Diagnosing Hunting Rifle Accuracy, Part Three

In the first two parts I took to task the ability of most shooters to achieve good accuracy. I include myself in this group. I have read, studied, and practiced the art of bench testing rifle for many years and still don’t call myself an expert. I freely admit to never attending a formal benchrest match. How can your casual shooter do any better? I can’t shoot good groups all the time. Fatigue, conditions, equipment, and poor technique all have something to do with it.

I love these gun writers who claiming the latest hunting rifle shoots half minute groups "all day long." No it won’t! Very few rifles and very few shooters can shoot that well the live-long day. I’ve never tried shooting all day long, though I’m considering shooting a five shot group every thirty minutes for twelve hours to see what happens and will bet group size will increase as the day goes along. It might make a good article. Enough crying about the shooter.

For now, let’s assume we’re champion benchrest competitors and concentrate on the rifle, taking human error out of the equation. A gunsmith has steps to cure inaccuracy. That’s why your customer brought you his rifle. What equipment does your customer present to you when complaining about accuracy? A $29.95 rifle scope from a big box store doesn’t instill confidence. I’ll wonder who mounted it and how soon it will let go. Hold on.

I have a little .22 Magnum with a Bushnell 3-6X 3/4" scope mounted on it that will shoot with the best of them. Fluke? Probably. But that’s the best we teenag- 22 Winchester Magnum for many years. Go figure. Below center: A parallax ring may read 100 yards when it really is 120 yards or something else. Check and set it at the range you intend to shoot. Some aren’t. ers could afford back in the ‘60s. It holds its zero now as good as it ever did and will stay under a quarter at fifty yards with ammunition it likes.

Go figure. Scopes are integral in any discussion of accuracy. Parallax can cost at least a half inch at 100 yards, is responsible for many fliers, and many hunting scopes don’t have adjustments to compensate, although turning the focusing ring might help. Most scopes are fixed at about 150 yards as a compromise and those with adjustable objectives cannot be trusted to be perfect at the marked yardage on the ring or dial. This can only be tested with a parallax check at a known distance.

Above center: Scope alignment bars (Brownells 080-918-000) can be used to help mount the scope correctly. A stressed scope can give false adjustments. If you didn’t mount the scope yourself there are some things to check. Given the current trend toward big scopes on hunting rifles, I start by checking if the scope’s objective housing is touching the barrel. A 50mm objective lens paired with incompatible rings can wreak havoc with accuracy.

With heavy scopes and hard-kicking rifles check the scope has not slipped in the rings. Scratch marks on the scope’s tube are evidence the rings cannot hold the scope properly and could mean the scope is under stress from improperly fitting rings. The cure for both of these is lapping the rings until scope alignment bars indicate the rings hold the scope securely and evenly at both ends when the torque wrench is applied.

Also check that the mount screws are not projecting too far into the receiver and binding on the bolt which will inhibit accuracy. Torque everything back up to spec we can go on to other areas of concern. Remember that bad things happen to good scopes. Trying a scope proven to be accurate on other rifles can make our lives easier by weeding out a problem optic. Most manufacturers will stand by their products, especially if you send them before and after targets.

Shooting great groups with iron sights can be accomplished with proper technique. Getting two or three-inch three-shot groups is a good indicator. If I can come back tomorrow or next week and have the first couple of shots hit the same place I’m pleased. If I can do this Below center: These two products are fine for their intended use but keep them off your wood stocks. This is a stock using the factory ferrule glassed in. under crappy hunting conditions I’m ecstatic!

What if your customer’s rifle is shooting one place this week and four inches away the next? This is either loose screws or improper bedding. Even a rifle shooting two shots here and three shots there in one group isn’t returning to the same place in its relationship with the stock after each shot. In a wood stock look for warping, usually evident along the barrel channel. I once had a .300 Winchester Magnum that cracked at the tang due to recoil even

Don’t forget to leave clearance for the screw. It should not touch the stock. I have a use for it. Today’s glass can’t be beat. If you are going to use a scope and want all the accuracy, don’t mount junk. though it was glass bedded. It threw fliers. Inspect the stock carefully. Another problem can be too much oil.

If your customer is dunking his rifle in 3-In-One or WD-40 every time he brings it home and then leaves it in the closest until next hunting season you can bet the stock will be "punked." Sometimes the bad areas can be hogged out and rebedded, but mostly anew stock is in order when damage goes this far. Even a heavilyoiled barrel can cause the gunk to migrate if the gun is stored in an upright position.

Most times this will cause the action (bolt and firing pin) to hang up during freezing conditions but it’s possible the stock could be contaminated. I’ve had folks hand me guns literally dripping with oil. Working the action meant buying anew shirt. Bad customer! I roll up a newspaper and try to show them the error of their ways. Some guys want to do things the same way their grandfather taught them to but a good explanation of what all that oil is doing to their gun will usually calm them down.

I demonstrate where possible. A light lube, wipe off the excess, point out the areas such as the bolt lugs and cocking piece where a little Gunslick may be in order, store the piece properly, and we’re good to go next year. Glass bedding can go south as well. I’ve seen enough old rifles with cracked or loose bedding or the victim of too much lube under it to consider glass bedding as a cure-all, especially as it ages. That’s not to say it’s no good, only that it should be checked.

I’ve discussed upward bedding pressure at the fore end tip used by many builders. This should be inspected to make sure one side of the barrel is not contacting the bedding with greater force than the other. This will definitely throw bullets, usually in the opposite direction from the pressure. The Winchester shoots minute-of-deer and the 40X shoots minute-of-bughole. Not too long ago pillar bedding was the darling of the gunsmithing world.

You couldn’t pick up a glossy rag without finding an article extolling its virtues and how it would make your rifle shoot like a bench rester. Pillar bedding isn’t new. Peter Paul Mauser incorporated it over a hundred years ago. The rear action screw of a 98 Mauser is set in a ferrule that rests on the bottom metal and contacts the receiver. The front action screw goes through an integral hole in the bottom metal that aligns with the extension in the bottom of the recoil lug. It serves the same purpose.

Herr Mauser had accuracy in mind but his idea was that a wood stock would compress as the action screws were tightened unless the "pillars" prevented this from happening. I have mentioned tightening loose action screws as the first step in checking for accuracy problems, but do you also check that they are not too tight? A good torque wrench will lessen the chance of this happening, but wood being what it is, compression is not impossible even when using the best practices.

Sometimes loosening the action screw, especially the front one, will have a remarkable effect on accuracy. This is only a stopgap measure even when using a torque wrench

This was the first group ever fired from this rifle. Above center: The RCBS Case Master allows you to check ammunition for best accuracy. A match bullet may shoot better than some but I like to check. and pillar bedding is a good option in this case. One more thing about bedding when fitting a Mauser-like receiver where the front action screw fits into the recoil lug. The bottom of the lug should be glass bedded on a wooden stock.

This is contrary to stocking most other bolt-action lugs where the current procedure is to only bed the back of the lug, leaving the sides and bottom free. I have found this is best for stable accuracy. The action screws themselves should not touch the stock and be free mounted in their "pillars." Synthetic stocks can benefit from pillar bedding. I’ve never seen a stock made of anything that I couldn’t make compress at the action screws at least a little if I used the most force I could muster.

The main part of the modern argument for the benefits of this process is to have absolute contact with the receiver in the stock. Pillar bedding will definitely help that. This type of bedding requires the use of some type of "glass" filling. If you have to bed a rifle anyway, why not? Brownells offers pillars and ferrules (080-000-417AK and 080-911-098AK, respectively.) This brings us to the newest practice of using an aluminum bedding block to mount the barreled action in the stock of a hunting rifle.

This sounds like a good idea on the surface, a concept that hearkens back to the bench rest practice of gluing the barreled action in the stock. Sometimes an aluminum block held the barrel and was attached permanently to the stock. The other method glass bedded a section of the barrel into the stock. Both methods allowed the barrel and the action to vibrate freely upon firing and were proven to be successful by the winning scores these rifles racked up at serious BR meets.

So far, I have only worked with one rifle using the aluminum bedding block concept —a Savage 110 short action chambered in .250 Savage. It shoots pretty well. Taking the barreled action out of the stock and replacing it is a pain, but this is not frequently necessary. I am still in the process of evaluating this rifle. It seems the consistency is there and I have shot some great groups with it.

Bore scoping has revealed "railroad track" tool marks evident in the grooves, a so-called flaw many Savage barrels exhibit but still shoot very well. I believe this one would shoot better than it has a right to do with anew barrel. Ruger has picked up on this concept with its American centerfire and rimfire rifles. Remington offers some of its line with this option. There is something to this, at least for a good synthetic stock. Stable is the key word here and those rifles so bedded exhibit that attribute.

Bedding a rifle with an aluminum fitting molded into the stock is beyond most of our capabilities but you will see them in your shop, either for accuracy problems or just that your customer took it apart and can’t get it back together. I haven’t said too much about single-shot rifles, mainly because I have limited experience with them. I own a Ruger No. 1 chambered for .257 Roberts. I purchased 500 pieces of R-P cases, 100 of four different brands of bullets, and four different powders.

Having never shot a No. 1 or a .257 Roberts, I wanted to wring this rifle out and carefully followed advice from the older gun writers extolling the virtues of the Roberts and the perceived accuracy problems with the Ruger. Over the course of a few months I carefully shot and chronographed handloads until I had used most of the components. I did not fire form the cases or do much with them except for straitening out the case necks a little by running them through a Lee Expander Die.

Bulk brass always has a lot of out-of-round necks. I champhered the inside of the necks so the bullets would not be shaved when seated. I did not size them at all. I do have a lot of fire-formed cases now. I loaded the brass with different components by using the same bullet and pow-

der with three progressive loads towards maximum in lots of ten then shooting two three-shot groups and one four-shot group with each lot at 100 yards. I also tried promising loads until I was out of bullets and powder. The average group size shooting over 400 rounds was well under two inches. Don’t tell me that single shots are inaccurate. Reports differ. I must’ve lucked into one of the good ones.

Helping a No. 1 shoot can involve glass bedding the hanger for the front stock or drilling holes and fitting screws to give different tension on the barrel. That is grist for another article. Suffice it to say that probably every Ruger you buy will give good hunting accuracy. If it doesn’t start by returning it to the factory and go from there. I’m old enough to remember that if you wanted a black powder rifle you ordered an original one from the Dixie catalog.

As the hunting seasons and popularity of these rifles evolved, replicas, new traditionals like the T/C, inline wonders from Tony Knight, bolt actions, smokeless powder options, and now break-open front stuffers. I have a Traditions Vortek and am well pleased. The first group I shot with it at fifty yards was just a serious hole. Deer, look out. T/Chas been offering their Encore break open for years and it is worth considering. How do you improve on accuracy like that?

If your gun won’t shoot quite that well it may be mangled by poor ramrod handling or has a damaged crown. All the tests apply as to tightening screws and maintaining scopes but not a lot can be done if your barrel is really messed up. I’m in the process of switching to break open guns for deer hunting with my grandson. They are very simple, extremely easy to clean, and shoot great. What’s not to like?

For this article, I’m not including guns like as the New England Firearms Handi-Rifle, not because I don’t like them, but with these inexpensive firearms the best choice is to buy some factory ammunition, get your scope mounted properly (assuming you use one), and go hunting. You won’t be disappointed. There are others that have come and went, such as the Ruger No. 3, the Savage .219, and a lot of old English guns. If you own one, treat them well and enjoy. The last subject I want to talk about is ammunition.

If you have ammo not up to the task of shooting well, forget it. Ask your customer what has been causing him grief in his rifle. If he pulls out a handful of lint-covered, mixed-brand shells, stop right there and have a conversation. A fellow I know has taken a lot of deer with his lever action .30-30. One day, we met in the field and he told me a story about how he had bought a box of 150 grain bullets instead of his usual 170 grainers from the same maker.

He explained that these new bullets weren’t any good since they didn’t shoot into the same place as his old ones did. I had no comment. What can you say to that? Many of our customers are ardent handloaders, but many are not. I am not going to tell you or anyone else how to handload unless asked. When working on a rifle for best hunting accuracy I always include premium factory ammunition in the mix. It’s difficult to find a tuned rifle that will not shoot some brand of factory offering well.

However, it is expensive and might be hard to find nowadays. When loading ammunition for myself I have some steps that I go through, or will save it for the range and never take it into the hunting woods. You have read about the steps benchrest guys go through to get quality ammunition for their most accurate machines. Most hunters can forget about a lot of this stuff. I don’t turn case necks when prepping cases for hunting rounds as most cases today are pretty good as is.

A neck too thick on one side means the whole case down to the bottom is also too thick. Use it for practice. I’ve never seen a hunting rifle that has benefited from turning necks. Leave it to the BR boys. I don’t clean primer pockets, nor do I uniform them. I also don’t uniform primer flash holes. I do look at this area when inspecting new cases. Some writers have sworn they’ve found cases with an absent flash hole. I never have. Flash holes are punched in most cases. Sometimes you may find one a little off center.

Dump that case. It’s easy to uniform the flash holes if you have the inclination and the right equipment, I just don’t think it’s necessary for what we are trying to accomplish. For prepping new cases I round the necks as most bulk brass comes with flattened areas. For hunting I resize full length. This is not necessarily for accuracy’s sake, it’s so the rifle will feed flawlessly in a tight situation. If you are fire forming brass or initially testing some specific loads this is probably not needed.

I keep omitting this step to save time and have only been caught with feeding and chambering problems occasionally. I check brass for excessive length, both new and after resizing. I haven’t yet found any new brass over length but I have found a .300 Savage case in a bag of .308 Winchester brass once. This is an important step more for safety than accuracy. I have not been able to determine that a neck a few thousandths longer than another will give accuracy problems in the hunting rifle.

If you are crimping the bullet all the cases should be of the same length. Weigh your cases and decrease your load for the heavier case accordingly if using mixed brass. Chronograph loads with each case manufacturer so you know where you stand as far as pressure goes. I don’t recommend using mixed brass for hunting loads but it may be all you have. Lastly, use a tool like the RCBS Case Master to check your loaded ammunition for bullet runout.

If your ammunition is not straight it will start out crooked when fired and continue that way. You will be disappointed with most factory offerings but some will make you happy. There are various cures for sloppy runout but that is for another day. AG