Day at the range. Should have listened to my instinct and stayed home Part 3

[imschur]

Part III - Rifles

CMMG Sierra - After the dismal time with the handguns I decided I would start at the 50 yard rifle range with my CMMG Sierra. This was a mixed start. I found out the combination of my Sporter lower with the CMMG Sierra I could not use the gray CMMG mags. They got stuck in the lower and were difficult to remove. The Black Dogs fit and functioned flawlessly. This was the first out with the MagPul GEN 2 MBUS on the Sierra. At 50 yards I could not get enough adjustment. I had to aim at the target frame to hit the target 2 feet down on the frame. After a few rounds I adjusted the sights so that when I aimed at the intersection of two boards I could hit the bullseye. Dialed in my shooting while odd was stellar. I was pummeling the corner diamond on one of those high visibility sight in targets. I can't speak highly enough of the Sierra. Not a single malfunction of any sort with the Federal bulk. Not sure what to do about the sights.

As a side note I once again forgot to try the 50 round drum or that heavy-duty magazine.

AR-15 Upper - I swapped out the Sierra for an unfired tricked out AR-15 upper. This thing is sweet. It has a 16" WOA match barrel, Larue FFHG, Troy Battle Sights, EOTech 557 AR223, Young match BCG and a GG&G bipod. In the surprise of the day the EOTECH was nearly dead on. I was floored. I was having such a good time I forgot I wanted to get the battle sights aligned.

Bushmaster ORC Carbon 15 - Mario's Bushmaster performed flawlessly. He has one of the Millet DMS scopes mounted. It's a great scope for the right money in the correct application. I know Im repeating myself but Millet has a winner with that optic.

FN FS2000 - Mario was chomping at the bit to shoot the "Halo Gun". Unfortunately while he enjoyed the rifle he had a lot of cycling issues. It was either his CProducts magazines, technique or a combination of both. He had a lot of misfeeds and jams. I did notice he was resting the rifle on the magazine. I use  the same brand magazines issue. When I shot the gun with the FN mags it functioned perfectly. The only issue I had was a floor plate kept falling off. First time I ever experienced that. The FS2000 is a blast to shoot. I had hoped to mount an Aimpoint CompM2 on the rifle and sight it in but that never happened as time was winding down and I still had one more rifle to go.

DPMS LR-308/SASS/SI Defense - I was saving the best for last. I had an unfired 308 AR  upper I built over the winter that needed function tested and a scope sighted in. I decided this rifle would be the home of a wonderful Leupold Microgunner helped me purchase a while back. Rather than use the new ammunition I bought for the trip I grabbed the bag of mystery 308 ammunition that I mentioned in my first post put one round in one PMAG and loaded a second to capacity. I lubed to receiver and the BCG, cycled the action many times and loaded the magazine with the single round. The rifle was previously bore sighted so I figured I would be on paper. Anyhow I got on target and squeezed the trigger. Click, no boom. I thought did I grab an empty magazine by accident? No there was only the two PMAGs. Well crap a dud. I go to cycle the action to clear the chamber only to find that the BCG is stuck. It appears that the bolt never completely locked and is now stuck. Insult to injury the bag of ammo that i thought I knew the origins of seems to be a hodge podge of military surplus that is unknown to me. I am so angry at myself and this day at this point.

now we are out of time and the range office would not let me perform the mortar technique to clear the weapon so here it sits with a live round in the chamber.

As a side note this also probably vindicates the CETME which would function on this ammunition.

[Microgunner]

  I found out the combination of my Sporter lower with the CMMG Sierra I could not use the gray CMMG mags. They got stuck in the lower and were difficult to remove.

 

On the back of the CMMG mags, near the top are two tabs that must be filed to fit your particular lower. This is to ensure a rattle free fit with any rifle.

The plastic is soft and very easy to file so go a little at a time. 

[imschur]

Thanks!! I think I got this from Madhouse when I bought his Spikes .22 conversion unit. First time using it.

[Microgunner]

  Well crap a dud. I go to cycle the action to clear the chamber only to find that the BCG is stuck. It appears that the bolt never completely locked and is now stuck.

 

Sounds like a head space issue.

[imschur]

I'm a stickler for checking headspace in 308's even though it's a pain in the butt. This was verified by me. I have seen a few other cases at the 308 site that appear to be out of spec ammo. Im hoping this is the case. There were also a few issues with bolts themselves getting stuck. Highly unlikely here. I see something odd looking at the bolt lugs through the mag well. It almost looks like there is something foreign in there.

Any time you build from DPMS parts you have to pay extra special attention to everything.

[asmurff]

I've found I have to keep a notebook in my range bag to write down what I plan to do on a given day at the range and leave it open where I can see it. Otherwise I start having fun shooting and forget the details I have handle.

I know shooting should always be fun, but there are those days. Like you I prefer to shoot alone, except during our matches. Otherwise I get distracted or with my wife and step-daughter feel rushed.

[imschur]

Well I have two problems with the 308. The bolt is very difficult to rotate so Im going to disassemble the bcg and examine the bolt and rings.

The ammo is also still suspect.

[Microgunner]

  This was the first out with the MagPul GEN 2 MBUS on the Sierra. At 50 yards I could not get enough adjustment. I had to aim at the target frame to hit the target 2 feet down on the frame. 

Drew, I hate the really crappy Ncstar folding sights I bought for my new CMMG upper and was thinking of these MBUS as a replacement.

Would you recommend them, knowing that if they don't work out for me it'll be no big loss?

They look SO much better than the Ncstars.

[imschur]

How about I send you mine to try. You see if you can get on paper without a new or modified front site post. In general I think these are an awesome value for any AR.

[Microgunner]

Cool, PM sent.