.50 Cal Reloading Page

50 BMG Cart

For those of you that are intending to reload for .50 BMG or .50 DTC cartridges, below is some useful information:

The Same Process, But Different

The basic process for reloading .50 BMG cases is the same as other metallic cartridges; i) resize / deprime, ii) prime, iii) charge wth propellant and iv) seat the projectile. However, there are some additional considerations that you need to be aware of:

1.  Resizing the cases requires a lot more force, because the cases are wider, longer and the brass much thicker, with cases weighing around 850grns each unprimed;

2.  They require specific .50 BMG primers, which are much larger than the two standard rifle sizes (large rifle and small rifle);

3.  The military brass has crimped primers, which require additional attention;

4.  They consume a lot more propellant, with typical charges running in the 240 - 250grns weight; and

5.  You will likely need specialist reloading tools for them due to their size (e.g. a .50 cal case trimmer).

So, what does this mean for reloading them?

We sell once-fired mlitary brass which makes feeding your .50 BMG rifle a lot more affordable. The military brass has most likely been fired through a .50 BMG M2 Browning Machinegun. These guns have relatively loose chambers to ensure reliable operation when the guns are used for extended periods and adverse conditions. This means that the brass tends to swell a little more on firing than a case fired in a tighter rifle chamber, and so need additional force to resize. The greatest amount of force is required at the bottom of the stroke, when you are not only sizing the full length of the body and encountering the solid head, but you are also trying to force out the primer from the crimped pocket at the same time. This can make it extremely difficult to get the case the last 5mm or so into the resizing die, and may in fact feel as if the case has seized in the die.

There are a couple of things that we can do with the military brass to make them easier to resize. First of all you can use a 3mm (or 3/8") hardened pin punch and a hammer to punch out the primers, prior to the resizing operation. This will reduce the extra resistance at the bottom of the stroke. Make sure that your properly locate the pin punch in the primer hole before you start hammering, so that you are not just banging away at the solid head of the case. It is harder than you wold think to find the hole in the bottom of the case with the punch. Ensure that your pin punch is sufficiently long to allow you to hold onto it and to prevent it falling into the case when the primer ejects. You can either de-prime on a block of wood with a hole in it (to allow the primer to fall free) or you can use the priming shell holder that screws into the top of your .50 cal press. Take care not to pinch your fingers between the pin punch and case mouth when the primer ejects. A look at the spent primers (which are often convex in the base) will show you just how much force is required to eject them from the crimped pocket.

Crimped Primer                                        Depriming with Pin Punch                                        Spent Primers

                                          Crimped Primer                                                   Depriming with Pin Punch                   Spent primers - (L) Easy extraction, (R) Difficult Extraction

The second thing you can do is to use a different lubricant than your regular resizing lube. Something that works well is 5W20 rated engine oil. This is a low viscosity oil designed for higher pressures and temperatures than standard resizing lube, and helps reduce the friction significantly. A 1 litre bottle of oil will last you virtually forever. Simply pour a little oil into the bottle cap or other small container, and touch your index finger to the oil surface. Touch your thumb to your index finger to spread the oil, and then rotate a case between your fingers until you have put a light smear of oil over the whole body, from base to shoulder junction. Do the same wth the case neck, but try to avoid the shoulder, so as to reduce the chance of oil dents. Remember to put a little oil on the inside of the case mouth also, to reduce friction when the sizing button passes back through the newly sized neck. A cotton bud dipped in oil is good for this. You should find that this will reduce the force required to resize the cases (although it may still be a lot compared to regular cases). Repeat this process for each case. At the end you'll need to thoroughly wipe all the oil off the cases with a dry soft cloth, and it's a good idea to either wash tumble your cases in an alcohol or  detergent solution, or to give them a final tumble to remove all traces of oil.

If the sizing operation is still very difficult, you may find that you need to use the following technique. This is essentially a resizing by stages process. Wind the resizing die into the press so that its bases is about 3 - 5mm from the top of the shell holder at full extension. Lube your cases as suggested above and then run them up into the sizing die. This will partially resize them. Once you've completed the first stage, then wind in the die a little further and repeat, sizing the cases a little more. Then wind the die down all the way until it makes firm contact with the shell holder and do the final full resize. What this does is to ensure that you are not trying to resize all parts of the case at the same time, but rather in stages, which makes the final stage far easier. Depending on how difficult it is to resize your cases, two or three stages can be used to achieve full sizing. Yes, it's a hassle, but it will prevent you needed to use excessive force and feeling as though you are going to get a case stuck in your press with every resize. Ensure that you lubricate the inside of the neck properly, so that you don't overly stretch the case neck with each resizing stage. Hopefully, after going through this process the first time and then firing the cases in your own rifle chamber, you may be able to resize them in a single operation without undue difficulty after that. Play it by ear.

Another thing that helps if using the Lee .50 cal press is to replace the handle with a longer one. The standard handle of the Lee press is 35.5cm long once the ball is removed from the end (friction fit). Replacing this with a handle 45 - 50cm long will give you additional leverage and so make the operation easier. Simply undo the locking screw on the opposite side of the handle with a spanner, and slip out the Lee hollow steel handle. Replace with a solid steel round bar of appropriate length that is 16mm (or 5/8") diameter. You can put a slight taper on the end of the handle with a file and then press fit the knob on with the aid of a rubber mallet. A cheap and easy upgrade that will help with the .50 cal cases.

After resizing, you will need to remove the crimp on the primer pocket, so that you can easily re-prime and deprime the case. The easiest way to do this is with a standard chamfer tool. Simply turn the tool in the primer pocket to ream away the top edge of the pocket (which removes the crimp). Don't take too much off, just enough for the primer to make easy entry into the pocket. This operation only needs to be done once per case, which can then be re-primed and deprimed easily thereafter. You will likely need to use the press priming system to reprime the case, as you are unlikely to find any hand priming tools for .50 cal primers.

Crimp No Crimp

Primer pocket with crimp (L), and with crimp removed (R)

Like any metallic cartridge case, if you want the best accuracy, then you'll need to prep your cases. Processes like weight sorting brass, trimming to consistent length, uniforming primer pockets and flash holes, and neck turning may all be warranted. Starting with a premium quality cases (such as those made by Lapua) is the best idea, but these are horribly expensive. If you are just shooting a big .50 for the fun of it, then there's probably no point going to these lengths, but certainly handloading will still allow you to shoot a lot more rounds for your dollar. 

Wilson / Sinclair make a .50 cal case trimmer that is available from Brownells, and there are also various primer pocket tools than can be sourced from the same location, if not found at your local gun shop. There are also outside neck turning tools suitable for .50 cal (e.g. Sinclair) and various other tools as well.

With respect to reloading presses, be aware that there are two separate die sizes for .50 BMG. Lee Precision offer dies and presses with 1.25" wide thread, while companies like Hornady and RCBS offer dies and presses wth 1.5" wide thread. Obviously dies and presses of different sizes are not compatible, so ensure that you get ones that match. We sell the Lee .50 cal Press Kit, as it represents the best value and also includes a set of dies ( 2 die set - full length sizing and seating dies). The Hornady and RCBS presses are bigger presses but are also twice the cost and some do not include dies.

Priming

Lee .50 cal Press with case in priming shell-holder

As mentioned, you are dealing with propellant charges that are 5 - 6 times the weight of a standard charge in a .308 Winchester. That being the case, small variations in propellant weight represent a much smaller variation than in smaller cases. For example, a one grain variation in a .308 Win charge may represent something like 2.2%, while in a .50 BMG case, the same one grain variation would likely be only around 0.4%. This is something that works in our favour, as it allows us more margin for error with our charges without undue effect on velocities or accuracy.

Projectiles for .50 BMG

There are fewer brands and options for .50 BMG than for most other calibres, but there are still enough to have some choice. Currently, MFS offers four projectile types that are suitable for either target shooting or hunting. The projectiles that MFS offer are:

Cutting Edge Bullets MTAC (Match / Tactical) projectiles, in 720grn, 762grn and 802grn - these high BC projectiles are designed primarily for long range target shooting, and are of solid copper construction with a solid meplat.

MTAC X03                              MTAC X02                              MTAC X03

(Cutting Edge Bullets L to R) 720grn MTAC X03, 762grn MTAC X02 and 802grn MTAC X01

Shop for Cutting Edge Bullets MTAC projectiles by clicking here.

Cutting Edge Bullets MTH (Match / Tactical / Hunting) projectiles in 798grn - these projectiles are the same shape as the MTAC 802grn projectiles, but incorporate a hollow point that allows the projectile to expand on game, making for greater trauma and hence cleaner kills.

MTH X04

Cutting Edge Bullets MTH X04 798grn

Shop for Cutting Edge Bullets MTH projectiles by clicking here.

Ex-Military Pulled M33 647grn FMJ (Full Metal Jacket) projectiles - these are the most economical projectiles that can still shoot well, but they do not have the same BCs or long range accuracy as the premium projectiles. They are fine for moderate range target shooting and shooting for fun.

M33 FMJ

M33 Full Metal Jacket

Shop for M33 647grn FMJ projectles by clicking here.

Propellants for .50 BMG

Suitable propellants include the very slow burning propellants like ADI AR2218, Hodgdon H-50BMG, Hodgdon US869 and VihtaVuori 24N41. If you intend to do a fair bit of shootng, then these are generally best purchased in 4kg or 8 lb tubs, due to the large charge sizes. A 4kg tub will charge around 257 cartridges (based on an average charge weight of 240grns), while an 8 lb tub will charge around 233 (based on the same charge weight). You can find .50 BMG load data in various reloading manuals, such the the ADI Handloadng Manual.

                               AR2218 Propellant                 Propellant Hodgdon H 50BMG          Propellant Hodgon US869                   Propellant VihtaVuori 24N41

Primers for .50 BMG

Primers that are available in Australia for .50 BMG seem to be the CCI # 35 primers and the RWS .50 cal primers. For the best accuracy results in long range competition, the RWS primers are said to give more consistent results.

Loading Cartridges for .50 DTC  [Under Construction]

This cartridge is a variation of the .50 BMG, for jurisdictions where the .50 BMG chambering is not civilian legal. Serbu Firearm rifles are chambered for the .50 DTC (EDM), with EDM the company who first made them in the US. The .50 DTC is a slightly shorter cartridge than the .50 BMG, with slightly less body taper, and a pushed down, but wider and slightly sharper shoulder. Case capacity and velocities are virtually identical with the .50 BMG. This cartridge can be formed from .50 BMG brass with only a full length .50 DTC resizing die and a case trimmer. However, you should anneal the formed case before firing it, as the forming process work hardens the neck making it more brittle. Annealing the neck / shoulder area will greatly extend case life and help to avoid neck splits.

Please note that we don't supply dies for .50 DTC rifles, but you can order dies yourself directly from the manufacturers. There are two companies that make reloading dies for .50 DTC that we currently know of; Lee Precision and CH4D.

Lee Precision make dies in 1 1/4" x 12 thread, which fits the Lee .50 cal press. In order to obtain dies, Lee asks for three fired cases that have been fired in the chamber of your rifle. We obtain these from Serbu Firearms after they manufacture your rifle and have them forwarded to Lee. The dies are expensive, so be aware of the cost. Click here to read about Lee custom dies.

CH4D also make reloading dies, but in 1 1/2" x 12 thread, which fts the Hornady and RCBS .50 cal presses. They manufacture to standard dimensions. Click here to read about .50 DTC dies from CH4D.

The forming process involves shortening the case by 2.5mm (0.1"), forming the new shoulder in the full length sizing die, and then fireforming by firing in your rifle which creates the new expanded body / shoulder dimensions. The process is shown visually in steps below.

BMG DTC conversion 2

Image shows (L to R): Original .50 BMG case; Trimmed to length; Formed in full length sizing die; and .50 DTC case after fireformng in rifle chamber.

Note that alternately, you should also be able to form the new case in the sizing die before trimming, and then trim the formed case afterwards, before fireforming.

Once your cases are formed, you should be able to use standard .50 BMG load data as the cartridge volume is virtually identical. It is advisable not to use hot loads when firing the newly formed cases for the first time. Use mild to moderate loads to fireform the case to the rifle chamber the first time, as the unfired case has less case volume and the shoulder needs to expand slightly to fit the chamber. You will see that the fireformed .50 DTC case has a greater shoulder diameter than the .50 BMG case

 

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