How to Spec Out Your Dream Rifle Build

I receive questions almost daily from people who are in the process of putting a custom rifle together, its usually a question about chambers, barrel lengths, different manufacturers or some other specific part. Many times during the discussion, it comes out that maybe one or more of the options aren’t ideal for the intended purpose of the rifle, and that inevitably ends up causing a change in strategy. In the interest of not wasting valuable time, money and other resources, I figured I would put down a good process so that anyone who is interested in a custom rifle build can follow along in the hopes of avoiding that waste. And perhaps the details that follow can get you on the range sooner.

Whether you are rebuilding a rifle or starting from scratch, there are a few very important criteria that should be considered every step of the way. There may be others, but the main two I will focus on, and the rest are based upon are; the intended purpose of the rifle, and the budget you have to spend on it.

The intended purpose of the rifle is very important, it will dictate many of the rifles aspects such as caliber, weight, quality, etc. If your intended purpose is a hunting rifle, then a twenty-plus pound rifle would not be a good starting point. Just as if you are building a match rifle for PRS style competition, a 338 Lapua Magnum may not be the ideal cartridge to choose. So it is very important to evaluate what you intend to do with this rifle when you’re done with it. Many people start with the idea of a do-all rifle when building a custom, in my experience, custom rifles are an addiction and if you build one, you will likely follow it with more. So don’t be too afraid to get fairly specific with your purpose.

The budget you have to spend on a rifle has just as much influence as the intended purpose because many of us are not rich, and the dollars we have available to spend are limited. You should make sure that your choices are made with that in mind. If you blow your entire budget on a receiver and barrel, you may not have enough left to spend on a good scope. With so many great options available to you today, there are components that will meet most every custom rifle build budget.

Moving forward, here is the order in which I typically choose my components. Afterward, I will discuss them individually:

  • Intended Purpose
  • Project Budget
  • Accuracy Required
  • Distances intended to shoot
  • Weight Limit
  • Bore Diameter
  • Bullet intended to shoot
  • Velocity required
  • Barrel Twist
  • Cartridge Selection
  • Barrel Length
  • Receiver Selection
  • Barrel selection
  • Capacity needed (magazine)
  • Chassis or Stock Choice
  • Trigger
  • Scope & Mounts
  • Accessories
  • The distances you intend to shoot are very important. If it is a match gun for thousand-yard benchrest, then you probably want to shoot something 6mm or larger. If you plan on dangerous game in Africa, then you probably want something .375 or bigger. It’s pretty easy to decide on this subject, if in doubt, just look at what most others are using to do the same. The important part is to match the distance and bore-size to the job at hand. Hitting targets at 1000 yards don’t require huge amounts of energy, whereas hitting a buffalo at 100 yards does. And it’s especially important if you plan on shooting animals at any significant distance, you need to know what kind of energy and accuracy you need before moving to the bullet.

    Selecting a bullet you’ll notice is almost at the top of the list, which may seem like putting the cart before the horse but you’ll soon see why. The only reason we shoot rifles is that we want to hit what we’re aiming at, accuracy then must be one of our top priorities. So once you figure out your available budget, and what you plan to do with the rifle, you should have a pretty good idea about the level of accuracy that will be necessary. Most of the time we want as good of accuracy as can possibly be achieved, so it goes almost without saying that we want a precise shooting rifle capable of sub-MOA (minute of angle) accuracy, and preferably better than half MOA.
    So the next step is choosing the bullet you intend on shooting. The reason this is so important and at the beginning of the list is because so much of the rest depends on it. You should pick a bullet that meets the criteria of your budget and purpose, personally, I try and use the most inexpensive and readily available bullet I can, but one that is heavy for caliber, and has the highest Ballistic Coefficient (BC) as possible. For example;
    If I am planning on shooting a 6.5 for competition, I would probably find something that is 140 grains or more, preferably with a high .290 or better BC, and available readily and in bulk packages to save money. Just how high a BC is up to you, there are plenty of inexpensive options like the Barnes Bullets Match Burner, or you could spend quite a bit more on something like a Berger Bullets 156 EOL.
    Another example; If you are building a hunting rifle and only anticipate shots inside of two hundred yards on whitetail sized game, then you probably don’t need to spend a fortune on specialty or high BC bullets. A simple and inexpensive soft pointed bullet would do the trick just fine. There are pros and cons to either, so pick a bullet that fits your budget and availability, I say bullet but it could be multiple bullets if you must. I prefer and suggest to others to stick to one bullet, if you dont know why, then you should read this when your done.

    Once you have decided on a bullet or perhaps bullets, then you know what kind of barrel twist is required by that manufacturer in order to shoot it well. So mark that down on your build list right next to the bullet. I like fast twist barrels, they are better for shooting the typically heavier bullets that have the higher BC’s. And with technology going the way it is, there are more and longer and heavier bullets headed our way. So favoring a faster twist may leave the door open to shooting better bullets in the future. I have at least one barrel that is an 8.5 twist and I wish it was an 8 or a 7.5, but that’s life in the fast lane.

    If your goal is to hunt big game animals at long range, then you will definitely need as much energy as possible, that can be achieved by higher velocity. A 308 and 300WM can both shoot a 180-grain bullet, but the 300WM can shoot it much faster and therefore carry more energy. The 300WM then would be the better choice of the two for long-range hunting. That is the simple way to choose a cartridge, you can make it as simple or as hard as you want. Just keep in mind the two governing factors we spoke of at the top, what fits both my purpose and budget. It might be a 300WM or it might be a 30 Nosler or PRC, one has more energy, one is cheaper, pick your poison.

    Now that you know your bullet and cartridge combination, you need to decide on a barrel length. How much barrel do you need to get your selected bullet up to speed for the job you’ve tasked it to? Bigger cases with lots of powder usually need a long barrel to burn it all, and that’s what gives those big cartridges their speed. So if you chose the 300WM with a twenty-two-inch barrel, you’ll be slower than had you chosen a twenty-six inch. With as much data as there is available today, this is a very simple calculation to find. Just figure what muzzle velocity you need to stay above the minimum required velocity and energy at the distance you have determined at the outset of the project. Today’s ballistic solvers are an extremely valuable tool for doing this, there are many available, I prefer Trasol.
    There are many fantastic barrel manufacturers, some cost more than others, and some have features and services others don’t. You may want a less expensive button-rifled barrel, or perhaps a cut rifle barrel. You may want flutes cut in the barrel to reduce weight, or maybe a carbon fiber wrapped barrel. Each has its pros and cons again, look into as many options as you can, so you don’t regret it after your rifle is done.

    With barrel details, and the cartridge now written down on your build sheet, its time to pick a receiver to house all this excitement. If you are building a short action cartridge like a 6.5 Creedmoor, then you can pick from a plethora of high-quality short action receivers. Whether it’s a simple Remington 700, or something real fancy like the Badger Ordnance 2013 Action, it once again comes back to your budget and purpose. There are too many manufacturers to list nowadays, making short, long, and XL actions. You can get them in the very common Remington 700 footprint, to use the huge aftermarket support of that pattern, or try one of the many others. Just make sure that when choosing a receiver, you make sure your components are compatible (chassis/stock, bottom metal, etc.).
    Keep in mind that some of these receiver options come with built-in canted scope bases, or available scope bases with various cant options. Do yourself a favor and research those options before buying to make sure it matches your intended purpose.

    The purpose of your rifle will also determine what kind of round capacity you will need. Whether its three, or twelve, you can feed your rifle through a magazine. Most hunting rifles use a blind box mag, and if that meets your requirements then you needn’t look any further. But if you want a larger capacity, then you may consider a detachable box magazine. If your not sure, you can always choose a DBM setup, and run five round mags, ten rounders, or whatever fits your needs. Just keep in mind that additional weight for your end goal.

    Another big choice you will need to decide on is what kind of chassis or stock you plan on using. But since you now know what action, barrel & contour, magazine or DBM, and of course what the purpose of the rifle is, it just comes down to choice and what you can fit in the budget. Keep in mind features between chassis, such as construction and accessories. A carbon fiber stock is much lighter than a fiberglass stock, but maybe you want a heavy chassis instead, with adjustable weights on it.

    Almost any rifle receiver worth having has a good trigger available. Again, do your research and see what you can get that fits your taste, your rifle, and your budget. I am a very big fan of Trigger Tech triggers, but there are many others as well. One thing on triggers, make dang sure you are getting the right model for your build, and ensure safeties, bolt stops, and releases are compatible before you order one. The last thing you want is to get everything put together only to find out your bolt release won’t work or some damn thing.

    The scope and mounting system are incredibly important, so don’t skimp on them. It can be very hard to know what heigh rings to get, or what base to mount them to if you don’t have the components in hands. Many of us order these parts online, so you cant really dry fit them until they arrive. Unfortunately, the best you can do is estimate from your best measurements, and see how it turns out.
    Your scope and base choice are critically dependent on your ballistic data (determined by numbers we figured out already above). You may need a 20, 30, or 40 MOA scope base in order to reach your distance goal, particularly if the scope you choose has inadequate internal travel. Whereas if you are building a short-range rifle or a super flat shooting rifle, you may not need any additional cant.
    Your scope magnification depends greatly on preference and your eyes. But choose one that will allow you to see targets within your intended range, and has the range of magnification you will need. Optics are very subjective because we all have different eyes, so you cant always take others’ opinions for granted, not even mine. Ideally, you should try out your prospective scopes beforehand, but if that isn’t an option, then you may just have to base your choice on other people’s reviews.

    The last thing to cover is accessories, things like bipods, slings, suppressors etc. Now that you have all of your other bases covered, it should be pretty easy to pick out accessories. A stockpack perhaps that fits the stock you already selected or a support bag that attaches directly to the chassis you picked out. With all the minutia of your build nailed down, you can select all the accessories that will fit it.

    Hopefully this has been a helpful walkthrough on how to put your dream rifle together, these steps can be followed or applied to additional build aspects. If you’ve done it right, you should basically have a build sheet with everything you need to aquire. The end goal is to have a rifle you are pleased with, functions as designed, and brings a smile to your face. But dont be too satisfied with it, as it won’t be long till the build bug bites you again and the whole process starts over again. And when it does, come back and read this again.

    -CBM

    3 thoughts on “How to Spec Out Your Dream Rifle Build

    1. Thank you for the advice to do research on the kind of rifle I want and if it fits in my budget. I thought about just buying a rifle honestly. But taking the time will be better for me and my wallet.

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