Pushing Short-Action Performance to Its True Limits
Short-action cartridges are capable of far more performance than most shooters ever see. Not because the cases are lacking — but because magazine length has always been the limiting factor.
Speed Freaks is our exploration of what happens when we remove those limitations across two performance categories:
- Medium and large short-action cartridges (Creedmoors, SAUMs, WSMs, etc.) running in 2.950" binderless AICS magazines
- AR-15–derived cartridges (.223 Rem, 22 ARC, 6 ARC, etc.) optimized for bolt guns using extended-length magazines (such as MDT) that support long bullets and long seating depths
Both paths lead to a single goal: maximum performance through intelligent throating, optimized freebore, and magazine systems that finally let bullets meet modern ballistic demands.
Why Magazine Length Is the Real Bottleneck
Category 1: 2.950" Binderless AICS Magazines
For cartridges designed initially around ~2.820" short-action boxes, removing the front binder plate opens the full 2.950" internal length. This single change completely reshapes what these cartridges can do.
Cartridges that benefit the most include:
- 25 Creedmoor
- 6.5 Creedmoor
- SAUMs and WSMs (short-throated builds)
- .308-based wildcats
What this extended COAL allows:
- Long, modern bullets without deep seating
- Significant increases in usable case capacity
- Lower pressure at equivalent velocities
- Higher velocities before encountering pressure signs
- Expanded powder selection
- Clean, independent seating-depth tuning without magazine interference
This environment is ideal for high-BC bullet use and max-performance bolt-gun builds.
Category 2: AR-15 Cartridges Optimized for Bolt Actions
Cartridges like .223 Rem, 22 ARC, and 6 ARC are physically shorter and benefit from specialty magazines rather than AICS expansions.
MDT metal and polymer magazines (depending on model) provide meaningful COAL increases:
- MDT .223 / 5.56 mags: ~2.500" + internal length (unmodified)
- MDT 6 ARC / 6.5 Grendel mags: typically ~2.390"–2.400"+
What this space unlocks:
- Long, heavy-for-caliber bullets
- (62–90gr in .223, 80–115gr in ARC class)
- Better case fill with slower powders
- Safer pressure behavior and wider nodes
- Noticeable velocity increases
- The ability to build true bolt-gun-optimized loads, not AR-restricted compromises
For ARC cartridges in particular, COAL is the primary limitation, not pressure — and extending COAL transforms what they can do.
Scientific-Method Testing for Every Caliber
Each cartridge in the Speed Freak series follows a consistent, transparent research process:
- Define the question
- Establish SAAMI-length baseline data
- Predict the benefits of extended COAL
- Conduct long-COAL load testing
- Record velocity, pressure, ES/SD, and accuracy data
- Analyze and compare SAAMI vs. extended results
- Publish cartridge-specific conclusions
This approach creates a uniform data library showing exactly how each cartridge benefits from its optimal magazine and chambering strategy.
Example Cartridges We’re Testing
2.950" Binderless AICS Group:
- 25 Creedmoor — almost done!
- 6.5 Creedmoor — in process
- .308 Winchester
- 300 WSM
- Additional SA / magnum wildcats
AR-15–Based Cartridges:
- .223 Remington (62–90gr loads) — almost done!
- 22 ARC
- 6 ARC — in process
Each caliber will receive a dedicated Speed Freak article with charts, graphs, and recommended load lanes.
Conclusion:
Speed Freaks isn’t just a load-development project — it’s a modernization of how short-action rifles can be designed, chambered, and tuned.
By removing outdated COAL limitations, we’re able to show the true capability of cartridges that were artificially constrained for decades. Whether you’re running a 2.950" Creedmoor build or a long-seated ARC bolt gun, Speed Freaks reveal what happens when every cartridge finally gets the room it deserves.
