The 7mm TCU (Trimmed Cartridge Universal) is an excellent cartridge choice for deer hunting. With light recoil, flat trajectories, and excellent terminal performance, the 7mm TCU provides hunters with several key advantages in the field. In this in-depth guide, we’ll cover everything you need to know about using the 7mm TCU for deer hunting.
Overview of the 7mm TCU
The 7mm TCU was created in 1997 by cutting down .223 Remington brass to 7mm and necking it up to accept .308″ bullets. This innovative wildcat cartridge was popularized by firearms writer Layne Simpson as a versatile, lightweight medium-game hunting round.
Here are some key facts about the 7mm TCU:
- Caliber: 7mm (.284″)
- Bullet Weights: 90gr to 120gr
- Case Length: 1.414″
- Max Pressure: 55,000 PSI
- Velocity: 3000-3200 FPS (depends on barrel length and bullet weight)
The 7mm TCU achieves excellent ballistics in a lightweight, compact package. The fast twist barrels this cartridge prefers (1:9″ being common) help it push lightweight 7mm bullets at high velocities with superb accuracy.
Benefits of Using the 7mm TCU for Deer Hunting
Here are some of the major benefits of using the 7mm TCU for deer hunting:
Light Recoil
The 7mm TCU generates substantially less felt recoil than larger caliber deer cartridges. This light recoil makes it easier to stay on target for quick follow-up shots. The minimal kick also reduces rifle fatigue on long days in the deer woods.
Flat Trajectory
The 7mm TCU maintains a very flat trajectory out to 300 yards, minimizing the need for dramatic aiming compensation on longer-range shots. The ability to confidently take shots at longer ranges expands your effective range.
Excellent Terminal Ballistics
Properly constructed 7mm bullets offer excellent penetration and rapid expansion. The 7mm TCU has more than enough power for deer, even at longer ranges. Well-placed shots provide clean, humane kills.
Lightweight
The compact 7mm TCU works well in lightweight rifles. You can comfortably carry a 7mm TCU rifle all day long in rough terrain. The easy-carrying capability enables you to hunt deeper into the woods away from other hunters.
Effective Bullet Weights for Deer
For deer hunting, most shooters will opt for 7mm TCU loads using bullet weights between 90gr and 120gr. Here are some of the most effective options:
- 90gr: Very fast with an ultra flat trajectory. Excellent for shots inside 200 yards. Popular options include the Nosler Ballistic Tip and Hornady GMX.
- 100gr: A great all around weight for most deer hunting. Maintains velocity well past 300 yards with excellent expansion. Good choices include the Sierra GameKing and Barnes TSX.
- 108gr: Popular weight for handloaders looking to maximize velocity from the 7mm TCU. Great for deer inside 250 yards. Bullets like the Hornady A-Max and Berger VLD work well.
- 120gr: Heavier bullets retain energy better at longer ranges. A good option if you need to take shots out to 300+ yards. The Nosler AccuBond Long Range and Swift Scirocco II shine in this weight.
The most versatile deer loads for the 7mm TCU will use 100-120 grain bullets. Lighter bullets can be very effective, but are best reserved for short range shots. Heavier bullets up to 120gr offer the best performance for regular long range shots past 250 yards.
Effective Deer Hunting Ranges
Here are the typical effective shooting ranges for the 7mm TCU on deer broken down by bullet weight:
- 90gr: 0-200 yards
- 100gr: 0-250 yards
- 108gr: 0-275 yards
- 120gr: 0-325 yards
Real world ballistics and your shooting ability may expand or shrink these maximal ranges. Keep shots within your personal limits and equipment capabilities.
With quality controlled expansion bullets, the 7mm TCU has sufficient power for deer out to 300 yards in the hands of an experienced marksman. Take the time to establish your maximal effective range through practice at the range.
Rifle and Optics for the 7mm TCU
To get the best performance out of the 7mm TCU, you need a rifle designed to handle the high velocity of this small bore cartridge. Here are some important considerations:
- Barrel Twist: A faster twist rate of 1:8″ or 1:9″ is ideal to stabilize the lighter weight 7mm bullets used for deer hunting.
- Barrel Length: A 22″ to 24″ barrel will provide maximum velocity without being excessively long.
- Action: A bolt action rifle is most common, but AR-15 platforms can also work well. Go with a sturdy action built for hot loads.
- Scope: A quality 3-9x or 4-12x variable scope in the 40mm size range works well. Scopes with bullet drop compensating reticles can aid with long range shots.
Top rifle choices for the 7mm TCU include the Ruger American, Savage 110 Lightweight Storm, and Browning X-Bolt. All provide good accuracy and handling. For optics, brands like Leupold, Nikon, and Vortex offer excellent hunting scopes well suited to the 7mm TCU’s capabilities.
Sample 7mm TCU Loads for Deer
Here are some excellent 7mm TCU factory and handload starting points for pursuing deer:
| Bullet | Weight | Velocity | Energy |
|---|---|---|---|
| Barnes TTSX | 100gr | 3100 fps | 1333 ft-lbs |
| Sierra GameKing | 115gr | 2950 fps | 1383 ft-lbs |
| Hornady A-Max | 108gr | 3000 fps | 1354 ft-lbs |
| Berger VLD | 105gr | 3050 fps | 1394 ft-lbs |
These loads all provide great terminal performance on deer sized game along with a flat trajectory that makes range estimation less critical. Work up a variety of 7mm TCU loads to find your rifle’s preferred bullet and optimal velocity.
Shot Placement
As with any caliber, proper shot placement is key to ensuring quick, ethical kills on deer. Here are the optimal shot angles and impact points:
- Broadside: Center the heart and lung area a third up from the bottom of the deer’s chest.
- Quartering Away: Aim through the onside shoulder aiming for the offside lung area.
- Head On: Place your shot centered on the middle of the chest to hit the vital organs.
Avoid extreme angle shots on deer with the 7mm TCU. While the cartridge has the power for deer, heavily angled impacts can lead to poor penetration and wounding loss. Limit shots to the high percentage angles listed above.
With good expanding bullets and proper shot placement, the 7mm TCU has proven to provide excellent lethality and knockdown power on deer of all sizes. Practice regularly at the range to ensure you know where your rifle shoots at normal deer hunting ranges.
Benefits of Handloading the 7mm TCU
Reloading your own 7mm TCU ammunition offers several benefits:
- Better Accuracy: You can fine tune loads specifically for your rifle and chamber dimensions.
- Cost Savings: Reloading reduces ammunition costs, especially for a niche cartridge like the 7mm TCU.
- Custom Loads: Handloading enables you to experiment with different bullet weights and powders not available commercially.
The 7mm TCU works very efficiently with slow to medium burning rifle powders like Reloder 15, IMR-4064, Hodgdon H4350, and VihtaVuori N140. Lightweight 7mm bullets also perform excellently in the high velocities generated by the 7mm TCU.
Work up test groups carefully, looking for the most consistent, accurate results from your rifle. Chase optimum precision, not just maximum velocity.
Is the 7mm TCU Right for You?
The 7mm TCU is an excellent medium game hunting cartridge, but it does have some limitations hunters should consider before choosing it as a primary deer rifle:
- Can be susceptible to wind drift at longer ranges
- Limited ammo selection and availability
- Marginal bullet weights for largest-bodied deer
- Relatively short barrel life compared to larger bores
For most average-sized deer, at normal hunting ranges, the 7mm TCU has outstanding capabilities and is fun to shoot. The minimal recoil, combined with excellent terminal performance, make it a versatile and effective deer cartridge given a hunter’s needs and constraints. Try one on your next whitetail hunt and see how the 7mm TCU stacks up against larger traditional deer calibers.