I know I have this in print somewhere but can never remember it so if one of you fine gentleman will post it I'll screenshot and save it.

Thanks,

Motor

I would not feel very safe adjusting loads in a Garand by ejection patterns.

Any of the standard Garand loads printed in known sources are going to be safer and better ( more accurate) than anything that is cooked up by watching where the brass lands.


Excuse me if I am reading between the lines of your post

If you are reading between the lines you couldn't be farther off the mark.

I only use Garand specific data but do notice a difference in ejection direction and know it's related to bolt speed.

I just wanted a quick reference so I would know which loads are producing faster or slower bolt speed which is in direct relationship to more or less port pressure.

Motor

If you're wanting to know to compare multiple M1 Garand specific loads that makes some sense. A load that barely cycles and a load that's at the limit of safe for the old girl are both GTG but ejection patterns are going to be very different. It's a sign/tale, I think that's all he and now I am interested in.

Changes in ejection pattern can be an indicator of the op rod spring wearing out.

Ok. I was forced to dig out my old article written by John R. Clark published in the March 1986 American Rifleman.

Faster bolt speed results in more forward ejection. As far forward as straight ahead (12 o'clock)

Slower bolt speed results in 2-3 o'clock ejection.

The funny thing is the heavier ball ammo and his 180gr Match loads actually produced slower bolt speed than 150gr ball and Match loads using 150 to 168gr bullets.

And yes he did mention that a strong or weak spring can alter ejection patterns which is good to know if you notice that your favorite load is now dropping the brass somewhere different.

So to sum it up.

Fast is forward. Slower to the right.

Motor

Not to mention, ... another variable that can be added is to replace the GI gas plug with a Schuster Mfg adjustable plug, which allows you to tune your M1s gas system to the ammo by turning the screw inside the plug 'out' or 'in' (i.e., more gas v. less gas).  That, too, will alter whether the ejected brass will land forward (12:00-1:00 o'clock), or to the side (3:00-4:00 o'clock).

Lots of variables, I would not judge any load by ejection pattern.

There's no doubt that the same load used in 2 different rifles can have different ejection patterns because of all the variables mentioned.

When you are working with one rifle it's seems like it could be useful to know or even make notes of since it does have a lot to do with spring conditions and other stuff.

I've seen a lot of good press on the after market gas plug and would like to fully understand it's entire operation and limitations but we're completely satisfied using Garand specific load data and our hand loads.

For you guys that use the after market gas plug. If it's adjustable what are your points of reference for adjustment?  Do you simply close it so the rifle doesn't function then open it just far enough so that it does?

Then what happens when you switch ammo? Do you have to do it again?

Motor

Yes, ... and you're looking for a solid 1:30-200 ejection of the spent brass.

Yes, ... not to mention that adjusting the internal screw inside the plug will alter POI.  So, assuming you're zero-ed for 200yds, and you turn that screw   -  even using the same ammo  - expect that you'll need to re-zero it.  Obviously, if you switch to different  ammo (say, another brand of factory "M1-safe" ammo), you'll still need to check and vet the POI,  or re-zero it.

Understand that adjustable plugs (I use the ones from Schuster Mfg) are intended to allow you to safely shoot ANY power-level of '06 ammo (like 180gn "hunting" ammo) without damaging the gas system or the op rod.