Colt canada sas gas block question

[*MALICE*]

Why do they have a cap screw at the front.

I read somewhere that it's so you can push/pull the gas tube out from the front......but being as that the gas tubes are straight, you could just as easily remove it out the back.
And Lots of low-pro gas blocks just have that tube hole open out the end so why bother with tapping the end and installing a screw?

What am i missing?

Is it cuz since the iur doesn't have a removeable handguard, you can thread something into it to pull it out if you need to remove the gas block from the barrel?

Added - the question is: why bother with having a cap screw at all, not why does the hole go all the way through

 

[73582]

The screw is for cleaning convenience.

 

[khw]

I think it's for adjusting the gas, but I haven't tried it since I don't need to. I imagine it was probably part of the contract with UKSF with them running suppressors and stuff.

 

[Twan]

I think it's for adjusting the gas, but I haven't tried it since I don't need to. I imagine it was probably part of the contract with UKSF with them running suppressors and stuff.

It's absolutely not for adjusting gas - Colt Canada designs their guns to function, no gas adjustment required. The screw is there so that the tube can be pushed through the front of the GB when doing maintenance.

 

[*MALICE*]

I knew this was going to happen.

Ok, so let's read my post again.

I KNOW that the reason for the hole in the gas block to be drilled straight through is to make it easy to remove/replace the gas tube. Got that.

But why bother installing a screw. The screw doesn't NEED to be there. The end of a gas tube has a plug crimped in place in addition to the roll pin going through it, so the gas CAN'T go forward (if there were no plug crimped into the gas tube you'd burn through your role pin). If you took the screw out and fired the gun, it would function perfectly fine, no gas would come out the muzzle end of the block.

There are many brands of low-profile gas block where the hole for the gas tube is drilled/reamed straight through the block, and they DON'T have a cap screw installed in the end. In fact, the Colt Canada MRR gas block is like this; hole goes straight through, no cap screw in the end.

So why install a cap screw that is functionally unnecessary? Did an engineer just decide they didn't like seeing the silver gas tube tip from the muzzle end? lol Is the screw there as a 'backup plug' ie. you install the gas tube and then thread the screw against the gas tube so that in the unlikely event the roll pin shears, the gas tube can't shift forward?

 

[Dek68]

stopping debris from entering the hole? a screw is far more secure than a push cap. apologies, just a spit balling newbie.

 

[*MALICE*]

stopping debris from entering the hole? a screw is far more secure than a push cap. apologies, just a spit balling newbie.

Maybe......I don't know that debris accumulation is really a problem......but maybe someone thought it could be?

I'm actually thinking my 'back-up screw'/stop idea might be the reason. A failsafe in case the roll pin shears, or to add support to prevent it from shearing?

 

[BioPace]

Maybe......I don't know that debris accumulation is really a problem......but maybe someone thought it could be?

I'm actually thinking my 'back-up screw'/stop idea might be the reason. A failsafe in case the roll pin shears, or to add support to prevent it from shearing?

I'd have to reckon that it was someones pet peeve or concern that in reality would require a 1 in a billion chance to happen, but its the SAS so they made it happen.

Would it help with aligning the gas tube roll pin hole? Over insert the gas tube and use the set screw to bring it back into alignment?

 

[*MALICE*]

I'd have to reckon that it was someones pet peeve or concern that in reality would require a 1 in a billion chance to happen, but its the SAS so they made it happen.

Would it help with aligning the gas tube roll pin hole? Over insert the gas tube and use the set screw to bring it back into alignment?

*shrugs* that wouldn't be my first (or 12th) idea for aligning a gas tube....lol but i guess it's as good a guess as my theory

 

[Twan]

I'd have to reckon that it was someones pet peeve or concern that in reality would require a 1 in a billion chance to happen, but its the SAS so they made it happen.

Would it help with aligning the gas tube roll pin hole? Over insert the gas tube and use the set screw to bring it back into alignment?

I do believe Malice above is correct with regards to retaining the tube in the event of a failed roll pin, or the likely-to-never-happen but possibility of the gas tube plug coming free.