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 Bushmaster sticking forward assist
silentmajority  [Team Member]
9/25/2007 9:31:55 AM EST
Ever since I got my AR, I've had to really mess with the forward assist button to get it to push in. Kind of have to wriggle it with my thumb while pressing in until it will move forward.

Is this a known issue? Is there an easy fix or something I am doing wrong?

Thanks.
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Bullet175  [Member]
9/25/2007 10:20:36 AM EST
Does it work with the bcg removed. If not I would drive the FA pin out and look to see if anything looks unusual.
silentmajority  [Team Member]
9/25/2007 11:09:06 AM EST

Originally Posted By Bullet175:
Does it work with the bcg removed. If not I would drive the FA pin out and look to see if anything looks unusual.


I'm pretty sure it moved ok with the bcg out when I cleaned it Saturday, but I will check again asap when I'm home and post back.

If it does move freely with the bcg out, but binds with it in, what would that indicate?


ETA: Per below, I will (carefully) test it loaded. Thanks again.
windyhill  [Member]
9/25/2007 11:26:32 AM EST
When you check it with the bolt carrier assembly in, make sure the bolt isn't fully forward, if the bolt is fully forward then the forward assist really won't move much.
Bullet175  [Member]
9/25/2007 12:07:12 PM EST

Originally Posted By silentmajority:

Originally Posted By Bullet175:
Does it work with the bcg removed. If not I would drive the FA pin out and look to see if anything looks unusual.


I'm pretty sure it moved ok with the bcg out when I cleaned it Saturday, but I will check again asap when I'm home and post back.

If it does move freely with the bcg out, but binds with it in, what would that indicate?


What you trying to find out is if its a FA to BCG conflict or a FA problem alone. Incorrect assembly could cause a problem. I put one together once and it wouldnt work for nothing. Took it apart and reassembled and still nothing. Took it apart again and took a close look and found an EPC e clip down in the FA button. Dont know how it got in there. Put it back together and worked fine.

Remove the upper and bring the BCG back a few inches and opperate the FA. if it dosnt bring the bolt forward smothly then remove the BCG and try it without. If its still not working drive the roll pin out and just look around for anything odd.

Edit.......Read post again...... but if you you push on it few times fast and then one time when you push it finally gives and pushes in thats normal. the inportant thing is will it opperate the BCG normally.
QUIB  [Team Member]
9/25/2007 12:27:30 PM EST
During your troubleshooting, you might want to place a few drops of CLP on the FA. I think the FA is one of those areas that gets neglected when it comes to lube.
bigez  [Team Member]
9/25/2007 6:06:24 PM EST
Do some people just disable the Forward Assist somehow??
silentmajority  [Team Member]
9/26/2007 3:07:25 AM EST
I checked the forward assist operation again last night.

It moves freely when the bolt carrier group is removed, and it moves ok when the bolt is in certain positions between being all the way forward or back.

The FA binds when the bolt is forward with a round in the chamber. As I said, if I wriggle it, sort of use my thumb to keep pressure inward towards the AR upper while pressing in, the FA will go in. If I don't use the inboard pressure along with pressing down, it binds. I did lube the FA with CLP especially well Saturday when I cleaned the gun after coming back from the range, and I've done so since I've owned the gun, so that should not be a problem.

I didn't have time to try to disassemble the FA last night, and honestly I am a little hesitant to do it because I don't want to break anything. I've never had to remove the type of pin that holds the assembly together. It looks like some kind of cylindrical expansion pin. Would I use a tiny brad to push that pin out, or what is the correct method for removing the pin?

Sorry for the ignorance. Thanks for your advice.
Schive  [Member]
9/26/2007 3:41:26 AM EST
It's probably fine. When the bolt carrier is fully forward and the FA will not move this is not binding, it's just that the FA cannot push the BC any further forward. When you wiggle it around and get it to move forward it's just the pawl in the FA slipping past the slot on the BC it was locked into and trying to move ahead to the next slot.

If it moves freely when the BC is removed and it will ratchet the BC fully into battery, then it is fine. Use the charging handle to hold the BC back a couple of inches from being fully in battery, then apply the FA to see if it will ratchet the BC closed. If it does, it's good to go.
Smead  [Member]
9/26/2007 3:42:11 AM EST
With a round in the chamber, you may just be on the uncut portion of the carrier instead of in a cut notch with the tip of the FA.

Just checked a rifle with no round in the chamber, the FA will fully depress to the shoulder while pushing the BCG forward. Once in battery, the FA will only depress halfway.
silentmajority  [Team Member]
9/26/2007 5:14:55 AM EST

Originally Posted By Smead:
With a round in the chamber, you may just be on the uncut portion of the carrier instead of in a cut notch with the tip of the FA.

Just checked a rifle with no round in the chamber, the FA will fully depress to the shoulder while pushing the BCG forward. Once in battery, the FA will only depress halfway.


I've noted the difference in the shorter travel of the FA button between when the bcg is completely removed and when the bolt is in postion with a round in the chamber. I know what you're talking about, and the binding I am describing is not that.

I believe you're correct that what may be happening is that the FA peg/button/whatever is hitting a rise instead of a notch on the bolt carrier. Somehow, pushing the FA in at an angle is letting it hit before or past the rise, and get into one of the notches.

I would think that the FA, bolt carrier notches, and the entire design of the chamber, etc, would be precision made so that the bolt would stop with a round in the chamber at a position where the FA is aligned to press into a notch?

Since I can cheat it by fiddling with the FA, I may just decide to live with it. But I would prefer that it worked correctly every time without having to mess around.

ChromeLined  [Member]
9/26/2007 7:24:07 AM EST
Take the upper off..leave the charging handle in place and just move the carrier back a few inches then use the forward assist it should ratchet the carrier forward until it locks then youll see if its doin its job.It should line up with the notches unless it was assembled wrong or notches in the carrier aerent cut right.
silentmajority  [Team Member]
9/26/2007 12:12:06 PM EST
Yes, i did as you describe during my testing yesterday. Upper separated from the lower. Felt/saw the bolt ratchet forward until it cound not move any more forward against the cartridge.

The last couple clicks, it started to bind up again. I guess either the top of the FA peg is not shaped right to catch the notches properly when it starts getting tight, the notches themselves are not spaced properly, or the bolt or cartridge aren't seating properly in the chamber, causing the notches to be a hair too far back?
silentmajority  [Team Member]
9/26/2007 12:16:17 PM EST

Originally Posted By Schive:
It's probably fine. When the bolt carrier is fully forward and the FA will not move this is not binding, it's just that the FA cannot push the BC any further forward. When you wiggle it around and get it to move forward it's just the pawl in the FA slipping past the slot on the BC it was locked into and trying to move ahead to the next slot.

If it moves freely when the BC is removed and it will ratchet the BC fully into battery, then it is fine. Use the charging handle to hold the BC back a couple of inches from being fully in battery, then apply the FA to see if it will ratchet the BC closed. If it does, it's good to go.


Just saw this after my last post. Hopefully that is the case. It won't move because it's already fully forward. I'll keep an eye on it and see how things go. It shoots fine, which I would think it wouldn't do if the bolt carrier and cartridge weren't properly seated.
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