bullet jam

[Waltech Jim]

[ QUOTE ]
so basically what we are looking at when you have founf the OAL of your loaded bullet add 10 thou to this measurment and with the correct neck tension lets say 2 thou this is enough to sft seat.jam the bullet so they are all correctly positioned to the rifleing ??

[/ QUOTE ]

Yes.



[ QUOTE ]
one more question I have tried this I have 2 thou of neck tension and when I add 10 thou to my OAL the bolt shuts fine with very little pressure but when I extrcat it the OAL has lengthend as i prsume the lands have held the bullet and with minimum neck tension has allowed the bullet to be pulled out slightly,I presume this is OK when you actually shoot each round topu chamber but will it efeect anything if you keep taking the bullet in and out as over here in the UK you are not guaranteed to make a shot

[/ QUOTE ]

What you describe I have experienced also. With little neck tension, the bullet is pulled forward as the shell is removed from the chamber.

You obviously are much luckier than I, as I am usually left with a chamber and action full of powder. /ubbthreads/images/graemlins/mad.gif

The bullet usually falls out with a sharp rap to the buttstock. The powder is dumped out of the action and with some very nasty language I am ready to go again.

Jim

 

[Pete L]

[ QUOTE ]
[ QUOTE ]
so basically what we are looking at when you have founf the OAL of your loaded bullet add 10 thou to this measurment and with the correct neck tension lets say 2 thou this is enough to sft seat.jam the bullet so they are all correctly positioned to the rifleing ??

[/ QUOTE ]

Yes.



[ QUOTE ]
one more question I have tried this I have 2 thou of neck tension and when I add 10 thou to my OAL the bolt shuts fine with very little pressure but when I extrcat it the OAL has lengthend as i prsume the lands have held the bullet and with minimum neck tension has allowed the bullet to be pulled out slightly,I presume this is OK when you actually shoot each round topu chamber but will it efeect anything if you keep taking the bullet in and out as over here in the UK you are not guaranteed to make a shot

[/ QUOTE ]

What you describe I have experienced also. With little neck tension, the bullet is pulled forward as the shell is removed from the chamber.

You obviously are much luckier than I, as I am usually left with a chamber and action full of powder. /ubbthreads/images/graemlins/mad.gif

The bullet usually falls out with a sharp rap to the buttstock. The powder is dumped out of the action and with some very nasty language I am ready to go again.

Jim

[/ QUOTE ]
Ahh my rifle is short throated /ubbthreads/images/graemlins/smile.gif

 

[Bart B]

For all you guys making head to bullet ogive datum (hopefully at bore diameter) measurements to the nearest .001-inch, note how the shoulder position effects the point where the bullet just touches the rifling.

Head to shoulder datum (measured by various gages) will vary by a couple thousandths of an inch across a batch of cases. More with some cases if they've been body sized and shoulder's set back with varying amounts of lube on the case.

And remember that spring loaded ejectors will push the case forward into the chamber where it stops with its shoulder against the chamber's shoulder. And when the firing pin strikes the primer, that's going to drive the case's shoulder harder against the chamber's shoulder. Sometimes the shoulder will set back .001-inch or so. I've reprimed the same empty case, popped its primer then measured its headspace, several times, noting the shoulder moving back a tiny bit each time; proof that this happens.

All of which means the shoulder datum to ogive datum is probably the best way to get the bullet to mate with the lands with whatever dimension desired. Now if someone would just make a gage to measure that with; it's gotta measure between two forward sloping parts.

As for belted cases; they don't have quite the same situation.