With the reduction of case capacity in the HBR benchrest class, I have chosen to research the 30 BRX case. Most shooter are shooting the 112 to 118 bullets in the 30 BR. I have a bunch of 125 gr. bullets and would like to have a couple extra grains of powder to keep the velocity up in the 2950, 3050 range and not be hard on the brass. Will be Emailing PTG for a reamer print, but in the meantime does anyone have one that the could email me that I could look over. Explain what bullets you are using and o give of the bullet and how far in the case the bullet is seated. Trying to determine the headspace of the case and distance to the lands for a 125gr 7 o give bullet. Thinking somewhere around .010 to .015 range maybe .020. That's why I'm asking Thanks, Randy
30 BRX help
- Thread starter Rewinder
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R.G. Robinett
"That'll never work."
With [tangent] 7 ogive bullets, based upon the 1.00" long jacket, you can get away with up to about 0.050" of free-bore - I'd not go over 0.030", as that leaves the door open to bullets based upon the .925" long jacket.
Via the 30 BR, and it's near relatives (30PPC, 30Major, Grendel, etc.), when opting for the 125 Gr. weight, in combination with H-4198, you will sacrifice little, if any velocity. For the 30BR capactiy and expansion ratio, this number is on the verge of being "too slow" - it's difficult to get enough 4198 into a 30BR case to generate excessive pressure with the 110 - 118 Gr. bullets, however, with the 125s, you may generate enough pressure to raise eyebrows!
With my LOT of 4198, I have used the same powder charge weight with all bullet weights - 112 to 125 Gr., getting excellent results. However, be wise and work up, as Your LOT may be different!
Oh, back to the velocity thing - it will probably prove counter-intuitive - within this bullet weight range, and same charge weight, my barrels and H-4198 LOT have produced remarkably similar 15' velocities! RG