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Lindcott Armory

Hodgdon Powder Company · Extruded

Retumbo

Ultra-slow extruded powder for large magnum rifle cases.

Also known as Retumbo
Manufacturer
Hodgdon
Grain shape
Extruded
Burn rank
#78
Category
Magnum Rifle
Temp sensitivity
Moderate
Application
Magnum Rifle
Origin
USA
Status
Active

Burn-rate position

FastestSlowest

Rank #78 on the burn-rate scale · Magnum Rifle

Typical cartridges

.300 Winchester Magnum, .300 Remington Ultra Magnum, .30-378 Weatherby Magnum, 7mm Remington Magnum, .338 Lapua Magnum

Substitutes

Listed substitutions with charge guidance. Always start at published minimums and work up.

AR 2218 · ADI Manufacturer

Identical formulation — use same charge weights.

IMR 8133 · IMR Published

ADI-based; similar burn rate to Retumbo for ultra-magnum cartridges. Start low.

Similar burn rate; reduce 3–5% when substituting.

N170 · Vihtavuori Community

Similar burn rate for ultra-magnums; reduce 4–6% when substituting.

By cartridge

Similar burn rate

Supply & handling

Availability (US)
Common
Shortage-prone
No
Suppressor-friendly
Yes
Flash-suppressed
No

About this powder

Retumbo (the name is "Retumbo" — a portmanteau of "return to magnums" or simply an invented name) is the slowest of the Hodgdon Extreme series, designed for the .338 Lapua, .300 Ultra Mag, .30-378 Wby, and similarly large cases. Its temperature stability makes it a staple for ELR (extreme long range) competitors who need consistency from 20°F to 100°F.

Head-to-headRetumbo vs AR 2218Head-to-headRetumbo vs IMR 8133Head-to-headRetumbo vs Reloader 26Head-to-headRetumbo vs N170 ChartSee it on the burn-rate spectrum BrowseEvery powder, ranked by burn rate

Sources & provenance