Which burns faster, H4350 or IMR 4350?

H4350 is the faster-burning of the two (rank #66 vs #67 — lower rank burns faster).

What cartridges do H4350 and IMR 4350 both load?

Both powders are listed for .243 Winchester, .30-06 Springfield, .308 Winchester, .270 Winchester, 7mm-08 Remington.

Powder head-to-head

Both powders on one page: burn-rate position, temperature sensitivity and the 5 cartridges they share, with the substitution note from the reference.

FastestSlowest

Similar application range but not identical. Start at lowest published charge for the target powder and work up. H4350 tends to be slightly slower.

Confidence: Published. Always start at published minimums and work up.

Can I substitute H4350 for IMR 4350?: Similar application range but not identical. Start at lowest published charge for the target powder and work up. H4350 tends to be slightly slower. Confidence: Published. Always start at published minimum charges and work up.
Which burns faster, H4350 or IMR 4350?: H4350 is the faster-burning of the two (rank #66 vs #67 — lower rank burns faster).
What cartridges do H4350 and IMR 4350 both load?: Both powders are listed for .243 Winchester, .30-06 Springfield, .308 Winchester, .270 Winchester, 7mm-08 Remington.