by Darrell Holland
The Remington 700 rifle platform is very popular, with millions of rifles made. It’s also a versatile platform on which to build a custom rifle. I will explain different aspects you should consider when planning a custom build. Hopefully, you will be in a better position to decide what you really need for your own application or for your customer’s, and how to get the most from your investment, in terms of both time and money.
The second and final part of this great article by AGI Instructor Darrell Holland. If you missed Part 1, you can find it by clicking here.
Another common upgrade for Remington 700 rifles is to replace the factory barrel with a custom barrel.
Most factory barrels are made using the button process, where the barrel is drilled, reamed, and sometimes lapped before a button is pulled through which swages the rifling into the bore. Other makers may use a forging process, where the barrel is hammer-forged around a mandrel that forms the bore and chamber. Another method, common among custom barrel makers such as Krieger and Bartlein, is the cut rifling method, where each groove in the rifling is individually cut. Some makers, such as Bartlein, can actually tune the twist rate to the customer’s specifications. Hart, Pac Nor, Lilja, and Schneider use the button rifling method. Both methods are capable of exceptional accuracy. While no factory barrel will shoot as well as a good custom barrel, they have been improving
in their rifling consistency.
Cryogenic freezing of barrels has been around for several years and has enjoyed modest success. When a barrel is turned down in the manufacturing process (from a blank to a sporter contour) it can and often times does induce stress into the rifle barrel. As the barrel heats up from prolonged firing this stress/tension in the barrel causes a shift in point of impact and often the rifle patterns rather than groups. Stress relieving in the form of cryo freezing and vibrating often eliminates this from the barrel blank. Better to have used a heavier barrel contour if prolonged strings of fire are to be done. Be practical in your expectations of your rifle and its capabilities for the task at hand.
Another thing to consider is the barrel’s profile. Despite the trend of using thin, lightweight barrels, I generally recommend the shooter choosing the heaviest barrel contour practical for their application. The lightweight barrels are easier to carry, but they won’t shoot as consistently nor as accurately as heavier barrels. And if you think about it, how much does that heavy-barrel rifle weigh compared to the hind quarter or front shoulder of a deer or elk? A heavy barrel on your rifle will help instill the confidence needed to take that shot and know you will hit your mark. The end result will make carrying that rifle worth the effort.
Anytime we build a custom rifle with a new barrel it’s important to go through and basically blueprint the action. There are several different methods, but basically we’re going to run a mandrel through the receiver and pilot it on centers. I use the middle screw to secure the mandrel and get a precise fit to indicate the mandrel in if we’re not running it between centers.
Then I face the front of the receiver square. This will usually require the removal of about .003-.005” of material from the receiver face ring. I put an aluminum sleeve over the front receiver ring and hold it in place with an 82-degree counter-bored ¼-28 screw.
Once I face the receiver square I will take a finish cut across the length of the aluminum sleeve. This makes the diameter of the sleeve concentric with the centerline of the action. It allows me to chuck the sleeve into my lathe and then indicate to the face of the receiver end that I have just faced square. Then I take a tool and re-machine the locking seats so they’re parallel to the face of the receiver. At that point the receiver is basically done. You can run a 1 1/16”-16 tpi tap into the receiver threads to clean out the debris that Remington puts in there during the assembly process.
Some people may say they have to set up those threads, indicate everything in, and re-machine the threads in the receiver. That is one way to do it, and I’ve done it before. I’ve done it both ways on literally hundreds of rifles and I don’t see a measurable difference in group size or performance having done one or the other. For new gunsmiths, or people that are not really skilled machinists, trying to go in, pick up the internal thread, and cut it oversize runs the risk of ruining the receiver and damaging the tooling.
Every now and then you will get a receiver from Remington where the threads are a little bit askew to the receiver but it’s very, very rare. The important thing is that when tightening the barrel in the gun we have 100-percent contact between the shoulder on the barrel tenon and the recoil lug. If this is done then thread-fit isn’t that important. We want to have a good thread fit, but if it takes a little looser thread to get that full circumferential contact between the barrel shoulder, recoil lug, and receiver face, that’s all that’s required. I’ve seen guns that have very sloppy thread fit and I’ve seen guns that have an incredibly precise thread fit, and both of them shot phenomenally well, inside .200” at 100 yards.
This negates the idea that thread fit is imperative for an accurate rifle. It isn’t. It’s a sign of good workmanship and something that we should always strive for, but lug contact is by far the most important element.
Aftermarket recoil lugs can be very beneficial for getting the most out of a custom rifle. I believe we build one of the finest competition recoil lugs on the market and I think our lug is probably used by more gunsmiths than all other lugs combined. Aftermarket recoil lugs are important because the factory lug is very seldom parallel or flat. The average gunsmith does not have a surface grinder at their disposal. If we go through all the time and trouble to face the receiver square, re-machine the locking seats and the bolt, and then put a recoil lug that is not parallel on it we’re not going to get that 100-percent contact on the barrel tenon and shoulder that we need for an accurate shooting rifle. It defeats the purpose of doing the action work. Fitting the barrel to the receiver is easier when installing a lug that has been ground perpendicular to its bore, front and back sides parallel and flat, with dual draft angles on the sides.
Now let’s discuss aftermarket bolts. Our new aftermarket bolt with the integral handle will be available here in the next month or two. That’s going to be a real good product for us. It has a fitting band in the back to allow you to take the vertical play out of the bolt. If the hole in the receiver is a little bit larger than the bolt body itself it allows you to fit those a little more precisely and makes the rifle feel a little bit smoother when opening and closing the bolt. Having an integral bolt handle makes that part of the gun much stronger. Remington bolt handles from the factory are silver-soldered on and every now and then they don’t do a real good job, allowing the bolt handle to come off. If the shooter is stressing his loads a little bit and having to work the bolt handles with force because he’s overloaded the cartridge, we will see handles bend or come off, being abused by the shooter trying to get it open to extract the shell.
Firing pin fit is very important. In our new bolt design it will allow the shooter to put a .065” pin tip in the bolt which minimizes or eliminates primer flow and cratering. Standard factory bolts by Remington will have a firing pin hole of .076-.078”. Depending upon the cartridge and the type of primer you’re using you may see some primer flow and cratering at that stage. We’ve also noticed in a lot of the newer Remingtons that they’re chamfering the firing pin hole in the bolt. When this happens you get excessive cratering of the primer and the only way to fix that is to either put a bushing in the firing pin hole and then drill it smaller to fit the pin tip, or TIG weld material to the firing pin hole and re-machine it to a smaller pin diameter to eliminate primer flow and cratering.
It’s important to understand why primer flow and cratering should be eliminated. Having primer flow and cratering doesn’t allow you to run your pressures up as high because the primer is going to come back into the firing pin hole. This can result in pierced primers. When that happens the shooter is going to get a little gas
attack back in his face. There is also the potential for pieces of brass and primer to enter the firing pin hole, binding up the firing pin. It also erodes the bolt face.
While we’re examining firing pin issues, it’s important to realize the value of springs. There are a lot of different aftermarket springs available. We make a fast lock-time spring for 700s with long and short actions. We also make a heavier bolt stop spring, a trigger spring, and a lighter ejector spring. Depending
on the customer’s applications these can be a great benefit. The heavy duty bolt stop spring provides a more positive return on the bolt stop. The ejector spring is lighter so if a customer is using a turned-neck gun it doesn’t dent the case mouth as we extract the cartridge from the chamber. The constant-tension ejector pushes it over to the right-side of the lug raceway and the receiver.
The Competition Rifle
Building a custom rifle for competition involves many of the same considerations as building a hunting rifle. However, there are some subtle differences. One of the main differences is the stock design. A competition rifle is fired from a bench with a rest under the forearm and a sandbag to stabilize the rear. It’s important to be able to repeatedly shoot well under these conditions, often allowing the gun to recoil freely to maximize the accuracy potential of the round being fired. Stocks used in these rifles often have wide, flat forearms to
accommodate shooting from a rest. The forearms may also be set up with adjustable weights in order to qualify for different disciplines. As with hunting rifles, heavy barrels are also highly recommended for stability and consistency.
Caliber selection in a competition rifle is very important. Barrel heat, recoil, and fouling are important considerations, as well as bullet selection.
When choosing a cartridge for competition look over the choice of your fellow competitors. More often than not you will see a cartridge that seems to dominate the type of shooting you are interested in. The 6mm Dasher, the 6mm XC, 6.5×284, 7mm WSM and 300 Win Mag are a few of the more popular selections for 600-1000 yard shoots at paper and steel targets. Shoot the most accurate bullet with the highest ballistic coefficient in your rifle. Take the time to do some serious handloading to obtain these results.
The 6mm’s are among my favorites as they are capable of shooting a relatively high BC bullet .53-.55 at 2900-3100 fps. They exhibit very low recoil, and are fuel efficient in powder consumption while minimizing barrel heat and fouling. The testosterone based magnums offer great performance on paper, but the huge amounts of powder burnt produce heat, fouling, and excessive recoil. Remember we are only punching holes in paper and 5000 ft. lbs of energy at the target are of no consequence. The 6mm XC and or Dasher would be my choice in 600 and 1000 yard matches.
The cartridge case design should be considered, too. I recommend turned necks for maximum accuracy. This will allow the customer to turn the neck thickness of the brass to a specified dimension with a very close tolerance for expansion when the bullet exits the cartridge and goes down the barrel. This gives us better alignment of the bullet to the bore. We minimize the sizing of our case and get considerably better and much more consistent accuracy in the long run by using a tight neck chambered gun for long range shooting.
For example, let’s say our cartridge has an unturned cartridge dimension of .275”. In order to meet SAAMI chamber specifications we may need .005–.006” clearance on the cartridge. Brass that’s thick on one side and thin on the other won’t provide a perfectly concentric fit into the throat. By using a tighter throat dimension of .270”, we can turn the brass to .268” for a more uniform thickness, which in turn allows the cartridge to align the bullet more concentrically in the throat. This maximizes the accuracy potential of the cartridge.
Another consideration is powder efficiency. The goal is to use only enough of a particular powder that will completely burn in a given length barrel with a particular bullet. For example, if you have a cartridge/powder/bullet combination that achieves its maximum velocity in a 24” barrel, then a 30” barrel would be a waste of the powder’s energy. Using the optimum amount of powder for a given load/barrel combination can also result in cleaner performance and less velocity deviation, which can affect shot-to-shot consistency during strings of fire.
This is one of the reasons why it’s so important for competitive long range shooters to develop proper handloads. Aside from using turned necks, just about every aspect of a cartridge’s assembly can impact its accuracy potential. This is why top shooters often experiment with different aspects of the cartridge, from different primers, to seating depth, to neck tension, and so on. Small details like these can have a substantial influence on how accurate a particular round will be in a particular rifle.
As we have seen, the Remington 700 is a great rifle to build on. There are many options to consider, from tuned factory rifles to highly customized competition rifles. The key to maximizing the 700’s potential is to recognize the purpose of the rifle, and then carefully select those features that will truly be beneficial.