M14 M1a QUESTION

HI, I am getting an older m14 or m1a and I have been told there is a pressure curve. Can anyone please inform me about loading and misc. anything else I have to know?

 

4895 powder would be my choice to start. Sierra info- https://www.sierrabullets.com/reload-basics/reloading-for-semi-autos-and-service-rifles/

 

I have a 90's vintage m1a. I load to M80 and M118 Ball standards per the TM-0001-27. Chamber pressure at 50K psi and velocity at 2700 fps.
IMR4895 and 3031work well with 150gr to 168gr projectiles.
I also installed a ported gas plug.

 

Use 150 or 168 grain bullets and powder from the middle of the list in the loading books. IMR 3031, 4895 up to 4064. The tougher brass works better. IMI, LC or other military headstamps hold up better.

 

There is a LOT more to loading successfully in the M1a, you will need to do some reading on it. A search here will bring some good threads up for you.

To answer the question about the pressure in the M1a... everyone here pretty much hit it... IMR or H 4895 is the standard with 150-168grn bullets, IMR4064 with the 168-175grn bullets; you can typically substitute similar powders within that burn rate window. As was also mentioned, both Hodgdon and Hornady have 'service rifle data' that covers the greatest hits for reloading the M1a. Some complain that the loads are 'watered down,' but they are reasonable loads unless you are shooting past 600yds.

 

One caveat do not use store bought 308 for all your shooting the pressure is usually higher than what is standard in a M1A loading.

 

I heard somewhere that the gas system was self regulating in an m14/m1a. It sounds like that is not true.

 

Check the head-space. Some military rifles have been shot a lot, which which wears the bolt lugs.
A load that loads and ejects, and goes into 1 MOA. is satisfactory.
Use lithium grease on the bolt and the operating rod and spring.

 

I don't necessarily agree with that, that would include all M80 surplus and it's equivalents. What I would avoid would be specialty ammos, like Hornady's Superformance, etc, and heavy for cartridge bullet loads; those would likely use slower powders than what would be appropriate for the M1a's action.

The military has never sold M14 rifles as surplus or otherwise. Under the BATFE's 'once a machine gun, always a machine gun' directive, an M14 cannot be modified to become a 'semi-auto,' and thus be sold as surplus. In reality it is quite easy, but that is not the Government Way. FWIW, I would have any older M1a checked for headspace, and have the bolt inspected for wear or damage.

 

Indeed.

There are a few places in the world where you can get an M14... but America, with very rare exception, ain't one of them. Very sad, indeed.

 

Download, read, and file the counsel below:
http://www.m14.ca/reloading/14_loading.pdf
It will address nearly all issues ... that really aren't all that hair-pulling.*






* But don't let anyone know.
We need to maintain the mystique.

 

It is true. There are three gas ports -- the barrel, the gas cylinder, and the piston. When the system is at rest, the three ports are aligned.

On firing, gas vents to the inside of the piston and is it expands the piston moves backward, moving its port out of alignment with the cylinder port and shutting off the gas flow. With high pressure, it moves fast and quickly shuts off the flow. With less pressure it moves more slowly and allows more gas to enter the cylinder.

 

The issue with the M14 specifically is... there are so very few of them to start with.

I got to do the full-auto thing when I was in the Army... it's fun when you are burning someone else's ammos, and particularly the M2 .50cal! ...but it's a poor means to an end in most cases if you are looking for accurate fire.

I thought Knob Creek was done with shoots?

 

I'd buy a copy of Kulek and McKee's "The M14 Complete Assembly Guide", a very comprehensive manual on the care and feeding of the M14/M1A.

The "pressure curve" you speak of, has to do with the deflagration rates of acceptable powders for use in the ammunition. The oprod is designed for a relatively short "kick" as gas pressure peaks and then rolls off, and inertia finishes the cycling of the action. Too long a kick becomes a constant "push", which keeps pressure on the oprod into the max bolt opening. The pressure can bend the oprod at the least, and at the worst can blow the bolt backwards out of its track. Someone mentioned loading by the Hornady data on the .308 service rifle; good advice. I've loaded my M1A Loaded model for 9 years by this data, and the rifle runs without incident, and accurately as well.

I agree, and I use Wilson case gauges for the same purpose.

If you use NATO cases, the case walls are a little thicker, so case volume is less than a standard .308 case. keep this in mind, as the same powder load in the .308 case will create greater pressure in the NATO case. I use Lake City once-fired NATO brass exclusively in my rifle, and stay with 168 grain bullets, either Hornady AMAX or ELD bullets, or Sierra Match King. I also only use H4895 or IMR 4895 powder, and Winchester Large Rifle primers.

The M1A is a nice rifle for bench rest shooting; it's a heavy beast, so if you do CMP shooting from sitting, standing or prone positions, beef up your arms a bit, and get a good GI leather sling for it. With eagle's eyes, or a scope, it's good out past 800 yards