Excessive play in forward assist or normal?

[Doc Safari]

First I want to say that I think this is probably normal. I've owned several AR's over the years and some do it and some don't.

I own three top-tier left-of-chart M4's. I always do a function check of things before heading to the range.

I noticed today that my newest one has a little more play in the forward assist than the other two rifles.

I want you guys' input before I relax and don't worry about it, or I call the manufacturer to let me send the rifle back.

With the bolt fully closed and locked on the rifle in question, if I push in on the forward assist plunger I can at times seem to line up the forward assist just right so that it feels like the pawl "slips" past the bolt carrier (since there are no slots to grab). To put it another way, I can push the plunger in further on this rifle than the other two if I line up the forward assist knob just right. This rifle's forward assist knob has more rotational play than the others also. On the other two rifles the forward assist just "stops". I tested the forward assist on the rifle in question by deliberately not allowing the bolt to go all the way foward, and the forward assist pushed the BCG forward to lock just like it's supposed to.

I examined the pawl on all three rifles and all three appear identical. I do not believe there is anything wrong with the forward assist itself. I believe the excess play of the forward assist in the receiver on the third rifle is what is allowing it to "slip" past the bolt carrier if I align it just right and push in on it with the bolt already closed.

I know that technically if the bolt is already closed then the forward assist is not needed, but could this excess play point to a possible problem if the forward assist actually had to be used to push the BCG forward? Or should I just chalk this up to a rifle with slightly looser tolerances in this area and not worry about it?

Again, I've owned other AR's over the years that would do this. On the rifles I've owned, it seems the gun either will do it or it won't.

I'm thinking it's normal, but do you guys agree?

[Iraqgunz]

Honestly I never use my forward assist, so it's hard to say. But, if you think something is wrong by all means follow it up.

When I was in the MIL I had a pawl break off and lodge into the upper receiver. In the end the upper got trashed as there was no way to remove it.

First I want to say that I think this is probably normal. I've owned several AR's over the years and some do it and some don't.

I own three top-tier left-of-chart M4's. I always do a function check of things before heading to the range.

I noticed today that my newest one has a little more play in the forward assist than the other two rifles.

I want you guys' input before I relax and don't worry about it, or I call the manufacturer to let me send the rifle back.

With the bolt fully closed and locked on the rifle in question, if I push in on the forward assist plunger I can at times seem to line up the forward assist just right so that it feels like the pawl "slips" past the bolt carrier (since there are no slots to grab). This rifle's forward assist knob has more rotational play than the others also. On the other two rifles the forward assist just "stops". I tested the forward assist on the rifle in question by deliberately not allowing the bolt to go all the way foward, and the forward assist pushed the BCG forward to lock just like it's supposed to.

I examined the pawl on all three rifles and all three appear identical. I do not believe there is anything wrong with the forward assist itself. I believe the excess play of the forward assist in the receiver on the third rifle is what is allowing it to "slip" past the bolt carrier if I align it just right and push in on it with the bolt already closed.

I know that technically if the bolt is already closed then the forward assist is not needed, but could this excess play point to a possible problem if the forward assist actually had to be used to push the BCG forward? Or should I just chalk this up to a rifle with slightly looser tolerances in this area and not worry about it?

Again, I've owned other AR's over the years that would do this. On the rifles I've owned, it seems the gun either will do it or it won't.

I'm thinking it's normal, but do you guys agree?

[Doc Safari]

But, if you think something is wrong by all means follow it up.

This is actually the reason for my thread.

Before I waste the manufacturer's time, I want to make sure it's not just a normal variation.

Had I not owned other rifles over the years that would do this, I would be more inclined to think it's a defect.

[Iraqgunz]

I assume you are using an aftermarket BCG with no cuts in the BCG based upon your description? Have you tried to put a standard BCG in there to see if it does the same?

This is actually the reason for my thread.

Before I waste the manufacturer's time, I want to make sure it's not just a normal variation.

Had I not owned other rifles over the years that would do this, I would be more inclined to think it's a defect.

[Doc Safari]

I assume you are using an aftermarket BCG with no cuts in the BCG based upon your description? Have you tried to put a standard BCG in there to see if it does the same?

Actually, it's the standard mil-spec BCG that came with the rifle. I guess I didn't type that very clearly.

It's just that if you picture the bolt fully closed then the pawl of the forward assist is past the part of the bolt carrier with slots.

In other words, I think the pawl is able to glance off the smooth part of the bolt carrier if you line it up just right. It does engage the slots when you deliberately hold the bolt carrier back so that the slots line up with the pawl.

[Iraqgunz]

Ok. I didn't quite get what you meant.

Actually, it's the standard mil-spec BCG that came with the rifle. I guess I didn't type that very clearly.

It's just that if you picture the bolt fully closed then the pawl of the forward assist is past the part of the bolt carrier with slots.

In other words, I think the pawl is able to glance off the smooth part of the bolt carrier if you line it up just right. It does engage the slots when you deliberately hold the bolt carrier back so that the slots line up with the pawl.

[Doc Safari]

I e-mailed the manufacturer pretty much word-for-word my first post late last night.

Surprise, surprise, they've already answered me:

"By you[r] description it probably is normal. Slight difference in the tolerance.

But as always, if you would like us to inspect it we are more than happy to."


I'm inclined to think it's normal, too. It's just one of those things like a rear sight that's a little cockeyed but zeroes just fine: don't nitpick as long as it works.

Once again, I've owned other AR's over the years that do the same thing.

I have to say I'm pleased with the manufacturer's fast and positive response.

I e-mailed them back that I will hold off sending the rifle back for now.

(I'm deliberately witholding the name of the manufacturer because people who disagree with their answer might not want to say so if they have to contradict them in public).

So what do you guys think?

I know some of you are armorers, right?

[Evil Bert]

Honestly I never use my forward assist, so it's hard to say. But, if you think something is wrong by all means follow it up.

When I was in the MIL I had a pawl break off and lodge into the upper receiver. In the end the upper got trashed as there was no way to remove it.

Not that I doubt it, but curious as to how that is even possible. I would love to hear more about that issue if you would be so kind. I am intrigued.

[Iraqgunz]

I can't tell you how it happened, because I was called to the boat to make a diagnosis and repair. The bolt carrier was completely frozen in place out of battery.

I had to tear apart the whole gun (lower receiver extension) just to get into it. Long story short at the end of the day I found that the pawl (which is 5 pieces) separated from the rear of the pawl assembly. If you look into your upper receiver where the forward assist is, there is a "cavern" or channel in there.

If the pawl broke off as the BCG was in it's rearward movement then it would be easy to see how it could lodge itself in there.

Not that I doubt it, but curious as to how that is even possible. I would love to hear more about that issue if you would be so kind. I am intrigued.

[bkb0000]

Not that I doubt it, but curious as to how that is even possible. I would love to hear more about that issue if you would be so kind. I am intrigued.

i had one of these not too long ago.. i didn't actually even get to see the weapon, one of my customers called me from the range and asked WTF his carrier wouldn't move. it sounded like a jammed primer to me.. he said he hand a stock wrench and was willing to use it, so i told him to pull the receiver extension and see if he could beat it forward the free up the obstruction- he emailed me back about a half hour later and said his forward assist had broken off and jammed between the carrier and receiver. he never did bring it in, so i assume he was able to fix it himself, or maybe still has a non-functioning FA... who knows.

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as to the question- this happens on some guns. im pretty sure my LMT 10.5 does this on a closed bolt, and i know i've had others that do it. it's been my experience that FAs contact the carrier teeth differently on different guns- some are way more positive on others. if in doubt, the solution is to test it at different levels of open- manually pull the carrier out of battery and hold it at different positions, and try to push it in with the FA. if it's missing more than grabbing, you should probably get a new plunger.