First time out with sport & BCM upper receiver question

ls2gto · #1 04-02-2012, 06:39 AM

Finally picking my sport up from jail on Tuesday (eotech 512 waiting to be mounted

) and I'd like to know how the rifle will be when it's brand new. Is it bone dry? What do I need to clean/lube (just the barrel or do I completely need to field strip the BCG, trigger, etc)

Also, I'm looking into a BCM upper when they get them back in stock (since they're relatively inexpensive, and the sport model upper looks a bit thin with a square Eotech on top). I've heard they match the M&P15 quite well. However, the parkerizing looks different on the "stripped" model vs. the assembled model:

Upper Receiver Assembly - M4 Flat Top

vs

Upper Receiver Assembly - M4 Flat Top

Are these both the same minus the assembly/stripped? They looked different, almost as bluing and parkerizing looks different (slight shine vs. matte). Is it just the way these pictures were taken? I'd hate to pick up one and realize that it doesn't match at all when it arrives in the mail.

Thanks!

oneyeopn · #2 04-02-2012, 08:13 AM

I dont get any pictures of anything...I get the pages but no pictures.

Breechloader · #3 04-02-2012, 09:23 AM

In the reviews for the fully assembled one, someone wrote:
"The receiver has a flawless finish and machining. It's very dark mil spec phosphate unlike in the picture where it's oiled down."

My m&p15 was not bone dry when new. I did add a drop of oil to the bolt area. The took the magazine out so the bolt wouldnt try to lock open and pulled the bolt all the way back and then forward.
I have done the back and forth with the bolt about 1000 times now and it moves much smoother and easier now.

oneyeopn · #4 04-02-2012, 11:19 AM

Define "thin with the Eotech mounted" I am trying to understand. Is it without the Forward Assist the receiver is thinner. I believe but am not sure but I am pretty sure the rails and the top of the receivers are the same thickness, no it doesnt have the hump of the F/A but it does have the hump of the brass deflector. Or does the Eotech just have a wide bottom or what? Also it has been a long time but I dont remember my M16 having the big ol brass deflector sticking out on the side. Is that something that they came up with later?

Splittiebus66 · #5 04-02-2012, 11:49 AM

I've done the receiver swap on my sport using an FN Hernstal contract over run upper. I'm pretty sure these are the same ones or very similar ones BCM are selling off their site. The one I bought is a bit more "grayish" looking in terms of the anodization but the match is close. Mine fits just as well as the original....nice and tight without alot of slop. Also a small note the T markings are painted not laser etched like the Sport upper. I'll post some pics soon, I have to get a new digital camera....mine took a ****

As for the original upper receiver I have a feeling its gonna start sprouting more parts soon, I'm gonna build something real light with maybe a longer SS barrel. We'll see

Splittiebus66 · #6 04-02-2012, 11:54 AM

Quote:

Originally Posted by oneyeopn

Define "thin with the Eotech mounted" I am trying to understand. Is it without the Forward Assist the receiver is thinner. I believe but am not sure but I am pretty sure the rails and the top of the receivers are the same thickness, no it doesnt have the hump of the F/A but it does have the hump of the brass deflector. Or does the Eotech just have a wide bottom or what? Also it has been a long time but I dont remember my M16 having the big ol brass deflector sticking out on the side. Is that something that they came up with later?

I think the brass deflector and F/A appeared 1st on the M16A1 but I could be wrong ( GOOGLE ME LOL). The original m16 was slick and had only the ejection port cover.

As for the rail on the sport its standard 1913 Pickkkkkk-a-tiiiinnny

oneyeopn · #7 04-02-2012, 11:58 AM

Quote:

Originally Posted by Splittiebus66

I think the brass deflector and F/A appeared 1st on the M16A1 but I could be wrong ( GOOGLE ME LOL). The original m16 was slick and had only the ejection port cover.

As for the rail on the sport its standard 1913 Pickkkkkk-a-tiiiinnny

I Bing searched and the brass deflector didn't come into existence until the 80's and I was already out. Some little whiny person was unhappy cause that mean brass kept coming back toward them and causing them to not be able to shoot right. I think when I build my rifle I am going to get a true slick-sided receiver cause I don't like the brass deflector either

Isnt that what happens when you split up the parts, new parts start appearing? LOL

Splittiebus66 · #8 04-02-2012, 01:05 PM

Quote:

Originally Posted by oneyeopn

. Some little whiny person was unhappy cause that mean brass kept coming back toward them and causing them to not be able to shoot right. I think when I build my rifle I am going to get a true slick-sided receiver cause I don't like the brass deflector either

Isnt that what happens when you split up the parts, new parts start appearing? LOL

It was for left handed shooters or shooting and transistioning to weak side. Catching brass in the face is not fun

Splittiebus66 · #9 04-02-2012, 01:11 PM

Ok it was the M16A2 with the brass deflector. I saw this pic a few days ago on " another site" from a recent hostage standoff......check the guy on the right with the A1

SSgt M · #10 04-02-2012, 02:39 PM

My neighbor, retired armor from Vietnam era, stated his first shipment were smooth like the DPMS sporticle with a black bolt, then the Army wanted a chrome bolt, this us when the rifle sucked, jammed all the time etc. soon the went back to the black bolt he called it. Years later they would show up with only a FA, then a DC, brass deflector, he said at some point they switched them all and have remained to what we have today, but then came the M-4 !