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Posted: 11/7/2002 3:46:07 PM EDT
I purchased what was supposed to be all Bushmaster upper.But my ARMS 22M68 is super tight fit and my SWAN sleeve will NOT go on.Which manufacturer can I count on to fit my ARMS 38ex?Is Fulton Armory uppers good?Help please.
Link Posted: 11/7/2002 6:37:50 PM EDT
Link Posted: 11/7/2002 9:19:49 PM EDT
Please let us all know the results.I compared the rail with my Badger Ordnance Rail and it is different.My #38 is older also.
Link Posted: 11/8/2002 6:48:44 PM EDT
I've had no problems with my 3 Bushmaster flattops that range in age from 2-5 years. Everything I have from ARMS, GGG, Trijicon and Elcan work on them fine. I know RRA made some that were out of spec.
Link Posted: 11/9/2002 6:32:25 AM EDT
Yea had the same, problem with a RRA upper but I send it back and had a new one in a week free of charge. if you cant get a replacement you can get a flat top upper for under $100. I know it sucks, but its better than taking a dremel to your $150 sight/mount.
Link Posted: 11/9/2002 9:47:10 AM EDT
From ARMS - some Bushmaster uppers are not in 'spec' - this was found to be the case on some board members SIR installations as well.
Link Posted: 11/9/2002 4:13:44 PM EDT
If some Bushmaster Uppers are not in spec... I wonder if Bushmaster will replace them with ones that are.

Rock River sent some uppers out that were not in spec, and although they appear to have concocted a fabulous story to try and cover up their mistake... at least they appear to be taking care of the problem by replacing their out of spec uppers with ones that are in spec.

I would hope Bushmaster will do the same.
Link Posted: 11/9/2002 4:41:57 PM EDT
If anyone has contacts for returns @RRA and Bushmaster please post.Also how do we identify RRA uppers?I can't find any marks anywhere.
Link Posted: 11/9/2002 6:02:38 PM EDT
Go to their website(RRA) and give them a call they will take care of it.
FREE
Link Posted: 11/10/2002 12:08:15 PM EDT
Link Posted: 11/10/2002 1:01:12 PM EDT
I wonder what motivated RRA to even accept the out of spec uppers from their supplier. And then to go as far as lying about a new spec. Makes you wonder! I've shyed away from RRA products since that happened.
Link Posted: 11/10/2002 2:27:52 PM EDT
Ok guys,anyone know how to positively I.D. Flattops so I can return it to RRA?hinking.gif
Link Posted: 11/10/2002 4:06:21 PM EDT
Link Posted: 11/10/2002 6:42:55 PM EDT
Posted by Troy...

...there is an updated spec called 1993 for the rail, which has to be wider to work with the heavier(!) night-vision scopes they have now, or they'll be unstable. Everyone will be changing soon!


That's right Troy! All the manufacturers are going to get together at the SHOT Show and "discuss" this change.

... At least that's what I heard from a friend of a friend's second cousin who knows someone who saw an M16 in a movie once. He knows about these types of things!!!
Link Posted: 11/10/2002 8:58:01 PM EDT
LOL
Troy -Thats the new M1993 rail as opposed to the M1913

From my undersatnd BM had a small run of mis-spec'd uppers - poor SF has one of these.
There are a few others out there.

However unlike RRA, BM admitted the error and hurried to make right.

Link Posted: 11/11/2002 9:31:49 AM EDT
Posted by CANADIAN_TACTICAL:


However unlike RRA, BM admitted the error and hurried to make right


What was BMs remedy for their uppers being out of spec? Specifically, the first rail, i.e. the largest rail on the front of the receiver, not measuring .450". I have one of these receivers that are out of spec, and the crossbars on a SIR do not line up.
Link Posted: 11/11/2002 10:06:11 AM EDT
I just called Bushmaster@1800-883-6229.Matt in Cust.Svc. said if you think you have an out of spec upper call for R.A.# and if upon receipt they verify that it is theirs they will replace it.Matt said best indicator for maker is presence of Gray dry film coat on inside of upper.Bushy sprays the inside.Hope this helps.Phil
Link Posted: 11/11/2002 11:05:59 AM EDT
The real answer to your mount problem can be solved with many of the fine mounts available that use a screw, clamp, nut method of rail grabbing.
Throw levers by their very nature don't possess enough "forgiveness". Over the years I have tried several of my personal throw lever mounts and long SWAN sleeves on very many real Colt military property upper receivers rails that meet the MilStd 1913 Picatinny Rail profile specifications.
All too often, the levers fail to "ker-plunk" securely (like they usally do if attaching to a SWAN rail of sister manufacture), or don't close at all. Some that close, are all too easy, and then noticable loose when closed. The long sleeve (2 of them) have been partially hammered onto some rails, and then removed before serios damage, whereas on other rails one or the other slips right on.
If you want to test this out, take your throw lever mount to a gun show and try it on any rail you can find. OK, you know ahead of time that its not going to fit them all 100% perfect, right? However, if you have a screw, clamp, nut type rail grabber, it will probably be 100% good to go on all of them, right?
Maybe that's why the US Amry standardized on a screw type rail grabber years ago. Yea, the horrible one with the "cricket chirp" self torquing thumb nut.
It should also be clear to all that its hard to make rails to the M1913 spec...all the more reason to invest in "more forgiving" designs of rail grabbers.
Enough said.
ColdBlue sends...
Link Posted: 11/11/2002 12:15:40 PM EDT
I really hate the missing search button. I'm afraid I might miss one of coldblue's posts.
Link Posted: 11/11/2002 10:24:20 PM EDT

Originally Posted By Bladewurk:
Matt said best indicator for maker is presence of Gray dry film coat on inside of upper.Bushy sprays the inside.



This may be a good way to check new BM uppers, but that doenst help a lot of people with older and used uppers. That dry film coat comes off easily when cleaned with many, many popular solvents. I remember when my upper was new and the day mine got cleaned out. Before I knew thats what this film was, I thought it was dirty ammo and I cleaned it all out quite easily.
Link Posted: 11/12/2002 4:46:31 PM EDT
Coldblue, Not only is your ignorance showing again, but you also seem predisposed to be less than candid with facts while you self promote yourself. Especially when another company has a product that you and your master wish you could own.
Jack
Link Posted: 11/13/2002 12:33:04 PM EDT
Dick, I don't think so.
AS I said above, I have some of your throw levers (that you personally sent me over the years) that are either too loose or too tight on some rails that are absolutely GI spec. And its just not me.
Don't you remember the phone call from a Colonel at Camp Pendleton about all the ARMS throw levers attached to Machine Gun Optics that were loose or too tight on his new M249 SAW Rail feed Covers? Or is FNMI yet another company on a long list that can't make a rail to your standards?
Or at a past Shot Show did we not have to use a stapler as a hammer to beat one of your long rails onto one of our upper receiver's?
And then I said, on other mil-spec rails they "ker-plunk" just fine, as if YOU had made the rails yourself in West Bridgewater, not a SDI, GGG, and the others who have manf'd your products to less than your standards.
That being said, throw levers that are not forgiving enough on nominal M1913 specs, and therefore not the best thing going, especially when screw type rail grabbers--by their very nature--readily accept normal manf'ing tolerances, are less expensive, etc.
And Dick, I think its time you toned down the bitterness a couple of notches. I am trying to keep these exchanges professional and objective.
ColdBlue (Dave Lutz @ KAC) sends...
Link Posted: 11/13/2002 1:05:32 PM EDT
Doh!!!
Link Posted: 11/13/2002 2:45:17 PM EDT
coldblue, your persistant at least in disinformation of who I and others are, plus consistant in trying to conteract the success of the various conpetition to include the throw levers and sleeves. The fact is (as you abserved)the sleeves do act as a very good guage to see if a receiver is to spec/, and since the throw levers are a precision attacment device, they do require pecision rails to go on, therefore you should be glad of that since the current KAC rails are to spec., but that wasn't always the case, but you wouldn't want to remember that, so I will just say my men like the throw levers on many of you weapon set ups.
If someone had to pound a sleeve onto one of your rails, I guess that you must have had a rail out of spec.
Good shootin, Jack
Link Posted: 11/14/2002 4:06:27 AM EDT
Dick and crew, why don't we just focus on Bladewurk's problem, that is the only thing I am trying to accomplish.
ColdBlue
Link Posted: 11/14/2002 5:18:26 AM EDT
[Last Edit: 11/14/2002 11:57:46 AM EDT by fight4yourrights]

Originally Posted By coldblue:

However, if you have a screw, clamp, nut type rail grabber, it will probably be 100% good to go on all of them, right?



No, not always.

I bought Leupold Mark IV rings, which are the screw clamp type. They didn't work on my Bushmaster flattop (very loose), were tighter on my RRA, but still not secure.

Both the RRA and Bushmaster were within specification, though they were at opposite ends of the tolerance specification.

Leupold sent me so different followers which worked fine with either upper.
Link Posted: 11/14/2002 11:41:35 AM EDT
Good to learn that Leupold has a fix for that problem. Thanks.
The bigger problem however, is that although Mk 4 bases & rings look like Picatinny's, they are not, as they were out much earlier. So that's the real problem. Obviously with different Leupold followers (we call them clamps) the piece is pulled to the side as well as down on top of the rail itself without the inside edge of the clamp contacting the base of the rail structure prematurely, making theirs one of the superior "line contact" designs vs "point contact" types.
For more on the rail's origin, check out my topic thread on Flat top Picatinny Rail origins. One of the first respondents posted some good info on the Army's M24 Rail, which evolved...became??, or is now the Leupold's Mk 4.
My favotite SF General said once, "a mind is like a parachute, it must be open in order to function".
Thanks again,
ColdBlue sends...
Link Posted: 11/14/2002 7:05:38 PM EDT
Link Posted: 11/15/2002 4:45:30 AM EDT
Looking at the front of a rail and you see a pair of 45 degree angles on each side of the rail. Point contact rail grabbers attempt to touch (and clamp between) each of these four 45's. If you look at an ARMS throw lever mount, you will see this happening as the levers are closed, but more importantly, you will see a gap between the top of the host rail and the underside of the ARMS mount. So this design absolutely depends on the 45's being perfect and uniform for repeatability.
Line contact uses the much larger cross sectional area of the top of the host rail for contact. This is how Leupold, KAC, and other rail grabbers are designed. In these designs, the opposing "fixed side female groove" engages the underside 45 on the rail and as the opposing nut/clamp is tightened, and this draws the mount down to contact the host rails top surface. The clamp's lower inside edge is now in contact with the underside 45 on its side. This relationship pulls the mount down (using both opposing 45's, towards the side with the clamp, and down into contact with top of the host rail
The simple way to compare these is the difference between a four leg stool (point contact) and one with three legs (line contact). I am sure you have experienced four-leg stools that "woobled", but never a three-leg one.
Unfortunately, the Army went for the point contact approach in the MilStd1913 spec because they were heavily influenced by ARMS mounts.
On the good side, again looking at the mil spec rail from the front, the rail itself sits atop a preety tall "root", this allows clearnances for line type grabber and clamps.
Obviously, both approaches can provide return to zero performance. That being said, my preference is for the three-leg stool, because things in this world just are not perfect, especially is Murphy is lurking about. I like forgiveness features.
ColdBlue sends...
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