AR "locking" charging handle purpose?

[ditcherman]

I have wondered for a while now what the obsession is with all the modifications done to charging handles and their locking mechanisms.

I normally buy whatever BCM wants to sell me when I do a build, but I have a Strike Industries charging handle that I am really digging at the moment. It has no lock and no moving parts except the spring steel that lightly friction fits it into the slot.

What has brought this question to fruition is the fact that I have a BCM Mod 4B that is extremely hard to get to open. I'm getting ready to file off the aggressive locking point a little at a time to see if I can make it more usable, but wanted to check to see if anyone had any input as to why it's needed or why I shouldn't.

I ordered three last time and might have 2 for sale, we'll see how the grinding goes.

TIA.

 

[hammerd13]

ditcherman,

The lock gives you a positive, tactile indication that it is completely forward...and stays there. If the charging handle is NOT completely forward when you release the bolt forward (to charge a round or otherwise), you run the risk of damaging the charging handle.

Secondly, in a very dirty rifle, it's possible that the charging handle could travel back towards the user's face/teeth as the bolt cycles...if the charging handle weren't locked in place. This issue normally doesn't present itself until you have a dirty weapon or end up with debris of some sort around bolt/charging handle area. This could certainly happen when using in the field for extended durations.

I'd say modify it if you like, but you definitely want it to lock positively into the forward position.

p.s. I've tried to standardize the charging handles in all my ARs. If you run a mix of "standard" handles, ambidextrous, oversized, small, etc. charging handles...it makes training your muscle memory difficult as you work each unique platform.

 

[jd4320t]

No answer to your question but just this week I got a new Mod4b and it didn’t want to unhook on my new PSA 10.5 upper. I tried it on a different upper and it works great.

When I ordered the Mod4b I didn’t realize how much different it is than the Mod4’s I have. I won’t be ordering any more. Apparently Vltor now makes the Mod 4 medium under their own name.

I don’t know why BCM made this change but in my opinion they dropped the ball big time. I love my Mod 4’s.

 

[MCgrease08]

No answer to your question but just this week I got a new Mod4b and it didn’t want to unhook on my new PSA 10.5 upper. I tried it on a different upper and it works great.

When I ordered the Mod4b I didn’t realize how much different it is than the Mod4’s I have. I won’t be ordering any more. Apparently Vltor now makes the Mod 4 medium under their own name.

I don’t know why BCM made this change but in my opinion they dropped the ball big time. I love my Mod 4’s.

Interseting. I actually ordered a new BCM upper this morning and picked the 4b hoping it would be similar to the Mod 4 I run on a different rifle. I'm curious to see how it works out.

 

[ditcherman]

ditcherman,

The lock gives you a positive, tactical indication that it is completely forward...and stays there. If the charging handle is NOT completely forward when you release the bolt forward (to charge a round or otherwise), you run the risk of damaging the charging handle.

Secondly, in a very dirty rifle, it's possible that the charging handle could travel back towards the user's face/teeth as the bolt cycles...if the charging handle weren't locked in place. This issue normally doesn't present itself until you have a dirty weapon or end up with debris of some sort around bolt/charging handle area. This could certainly happen when using in the field for extended durations.

I'd say modify it if you like, but you definitely want it to lock positively into the forward position.

p.s. I've tried to standardize the charging handles in all my ARs. If you run a mix of "standard" handles, ambidextrous, oversized, small, etc. charging handles...it makes training your muscle memory difficult as you work each unique platform.

Thank you, this is really good information. I will check it in some other lowers and do a very mild, cautious grind.
I have the same or similar handles in everything except the Strike Industries and this latest from BCM. I’ll pay more attention.

 

[ditcherman]

No answer to your question but just this week I got a new Mod4b and it didn’t want to unhook on my new PSA 10.5 upper. I tried it on a different upper and it works great.

When I ordered the Mod4b I didn’t realize how much different it is than the Mod4’s I have. I won’t be ordering any more. Apparently Vltor now makes the Mod 4 medium under their own name.

I don’t know why BCM made this change but in my opinion they dropped the ball big time. I love my Mod 4’s.

Thanks, glad to know it isn’t just me. I might try contacting BCM to see if they have a fix. It could just be a spring or hook replacement.

 

[ditcherman]

Interseting. I actually ordered a new BCM upper this morning and picked the 4b hoping it would be similar to the Mod 4 I run on a different rifle. I'm curious to see how it works out.

If you end up liking them I have 2 more, you’ll just have to order 2 more uppers to go along with. Great solution!

 

[Tombs]

It's a non-reciprocating charging handle.

If you do not want it bouncing around, it needs to have some degree of positive forward lock. Almost every firearm with a non-reciprocating charging handle has something similar.

Difference is, most won't smack you in the face if something goes wrong, but the T handle could. Therefor it has a more significant lock than most.

 

[magic man]

No answer to your question but just this week I got a new Mod4b and it didn’t want to unhook on my new PSA 10.5 upper. I tried it on a different upper and it works great.

When I ordered the Mod4b I didn’t realize how much different it is than the Mod4’s I have. I won’t be ordering any more. Apparently Vltor now makes the Mod 4 medium under their own name.

I don’t know why BCM made this change but in my opinion they dropped the ball big time. I love my Mod 4’s.

I bought a new Mod4 thinking it would be the same size as the old one. Pretty disappointed also.

 

[ditcherman]

No answer to your question but just this week I got a new Mod4b and it didn’t want to unhook on my new PSA 10.5 upper. I tried it on a different upper and it works great.

When I ordered the Mod4b I didn’t realize how much different it is than the Mod4’s I have. I won’t be ordering any more. Apparently Vltor now makes the Mod 4 medium under their own name.

I don’t know why BCM made this change but in my opinion they dropped the ball big time. I love my Mod 4’s.

left to right,
Strike industries with just a spring detention, works great but apparently could bust some teeth out,
BCM mod4b ground down. This was very soft metal and I didn’t do the neatest job but it works. Pretty confident no teeth will be busted.
Original mod 4b
Original mod 4. Definitely a softer spring, different leverage style, very nice.

 

[ditcherman]

I bought a new Mod4 thinking it would be the same size as the old one. Pretty disappointed also.

Should of got you quoted in the above, in case you want to try to mod. I used a dremel assuming it would be hard. File or sandpaper will work.

 

[Clay Pigeon]

What is... When shooting uphill it doesn't slide out and poke you in the face....

Or... For the same reason we have a zipper on our pants..

 

[ditcherman]

What is... When shooting uphill it doesn't slide out and poke you in the face....

Or... For the same reason we have a zipper on our pants..

Nope, I think I could slam the rifle down on the butt and it wouldn’t come out.

But what keeps the zipper up, huh?

 

[Clay Pigeon]

Nope, I think I could slam the rifle down on the butt and it wouldn’t come out.

But what keeps the zipper up, huh?

That little lock on the charging handle keeps it closed when its not in use, who would want it to slide out when the bolt is in motion at 650 rounds a min much less on semi auto.

And the charging handles little lock serves as the same function as the little locking tap on the backside of your zipper pull.

[video=youtube_share;PunJVOjKfno]https://youtu.be/PunJVOjKfno[/video]

 

[ditcherman]

That little lock on the charging handle keeps it closed when its not in use, who would want it to slide out when the bolt is in motion at 650 rounds a min much less on semi auto.

And the charging handles little lock serves as the same function as the little locking tap on the backside of your zipper pull.

[video=youtube_share;PunJVOjKfno]https://youtu.be/PunJVOjKfno[/video]

No one wants the charging handle sliding around.
I think I understand what the lock does. The strike Industries with “no” lock is the one I’m talking about that I could slam down and it wouldn’t open. Nothings coming open. I understand the function, my original question had to do with all the crazy mods that are done to really really lock it down, when friction will do “most” of the time, with exceptions explained in post 2 when friction might not be enough. I’ve built a few, and by built I don’t mean buying some kit and assembling two halves together. I will probably never turn my own barrel on my lathe. Maybe.

 

[TREETOP]

I had a .458 SOCOM AR that would occasionally release the charging handle latch on its own and it would disengage from its locked position during recoil. I like the idea of a spring detent rather than a mechanical latch, but I’d be pretty careful trusting one on anything heavier than 5.56.

 

[MCgrease08]

Interseting. I actually ordered a new BCM upper this morning and picked the 4b hoping it would be similar to the Mod 4 I run on a different rifle. I'm curious to see how it works out.

After spending a little bit of time this weekend running the 4b, I think I like the old Mod 4 better. Maybe is because I have much more time on the Mod 4 it's broken in more. I'm not sure. But the 4b does feel a bit stiffer. It seems to work better for me if I just hook the release with my left hand index finger and pull back solely with that finger (verses pinching it with index finger on the latch and thumb on back of the handle).

I don't know if my thumb is making it harder for the latch to pivot back or if it's just stiff because the latch and upper are so new. It's not what I would call hard to run, but it's not butter smooth either. I'm sure time and reps will help with that.

 

[ditcherman]

After spending a little bit of time this weekend running the 4b, I think I like the old Mod 4 better. Maybe is because I have much more time on the Mod 4 it's broken in more. I'm not sure. But the 4b does feel a bit stiffer. It seems to work better for me if I just hook the release with my left hand index finger and pull back solely with that finger (verses pinching it with index finger on the latch and thumb on back of the handle).

I don't know if my thumb is making it harder for the latch to pivot back or if it's just stiff because the latch and upper are so new. It's not what I would call hard to run, but it's not butter smooth either. I'm sure time and reps will help with that.

That 4b lever is longer, and it's the whole left side handle, combined with a stiffer spring, as opposed to the latch being imbedded in just the front left side of the handle, returning into the handle. Keeping your thumb on the back actually can retard operation, which is very frustrating when you're used to being able to pinch to open. It's a whole 'nother mode of learning to operate.

 

[mike4]

When OP says modifications I'm not sure if that means modifications by users, or the wide range of various designs in the marketplace. Folks have pretty well covered the reason for the charging handle to lock into place, but the purpose of a lot of diverse lever designs on charging handles is not so much to facilitate the unlocking as it is to facilitate racking the bolt carrier with the charging handle, usually trying to make that easier to do from one or both sides with one hand only. Then you have designs like the Gasbuster to reduce gas blowing by the back of the charging handle, esp. shooting with suppressors.

 

[2A_Tom]

Why? Well, let me tell you.

Basic Training. My first day on the range. My first round. I inserted the magazine, pulled the charging handle to the rear and released it, took the weapon off safe, took aim and fired.

The charging handle did not lock and it slid back (not with the full force of the bolt carrier) justt slowly tapped me very lightly in my cheek just below my eye.

I developed in that one incident a years long flinch that kept me a marksman for years.