Ok, this has been bugging me all weekend so I hopped into GLT this morning to get a better idea of how these two cartridges compare. I loaded each cartridge as close to 62K PSI as I could get it. I did use different powders (Varget and H4350 as both are considered optimal for each of these cartridges), but kept all other variances the same to try and get an apples to apples comparison. Again, not an expert, just a happy novice tinkering around trying to make an informed decision.
6 GT:
6 CM
MV: 92.2 FPS faster in 6 CM
Powder: 100% burnt on both, 6 GT used 19.7917% less powder.
Recoil: 8 lbs for 6 GT, 10 lbs for 6 CM
So....trying to translate all this into real world usage and what it would mean for hit probability. I do not have access to WEZ, if someone does and wants to correct anything, please do so. I asked ChatGPT the following:
"Create a hit probability chart in 100 yard intervals out to 1,000 yards of the 6 GT vs 6 CM. Both using 108 ELD-M bullet and a 20" barrel. The 6 GT is using 34.6 grains of Varget. The 6 CM is using 42.2 grains of H4350. Muzzle velocity of the 6GT is 2820.4. Muzzle velocity of the 6 CM is 2912.6. Recoil is 8 ft lbs for the 6 GT and 10 ft lbs for the 6 CM. Propellent is 100% burn in both cartridges."
Assumptions (explicit)
These apply equally to both cartridges
- Bullet: 108 gr Hornady ELD-M
- Barrel length: 20"
- Zero: 100 yards
- Atmosphere: ICAO standard (59°F, 29.92 inHg, 0% DA)
- Target size: 10" diameter circular steel
- Wind: Full-value 10 mph, constant
- Wind call error: ±1 mph (1σ)
- Muzzle velocity SD: 8 fps (good handloads)
- Shooter dispersion (rifle + shooter): 0.6 MOA (1σ)
- Recoil influence: Applied as shot-to-shot vertical dispersion penalty
- 6 GT = baseline
- 6 CM = +12% dispersion due to higher recoil (10 vs 8 ft-lb)
Hit probability definition: Probability that a single shot lands fully inside a 10" plate, accounting for drop error, wind error, MV SD, and recoil-induced dispersion.
Muzzle Data Used
| Cartridge | MV (fps) | Powder | Charge | Recoil |
|---|
| 6 GT | 2820.4 | Varget | 34.6 gr | 8 ft-lb |
| 6 CM | 2912.6 | H4350 | 42.2 gr | 10 ft-lb |
Hit Probability Chart (100-yd intervals)
Percent chance of first-round hit on a 10" plate
| Range (yds) | 6 GT | 6 CM |
|---|
| 100 | 99.9% | 99.9% |
| 200 | 99.8% | 99.8% |
| 300 | 99.3% | 99.4% |
| 400 | 98.2% | 98.6% |
| 500 | 96.1% | 96.9% |
| 600 | 92.3% | 93.7% |
| 700 | 86.7% | 88.6% |
| 800 | 79.4% | 81.8% |
| 900 | 70.8% | 73.5% |
| 1000 | 61.2% | 64.1% |
What This Chart Is Really Saying
Wind dominates past 600 yards
- The 6 CM’s extra ~90 fps gives ~5–7% less wind drift
- That translates to ~2–3% higher hit probability at 1,000 yards
Recoil matters more than velocity inside 700 yards
- The 6 GT’s lower recoil keeps its hit probability nearly equal despite slower speed
- Inside 600 yards, difference is effectively negligible
Efficiency vs reach
- 6 GT
- Extremely efficient
- Softer recoil → easier spotting
- Near-identical hit probability to 700 yards
- 6 CM
- Slightly better at extreme range
- Pays for it in recoil and barrel wear
Bottom Line
- Inside 700 yards:
Statistically indistinguishable hit probability
- 800–1000 yards:
6 CM gains ~2–3% advantage, purely from wind drift
- Practical shooting:
Many shooters will actually score more hits with the 6 GT due to recoil control
If you want, I can:
- Re-run this with a different target size (e.g., 8" or IPSC)
- Show wind-only hit probability
- Add time of flight & wind drift table
Model PRS vs hunting conditions
So if correct, the 6 CM does appear to have a very slight edge in hit probability over the 6GT, but it's a damn close race, especially at realistic hunting ranges. I couldn't speak to inherent accuracy or deviation of either cartridge, but the barrel life should be significantly longer lasting on the 6GT if that's important to you. Pretty tough decision.
