Better performance with under stabilized 75-77gr?

[Jack-O]

I have not noticed disproportionate accuracy degradation with the 75/ 1-9 combo until after 300 or so yards.

with multiple guns i have gotten acceptable accuracy at 100 yards with this combo.

[Tactical Rancher]

Good observation. All my tests were at 100...

[signal4l]

It's not the weight of the bullet but the LENGTH. Not all 75gr bullets are the same length, and the AMAX is a very long bullet. Same for the 70gr TSX.

We generally use weight as a guideline when it comes to specifying what bullet is stabilized in what twist rate barrel since weight it easier to quantify than the length of the bullet. This works most of the time, but the limitations are shown when you're on the borderline already.

BTW - Molon's tests have clearly shown that a 1:7 barrel is more accurate than a 1:9 (assuming that the 1:9 properly stabilizes the bullet). The difference was noticeable. It won't make a difference at CQB distances or out to 100 yards (unless you're going for precision), but I'd be hesitant to try for much beyond that range.

50 gr Winchester frangible. M-16 A1 1:12 barrel. The bullet is lightweight but long. Unstable at 5 yards.

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