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.
Loading your first 40 S&W round is a genuine milestone, and it deserves the same careful, methodical approach I bring to any cartridge running real pressure. This is a 35,000 psi round in a case that has a well-earned reputation for chamber bulging, and both of those facts should shape how you approach your first batch. Done conservatively, with attention at every step, your first rounds will be safe, reliable, and a solid foundation for everything you load after them.
This guide walks through a proven starter recipe and the full process behind it, from case inspection through the final check before you head to the range. The goal here is not to get you to maximum performance fast. It is to get you comfortable with the fundamentals this cartridge specifically demands before you start experimenting.
A Starter Load Worth Trusting
For a first 40 S&W batch, I recommend a 180-grain full metal jacket bullet over 5.5 grains of Alliant Unique. This combination shows up across multiple manuals and produces roughly 950 fps from a 4-inch barrel with mild recoil and dependable ignition.
Be precise about where this charge actually sits, since manual-to-manual spread on this exact pairing is wider than usual. Lyman’s cast-bullet data for a 180-grain bullet with Unique runs as low as 4.6 to 5.2 grains, while Alliant’s own published figure for a 180-grain full metal case bullet runs closer to 6.6 grains at maximum. Given that range, 5.5 grains is a genuinely conservative starting point for a jacketed bullet, not a number sitting in the exact middle of the safe range. That is exactly the right place to be for a first batch: real margin below maximum, with room to work up once you have confirmed the basics function correctly in your specific pistol.
Cross-reference this recipe against at least two current manuals before you load a single round, and treat any number here as a starting reference, not a substitute for the data in front of you. Alliant’s own current data, Lyman’s 50th Edition, and Hornady’s 10th Edition all carry entries for 180-grain bullets with Unique, though the exact figures shift depending on bullet construction, jacketed, plated, or cast. Match your data to your actual bullet type.
What you need for a first batch:
- 40 S&W brass, once-fired or new
- 180-grain FMJ bullets
- Alliant Unique powder, or another chosen powder with published data
- Standard small pistol primers, not magnum
- A press with 40 S&W dies
- A digital or beam powder scale
- Calipers for measuring OAL
- A case gauge, or your actual pistol, for function testing
- At least one current reloading manual
Case Prep: Inspect, Resize, Prime
Start with clean brass that has already been inspected for cracks, splits, or bulging near the base. Rinse once-fired range brass in soapy water, dry it thoroughly, and look over every case under good light before it goes anywhere near your press. At 35,000 psi, a compromised case is not worth the risk of finding out the hard way; discard anything questionable.
Full-length resizing is not optional here. This cartridge headspaces on the case mouth, and consistent chamber fit depends on it. Lubricate lightly, run each case through your resizing die per the manufacturer’s instructions, then wipe off the excess lube and confirm the decapping pin cleared every spent primer cleanly. Our guide on tuning a sizing die covers this adjustment in more depth if you are setting one up for the first time.
Priming deserves real attention, since pistol primers are sensitive to seating depth. Seat every standard small pistol primer flush with the case head or up to 0.003 inches below it, never proud. A protruding primer risks a slam-fire or a feeding problem. You should feel steady, even resistance through the stroke and a firm seat at the end, not a soft or inconsistent one.
Checking for the Case Bulge This Cartridge Is Known For
40 S&W has a well-earned reputation for bulging cases just above the extractor groove, particularly in pistols with generous, unsupported chamber dimensions, Glocks being the most commonly cited example. Run every resized case through a case gauge, or drop it into your pistol’s chamber with the barrel removed. It should fall in freely and sit flush with the chamber face.
Any case that fails that check needs additional attention before it goes any further. A bulge buster die can sometimes bring a case back into spec; if it doesn’t, discard the case rather than risk a round that won’t chamber cleanly or extracts poorly under pressure.
Setting OAL for Your Specific Pistol
SAAMI’s maximum overall length for 40 S&W is 1.135 inches, but your pistol may prefer something a touch shorter. Start with an OAL of 1.125 inches for 180-grain FMJ bullets, a length that works reliably across most pistols while keeping chamber pressure where it should be.
Measure OAL with calipers, case base to bullet tip, on at least every fifth round. Bullet manufacturing tolerances shift seating depth more than people expect, and seating too deep raises pressure in a way that is easy to miss without checking. If your pistol has a tight chamber or a short throat, you may need to trim OAL to 1.120 inches, but never go shorter than that without pulling data specific to that length from your manual.
Before you load a live round, verify feeding. Seat bullets in five dummy rounds, no powder or primer, at your chosen OAL. Load them into a magazine and cycle them through the action by hand. They should feed smoothly, chamber fully, and eject without hanging up. If the slide won’t close completely, reduce OAL by 0.005 inches and test again before moving on.
| Measurement | Target Range | Why It Matters |
|---|---|---|
| OAL | 1.120-1.125″ | Reliable feeding at safe pressure |
| Case mouth diameter | 0.421-0.423″ | Prevents setback without over-crimping |
| Primer depth | Flush to -0.003″ | Avoids slam-fires and ignition problems |
Seating and Taper Crimp
Seating and crimping are typically two separate steps on pistol dies, though some progressive setups combine them. Set your seating die to your target OAL of 1.125 inches, and back the crimp shoulder off completely for that first pass. Seat 10 to 15 cases and measure OAL frequently, aiming for consistency within 0.005 inches across the batch.
40 S&W needs a taper crimp, not a roll crimp, since the case headspaces on the mouth and a roll crimp would interfere with that. Adjust your crimp die to remove the flare left from case expansion and bring the finished case mouth to 0.421-0.423 inches, checked with calipers just below the mouth. Too much crimp buckles cases or deforms bullets; too little lets a bullet set back under recoil, which raises pressure meaningfully. Our guide on tuning a bullet seating die walks through the crimp adjustment in more detail.
Mistakes That Show Up on a First Batch
Skipping the case gauge check is the single most common error with this cartridge specifically. A case that looks fine by eye can still carry a bulge that keeps it from chambering or causes extraction problems later. Every case gets checked before it goes to the priming step, no exceptions.
Mixed brass from unknown sources introduces inconsistency you don’t need on a first batch. Different manufacturers produce cases with different internal volumes, and that variation can shift pressure by 2,000 to 3,000 psi at an identical charge weight. Stick with brass from one manufacturer, Federal, Winchester, or Starline, for your early batches.
Inadequate crimp lets bullets set back as they slam against the feed ramp during cycling; this cartridge feeds aggressively, and even 0.020 inches of setback can push pressure into genuinely dangerous territory. Check five random rounds per batch by pressing the bullet against a hard surface; it should not move at all.
Skipping the powder check is inexcusable but happens the moment complacency sets in. Look into every charged case under good light before a bullet goes on top. Powder levels should look identical across the batch, and every case should show powder. A double charge of a fast powder like Unique will usually overflow visibly, but a missed, empty case will still chamber and fire, and that is how guns get damaged.
Loading close to maximum on a first batch removes the safety margin you actually need while you’re still learning. Published maximums assume ideal components and technique in a specific test barrel. Start at a genuine minimum, work up gradually, and watch for pressure signs, flattened primers, difficult extraction, or case head expansion, at every step.
Frequently Asked Questions
Can I use once-fired range brass for my first loads? Yes, but inspect it carefully. A lot of 40 S&W range brass has been fired in pistols with unsupported chambers, which is exactly what creates the bulging this cartridge is known for, and standard resizing doesn’t always remove it fully. Every case needs a case gauge or chamber check, and anything with a crack near the mouth, a split body, or a loose primer pocket gets discarded.
Is Unique the only option for a starter load? No, it’s just a forgiving one. Titegroup, Power Pistol, and WST are all solid alternatives with their own published data. Unique earns its reputation with beginners because it meters consistently and leaves a powder level in the case that makes a double-charge mistake genuinely hard to miss.
How do I confirm OAL is right for my specific pistol? Build dummy rounds at your target OAL and cycle them through the action by hand. The slide should close fully with normal effort and the round should eject cleanly. If it doesn’t, back OAL off in 0.005-inch increments and retest. Most 40 S&W pistols run well at 1.125 inches, though some 1911-pattern guns want 1.120.
What does excessive pressure actually look like? Flattened primers with no rounded edge left, cratered primers where the firing pin has punched a deep impression, extraction that takes real force, and shiny marks on the case head from breech face contact. Any of these means stop immediately and back the charge off by at least 0.2 grains before you load another round.
Should I use magnum primers? Not for a starter load. Standard small pistol primers handle Unique and similar powders fine. A magnum primer runs hotter and can raise pressure by 1,500 to 2,500 psi at an identical charge, so only reach for one when your specific published data actually calls for it, typically with a slower ball powder.
How many rounds should I load for a first test? 25 to 50, no more. That’s enough to confirm function and accuracy without burning through components if an adjustment turns out to be needed. Shoot slowly, inspect brass after every magazine, and once everything checks out clean, no pressure signs, reliable cycling, acceptable groups, you can scale up with real confidence.
Quick Takeaways
- Start with 180-grain FMJ over 5.5 grains of Unique, a genuinely conservative first recipe with real margin below maximum
- Every case needs a gauge or chamber check before priming; this cartridge’s bulging problem is well documented
- Set OAL to 1.125 inches and confirm feeding with dummy rounds before loading anything live
- Apply enough taper crimp to hit 0.421-0.423 inches at the case mouth, no more
- Inspect every charged case visually before seating a bullet
- Load only 25 to 50 rounds for your first test and watch closely for pressure signs
- Never load past a published maximum, and check your recipe against at least two current manuals
Your first batch is a foundation, not a finished product. Build it conservatively, inspect at every step, and you’ll walk away with the fundamentals this cartridge actually demands. From here, our guides to common 40 S&W mistakes, best bullets for 40 S&W, and best powders for 40 S&W are the natural next stops once this first batch is behind you.
Related reading: Best Powders for 40 S&W Handloading.
