The difficulty is that the guys buying poly lowers were - aside from the bucks ups experimenters - largely doing so on price. Then forged lowers were 2-3 times the price of poly. Now you can get Anderson blems for $39.99 and there are plenty of reports from happy owners they mostly work fine.
Unlike poly owners who, altho not legion, seem to have issues they report. And being they were strapped for cash, could also shoot a lot less because of it. So it may take a long time to get 50,000 round feedback on them.
Not to mention how many were used on .22 builds, which only leaves the handling and banging around in storage as an example.
Aside from the price point difference, which is now small, there are other questions we all have.
Can you get your loaded out teammate to stand on one used in a battle rifle and lift him into a high first story window? That is a tactic and spec for the M16/M4.
Will the poly lower handle bayonet and CQB training and use? Buttstroke impacts or being driven as hard as possible into a tire rubber target while being pushed with the grip hand? Downward slash or impact with a CQB muzzle device? Another tactic and spec for forged lowers.
There is some video of them getting squeezed in a vise, etc, got to say, use it as a ladder rung, impact device, and then store it in a 140 degree car in August for 6 hours, load and fire.
You can do some of that with a Glock, yes, same as the Remington Nylon 66 that was famously advertised as the Inuit's seal dispatching gun hunting out of kayaks up north. The real issue is that shooters are extremely conservative and aren't willing to take any chance at all, ever, so it's going to be a high hurdle to jump over to get their acceptance. It took Glock generations of guns and at least 25 years.
There is an up and coming "80%" lower in the market, one cut from light plate and bolted together, or extruded parts. Poly is going to have to compete with them, too. Plus poly has the difficulty of being accused of not having it's own design elements - but when Omni goes "billet" and Tennessee Arrms "milspec" in looks, you lose the other customer. The metal reinforcements seem to help, but - still no side by side load out tests of what soldiers have been doing to forged all these years.
Like, mortaring stuck rounds. I'd like to see side by side tests to destruction. We don't actually abuse our guns that much, but if poly can keep up, it would be a huge selling point. How much side loading will they withstand? Can they be impact mortared as much as forged? How many bayonet thrusts in their service life? Can you prop it up at a 45 degree angle and repeatedly drop 85 pound loaded rucksacks on it from 6 feet up? Drop to the ground with it butt first and use it in leverage to cushion your fall in the three second rush? Repeatedly, for a 20 year service life?
Be nice to see some of these go thru about ten cycles of Basic Training and give us the report. I wouldn't expect "operator" level acceptance from that test, but it would be a significant landmark to accomplish.
Nobody said the SCAR had any issues in that regard - begs the question, tho. Was there a known issue, however small, or was it just the same as the forged lower? FN sure isn't saying, and I very much expect a non-disclosure agreement was part of the arrangement. Taking no news is good news, tho - there were no leaks or complaints I've heard of - it stands as a testimony to the poly lower being just as good for less expense.
We just haven't found which AR poly lower does that yet. Too early to tell, too many go under too soon. Even Cav Arms didn't make it - and their product seemed to be that lower (if you like a permanent fixed stock.)
