Preface ;
If it's weird , peculiar, or a production "opps let's ship it anyway" it's probably been in my hands . I had a .025 over 383 factory sealed Chrysler once and 1-8.5" Savage 110 06' .........
I mastered paper patch to A avoid gas checks and B make assorted fat 30s fit a .318 7.62 ......
I've been through the awe of high speed slow twist and the fast twist poof .
I've seen groups grow and shrink and pick up the shrink stepping to the next slower powders primer changes etc .
I've had the rifle that tosses 12" over there for case volume changes within a single box of factory ammo .
What I have is Dad's 1972 700 BDL Varmint Master 25-06' 26" 1-9" twist .250×.257 . A 258 front drive band markes at .08 above the case mouth at 2.5-.002 " . It's had less than 800 rounds through it , before I started, most of them handloads of Sierra 100 gr Game Kings or Pro Hunters at about 3100 fps by the book . It never shot the 115,117, or 120s well although I did get a partial box and 17 loaded with the plain base Pro Hunter 115 he took on a 3 tag hunt in Montana circa 1987 for deer , elk , and bear . The load must have delivered under under 1.5 at 100 or he wouldn't have taken it .
So I have the NOE 260-120@124 gr and 257312 @.259-100 . Sizing is good , the throat is tight enough that the NOE nose kisses the lands even seated covering the crimp groove .
Both bullets as I work up do the usual group shrink in matched cases as the charges increase until they get down to about 1.5" at 50 yd then it's just flat . It hits at about 12.5 gr and on up to 14.5 it just hovers it doesn't strip , lead , tip , tilt or any of the normal or weirdness I've encountered. I've used 3 cases and will try the 2003 vintage new Winchester when I find it . I've used new unprimed virgin 1972 RP , EW42 formed , WW , and Super X in weigh matched , trimmed , and annealed . Loads have been sent in work ups from 9.5 to14.5 gr Unique in each case @5 each with Aluminum Sages , Hornady new copper and 195?-1965ish Lyman copper checks and Win LRP, CCI 300 and a load set pending with FC 210s . I even had another user involved to ensure it wasn't me . Same results. I've been from nominal seating to hard jamb with the NOE literally finishing the seating with the bolt to half the top band in the case .
The max loads should be upwards of 2100 fps MV.
I've had lots of arms do lots of things but I've never had one just go flat ......"that's it that's all you're getting beat the mule all you want" this would really great if it were at a 100 and I could just push up to the desired speed for desired energy and terminal performance but it's not there yet.
Last item it's about the hunt so the alloy is what it is at this stage , which is handling the pressure, not running out of lube , and going straight .
I'm open to suggestions the next step is to move to full cases of too slow powder and see if 3" holds 24- 2700 fps . That is kind of the start point with the next step so .......