I am surprised that the 26-inch barrel didn't provide more velocity boost. I suppose it just can't do it when powder capacity is limited as it is in the .30-30 case.


Just for comparison's sake, a 170-grain Sierra (but at the same OAL, which you probably would not do):


Code
Cartridge          : .30-30 Win. (SAAMI)
Bullet             : .308, 170, Sierra SPFN 30-30 2010
Useable Case Capaci: 39.330 grain H2O = 2.554 cm³
Cartridge O.A.L. L6: 2.734 inch = 69.44 mm
Barrel Length      : 26.0 inch = 660.4 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 42000 psi, or 289 MPa
or a maximum loading ratio or filling of 107 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

Powder type          Filling/Loading Ratio  Charge    Charge   Vel. Prop.Burnt P max  P muzz  B_Time
                                      %     Grains    Gramm   fps     %       psi     psi    ms
---------------------------------  -----------------------------------------------------------------
Accurate 2520                       92.0     35.2     2.28    2349    98.9    42000    5120   1.454
Hodgdon H4895                       92.1     33.4     2.16    2332    96.6    42000    5187   1.453
Hodgdon H335                        83.7     33.1     2.15    2322    99.2    42000    4940   1.448
Hodgdon H322                        88.5     31.1     2.02    2319    99.7    42000    4790   1.443



Don't be the darkness.

America will perish while those who should be standing guard are satisfying their lusts.