I'm trying to figure out who makes my upper. The only markings that I can find on it are an "FK" on the side of the upper by the rear site. On the front site located on the side of it is an A (then an R1 with a circle around it) followed by the number 1. On the other side of the front sight is the letter F.

Would there be more information under the forearm like stamped to the barrel?

http://imagecloset.com/8/03031018-100_0637%20(Small).JPG
http://imagecloset.com/8/03331018-100_0632%20(Small).JPG
http://imagecloset.com/8/03141018-100_0634%20(Small).JPG
http://imagecloset.com/8/03341018-100_0643%20(Small).JPG
http://imagecloset.com/8/03151018-100_0642%20(Small).JPG
http://imagecloset.com/8/03161018-100_0638%20(Small).JPG

Believe ya got a Bushmaster upper there, w/ a forged FSB.

Mike

Are there any markings on the barrel itself, stamped into it in front of the front sight base?  The markings on the upper itself aren't really going to help as they would only indicate where the forging came from and not who machined/finished/assembled it.  

Sounds like a FN / Kaiser receiver... If the FSB is stamped "F" on the left side that would indicate a mil-spec FSB... It could be a FN or COLT barrel... Is there anything stamped onto the barrel, on the top, right before the muzzle? What profile barrel is it?

Thanks for the comments.  I don't find any markings on the barrel itself.  I looked at the barrel in front of the front sight on top and don't see anything.  Would there be any markings on the barrel underneath the forearm grip?

If it is an FN/Kaiser is that a so so brand or how does it compare with the others?  Is the forged FSB just the barrel and is that a good or bad brand?

Sorry about all my ignorant comments.  I just started to get into the AR scene and my learning curve is very large.

I know that RRA stamps their barrels under the hand guards... What profile is the barrel? Is it heavy, medium, light, M4 or government?

Do you have any pictures... Its starting to sound like its a frankenstein upper...

Is the front sight base (FSB) stamped on the left side (opposite side that the brass is ejected from) with the letter "F" ?

I'll try to get a picture of it tomorrow.  Hopefully that will help.

Stamping                                                   Source  
CAF                                                                     Colt / Alcoa Forge (See above for photo)
CH                                                                       Colt / Harvey Aluminum (1st Colt Forgings)
CM                                                                       Colt / Martin Marietta (See above for photos)
DK                                                                        Diemaco / Kaiser
FK, FS, BK, DK, EK, FK, AF, CW, AA, FS    Bushmaster
LK                                                                         FN / Kaiser
LM                                                                         LAR / Martin Marietta (Army Spares Contract)
Splintered A                                                            Olympic Arms


from www.biggerhammer.net

Mike

Quoted: Stamping                                                   Source   CAF                                                                     Colt / Alcoa Forge (See above for photo) CH                                                                       Colt / Harvey Aluminum (1st Colt Forgings) CM                                                                       Colt / Martin Marietta (See above for photos) DK                                                                        Diemaco / Kaiser FK, FS, BK, DK, EK, FK, AF, CW, AA, FS    Bushmaster LK                                                                         FN / Kaiser LM                                                                         LAR / Martin Marietta (Army Spares Contract) Splintered A                                                            Olympic Arms from www.biggerhammer.net Mike

biggerhammer.net information is not accurate or up to date... That info has not been corrected or updated since early to mid 90's...

Quoted: I'll try to get a picture of it tomorrow.  Hopefully that will help.

A picture is better than a thousand words...

Quoted: biggerhammer.net information is not accurate or up to date... That info has not been corrected or updated since early to mid 90's...

Fix your post for ya.....

True it ain't been updated in a coon's age, but there is plenty of ACCURATE information there.

Mike

Quoted: Quoted: biggerhammer.net information is not accurate or up to date... That info has not been corrected or updated since early to mid 90's... Fix your post for ya..... True it ain't been updated in a coon's age, but there is plenty of ACCURATE information there. Mike

Well, you almost got it right... That Bushmaster information is still wrong as in being not accurate...

2nd ignorant question.  How do I add pictures to this post?

Got the pictures taken finally now I just have to figure out how to get them posted.

No problem... You first need to host the pictures... I use Image Closet for hosting... After you upload the pics to the host, just copy the link that the host gives you then when making a reply to this thread look at the bottom of the message box and click on the yellow envelope... You will see what to do next....

New Pics

That looks like a chopped COLT barrel that has a neutered "F" marked FSB... That type FSB is designed to be used with a flattop receiver...

Since it is attached to a A2 receiver, I'd venture and say that it is a Frankenstein creation... It looks to be a Kaiser forged receiver (which could have been sold by Bushmaster) and a COLT barrel... That ain't a bad combination at all...

Quoted: That looks like a chopped COLT barrel that has a neutered "F" marked FSB... That type FSB is designed to be used with a flattop receiver... Since it is attached to a A2 receiver, I'd venture and say that it is a Frankenstein creation... It looks to be a Kaiser forged receiver (which could have been sold by Bushmaster) and a COLT barrel... That ain't a bad combination at all...hr

Your always on top of  the replys!  Thanks for the response