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Mine land 4 feet away at 14:00...consistently.

I also fanatically clean and lube my M1A.
 

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cockednlockeed - op rod velocity is determined by the amount of gas fed into the system and whatever resistance may be encountered. A lot of things effect it's velocity. Making adjustments to the gas port is the last thing anyone should contemplate when trying to deal with this issue. Sometimes it is best to live with brass flying back over your shoulder. However, the guy next to you on the firing line may not appreciate your hot brass landing on his neck during a match. On our range, the brass going out at one or two o'clock ends up in the weeds (or a gopher hole) and can be hard to recover. On the range at 29 Palms USMCAGCTC they won't even allow anyone to go forward of the firing line to pick up brass. So ejection patterns can work either way.
 

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Mine was throwing brass at 1 o'clock, but as the afternoon progressed it ended up throwing it at 4 o'clock. Then I packed up and went home at 4:30.

Sorry, guys, couldn't resist. Mine throws it consistently between 3 and 4 o'clock, and they land just before hitting the shooting position to my right (about 4-5 feet). So, Ted, I suppose the velocity of the oprod isn't regulated by the strength of the load at all? I'm running the "usual", 41.5 of H4895 pushing a 168 AMAX or SMK. Is it a problem if the gun cycles at this rate?
My SAI SS used to push casings all over, no consistency with many of them forward. I reload so there is good consistency. I installed an adjustable gas block. I followed the directions and first adjusted down until cases did not cycle and remained in the chamber, then adjusted it up until the rifle consistently ejected and then adjusted it up and down until I achieved the tightest group.

Now, my cases do not hit the forward moving OpRod and eject at 3-4 o’clock. I wish that I would have paid attention to where the cases were ejecting as I increased gas pressure but did not. My guess is that the slower ejected casings get hit by the OpRod and consistently go forward. Slightly faster ejected cases get past the OpRod and go sideways. Again, Just my guess is that the fastest ones end up Getting ejected at a 5 o’clock angle, but because of that steep angle they can also intermittently engage the OpRod and end up all over the clock?

Incidentally, I don’t think the adjustable port did much for accuracy but I think the rifle is happier in terms of parts wear, etc?
 

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When your rifle is cycling fast, the oprod hits the cases to the 1-2 o'clock position. Chrome lined NATO chambers and full power ammunition will usually allow this.

When your rifle is cycling slow, the extractor and ejector will flip the cases to the 3-4 o'clock position, before the oprod returns forward to hit them. Tight, unlined Match chambers and anemic handloads can contribute to this. Sometimes the cases will tumble out the side, marring the stock and oprod arm.
 

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When your rifle is cycling fast, the oprod hits the cases to the 1-2 o'clock position. Chrome lined NATO chambers and full power ammunition will usually allow this.

When your rifle is cycling slow, the extractor and ejector will flip the cases to the 3-4 o'clock position, before the oprod returns forward to hit them. Tight, unlined Match chambers and anemic handloads can contribute to this. Sometimes the cases will tumble out the side, marring the stock and oprod arm.
i think we are saying the same thing, except my hand loads are not anemic, instead I have tuned my gas port down to a slower ejection to facilitate the side ejection and no contact to the OpRod. I wholeheartedly recommend the variable gas port sold at Fulton. Because of it I am able to operate at the higher but recommended charge/load development ranges, With increased velocity while mitigating pressures on the working parts of the gas system.

Before the adjustable gas port, I damaged an OpRod which required warranty replacement. There was some speculation (not by SAI) that there may have been a heat treatment issue with its original manufacture. The new one shows no sign of wear around the bolt roller. Is that because of the adjustable gas port or because the new OpRod was better heat treated? Don’t know the answer to that one.
 

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I use the Schuster ported and overbored (non-adjustable) gas plug in all my rifles. I only use full power 175gr match loads. My chrome lined USGI barrels knock the brass sharply to the 1-2 o'clock position, as designed. My match barrels have tighter chambers, the brass goes to the 2-3 o'clock position.
 

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I"m all of the above everything or whatever floats your boat guy....

#1. Most guy's have had pretty good success with just trimming a coil or two (max) off the ejector spring and giving that a whirl. Have a spare just in-case your not happy with the result. There cheap.

#2. Some have replaced there gas piston with the grooved type and have also been satisfied.

#3. Some have done both and have been super satisfied.

However being a tinker type guy I've also tried adjustable and overbored gas plugs, having tried both of them they just were not too my liking, cheifly there prone too carbon fouling. Now being a hard headed Irishman I took the long road. I've played the potty training game and I really love too burn AR shooters with hot .308 brass, its the saidist in me as I do take silent pleasure in doing it. So here is what I do, after I have done steps 1 and 2 from above.....

#1. I like too advance the gas cylinder as far forward too the F/H as I can. Just enough too keep the gas port fully exposed in the gas cylinder that's it. Sometimes the threads on the barrel for the G/C Lock can get a little short (not often) so flipping the G/C Lock over helps get you a little more thread contact, sometime not but when that happens I work with what I have and split the differance...

#2. Once that is established I unscrew the G/C plug enough so the bolt roller notch in the op-rod makes light contact against the bolt roller then I use stacked feeler gauges too measure this gap from the G/C plugs shoulder and G/C lock face, write this measurement down. We don't want bolt roller contact with the op-rod, because the bolt roller will eventually fail and snap off. I will then subtract .015 from the G/C gap figure measurement. This new figure/measurement, will get removed from the tail end of the piston. Now keeping a safe clearance between the bolt roller and op-rod. Where did the .015 measurement come from? I made it up as I feel it is a safe figure too keep the two parts from making contact with each other.

This is called building in dwell time, and the rifle doesn't unlock/cycle until it has too or should have from the very beginning. The M-rifles have about the fastest bolt speed of any semi-auto rifle. Being a military style rifle they really like too rip the fired case out more than likely before its completely blown down and still super hot and sling that spent case a country mile away. Slowing it down for even a few mil-secs doesn't hurt and If you reload your ammo, fired cases are easier to find and later size for the next firing.

I also run with a grooved piston for a few reasons but many poo-poo them claiming that they have inconstant operation with a verity of ammunition. I haven't had that experience with any of my rifles and I've loaded whimpy 125grns too heavy 185grns and everything in between and have also fired more than my share of mil-surp ammo never a issue, knock on wood. But YMMV.

#3. When I was digging threw my magical box-o-parts during my last rifle build I discovered a noticeably odd but shorter ejector. Being a cheap guy (frugal), waist not want not I slid it in as well. Too date, my rifle ejects too the 3 o`clock with just about every load I've run doesn't matter.
 
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Mine ejects gently at 1:00. I regulate the operation of my M1-A's using Schuster adjustable gas valves. The M1-A is a "chewer-upper" of casings. The chewing up is worse with high speed ejections. (case body dents, ejector dents in the bottom of the casing, etc.).
GregT
 
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