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Chamber question

232593

Fuck your democracy
Full Member
Minuteman
  • May 25, 2022
    3,106
    8,108
    Shithole
    I thought chambers were supposed to be polished. On all my other firearms they are.

    Are they supposed to look like this?

    IMG_3608.jpeg
     
    That’s not the best photo but it looks like marks from the brass going in and out and not the chamber cut.
    Try to get another photo if you can.


    A bad chamber cut looks like this and marks the brass accordingly when fired. That shit came from a manufacturer of a prefit.
     

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    That’s not the best photo but it looks like marks from the brass going in and out and not the chamber cut.
    Try to get another photo if you can.


    A bad chamber cut looks like this and marks the brass accordingly when fired. That shit came from a manufacturer of a prefit.

    Proof lol?
     
    That’s not the best photo but it looks like marks from the brass going in and out and not the chamber cut.
    Try to get another photo if you can.


    A bad chamber cut looks like this and marks the brass accordingly when fired. That shit came from a manufacturer of a prefit.
    I didn’t think brass was hard enough to scratch steel.

    My pic is admittedly a bit shitty, the gunsmith’s bore scope was having some issues when we tried to get a screen capture. But it looked similar to the pic you posted.
     
    Does it feed well?
    If you get a chamber too smooth you lose grip on the brass and can give you false pressure signs. A cross hatch finish like on piston cylinder walls is about ideal.
    If it feeds without sticking it’s fine. If brass sticks while trying to eject, you can deburr with a dowel rod and Emory cloth.
     
    Last edited:
    Does it feed well?
    If you get a chamber too smooth you lose grip on the brass and can get false pressure signs. A cross hatch finish like on piston cylinder walls is about ideal.
    If it feeds without sticking it’s fine. If brass sticks while trying to eject, you can deburr with a dowel rod and Emory cloth.
    So far it has fed ok. The gunsmith that I took it to said it was way too rough. He showed me a pic of some cheap AK chambers he had and mine was way rougher.
     
    I understand that this is in "Bolt Action Rifles", and I'm not implying that your barrel's chamber was done intentionally, but the LaRue OBR barrel chambers have longitudinal grooves intended to help with extraction. They call it "Xtraxn", and more than one person has lapped the chamber to remove the grooves thinking it was a flaw or defect.
     
    Desert Tech
    Does Desert Tech chamber their own or do they outsource it?

    I have an ES tactical desert tech barrel that is rough at the neck/shoulder junction. Intentional or not, I don’t know. Smooth everywhere else. The brass looks good after firing. What does your fired brass look like?
     
    Does it feed well?
    If you get a chamber too smooth you lose grip on the brass and can give you false pressure signs. A cross hatch finish like on piston cylinder walls is about ideal.
    If it feeds without sticking it’s fine. If brass sticks while trying to eject, you can deburr with a dowel rod and Emory cloth.
    You know that cylinder crosshatching is used to hold oil for lubrication and guiding piston ring rotation right?

    I've yet to see evidence of "too smooth" chamber finish. Under firing pressure the case is going to compress the ejector (and spring) before brass expands.......the whole path of least resistance thing. As far as "wall grip"......take two precision ground surfaces and squeeze them together......good luck getting them apart. Just my observations over the years.

    In my experience, I like to use 400grit polishing to knock down reamer machining marks and break any sharp edges that can shave jacket or brass during operation.

    Not sure what happened to the above chamber. Either live with it or contact the maker. Completely your call, I've seen both extremes......shooters who can't live with any evidence of use.......and shooters that are shooting homebrew mixed part rifles because it shoots decent enough.

    Ern
     
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    You know that cylinder crosshatching is used to hold oil for lubrication and guiding piston ring rotation right?

    I've yet to see evidence of "too smooth" chamber finish. Under firing pressure the case is going to compress the ejector (and spring) before brass expands.......the whole path of least resistance thing. As far as "wall grip"......take two precision ground surfaces and squeeze them together......good luck getting them apart. Just my observations over the years.

    In my experience, I like to use 400grit polishing to knock down reamer machining marks and break any sharp edges that can shave jacket or brass during operation.

    Not sure what happened to the above chamber. Either live with it or contact the maker. Completely your call, I've seen both extremes......shooters who can't live with any evidence of use.......and shooters that are shooting homebrew mixed part rifles because it shoots decent enough.

    Ern
    The manufacturer has been contacted and I’m awaiting a response.

    I can deal with evidence of use, however this was supposed to be a new barrel extension. But I don’t want a defect that will cause issues later on.