Squib_Load
Active member
- Joined
- Jul 2, 2025
- Messages
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I asked ChatGPT: In handloading 45 Colt at standard pressure for a revolver with a 3½ inch barrel and a 250 gr bullet, which powder, and how much of it, should I use to get 700 fps?
ChatGPT answered:
For .45 Colt at standard pressure from a short 3½-inch revolver, getting ~700 fps with a 250 gr bullet is very doable with several classic powders. The key is choosing a powder that burns efficiently in a short barrel without needing higher pressure.
Below are well-established, conservative combinations that typically land right around 650–725 fps from short barrels.
ChatGPT answered:
For .45 Colt at standard pressure from a short 3½-inch revolver, getting ~700 fps with a 250 gr bullet is very doable with several classic powders. The key is choosing a powder that burns efficiently in a short barrel without needing higher pressure.
Below are well-established, conservative combinations that typically land right around 650–725 fps from short barrels.
Best Powder Choices for This Goal
Trail Boss (excellent for short barrels & low velocity)
- Charge: 5.5–6.0 grains
- Velocity: ~650–725 fps
- Why: Very forgiving, bulky, mild pressure, extremely consistent
- Notes: Fill to base-of-bullet rule applies; do NOT compress
This is arguably the easiest and safest way to hit 700 fps.
Unique (classic .45 Colt powder)
- Charge: 6.5–7.0 grains
- Velocity: ~675–725 fps
- Why: Efficient burn, widely available, proven for 100+ years
- Notes: Start at 6.5 gr and work up; short barrels usually hit 700 fps before pressure rises
Red Dot
- Charge: 5.5–6.0 grains
- Velocity: ~675–725 fps
- Why: Fast burn, excellent in short barrels
- Notes: Spikes faster than Unique—stay conservative
Bullseye (very efficient, very fast)
- Charge: 5.0–5.5 grains
- Velocity: ~650–725 fps
- Why: Excellent for mild cowboy/defensive loads
- Notes: Small charge—double-check powder levels every case
Recommended “Set-and-Forget” Loads (Most People Choose These)
| Powder | Charge | Result |
|---|---|---|
| Trail Boss | 5.8 gr | Soft, accurate ~700 fps |
| Unique | 6.8 gr | Traditional feel, clean burn |
| Red Dot | 5.8 gr | Snappy but mild |
| Bullseye | 5.2 gr | Efficient, low recoil |
Setup Details (Important)
- Bullet: 250 gr LRN or SWC
- Primer: Standard Large Pistol
- Crimp: Firm roll crimp
- OAL: Seat to crimp groove
- Firearm: Standard-pressure revolver (NOT Ruger-only)
Why 700 fps Is a Sweet Spot
- Very low wear on older revolvers
- Mild recoil from short barrels
- Excellent accuracy
- Minimal blast and flash
- Bullet type (LRN vs SWC)
- Alloy hardness
- Whether this is for cowboy shooting, general plinking, or woods carry