Published: September 2026
Disclaimer: This article is for informational and educational purposes only. Reloading involves inherent risks. Always consult current manufacturer load data, follow established safety protocols, and work up loads incrementally. Neither the author nor MyReloading.com assumes liability for the use of the information presented here.
Powder choice shapes everything about how 40 S&W actually performs at the bench and downrange, and this cartridge covers a genuinely wide range of viable burn rates depending on what you’re loading for. A fast powder that meters beautifully for target work isn’t the right choice for a hunting load chasing real velocity, and a medium-burn powder built for consistency can leave a competition shooter wanting more speed. This guide breaks powder selection down by what you’re actually trying to accomplish, with charge and velocity data cross-checked across current manuals where I could find agreement between them, and flagged clearly where I couldn’t.
Burn Rate Tiers for 40 S&W
40 S&W’s short, wide case and 35,000 psi ceiling put it in comfortable territory for fast-to-medium pistol powders, roughly the same range that works well in 9mm and 45 ACP, though the specific charge weights never carry over between cartridges.
Fast powders, Clays, Titegroup, and HP-38, sold under the Winchester label as 231, meter cleanly in small charges and are the standard choice for target and practice loads at moderate velocity. Medium-burn powders, Alliant Unique, Power Pistol, and Herco among them, fill more case volume and give you a genuine working window between mild and full-power loads. Medium-slow powders, Blue Dot and Longshot, are where you go for maximum velocity with heavier bullets, at the cost of more muzzle flash than the faster options produce.
Verified Charge Data by Powder
The figures below are drawn from current manufacturer data and cross-checked where more than one source publishes a load for the same bullet weight. Treat every number here as a reference point, not a substitute for the specific entry in your own manual; start at or below the listed minimum and work up in small increments regardless of how many sources agree.
Longshot, 180gr XTP, COL 1.125″: start 6.5gr for roughly 1,009 fps, max 8.0gr for roughly 1,159 fps at approximately 32,300 psi. This is Hodgdon’s own published range and it’s well corroborated by independent chronograph testing; several handloaders report near-identical results at the 8.0-grain maximum. Longshot is the powder to reach for when you want real velocity out of a heavy bullet without walking anywhere near the pressure ceiling, and it produces noticeably more flash than a faster powder in exchange for that performance.
HP-38 / Winchester 231, 180gr plated round-nose: commonly loaded 4.2 to 4.6 grains, producing roughly 790 to 860 fps depending on exact charge and barrel. This sits well below any published maximum and represents a genuinely mild, easy-shooting practice load rather than a full-power recipe; if you want more velocity from this powder, pull current data for your specific bullet rather than assuming this range scales linearly upward.
Titegroup, 180gr RNFP: commonly loaded 3.5 to 3.9 grains for roughly 800 to 860 fps. Titegroup’s small charge and fast burn make it economical and clean, but it occupies relatively little case volume at these charge weights, which is exactly why visual charge inspection matters more with this powder than with a bulkier one; a missed double charge is harder to catch by eye here than with Longshot or Unique.
Alliant Unique, 180gr jacketed: manuals show real spread here, generally 5.5 to 6.6 grains depending on source and exact bullet construction, landing in the 950 to 1,050 fps range. This is the same powder and general charge range covered in our first 40 S&W handload guide, where 5.5 grains with a 180-grain FMJ is presented as a genuinely conservative starting point rather than a mid-range number, consistent with the spread noted here.
Power Pistol: widely used across 155 to 180-grain bullets for a solid balance of velocity and manageable flash; consult current data for your specific bullet weight, since Power Pistol’s charge range shifts meaningfully between a 155-grain and a 180-grain bullet in ways a flat number wouldn’t capture accurately.
A Real Manual Disagreement Worth Knowing About
Clays deserves a specific warning. Published data for a 165-grain JHP shows a genuinely significant gap between sources: Hodgdon, the powder’s own manufacturer, lists a starting charge of 3.5 grains and a hard maximum of 3.9 grains. Sierra’s manual for the same bullet weight lists a range running from 3.4 grains up to 5.2 grains, calling 5.2 their preferred accuracy load, a full 1.3 grains past Hodgdon’s own stated maximum.
This is not a case where the two sources are simply using different test barrels and rounding differently; it’s a meaningfully large gap on the exact same bullet weight from the powder’s own manufacturer versus a bullet manufacturer’s independently developed data. When you’re working with Clays in this cartridge, default to Hodgdon’s figures over any other source, since they control the actual powder formulation and testing. If you already have loads at the higher end of another manual’s range, treat that as a reason to re-verify with a chronograph and close pressure-sign attention, not as a green light to continue.
Quick Reference Table
| Powder | Bullet Weight | Charge Range | Approx. Velocity | Burn Rate |
|---|---|---|---|---|
| Longshot | 180gr XTP | 6.5-8.0gr | 1,009-1,159 fps | Medium-slow |
| HP-38 / W231 | 180gr plated | 4.2-4.6gr | 790-860 fps | Fast |
| Titegroup | 180gr RNFP | 3.5-3.9gr | 800-860 fps | Fast |
| Unique | 180gr jacketed | 5.5-6.6gr | 950-1,050 fps | Medium |
| Clays (Hodgdon data) | 165gr JHP | 3.5-3.9gr | 850-900 fps | Fast |
Matching Powder to Purpose
Target and practice loads want a fast, economical powder that meters consistently through thousands of rounds without breaking the bank. Titegroup and HP-38/231 both fit that job well; keep charges toward the lower half of their published range and prioritize consistency over velocity.
Defensive loads generally want a medium-burn powder, Unique or Power Pistol among the proven choices, landing your bullet in the velocity window where it’s actually documented to expand reliably. Our 40 S&W self-defense guide covers that expansion-velocity target in depth; the powder choice here should serve that target, not chase maximum velocity for its own sake.
Hunting or maximum-velocity loads, where you’re deliberately pushing a heavy bullet as hard as this cartridge safely allows, point toward Longshot or Blue Dot. Both fill more case volume at their working charges and deliver the highest documented velocities for 165 to 180-grain bullets in this cartridge, at the cost of noticeably more muzzle flash than a faster powder produces. If you’re loading for a pistol-caliber carbine, these slower powders also make better use of the added barrel length than a fast powder optimized for a 4-inch pistol barrel ever will.
Mistakes Specific to Powder Selection
Treating charge weights as interchangeable between bullet constructions causes real problems here. A charge developed for a plated bullet doesn’t automatically suit a jacketed or cast bullet of the identical weight; bearing surface and jacket material both change the pressure curve enough to matter, and the Unique spread noted above between sources is partly a function of exactly this kind of construction difference.
Assuming one manual’s maximum is universally safe is the second recurring error, and the Clays example above is the clearest illustration of why that assumption fails. Cross-reference at least two current sources for any load you’re pushing toward maximum, and when they disagree meaningfully, default to the powder manufacturer’s own published data over a bullet manufacturer’s.
Chasing velocity with the wrong powder family wastes both components and case life. A fast powder pushed hard for extra velocity produces a sharp pressure spike rather than a smooth curve, and it will not get you meaningfully closer to what a medium-slow powder delivers safely within its own working range. If you want more velocity than a fast powder can give you at a reasonable charge, switch powder families rather than pushing the fast one past where it’s comfortable.
Frequently Asked Questions
What’s the best all-around powder for 40 S&W? Alliant Unique is the closest thing to a genuine all-rounder here, with real data across a wide bullet weight range and a track record in both practice and defensive loading. It won’t give you Longshot’s top-end velocity with a heavy bullet, but it covers more use cases competently than any single fast or slow powder does on its own.
Why does Clays show such different numbers between manuals? Bullet manufacturers sometimes develop their own independent load data using their specific bullet construction and test equipment, which can diverge meaningfully from the powder manufacturer’s own published figures, as it does here. When the gap is this large, roughly 1.3 grains on the same bullet weight, default to the powder manufacturer’s data specifically, since they control the formulation being tested.
Do I need a different primer depending on which powder I choose? Usually not for the powders covered here; standard small pistol primers handle all of them well at the charge ranges listed. A magnum primer occasionally benefits a slower powder like Longshot in cold conditions, but only when your specific published data actually calls for it.
Can I use rifle powder in 40 S&W if I have some on hand? No. Rifle powders burn far too slowly for this case and bore combination and will not ignite or perform predictably at pistol pressures and barrel lengths. Stick to powders specifically listed in pistol reloading data for this cartridge.
How much does barrel length change which powder makes sense? Meaningfully, if you’re loading for a carbine as well as a pistol. A fast powder optimized for a 4-inch barrel has largely finished burning before a 16-inch carbine barrel gets any benefit from it, while a medium-slow powder like Longshot or Blue Dot keeps contributing velocity through that extra barrel length. Our 40 S&W in a pistol-caliber carbine guide covers that relationship in more depth.
Quick Takeaways
- Fast powders, Titegroup and HP-38/231, suit economical target and practice loads
- Medium-burn Unique and Power Pistol cover defensive loading and general-purpose work well
- Longshot and Blue Dot deliver the highest documented velocities for heavier bullets, with more flash in return
- Clays shows a genuine, significant disagreement between Hodgdon’s and Sierra’s published data; default to Hodgdon’s figures
- Cross-reference at least two current manuals before working toward any published maximum
- Match powder family to purpose rather than pushing one powder past its comfortable working range to chase velocity it wasn’t built to deliver
Powder selection for 40 S&W rewards matching the burn rate to the actual job rather than defaulting to whatever’s already on the shelf. Fast powders for volume and economy, medium-burn for defensive work and general use, medium-slow when you’re chasing real velocity with a heavy bullet. Cross-check your data, respect genuine disagreement between sources when you find it, and work up carefully regardless of how confident the label looks. From here, our guides to best bullets for 40 S&W and common 40 S&W mistakes round out the component and safety picture this article leaves off.
