Thread: forcing cone
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Old 08-23-2009, 07:24 PM
dfariswheel dfariswheel is offline
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A constricted bore in the thread area is known as "pressure dimpling" or "pressure compression".

If the barrel is torqued in too tight, the pressure causes the area to compress, leaving a tight spot in the rear of the revolver barrel.
S&W had a real problem with this when they first went from pinned barrels to torqued barrels.
The pinned barrels weren't torqued in that tight since they had a pin to prevent it unscrewing.
The new non-pinned barrels required torquing much tighter, and S&W had some trouble with over-torqued barrels with pressure compression tight spots.
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