Reloading for the M1A

When it comes to reloading, my *Springfield Armory M1A has required more research and patience than all my other guns combined.

The most useful document for this endeavor was written by Glen Zedicker, Reloading for the Match M14.  This is a 17 page PDF file, with information intended for more advanced competitive shooters.  Allow me to condense it for someone who is just starting to reload; I’ll throw in my own experience for you who are new to reloading for the M1A:

Brass

  • The M1A/M14 action is extremely hard on brass, do not allow more than four firings per case or you will start to see case head separations.
  • Lake City military brass, marked “LC” on the head stamp, has thicker case walls, and therefore reduced case capacity.  This results in higher chamber pressures than you would see with the same powder load in a commercial case.  The “rule” that many reloaders recommend is use two grains less powder in an LC case.
  • Many M1A/M14 shooters/reloaders prefer to use LC military brass because of the before stated characteristics – it is more durable and makes for more efficient use of powder.

Bullet Selection

I have only reloaded 168 grain Sierra Match Kings and 150 grain Hornady Interlock Soft Points for my M1A.  The reason is that the construction of the M1A’s gas operation system is such that too light of a bullet will not sufficiently engage the operating rod, and too heavy of a bullet can damage the operating rod.  I have fired some 110 Hornady Vmax loads through my M1A out of curiosity – the only drawback was that I had to manually cycle the bolt after each shot.

Zedicker recommends not using bullets heavier than 175 grains, without modification of the gas system (a prospect complicated enough that Zedicker refused to “go there” in his article).  The Army seems to agree with him, considering the development of their new 175 grain sniper ammunition, Mk 316 Mod 0.

Powder Selection

I have spoken with several people about powder selection (including that super opinionated 300 lbs guy wearing fireman suspenders who seems to always be hanging out by the reloading supplies at the Sportman’s Warehouse), and have read as much as I can on the subject of powder selection.  Some favor Varget, others like Reloder 15.  I prefer to use H4895.

I tend to lean on the safe side, and trust Mr. Zedicker’s advice since he has yet to lead me astray.  In pages 10-12 of his article on reloading for the M14, he explains in detail why it is important that you stay within the recommend powder burn rate range – in fact, page 11 has a diagram (that I won’t post here for copyright purposes) that explains the concept quite satisfactorily.

Varget is a favorite for those who load .308 Winchester; its slow and consistent burn rate allow for uniform velocities and excellent accuracy.  Additionally it is from Hodgdon’s “Extreme Powders” family – the grains are coated so as to minimize deviations in burn rate when using it at different temperatures.  The problem is Varget is that it burns too slow for the cycling action of the M1A, and according to the concepts laid out by Glen Zedicker, over time it will damage the gun.

In short, he recommends three powders that have been thoroughly tested:

  • IMR 4895
  • Hodgdon H4895
  • Accurate Arms 2495

I have tested the first two with great results, but I prefer H4895 because like Varget, it is an Extreme Powder.

Sizing

I was fairly new to reloading when I started making rounds for my M1A, and that’s probably most of the reason that I had problems with this step.  Even though I had followed to the tee all the instructions on how to setup rifle dies for use in my press, I still had trouble getting the rounds to chamber.

When I looked for help online, I read that ff your rifle has a match chamber (or even a tighter standard chamber), you might need a small base resizing die in order to ensure proper cycling/extraction of ammunition.  This didn’t make too much sense to me, since my variant was a standard M1A scout.

After quite a bit of research, I finally came across a gun forum discussion that talked about “cam over” on a press.  The instructions for my Hornady .308 Win die explained that after screwing the die into the press until it made contact with the shell plate/holder.  I needed to continue to lower the die to achieve proper headspace.  Lowering the die further will cause the press to “cam over” as the ram is raised – meaning that as the shell holder/plate makes contact with the die, upward pressure will continue to be applied on the press hand and a slight pop will be heard.

Headspace

On the .308 Winchester casing, headspace is a measurement from the bottom of the cartridge (the end where you insert a primer), to the datum line on the shoulder.  The datum line isn’t something you can see just by picking up a round and looking at it – you need machined gauge, like this one from Hornady:

The gauge is composed of a body (red) that attaches to a set of calipers.  Silver bushings like the one in the picture fit a certain range of calibers and are inserted into the body.  Re-zero calipers to account for the length of the assembled body and bushing, then the assembled gauge fits over the open end of the sized case.  It will naturally rests on the datum line and you can now measure the length from the base of the cartridge to the datum line.

Every Springfield M1A will come from the factory with a card like this one:

Springfield M1A Factory Headspace Card

It will have a number, which is the measurement of the headspace of your rifle’s chamber.  As you can see, my rifles factory headspace is 1.632″.  Be aware that throat erosion from continual use of the rifle may change this number – however the relatively low velocity/chamber pressure of the .308 Winchester round usually provides a long barrel life and shouldn’t drastically affect your headspace for quite some time.

The recommended starting point for resizing cases is to make the headspace .004″ smaller than your chamber.  For my rifle, I had to go a bit shorter to ensure reliable cycling at 1.626″.

Two other methods for achieving proper headspace

  1. The cheapest/Doesn’t require a trip to the store or waiting for a gauge online.  Assuming that your headspaced rounds are too big for your chamber, simply adjust your sizing die downward, 1/4 turn at a time, and then test to see if the round chambers.  Do this by pulling the charging handle to the rear and locking it – while still holding the charging handle (so you don’t break a finger/thumb) carefully placed the resized case in the chamber.  Then move the charging handle so the bolt is halfway back, and let it slide home.  Once you have achieved the right setting on your resizing die, the bolt should easily close on a resized case.
  2. Buy a case length gauge - Lyman, or L.E. Wilson are among companies that make a simple drop in gauge.  Simple resize the brass and then drop it into the gauge to see if it meets SAAMI specs.  An additional benefit of these gauges is that they visually show if your brass needs to be trimmed – however, a simple measurement with your calipers will show if your brass is longer than the recommended 2.050″

Velocities

Like choosing bullets and powders, you must not exceed a recommended velocity range when loading the M1A.  This velocity is relative the bullet weight being used.  168 grain projectiles should stay around 2,600 fps, and 155 grain bullets can be pushed a little beyond 2,700 fps.  Keep in mind, conventional loading wisdom shouldn’t go out the window – always use manuals, and work up from the minimums to find your best groupings.

I will update this pages with my velocities and groupings in the near future, but as you can see by the above picture, 150 grain soft points moving at ~2,700 fps are sufficient for taking out the dangerous white tailed jack rabbit.

Conclusion

Reloading for the M1A is a little bit more complicated than loading for most other firearms.  However, once you understand these key principles, it’s pretty easy and it will allow you to keep your shooting costs down and enjoy one of the most fun rifles you can legally own.  Fantastic accuracy can be achieved by reloading, but my primary goal has been to make cheap, reliable ammo, that is “accurate enough” to have fun with.

Good luck, and feel free to comment with your own loads, observations, or questions.

-Scarbelly

*My experience with reloading is limited to the Springfield M1A – in fact, M1A is a trade name used only by Springfield Armory.  Fulton ArmoryLRB Arms and other producers of these rifles use the “M14″ nomenclature.

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