one of those you'll quickly see if its the bedding or the barreled action that is causing your frustration.
While you have the gun apart it's never a bad idea to weigh the trigger with a trigger pull gauge. It's very difficult to snap caps on a target accurately when the lawyer-trigger on your rifle is much over four-pounds, most shooters find that three is about right, a good compromise of safety and accurate shooting.
Creep, the distance your trigger moves before firing, can also be a problem. This issue is a little more complex because it is related to sear engagement. Too little sear engagement can be hazardous to your health so it is extremely important that it be set by a qualified individual as it pertains to the particular brand of trigger to avoid accidental discharges. This is especially critical on rifles where the safety engages the trigger and not the firing pin.
For example, the famous Winchester Model 70 three-position safety blocks the firing pin as does just about any safety located on the back of the bolt shroud. Safeties that are located behind the tang (older Ruger 77) or along side the receiver (Remington 700) do not block the firing pin, they simply stop the trigger movement, making adequate sear engagement even more critical. On non-blocking rifles it is best practice to replace triggers for one with a crisper, lighter pull, not simply adjust them.
It is important to note that by reducing trigger pull you are also reducing the margin of safety. It's always a trade-off. On a hunting rifle it's best to err on the side of safety.
Now that we have our rifle bedded in a good stock, a parallax-free scope and our trigger breaking like a glass rod it's time to repeat the firing test. At least 75% of the time our accuracy ills will be cured because the barreled actions on most factory rifles today are capable of 1" groups, but I've not come to expect a lot better than MOA these days. If you are still something less than delighted or simply want to keep going, it is time to evaluate our barrel and action.
The spot many factory barrels go array is at the muzzle, called the muzzle crown. The most important point of the crown is at the rifling. An uneven or even slightly damaged crown can cause the jet of escaping gas to push the base of the bullet irregularly as it leaves the bore. At this critical juncture the projectile transitions from the center-of-axis spin imparted by the barrel to the center-of-mass spin it retains throughout its flight. Any force acting on the base can be disrupting, however minute.
Power Custom offers a very simple, useful tool for the layman to correct this, their muzzle crowning lap. I have used this successfully on a couple notable occasions to magically cut groups in half on factory rifles. For an investment of about $30 bucks, including the paste, chuck it into a slow drill and simply polish the crown until it shoots. Just be careful and don't over do it. You can of course also delegate this task to a gunsmith, although he will most likely simply wish to re-crown with his favorite method, if it works you'll experience a considerable savings over a complete rebarreling job.
Although I cannot recall a case where re crowning failed to show improvement, don’t expect miracles. The examples I mentioned took 2 MOA rifles down closer to an inch, but unless your crown is seriously out of whack don’t expect your rifle to be miraculously cured of all its accuracy ills.
At this point most folks will have been bitten by the accuracy bug and opt for a complete rebarrel and action truing job. Be prepared to spend at least $500 for this. However, when considering which barrel, here's the dilemma you'll face...
There are a lot of great barrel makers out there, it's hard to choose among them even if they were all in stock somewhere. In this anti-gun age most of the best ones are months if not years out on their orders. The lions share of their barrels being gobbled-up by professionals. This means you'll either have to wait forever or take what you can get, more often than not this will dictate what you use.
Rock Creek, Benchmark, Bartlein and others are now producing premium-quality cut-rifled barrels with 5 grooves, this is called 5r rifling. The advantages of 5r were discovered by our military snipers long ago and it's finally making its way into the mainstream. Simply put, by utilizing an odd number of grooves, the bullet is not pinched between two opposing lands so it is not deformed to the extent that a 6 groove barrel does. It's not so much that we weren't happy with the 6 groove accuracy, it's more like we want to maximize our chance to get a superb barrel (minimize the risk of getting a 'bad' one), so this seems to be the direction many of the top accuracy gunsmiths are opting to take. I've had many of our customers guns of late built with the 5r Rock Creek and Benchmark barrels and have been delighted with the results.
In recent years, Proof Research carbon-fiber wrapped barrels have become extremely popular and are also worthy of some serious consideration especially for the weight-conscious. By using a Proof Research CF barrel, building an eight-pound rifle with bull-barrel accuracy is very doable. I’ve used them - not only do they save a significant about of weight, but also really do run noticeably cooler for extended shooting. It is not unreasonable to expect well under MOA with any of them, steel or carbon wrapped, when properly installed.
No rifle builder worth his wages would recommend rebarreling your rifle without truing the receiver in the process. This involves lapping the locking lugs into their recesses for 100% even contact under stress, as well as squaring the bolt face to the barrel axis. Be sure to specify this to be done, taking care not to insult the fellow should he be one of those that does it as a matter of course during his barrel job. He can also float your barrel in the barrel channel and bed the entire contraption to his proven specifications as well. It'd be a real shame to come this far and not have a properly bedded rifle come out of it.
At this point you'll be justified to expect a sub-MOA shooter that holds a zero under any and all conditions for your approximately $1000 investment, depending on the components you choose. It shouldn't surprise you at all if it does two or three times better than that.
I've come to the opinion that money is better spent on accurizing a rifle I own, or I'll buy the cheap model (an SPS versus a Sendero, for example) and start upgrading, rather that spending just as much (or more) $100 at a time on ammo only to find you have to spend more doing one or more of these things anyway.
Another nice thing about it is that you can have it rebarreled in any compatible cartridge you wish. Your 30'06 can become a .280, your 7 Mag. a .300 Winchester. For that matter, that bargain priced .270 can become a .338 Win Mag if you opt for a new mag box and have him open up the bolt face. You can find a great deal on a WalMart 700 ADL and have it rebuilt into a full-blown, tack-driving custom for about the same price as buying another premium rifle, using the best stocks, barrels and triggers available in the world today, with the knowledge all along the way that it WILL shoot like a house afire when completed.
(Or you can buy another factory rifle and hope it shoots better than the last.)