I have been playing around with my new scope (long thread on it in the equipment forum) and thought of a potential use. Last night after a few beers I took a fired case and chambered it. Then I passed the scope down the barrel and looked at the case mouth/throat junction. It looks like the gap is several thou wide. In other words, the case could stand to grow quite a bit through firing before it would start to cause issues. Seems to me the closer you can get this gap the better for accuracy, fouling, etc. Any thoughts on this? I wish I would have taken a screenshot but the beers were working. LOL
Potential use for new bore scope
- Thread starter Cerwinski
- Start date
There's supposed to be a gap so the bolt can close without a problem. Minimize the gap, maximize the chances of your ammo not feeding properly.
Better use would be to examine a few cases on the inside for hairline cracks or thin spots on brass with multiple firings on it.
Better use would be to examine a few cases on the inside for hairline cracks or thin spots on brass with multiple firings on it.
However... don’t make the assumption a trim length that takes you a wisp away from the max has anything to do with more accuracy.
Staying a margin away from the disaster that can happen if the case mouth gets squeezed on closure is what drives all these safety dimensions.
You can find the reamer was generous and your particular chamber has more margin than the specs, but there isn’t a direct correlation to accuracy there that I know of. What we do know is how bad a pressure spike can get if you accidentally crimp down on a case neck with your chamber. Good observations, but don’t jump to the conclusion that closing that gap will increase your accuracy.
Staying a margin away from the disaster that can happen if the case mouth gets squeezed on closure is what drives all these safety dimensions.
You can find the reamer was generous and your particular chamber has more margin than the specs, but there isn’t a direct correlation to accuracy there that I know of. What we do know is how bad a pressure spike can get if you accidentally crimp down on a case neck with your chamber. Good observations, but don’t jump to the conclusion that closing that gap will increase your accuracy.
With a borescope I found my chamber cleaning in a semi AR platform was inadequate. My borescope taught me I had to try to shove the chamber brush into the lands to get it in far enough then turn twice as many rotations as I was normally using to clean carbon deposits from that gap you speak of.
Normal brushing and my old "insert chamber brush till the bristles pass the lugs and spin a few times" did not cut the carbon ring just behind the throat in front of where the brass stopped.
Normal brushing and my old "insert chamber brush till the bristles pass the lugs and spin a few times" did not cut the carbon ring just behind the throat in front of where the brass stopped.
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D
Deleted member 10043
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I'm going to it stick up my ass and post it here unless that is considered Po RN. I'm going to verify the results of my last colonoscopy myself and then turn around and use it for a refund.
If this thread appeared in the Pit..... *that* would be concerning.I was about half scared to click on this thread.
