Estimated peak energy for 214 gr after mods
Based on pre‑mod 214 gr baseline around 845 fps (≈339 ft‑lbs) and the post‑mod velocity gains demonstrated on lighter slugs, a realistic peak for 214 gr after the port/valve work is in the 370–400 ft‑lbs range,
Quick verdict
Most likely peak: 380–395 ft‑lbs (≈890–905 fps), if the mod’s flow gains carry over to heavy slugs without hitting valve lock.
Stretch goal: ~405 ft‑lbs (≈925 fps) if the port and spring balance let the heavy slug ride the peak without choking. To see the 357s true numbers will have to wait until warmer weather.
Time to switch optics and platforms for winter coyote sits.
With temps dropping into the 10–20°F range at night, my .308 Texan (modified, tuned for 3,500 psi with 150 gr slugs) is seeing pressure sag down toward 3,200 psi or lower. That drop cuts into consistency and makes it harder to hold tight groups past 100 yards.
For winter, I’m moving the DNT Zulus HD 5–20x LRF with ballistic calculator over to the AEA .357 Challenger big bore. Here’s why:
AEA tune: 3,200 psi baseline with 150 gr slugs.
Fill rate: Higher capacity at 3,800 psi, which holds up better in cold temps.
Result: More stable velocity and energy across the 20–80+ yard bait ranges, with reliable penetration even when the thermometer dips.
And with the solid slugs I’ve chosen (147–150 gr flat‑point designs), the terminal effect is exactly what’s needed for coyotes:
Broadside: Clean pass‑throughs, fast bleed‑out, minimal deflection.
Shoulder hits: Enough energy to break bone, driving fragments into the chest cavity for lethal trauma.
Quartering angles: Straight penetration through ribs and muscle, often exiting behind the opposite rib cage.
Frontal shots: Sternum penetration with deep lodging in the chest cavity.
Different rifles, different seasons — but the goal stays the same: repeatable accuracy and dependable field performance when the coyotes move in.
Based on pre‑mod 214 gr baseline around 845 fps (≈339 ft‑lbs) and the post‑mod velocity gains demonstrated on lighter slugs, a realistic peak for 214 gr after the port/valve work is in the 370–400 ft‑lbs range,
Quick verdict
Most likely peak: 380–395 ft‑lbs (≈890–905 fps), if the mod’s flow gains carry over to heavy slugs without hitting valve lock.
Stretch goal: ~405 ft‑lbs (≈925 fps) if the port and spring balance let the heavy slug ride the peak without choking. To see the 357s true numbers will have to wait until warmer weather.
Time to switch optics and platforms for winter coyote sits.
With temps dropping into the 10–20°F range at night, my .308 Texan (modified, tuned for 3,500 psi with 150 gr slugs) is seeing pressure sag down toward 3,200 psi or lower. That drop cuts into consistency and makes it harder to hold tight groups past 100 yards.
For winter, I’m moving the DNT Zulus HD 5–20x LRF with ballistic calculator over to the AEA .357 Challenger big bore. Here’s why:
AEA tune: 3,200 psi baseline with 150 gr slugs.
Fill rate: Higher capacity at 3,800 psi, which holds up better in cold temps.
Result: More stable velocity and energy across the 20–80+ yard bait ranges, with reliable penetration even when the thermometer dips.
And with the solid slugs I’ve chosen (147–150 gr flat‑point designs), the terminal effect is exactly what’s needed for coyotes:
Broadside: Clean pass‑throughs, fast bleed‑out, minimal deflection.
Shoulder hits: Enough energy to break bone, driving fragments into the chest cavity for lethal trauma.
Quartering angles: Straight penetration through ribs and muscle, often exiting behind the opposite rib cage.
Frontal shots: Sternum penetration with deep lodging in the chest cavity.
Different rifles, different seasons — but the goal stays the same: repeatable accuracy and dependable field performance when the coyotes move in.
