I already own a DPMS LR-308T rifle.

I want to shoot that rifle from prone position, using a service-rifle type sling.

The existing handguard on the LR-308T might be strong enough. But the sling swivel mount is a joke. Just a stud, threaded into the aluminum handguard. Any amount of sling-tension, and I'm sure I'd rip that stud right out of the handguard, leaving me with a broken gun and wasted range trip. I'm getting too old to waste my time that way.

I've considered attempting to reinforce the sling-mount position on the LR-308T handguard. But, it looks like the only way to do it right (or at least do it without feeling like I'm building a ship inside a bottle) is to disassemble the upper, so I can get full access to the inside of the handguard. I'm concerned that if I start wrestling that upper apart, I may open a can of worms I don't want to eat.

I won't say "money isn't an issue." Money is always an issue. But, the ~$550 for complete Aero upper isn't going to cause me to miss a mortgage payment. Also, I might recoup some of it if the Aero upper turns out to be perfect for my application, and I can sell the then-un-needed LR-308T upper.

So, I think I'll just replace the LR-308T upper with an Aero Precision upper.
I'm looking at this web page: https://www.aeroprecisionusa.com/m5e1-308-20in-cmv-complete-upper

Here are a few questions I have.

1. Is the Aero Precision upper going to mate right up with my DPMS lower?

2. Is the Aero Precision upper going to mate right up with my DPMS (Generation 1) .308 bolt and carrier?

3. Aero Precision requires that the buyer select Keymod vs. M-Lok on the handguard choice. Is there any rhyme or reason for selecting one over the other? Remember, my sole criteria is that the thing has to be STRONG ENOUGH to withstand the sort of sling-tension that gets applied when shooting prone, with a service-rifle sling.

4. I'm considering attaching a pushbutton-release sling swivel at 6 o'clock on the Aero Precision handguard. Is there any particular model of pushbutton swivel that is to be avoided, or any particular model that has a reputation for being undoubtedly the best choice?

FYI, here is a pic of the weak-link swivel on the existing handguard.

Bartocci says Aero is good to go.  So I assume they are good to go.  That is all.

I think it's hit or miss on whether the Aero M5 upper will mate with the DPMS LR-308 lower.  The probable issue is the radius of the curvature at the receiver extension (buffer tube) mount.  The curve at the back end of the Aero upper might not mate with the DPMS lower.  you might have to find somebody that has an Aero M5 and try it out.  or spend the $130-or-so to buy a stripped Aero M5 upper to find out first-hand.  After all, if it does fit, you might end up building more uppers to go with your DPMS LR308 lower.

re-using your old bolt with new barrel:  you should be good to go with your DPMS BCG, although you'll need to check the headspace of your old DPMS BCG with your new Aero upper.  Typically folks consider the bolt to be mated to the barrel.  your call.

KM vs M-LOK:  popular trend nowadays is towards M-LOK, everybody's citing some Naval Surface Warfare Center powerpoint briefing slides which indicate that M-LOK is stronger, although I suspect both systems exceed the requirement of your situation.

pushbutton swivel to be avoided: anything of Chinesium.

Just got this reply via the "chat" on the Aero site.

Aero upper and DPMS lower should work fine. May look wonky, with certain *cosmetic*  features not lining up right, but the pins and stuff will line up fine. Bolt will work fine. Keymod vs M-lok is just buyers choice, but the guy above is right when he says industry is moving towards M-Lok. Any non chinesium sling stud should work fine.

Just get a better handguard.

Or better yet, put a washer and nut on the screw and be done with it. Slightly possible you can pull just the screw out of threaded aluminum, but next to impossible to pull it out with a nut and washer on the back end.

Then you can get more ammo. Instead of an upper.

You have tons of options when it comes to rails for your upper. I hope youre not indecisive. You have a pretty good upper, with a rather good barrel, if its factory. Aero certainly wont be any better.

They copied the LR308 and made it just different enough to use their parts. Started the whole M5 deal to use other peoples parts, then found out none of it worked right, and now we have that disclaimer.

I wonder what they say when you use all Aero and BA parts and it still runs like shit?

Thanks for the replies.

I think I'll give the Harris bipod adapter/flange a try before I go crazy buying other stuff.

Hopefully, I can snake the backing plate in there and get it to seat without stripping/cracking/breaking something.

$10 on Amazon https://www.amazon.com/gp/product/B0007OGT40/ref=od_aui_detailpages00?ie=UTF8&psc=1

Hey, Dr. Gary!  Long time, no see.  Hope everything is well in FAL land!
Best,
JBR

Right on man.

Aero Precision's Enhanced lower receiver does make for a heavy duty handguard mount with the 8 screws and the three way sling mounts is another plus.

Hey, Gary, another long-time-no-see reply from the ‘Files.

Just an FYI, if you do end up wrenching off that handguard, note that it’s a two-piece unit.  The barrel nut portion is relatively short, perhaps 1.5”-ish, and that’s what the remainder of the handguard threads onto.   The joint on mine was so imperceptible that I was surprised to find out it was a two piece.  Home Depot heavy duty strap wrench for the win.

Handguard won’t unscrew without removing the gas block. Almost zero clearance between handguard and gas block.

I test-fired it today with the UBR butt. Function was A-OK.

But, lord-jeezuz accuracy with the Santa Barbara surplus ammo was horrendous! About 4 MOA. I was able to fire it prone with the service rifle sling. Trigger is already swapped out to a Rock River two stage.

Last time I tested accuracy with this rifle I shot a small knot with M-852 match ammo, and different scope, different buttstock,  and from benchrest support. I’m going to try to get back to the range day after tomorrow with some better ammo. Hoping the current configuration just hates Santa Barbara.

Surplus ammo =/= match ammo.  throw some FGMM downrange or black hills.

41 years old.

Good suggestion.

I've got plenty of match ammo. I just didn't bring any to the range today. Really didn't think the Santa Barbara would be THAT bad.

At least I accomplished the primary objective today, which was to be sure the thing functioned with the new buffer and buffer tube, and get a rough zero for the Larue/Leupold scope combo.

I'll shoot it off my belly with the sling again next time. Using Sierra 168 SMK and 41.5 grains IMR 4895. Should be fine.

Tweaking the milsurp ammo might be something to consider. But, I'm getting old. Not so much time left to tweak substandard stuff in the hopes of bringing it up from suck to mediocre. I can always use the milsurp stuff to shoot soup cans on the pistol range with a FAL. I still do that once in a while.

Hey WEG-

I've got an Aero Precision M5E1 upper that I am in the process of assembling and we try to see if it will fit your lower.  It is in 6.5 Creedmore though.  but at least we can see if it fits and try to shoot with your lower.  I also have a Armalite AR-10B in 308 but that's not likely going to work in your DPMS.  I'm local to you so we can setup a time to give it a try at your range or mine.

Went to the range today.

Mystified with weird groups for about two hours.

Then discovered scope mount was loose.

Duhhhhhhh...

I hate making tyro mistakes.

Ran out of light, but last four shots were in the X-ring of the SR target (200 yards).
There may be hope yet.

BMWguy, much obliged your offer.
I’m a range bum at Fairfax Rod and Gun Club.
Message me when you’d like to burn some ammo and watch me do simple-minded stuff at the range.

I think this adds some strength.

“Acorn” nut from swivel set.

So, you epoxied a nut to the screw?

That'll definitely help. Its still unlikely youd pull it out, unless you gorilla the fuck out of it.

Blue Loctite

Today

168 SMK / 41.5 gr. IMR4895

200 yards

10 shots

Rifle laid over rolled-up coat on top of ammo can.

Now that I feel like the swivel stud won’t rip out of the handguard, I’m looking forward to shooting from
Sling-supported position next outing.

The accuracy element seems to be solid now.

The Santa Barbara wasn’t as bad as I feared, but still not likely to be useful for anything more than very casual trigger time.