I have heard of few M14's oprods being damaged by using heavy bullets. Like 180GR and heavier for extended periods of time.
My M25 is about ready for a new barrel. The throat is far-far out there...... it's still MOA at 900 (barely), so I'm not changing it out yet. I doubt it will go another full year though. I'd like to go ahead and change out the barrel now -in the off season- but Barnett turned Kreigers are a touch expensive, and I've got other stuff that needs to happen before it's too late.
The ONLY bullets that have been down the tube are 175 SMKs and 178 AMAXes. Just a few hundred of the AMAXes 'cause I couldn't get them to shoot at a decent velocity for me, regardless of the powder I tried. The 175 SMKs though, they were all Good To Go, 8 fps standard deviation on 2685 fps.
Why did I feel the need for that velocity? Simple - to match the bullet drop compensator on my scope. If you've got a Leupold Mark 4 M3, that would be the 30-06 dial designed around the 180 grainer. Where I'm at, that's the velocity that tracks the dial like the pill rode on rails. Dial 1, hit at 100 precisely - dial 10, hit at 1K, beautifully.
Anyone should understand that 2685 fps is a "pretty warm" load for a 175 grainer. Just as a note, that's with a touch over 45 grains of Varget in a Lapua casing, COAL at 2.820" to keep 'em feeding from the mag. Velocities and stats come from my old Oehler 35.
I ran the first sniper course with this rifle, essentially that load, and the M308 dial - designed around the 168 SMK doing between 2600 and 2650, depending on where you're at. I found out just how much flatter the 175 flew, once past 500 yards, and "went up a notch". That's where the rifle has run the last several thousand rounds, and that's exactly what I did the advanced sniper course with.
I'm not saying that someone hasn't bent an oprod, but if he did, he's running some mighty stiff charges. Nothing SAAMI spec. My stick has seen several thousand (my log shows over 6K now) rounds of fast 175s. And I'm not concerned in the least, 'cause my gunsmith's load is much more abusive than mine. He's run several barrels with his load.
Not that I don't have an FAL - and mine isn't for sale. This one (my current FAL) was built up on a Dan Coonan, using selected choice bits. Got it done the way I wanted it.
Back when the developed Belgian FAL was put up against the M14 that was being developed at the time (the T44/T48 tests), the weaknesses of both designs were found. ALL designs have a weakness. ALL designs have their strengths. Pick your poison, and drive on. Weaknesses are fine, if you know they're there and can work around them. Pick the rifle that plays to your personal strengths - that's optimizing performance both the operator and the stick.
For 99.947% of what I would / could / do / have used a rifle for (excluding precision shooting competitions - including practical rifle competitions), the FAL and the M14 are interchangeable. In the end, it's all about operators, not designs. It's about skills, not calibers. I'd feel fine with either one - because I've used 'em enough to know what they'll take and what they won't. Confidence - derived from DOING, not READING - is worth the price of admission by itself.
"Amateurs talk hardware. Professionals talk software. It doesn't matter what's in your hand or between your legs. It matters what's in your heart and in your head." - Lt. Col. Dave Grossman