I have been shooting Bart's bullets in my 30BR that was chambered by Dusty Stevens with a Robinette reamer and everything has gone well. But while waiting for a response to a question posed to Bart thru Dusty I purchased some BIB 112 grain bullets after reading the NBRSA match equipment lists.
I was working up the seating depth when I have ran into a problem. The BIB bullets when seated in the cases (that work just fine with Bart's bullets) will not chamber due to the case necks being expanded about .005" larger than with the Bart's bullets.
I know, my chamber and neck walls are tight, but has anyone else run into this before?
As others have stated, your figure surely lacks a ZERO!
The 112 Gr. bullets you purchased should measure 0.3087" across the heel (pressure-ring), and .3083" on the shank. Some older LOTs of J4 jackets would make a P-R as large as .3088", along with the [usual] .3083" shank diameter. The Hines/Allied Precision Tool jackets (sold by Bart's and StaMoly) have been pretty consistent, at .3083" shank, with .3085- .0387" P-R - about average, but for the Niemi dies, tending toward the small end of the P-R range.
When measuring 1/10ths of one thousandth of an inch, one should verify the micrometer via a standard - even then, the instrument may display +/- 0.0001", depending upon user, and/or, many other factors. I verify micrometer calibration to a standard daily - often several times.
Seven ogive BIB bullets , depending upon jacket LOT, have run from 0.3085" (rare with J4) to 0.3088" (unusual), with .3086-7" being the overwhelming "norm". I have always turned [thirty caliber] case necks to 0.0098", which usually results in loaded-round neck-diameter of .3282 -.3283", or, .0017" to .0018" of total clearance for a .330" chamber neck diameter. With my .0098" neck-wall thickness, a true .3080" heel/pressure-ring would result in a loaded-round neck diameter of .3278", or, .0022" of total clearance. The BIB thirty caliber dies were made to make the shank diameter .3083" - the pressure-ring is a variable, which is, normally, of little consequence.
It would appear that you have been shooting the BARTs with minimal neck-clearance - probably 0.0005" , or, less.
I'd predict much better Agging capability if you turn necks to 0.0010" wall thickness, or slightly less. Assuring that total clearance is .0015", or greater is usually desirable. While "fitted necks" can work, not many individuals even attempt it any more. Good shootin'! RG