How much powder reduction would be required to compensate for the "no free bore".
Thanks Fred M.

Hard to say, but why? There's not a lot of difference between the weatherby and the 25-06 (I happen to like the weatherby better), so without the freebore and having to cut loading, just get a stock 25-06. Why pay hundreds for a custom reamer to lower performance? I know everyone gets wound up about freebore, but the few 257's I have seen all outshoot the several 25-06's I have owned. The 257 is not a target or varmint rifle by any stretch. It has plenty of inherent accuracy for big game hunting as is. Most owners are really surprised by the accuracy they do get.

Sorry for the late reply, I just saw the thread. I have a Jarrett-built No. 1 in .257 Weatherby without the freebore. I found I needed about 3 to 4 grains less powder for the same velocity I got from either of my my MkVs. Yet I cannot get higher velocities with the free-bored rifles, probably because the Jarrett chamber is tighter. I get 3620 fps with any of them using 100-grain ballistic Tips. Try to get velocity that from a .25-06.

The reason to do this? Long range target and varmint work needs better accuracy than factory MkVs give. My No.1 aggs in the .5s for five consecutive three-shot groups with individual groups in the .3s. Try to get that level of accuracy with a freebored rifle....



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I'm using 65.3 7828 and 120 partitions .15 off the lands@3290fps. The load is about4.5 grains lower than my mrk 5's. My barrel is a Krieger without free bore .