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Low neck tension = lack of expansion and seal ???
Posted: Sat Jul 28, 2012 6:01 pm
by Promapper
If my neck tension is to low will it cause a condition that keeps the brass from expanding and sealing the chamber thereby creating blow back. I noticed 2 out of 8 fired cases looks like they have burn marks down one side of the case in kind of an arc pattern.
currently using a bushing that results in the ID of the case being .002 less that the diameter of the bullet. Loading 6.5 x 284 with 140 grain berger VLD's.
Thanks for helping out us newbee's.
Greg
Re: Low neck tension = lack of expansion and seal ???
Posted: Sat Jul 28, 2012 10:01 pm
by Hedge
.002" of neck compression should be more than adequate. Sounds more like a light powder charge. The shoulder should be expanding to seal the chamber.
Re: Low neck tension = lack of expansion and seal ???
Posted: Mon Jul 30, 2012 6:10 am
by Nor Cal Mikie
And, it could also relate to how many times the brass had been fired. Work hardened brass won't expand and contract like softer brass. Same when resizing. You may think it's OK with the bushing you're using but you may be getting false readings.
Re: Low neck tension = lack of expansion and seal ???
Posted: Mon Jul 30, 2012 9:21 am
by bow shot
Not an expert here, but I concur with light powder charge, or incorrect type (too slow or fast or whatever...)
Re: Low neck tension = lack of expansion and seal ???
Posted: Mon Jul 30, 2012 3:04 pm
by Promapper
reduced charge by 1 grain and the issue solved itself. Thanks fella's for your input as I can assure you I looked into them all,