Bullet scoring upon feeding

[BufordTJustice]

I thought the scoring was from the square notch in the back edge of the feed ramps. I could be wrong.

I'll do a test once i get off shift and will advise the outcome.

I'll put a dot with a Sharpie onto the top of the case while it is loaded into the magazine. I'll then slowly feed it into the chamber and slowly eject it (noting the position of the dot during the process). I'll report back.

The scoring certainly could be from the ejector and extractor dragging the case against the ejection port side of the barrel extension. I'll report back.

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[TomMcC]

I stand corrected. the last sentence of the 2nd paragraph threw me.

[ouchonyee]

Looking forward to your results Buford! I just did a quick test myself and find that the bullet gets scored both on chambering and extraction.

My testing method was this.

1. hand chamber a round, then extract normally
2. chamber a round normally, then extract slowly with finger pressing on case so the tip does not rub against barrel extension.

The marks are the same shape, at least on my particular setup.

[BufordTJustice]

Hookuleez is right in my case. I conducted my experiment on my upper (which leaves some very slight scratches that are even more faint than the above picture) and the scratches are actually engraving on the bullet as it is dragged against the ejection-port-side of the barrel extension upon EXTRACTION.

Granted, I have already polished my feed ramps (as I do on every barrel I install), so any marks that may be left by the feedramps are simply non-existent.

And we learn something new every day.....

[ouchonyee]

Ah ha! Nice update Buford, I guess I should polish my feed ramps..

I should mention my feed marks were slightly less marring, a smoother line, whereas my ejection marks looked exactly like talywhacker's picture above, with a little bit of chatter

[BufordTJustice]

Yeah, I don't see any feed marks on my upper....only extraction marks. This was after feeding and extracting 12 rounds. 6 fast and 6 slow.

Obviously, the extraction marks will not affect a round that is fired.

Ah ha! Nice update Buford, I guess I should polish my feed ramps..

I should mention my feed marks were slightly less marring, a smoother line, whereas my ejection marks looked exactly like talywhacker's picture above, with a little bit of chatter