AR bolt lugs stay locked if no gas system present, correct?

[homeuser6]

good grief ! nevermind

 

[asiparks]

The straight pull AR's I've shot very much have recoil

"How would the carrier move back without the bolt rotating to unlock"==the gas impingement system uses gas from the gas tube to force the carrier back, thus unlocking the bolt by use of the cam pin.

"Take out the rear pin on your AR and break it open. Now, point the muzzle at the ceiling. just the weight of the bolt is probably going to cause itself to unlock and drop rearwards until it catches on the CH."==the weight of the carrier will unlock the bolt and it will fall out. Put just the bolt in, lock it up, and I bet it won't move.
Thing to remember about ARs...there is a 'bolt' and a 'carrier'. Together they are not called 'the bolt'. Together they are called the 'bolt carrier group' or BCG. Without the carrier the bolt won't rotate either way.
As for bolt action rifles locking... that is to prevent out-of-battery detonation and to properly align the trigger group for proper operation.

yes a BCG. But for every part of this conversation, and for the OP's original question, the BCG is staying together. In the AR, they stay together. That is the collective mass that we are dealing with. And as can be clearly demonstrated

With your AR open, see how little fingertip effort it takes to pull back the "BCG" from it's locked position. Now, with even without the gas system, imagine the force the detonating cartridge is applying, trying to push the bolt rearward. If there's no recoil spring and buffer to resist the rearward movement of the firing cartridge, you imagine the bolt is just going to sit there, locked to the lugs ?

I would invite anyone with an adjustable gas block to turn off the gas, remove the recoil spring and buffer from the weapon and fire it. See if the bolt just sits there.

So, bolt actions, you are saying that the locking of the lugs is in no way designed not to have the bolt fly back and smash out all your teeth ... it's just there for "trigger group alignment and prevent out of battery detonation" ? Ok then.

Straight pull AR rifles do have recoil springs and buffers. The "pull" part is just the extraction part of the cycle. the recoil system still chambers the next round.

 

[Member 34319]

@asiparks go back a page or two and literally watch the video of the guys cutting up carriers to make pistols. Zero springs, half a carrier. Bolt only rotates once they manually operate the action. I think your confused on how a bolt works.

 

[Member 34319]

a) I can't speak for all bolt actions, but on mine, and all those I've seen, after you push the bolt forward, you invariably push it down to lock it. Then you lift it up to unlock it, before pulling it rearwards.
b)The lugs are square. The lugs on the barrel extension are square. How would the carrier move back without the bolt rotating to unlock ?- If the lugs and bolts were all truly square then nothin g would move. Something you can try at home: Take out the rear pin on your AR and break it open. Now, point the muzzle at the ceiling. just the weight of the bolt is probably going to cause itself to unlock and drop rearwards until it catches on the CH.

Equal and opposite forces- as the bullet moves forward down the barrel and equal amount of force is pushing back against the bolt face. It how most of your 9mm ARs work: Blowback.

Lol, I'd literally would love for you to try this exact thing.

 

[asiparks]

As I said earlier, I lack the balls for such things. Happy to be wrong about the exact function of the AR bolt and look forward to the OP's experiment.
edit - wait " the point the muzzle upwards and see the BCG fall out under its own weight" thing ? That I have done. It falls out under it's own weight.

edit again: so yes, I was wrong about the AR bolt unlocking. I broke open my AR, then put a long cleaning rod down the barrel from the muzzle end and tried to force the bolt open by whaling on the end of the rod. Wouldn't budge. So the OP can go back to fearlessly hammering on his firing pin.

BUT.... I'm not acceding on bolt action rifles.

 

[arakboss]

a) I can't speak for all bolt actions, but on mine, and all those I've seen, after you push the bolt forward, you invariably push it down to lock it. Then you lift it up to unlock it, before pulling it rearwards.
b)The lugs are square. The lugs on the barrel extension are square. How would the carrier move back without the bolt rotating to unlock ?- If the lugs and bolts were all truly square then nothin g would move. Something you can try at home: Take out the rear pin on your AR and break it open. Now, point the muzzle at the ceiling. just the weight of the bolt is probably going to cause itself to unlock and drop rearwards until it catches on the CH.

Equal and opposite forces- as the bullet moves forward down the barrel and equal amount of force is pushing back against the bolt face. It how most of your 9mm ARs work: Blowback.

Gravity would be a concern. I won't point the upper at the sky and I will make sure the carrier is flush with upper before giving it a smack.

 

[arakboss]

I am delaying my trip to cabin until next weekend. I have calf injury that just won't go away and was acting up big time at work last night. I already requested PTO for this Thursday night so I will give the calf a rest for three full days this weekend. I will try firing the upper at the cabin next weekend (4th of July). I will have some more rounds loaded with MP 842 for those following that thread.

 

[TTSX]

I just wanted to make sure that the buffer and spring wasn't somehow helping to keep lugs from unlocking in non-gas set up.

I'm very sure the buffer/spring are applying exactly zero pressure on the bolt carrier when it's locked in battery. Otherwise things would have a tendency to go SPROING any time you removed an upper from it's lower

 

[spookshack]

Guy cuts half the carrier off and mills out the left side of the upper receiver to attach a charging handle.

Han Solo blaster. Nice!

 

[MrRob96]

Gravity would be a concern. I won't point the upper at the sky and I will make sure the carrier is flush with upper before giving it a smack.

It really seems dangerous to you, and those that may shoot this thing, that you don't have any mechanism to keep the bolt positively locked, but able to freely float around in the upper. There should at least be some mechanism resisting the force of gravity at a minimum.

How are you planning to run the bolt forward into battery if there's no action spring and a non-reciprocating charging handle? Are you going to place a dingus on the carrier somewhere? Would it be difficult to add a catch that will keep the dingus in the closed position? Something as stupid as a bent piece of spring steel could work like a cabinet catch and really up the safety beyond "I won't point it at the sky".

 

[arakboss]

Reviving old topic as it relates to my project idea from this thread.

Imagine I have an AR15 barrel (gas port blocked) with barrel ext (no upper receiver) and insert a cartridge followed by a BCG. If I tap on firing pin and fire cartridge what is likely to happen with the BCG? Will it stay locked in the barrel extension until I pull it out?

This is a pic of the configuration I am talking about firing.




This pic is from the 3:00 min mark of this video:

 

[American123]

Reviving old topic as it relates to my project idea from this thread.

Imagine I have an AR15 barrel (gas port blocked) with barrel ext (no upper receiver) and insert a cartridge followed by a BCG. If I tap on firing pin and fire cartridge what is likely to happen with the BCG? Will it stay locked in the barrel extension until I pull it out?

Looking at this from a logical standpoint. If the firing of a cartridge unlocks the bolt in an AR even without the gas system in place, what would be the purpose of having a gas tube and a vent hole in the barrel going back into the chamber to push on the carrier?

Hence why, no, it doesn't make any sense that people are claiming the BCG would unlock itself if the gas system was disengaged. They are wrong.

You could function test this without a cartridge, just take the bolt out of the BCG, push it into the barrel as if it was going into battery, rotate it into position as if it was put into battery so the lugs are engaged against eachother, then try pulling the bolt out without rotating it. The lugs will be pushing against eachother and it won't be going anywhere until you rotate the bolt again to clear the lugs.

The bolt carrier rotates the bolt throughout it's movement after getting pushed backward via the gas pressure through the gas tube. No gas tube, no gas vented to carrier, no carrier push, no rotation of bolt, no unlocking of lugs, no bolt getting pulled backward.

People who are saying otherwise don't seem to fully understand how the AR works from a mechanical/gas pressure standpoint.

If you clamp an upper down without a gas system engaged and hit the firing pin, it will fire, the bolt will stay locked against the lugs of the barrel, only after you pull on the carrier, forcing the bolt to rotate and clear the locking lugs, will the bolt be able to move rearward.

Good grief…

 

[Stomper]

OMG….. it's 0130-hrs,
go to bed you weirdos!!

 

[American123]

Simple easy example of mechanical function. This is a blowback operated 9mm BCG. No interlocking lugs, straight blow back. No gas key because it isn't needed BECAUSE there are no interlocking lugs that would hold the chamber closed. Compare that to the AR 5.56 BCG, interlocking lugs holding the chamber closed until rearward pressure on the carrier forces the rotation of the bolt, unlocking the lugs.

 

[American123]

OMG….. it's 0130-hrs,
go to bed you weirdos!!

The lack of mechanical knowledge of how an AR functions present in this thread was concerning, it couldn't wait!

 

[arakboss]

OMG….. it's 0130-hrs,
go to bed you weirdos!!

Sorry I gotta get back to work.

 

[Stomper]

The lack of mechanical knowledge of how an AR functions present in this thread was concerning, it couldn't wait!

I understand your frustration… I just got home from an "emergency" after-hours service call that involved an hour of travel time each way (all billable overtime, BTW), and about 15 minutes onsite to affect the repair all because a millennial mouth-breather was too dumb to slide a rubber hose connector on an HVAC condensate drain back onto copper pipe…. I hit them with a 3-hr service call @ $200/hr because I'm a firm believer that being stupid should hurt.


Baby needs new shoes!!

 

[American123]

I understand your frustration… I just got home from an "emergency" after-hours service call that involved an hour of travel time each way (all billable overtime, BTW), and about 15 minutes onsite to affect the repair all because a millennial mouth-breather was too dumb to slide a rubber hose connector on an HVAC condensate drain back onto copper pipe…. I hit them with a 3-hr service call @ $200/hr because I'm a firm believer that being stupid should hurt.


Baby needs new shoes!!

Reminds me of a plumbing call my dad told me about where a guy called because "the toilet was broke." Get there, the handle lever had become disengaged from the tank lever, nothing actually broke or wrong with anything, they had just slipped off eachother and needed to be reengaged.

About 3 minutes on site for 1 hour of billable time. An alternate big name plumbing outfit had quoted him $1000, he called my dad as a second opinion.

Part of the reason this country is going in the bubblegumter is because stupid people are shielded over and over again from the reality of their failures and they never are forced to improve as a result.

 

[308]

Part of the reason this country is going in the bubblegumter is because stupid people are shielded over and over again from the reality of their failures and they never are forced to improve as a result.

Not to mention the ease at which one can self medicate nowadays making it simpler to avoid having to face reality

 

[Certaindeaf]

Here's FLT and company building and shooting some modified 300blk and 500 beowulf AR repeating pistols. They stay locked up just fine and are operated manually with no buffer spring.