question about colt m4 carbine. 22lr

[Rockgod]

I have a colt m4 carbine .22lr and im having a strange issue with it. After i fire the last round i notice that the bolt stays open half way, almost like how the slide on an automatic pistol stays racked backed until you release it. It requires me to rack the handle without the mag in it to close it. If i just put a new mag in it will not chamber the new round and i have to take the mag out and rack the handle to close it before it will load the new round. Is this just how the gun is designed or is there some kind of issue with my gun. Forgive me if im not using the correct terms for parts im fairly new to shooting, but hopfully you understand what i am talking about.

[GM4spd]

What you describe should not be happening. You don't mention types of
22 ammo you are using. You should try different types of LR ammo and/or
switch magazines if you have more then one. Pete

[CWDraco]

Sounds like a bent bar. I dont know the actual Bolt Carrier Group used by Colt on their .22. but if this was a regular AR15 with a conversion BCG system, I would be looking at the bars where the Bolt slides on or the Bolt release paddle.

On a regular Ar15 the Bolt release paddle has a arm that gets pushed up by the magazine follower, if the magazine is empty that paddle arm snags the BCG stopping it.

Your paddle arm MIGHT be acting as a brake on the 22lr BCG on an empty magazine.

[Eddbot]

Your paddle arm MIGHT be acting as a brake on the 22lr BCG on an empty magazine.

The bolt release on the colt m4 .22lr is purely cosmetic.
I'll take a look at mine tonight and see what could be interfering.

[Rockgod]

Ive tried winchester super x and federal ammo the bulk 325 round box. Cci mini mags are hard to find where I live, i know thats the usual see if this round works answer. From what ive read these guns will usually eat anthing. I only have the one mag that came with the gun. I tried turning the bolt adjustment speed up 3 or 4 turns and the first couple mag loads seemed to cycle fine so maybe i just need to keep playing with that until i get it tuned in properly. From my research i have the second gen model, the safty switch requires a 90% turn not the 180% of the first gen. I know the first gen had alot of issues but from my research the second gen are great guns and with the exception of this issue im ceraintinly enjoying it. I havnt put many rounds through it yet either so it might just need to be broken in more. I just wanted some opinions to see if this is normal or if i should be getting ahold of colt and see about getting it looked at.

[Rockgod]

I figured out the issue the bolt is catching on the magazine when its empty. Im not sure what you would call it but the very top of the mag, the part that holds the top round is stoping the bolt from closing. Im not sure why it doesnt catch when there is a round in it. It only catches when the mag is empty. Do you think the issue is the mag or the bolt? I took a pic bit im not sure how to post them on here. I only have the one stock mag that came with the gun im not using an aftermarket brand or anything ao not sure whats causing the issue exactly

[Rockgod]

So after more tinkering, inspection and reserach i discovered there is an internal bolt catch that holds the bolt back after the last round is fired. Very annoying but im glad to have figured out what is going on and know that there is not an issue. The bolt catch looks like it is possible be removed but ive heard that disassembleing this guns is a chore.

[donw]

Spikes Tactical ST-22 operates the same way.

the empty magazine acts like a bolt stop after the last round is expended.

not an 'issue'...just a design feature.

[Jimi Jah]

I have one and that's what they do. Cleaning it is a major PITA. It sits while I use a couple of AR's with conversion bolts, easy to clean.