Arrow spine for a 70 lb compound at a 27 inch arrow with a 100 grain point: a 340 spine (band 340-400), plus the 350 grain minimum weight. Sourced.
Updated 05 September 2026.
What arrow spine for 70 lb draw at a 27 inch arrow
The starting spine for a 70 lb draw at a 27 inch arrow with a 100 grain point, and the weight floor.
| Draw weight | 70 lb |
|---|---|
| Arrow length | 27 in (cut, nock groove to shaft end) |
| Point weight | 100 gr |
| Recommended spine | 340 (published band 340-400) |
| Minimum total weight | 350 gr, from the 5-grains-per-pound floor |
Easton 5mm Axis carbon arrow shaft (340 spine)
Shop Easton 5mm Axis carbon arrow shaft (340 spine) on AmazonaffiliateFind Easton 5mm Axis carbon arrow shaft (340 spine) on eBayaffiliateField notes
A 70 lb bow at a short 27 inch arrow flexes less than a 29 inch cut, so it takes a 340 rather than a 300. Cutting arrows short is one way a heavy-draw shooter can use a slightly weaker spine.
Spine is a starting point, not a guarantee, because a 340 from one brand can differ from another. Confirm on your arrow maker's chart at 27 inches and 70 pounds, or bare-shaft test before cutting a dozen.
Whatever spine you land on, keep the finished arrow at or above 350 grains total, the 5-grains-per-pound floor, so the bow is not shooting dangerously light.
The rules behind this pick
Questions and answers
What arrow spine for 70 lb draw at a 27 inch arrow?
For a 70 lb draw at a 27 inch arrow with a 100 grain point, start with a 340 spine (the 340-400 band), and keep the finished arrow at or above 350 grains total.