Last Sunday I took the local intermediate carbine class again using my STG w/the E4 optics rail & Eotech 517, here's a link to the first report: http://www.ar15.com/forums/topic.html?b=6&f=43&t=281115
STG was cleaned & lubed & I used my "go-to" 42rd mags loaded w/Prvi Partizan M193 (these mags have been fully loaded for over a year).
The dust is *very* fine as evidenced by the pic of my FN57 taken after the course and with all the unconventional positions that dust got into *everything*! (And the FN57 performed perfectly during transitions despite the dust/dirt).
The STG performed flawlessly for the appx 420rds fired that afternoon except for a single stuck casing (the first stuck brass casing I've experienced w/the STG's). The mags fed & locked back perfectly even after having been stored loaded for so long.
Everyone who handled the STG commented on how fast/easy it handled & the lack of perceived recoil.
The bottom quadrant tick in the Eotech's circle/dot reticle was perfect for making close-in shots when POI is still below POA.
The moving target (carboard box w/teeshirt suspended by a balloon inside the box) was lots of fun & with the Eotech I was making the "heart" (balloon) shots fast & easy to the point where they deliberately started making *my* balloons smallers!
Especially funny was the balloon that was so small that the box fell off the balloon before I could make a shot but I persevered and still shot the moving/bobbling "heart" anyway.
I managed to finish all the drills despite the 90+F heat and consumed over 8x20oz bottles of water in 5 hrs but at the end of the day you could have knocked me over w/a feather (it sux getting old! ).
Had a great time, it helped me remember some of the things I'd nearly forgotten from the first time I took the class and the gear changes I'd made since the first class worked *much* better this time around.
My best friend and I plan on taking this class again next year when he visits.
Tomac
Inverted prone:

Transition shots taken w/primary still extended:

Firing while changing positions from on your back to sitting up to kneeling to standing:

One of the gear changes: Skiddy's "patch" for the Eagle Chest Rig to prevent strap movement, works great!:

FN57 after the class:

nicely done!

Another great post.  The class sounds great and it's always nice to see the MSAR platform put to the test.   Thanks for the info.

Would polishing the chamber alleviate the stuck cases?

Unknown. This is the first stuck brass casing I've experienced w/the STG. I still get the occasional stuck casing when using steel-cased ammo (that's normal w/many rifles) but a broken-in STG can go hundreds of rds of steel-cased w/o problems (during the first carbine class last June, my best friend and I put nearly 2K rds of Brown Bear 55gr through our two STG's w/his going 100% and mine going nearly 100% experiencing a few stuck casings at the very end of the last day).
Tomac

mmmmm field worn five-seven

very nice!

Might be worth a shot. I was experiencing occasional stuck casings in my PS90 shooting reloads until I got in there with some polishing compound and now it's 100% with anything I run in it. (NOTE: It already ran 100% with factory ammo)

Nice to see some folks on ARF.com who actually take their weapons out of the safe and get them dirty.  Bravo!  

right on Tom! Was there any offand shooting in the class? Im wanting to use my STG for a practical shooting competition that will include some offhand shooting which scares me a bit with the stg

Thx! Do you mean support-side shooting? DefTac doesn't teach that as they believe (and I agree) that unless you practice a heck of a lot the loss of speed, accuracy & familiarity more than offsets the increased exposure.
However, they demonstrated that w/the STG you can do support-side shooting w/o getting a face full of brass by rotating the STG clockwise when it's on your left shoulder so the brass angles away from your face. For the extreme competition crowd the 10:30 rail position on the E4 might be the perfect place for an Aimpoint Micro when shooting from the support side.
When shooting from rollover support-side prone you push the STG away from you until there's tension on the sling, the tension provides a measure of stability and the rifle is far enough away that the brass doesn't goes over your head.
Tomac

You can rotate as Tom mentioned, or just put your hand against the stock behind the ejection port.  Just having the heel of my hand there deflects the brass away nicely, and I can do it without gloves.  I'll have someone take a pic of me doing it.

In fact, it takes so little to deflect the brass, I'm thinking of just velcro'ing a piece of plastic there to see how it does.