Beginning to Load for the AR-15 (223 Remington) | Top Rated Supplier of Firearm Reloading Equipment, Supplies, and Tools - Colt

Beginning to Load for the AR-15 (223 Remington)

If you enjoy shooting an AR-15 like many of us do, reloading for the AR-15 rifle is definitely worth looking into. Not only can you save a good bit of money reloading your own ammunition, but you can load better quality ammunition handcrafted to your specific rifle and your application. Whether you are using your AR for plinking, varmint hunting, competition, or personal protection you have a wide variety of components to choose from.

Starting with the brass cases, there are several choices for the 223 Remington cartridge. Remington and Winchester make new cases for the reloader that are available in quantities as small as 100 piece lots. Lapua and Norma make some great brass but their cases are a little more expensive. The Sinclair Technical Staff highly recommends beginning with new cases or utilizing once fired cases from ammo fired in your own rifle. Avoid the once fired stuff found at the range that was fired in someone else’s rifle. You don’t know what condition it is in or how it was previously loaded.

Bullet selection for the 223 Remington cartridge is outstanding. Depending on your twist rate and your application, there are dozens of great bullets for your AR. The Hornady V-Max bullets are a great choice for varmint shooting. If you are punching paper, Hornady, Sierra, and Nosler make a wide variety of match bullets, many of which were designed specifically for the AR. If you have a standard 1:9 twist factory barrel, stick with the lighter bullets. The heavy bullets like the 69 grain bullets or heavier need a minimum of 1:8 twist to stabilize and preferably a 1:7 as you go even heavier towards 80 grain bullets. The 90 grain bullets need a 1:6.5 twist barrel to perform at their best (a few people have had them work in 1:7 barrels). The heavier, longer match bullets cannot be loaded to magazine length, but are an excellent choice for single-shot shooting especially at longer ranges. The use of a Sinclair Single-Shot Follower in your AR makes single round loading much easier.

There is a wide variety of powders to choose when loading for the AR. Vihtavouri N140, Hodgdon Varget, Vihtavouri N135, H322, and Accurate 2460 are just a few to choose from. Use any of the popular reloading manuals to find a great load. Do not start with the maximum load, work your way up! If you already have some of the powders listed in the reloading manual on your shelf, start with them before going out and buying an 8 lb can.

If you already have some small rifle primers, give the ones you have a try first. The AR is not particularly finicky about primers. Winchester small rifle (WSR), Remington 7-1/2’s, Sellier & Bellot and Wolf small rifle primers are good and reasonably economically priced primers. Once you have developed a load that works fairly well, you might want to try some other primers such as Federal 205M’s to see if you notice any difference (they have been scarce lately). Comparing different primers is a good way to fine tune your load.

Okay, we have our four (4) components (bullets, brass, powder, and primers), let’s move onto tools. If this is your first venture into reloading, we highly recommend the RCBS Master Supreme Kit. It has everything you need to get started in reloading at a very reasonable price. The only thing you need to add is a set of dies and a case trimmer. For the 223 Remington in an AR rifle, we recommend buying a full length die set. You really don’t need a neck die for this rifle/cartridge combination and it will save you a few bucks. Redding makes several good sets as do Hornady, Forster, and RCBS. If you just want the a good basic set to start with, the RCBS and Redding basic set would be our recommendations. Redding offers a higher-end set that includes a competition bullet seater with some great features. The Redding competition bullet seater has a micrometer for adjusting seating depth in increments of .001” and a sliding chamber that holds the case in place and aligns it with the seating plug. The micrometer isn’t really necessary if you are mainly loading magazine length cartridges, but the sliding chamber is a nice feature. Oh yes, don’t forget the shellholder since one probably didn’t come with your die set. You’ll need a #10 RCBS, a #10 Redding, or a #16 Hornady.

For case trimmers, two of our favorites are the Wilson Case Trimmer and the Hornady Case Trimmer. Either one of these trimmers will do an excellent job. The Wilson Case Trimmer is available in several variations and holds the case by the case body without the use of guide/support pilots. This unique manner of holding the case insures that the case is held perfectly square to the trimmer and that each trimmed case is the same length. Setup of the Wilson Case Trimmer for the correct length just takes a couple of minutes. The Hornady Case Trimmer holds the case by the rim and utilizes a pilot to align and support the case neck. It is a very easy tool to setup and use. Trim length on a 223 Remington case is 1.750”. For more on choosing case trimmers, we have an article listed on our blog discussing this subject.

The reloading steps for the 223 Remington are like any other bottle necked metallic cartridge. Just follow the steps in your reloading manual and you’ll soon be at the range shooting your own ammunition handloaded to fit your rifle. For initial load development, utilize a good match bullet or the one you know you want to shoot. Then change only your powder load or selection. Load testing works best when you only change one variable at a time. Work your way up the charge chart in your reloading manual and only load a few rounds at a time (5 will generally tell you whether a load is working or not). Shoot 5-round groups to begin with, then shoot a few more 5-round groups once you have found something that looks promising. Use a well supported firing position for your load testing. A rest or bipod would be great but sandbags or shot bags will work in a pinch. If you are willing to shoot single-shot, you may find extending the overall length of your loaded rounds beyond magazine length worth looking into. The results may surprise you. If you are going to load rounds longer than magazine length, buy a seating depth tool such as the Sinclair Seating Depth Tool or the Hornady Lock N’ Load tool so you can measure the overall length to the beginning of the rifling. This measurement will become your baseline for developing longer rounds and help you adjust your bullet seater.

After developing a good load, you can begin experimenting with various bullets to see what works best out of your rifle. If you change bullet weights, you will want to re-evaluate the powder charge as well as your overall length and setting on your bullet seater.

A few reminders regarding your reloading.

  1. After the initial firing, check your case length with calipers to make sure it meets the dimensions in your reloading manual. If the case length is longer than the published maximum case length, you will need to trim your cases. We recommend trimming the entire batch at one time. Of course, chamfer and debur the case mouths after trimming.
  2. Make sure your primers are seated slightly below flush.
  3. Watch for pressure signs as you increase the powder charge each time. High pressure signs would include; an increase in case head expansion, hard or sticky extraction, flattened primers, severely cratered primers, ejector marks on the case head, enlarged primer pockets, and primers falling out of cases. If any of these signs appear, stop immediately and begin to look for the cause of the high pressure. Check the following:
    1. Is your powder measure set correctly? Re-weigh the load your measure is throwing.
    2. Did you grab the right powder off the shelf?
    3. Did you change from one lot number of the same powder to another? A variation in lots can be quite severe with some powders. Reduce your load.
    4. Check your case length. Trim if needed.
    5. Check your overall length; make sure the bullet is not jammed into the throat of the rifle.
    6. Is your barrel overheated from excessive firing?
    7. Is the outside temperature hotter than when you originally developed the load? Reduce your load.

We wish you the best of luck loading for the 223 Remington in your AR-15. It is a very easy cartridge to load for and extremely versatile. You will be amazed how quickly you can load accurate and affordable ammunition. The satisfaction and savings of loading your own is worth the little bit of effort, but most of us find the reloading an enjoyable hobby. Remember to give the staff at Sinclair a call if you need some help (technical help that is).


Components have been flying off the shelves everywhere in the country. Bullets and powder supplies are in decent shape at the time of this article, but primers have been a bit scarce. We are expecting some more primers in during late-March or early April. Brass has been available most of the time but currently there are some shortages in the marketplace.
March 24, 2009