Are you using an Adj gas block?

[Klem]

I'm confused now. Have we decided INCREASED port erosion from an ADJUSTABLE block IS OR ISN'T a real thing?

To be clear, I doubt the claim that adjustable gas blocks erode faster than non-adjustable. However, given there is no empirical evidence to suggest either way then the correct answer would be to say...we simply do not know (all of us). It is yet to be proven or disproven.

I am also saying that regardless of if it is true I think it is moot. Moot in the decision to buy one type or the other. Both types of block are capable of sealing the area around the port equally. If any erosion is happening it still remains effectively sealed until it is time to replace the barrel for some other reason. All the normal reasons like wear-and-tear on the throat, lands and crown, which for some shooters is going to be years down the track.

As for blocks leaking gas, frankly I think this is moot also. Any venting of gas through imperfect seals is rarely to the extent that reliable cycling or accuracy is affected. As long as reliable cycling happens for the life of the barrel then your block has done its job. I know some of you glue your blocks for a better seal but I don't. I just don't care about minor leaks. I don't believe leaks around a gas block affects accuracy, certainly not to the extent that a block of metal sitting half-way down the barrel and connected to the receiver by a gas tube does. I know marketers have the hide to call AR15's 'Free floating' but that is where the block is going to influence accuracy, by just being there and connected to the receiver, and syphoning gas, not because it might leak. My opinion is different from 52's on this point and I accept that, and respect his.

The idea of the port 'galling' the round as it passes is an interesting one, but moving away from the thread topic of adjustable/non adjustable blocks for suppressors. On this I agree with 52. If the port drilled by the manufacturer to enter the barrel half way on a land and half on the adjacent groove then I can see how this might occur. It certainly makes lapping the drill-hole burrs more difficult (which cheaper barrel manufacturers don't do). If increased port erosion is happening over the life of the barrel however I can imagine it might actually help the gas flow rather than gall the bullet. Port erosion lapping the port?

All that said, I'm quoting Shakespeare on port erosion, 'Much ado about nothing'.