Knight picatinny rail on bushmaster

ssduck30 · #1 11-24-08, 02:46

I bought a knight manufacturing picatinny rail front grip at a gun show for my bushmaster ar-15 the guy said it will fit all ar-15s I have tried several times to put it on and it will not go on to the gun it will not fit inside grip retaining nut near the receiver does anyone have any ideas why? if this has been discussed before sorry for the post.

Iraqgunz · #2 11-24-08, 02:56

ssduck,

Can you please clarify this as it really makes no sense. If you can't articulate it we can't fix it.

Quote:

Originally Posted by ssduck30

I bought a knight manufacturing picatinny rail front grip at a gun show for my bushmaster ar-15 the guy said it will fit all ar-15s I have tried several times to put it on and it will not go on to the gun it will not fit inside grip retaining nut near the receiver does anyone have any ideas why? if this has been discussed before sorry for the post.

Frens · #3 11-24-08, 07:56

http://www.quarterbore.com/library/p...c_ras_inst.pdf

Dave L. · #4 11-24-08, 08:04

I have no idea what this dude is talking about...

What kind of rail is it?
Clarify what you mean by picatinny rail front grip and grip retaining nut...

Are you talking about a KAC Vertical Fore Grip or a KAC Rib Panel?

markm · #5 11-24-08, 08:37

I think he has a KAC RAS. But we need the exact model to make sure.

ssduck30 · #6 11-25-08, 02:28

Sorry for the confusing post from last night long shift with no sleep. My problem was to get a knight manufactoring quad rail front hand guard onto my bushmaster ar-15 carbine I can't get it over the delta ring. One of you posted me the instruction page from Knight's I think the screw in the rail is the problem I have to unscrew it then try to get it to fit on the rifle. Thanks for the help if it works I will let you know if not I will try to explain the problem better to you with the rifle in front of me.

Iraqgunz · #7 11-25-08, 03:02

ssduck,

Just an FYI. There is a possibility that it may not fit (I know that you were going to remove screw and re-attempt) but I have seen a few BM carbines that would not allow the KAC rails to fit properly. Hopefully you won't have that issue.

Quote:

Originally Posted by ssduck30

Sorry for the confusing post from last night long shift with no sleep. My problem was to get a knight manufactoring quad rail front hand guard onto my bushmaster ar-15 carbine I can't get it over the delta ring. One of you posted me the instruction page from Knight's I think the screw in the rail is the problem I have to unscrew it then try to get it to fit on the rifle. Thanks for the help if it works I will let you know if not I will try to explain the problem better to you with the rifle in front of me.

markm · #8 11-25-08, 08:00

You definitely have to take the screw out to get it UNDER not OVER the delta ring.

xcibes · #9 11-27-08, 19:38

You have to loosen the screw, you do not need to take it out. I had this problem the first time I tried to install one, it pissed me off to no end. I felt so stupid when a friend told me what the problem was.

**KevinB** · #10 11-28-08, 00:31

Easiest to drop the screw out - and the fork falls down - making it easier to seat.

If your BM is a HBAR, odds are a M4RAS will not clear the front handguard cap, s the bbl will be too thick. It is fixable (with a mod to the RAS though)

George Mac · #11 11-28-08, 09:38

It may help to loosen the nut on the RAS and install it on your rifle while holding the rifle horizontally. Gravity is your friend. I did this and it went on without a hitch.

ssduck30 · #12 12-04-08, 00:44

I have tried to loosen the screw and took it out no go to get the KAC on the bushmaster! A friend talked to a gunsmith that deals with black rifles and he told him that the goverment M-16 A-4's are just a bit larger them civilian rifles and the rails won't fit. I looked at the rail and it seams that with a small amount of grinding on corners it would fit but I don't want to ruin the rail. Thanks for everyones help on the problem.

George Mac · #13 12-04-08, 01:03

I have watched our armorers put them on department Bushmasters. As long as the weapon was held in the horizontal position they went on fine. You may need the handguard tool to pull the delta ring down far enough while the weapon is horizontal.

If that does not work something may be out of spec.

**KevinB** · #14 12-04-08, 01:13

Quote:

Originally Posted by ssduck30

I have tried to loosen the screw and took it out no go to get the KAC on the bushmaster! A friend talked to a gunsmith that deals with black rifles and he told him that the goverment M-16 A-4's are just a bit larger them civilian rifles and the rails won't fit. I looked at the rail and it seams that with a small amount of grinding on corners it would fit but I don't want to ruin the rail. Thanks for everyones help on the problem.

Dude anyone saying that the M16A4 is larger than civilian rifles is feeding you a line...

tex45acp · #15 03-04-09, 09:39

ssduck30,

Before you grind, knock out the roll pins, take out the parts held in by them and install the rails. I had to do mine that way and the rail is rock solid, no movement whatso ever.

tex

sgtrock82 · #16 03-04-09, 13:04

I agree that the key is to remove the screw and let gravity take over. It may be possible to do it without removing but I sure couldn't do it on my carbine or my friends A4. It can be a bit of a pain doing all the manipulating while holding back the delta ring. IIRC you remove the screw tip, the front into the handguard cap, lay the rifle horizontal. Pull back on the delta ring, the rear retainer should flop down far enough and with some jiggling get into position. The rear of the handguard body may not want to go in but should start, I just smack it with the palm of my hand and it falls in. Insert screw, tighten drop in bottom portion. Overll it may have been easier with a handguard tool but I can't bring myself to buy one.