Saturday, December 16, 2017

More on Dwell Time

Remember earlier this week, we talked about dwell time, that fact of physics that combines momentum, recoil, bullet speed and barrel time to affect the way a firearm shoots a particular bullet?

Yeah, dwell time.

The firearm in that example was a new, Uberti Cattleman in .357 magnum that sowed a tendency to shoot 180 grain hardcast handloads a bit high; about 3 inches at 15 yards.

Today, we used the exact same handgun, but we tried 125 grain Winchester fodder.

It's throwing those a little bit low, which tends to support the dwell time  experience I've had for most of my gunning career.

I'm betting that 158 grain magnum ammo would shoot close to the point of aim. 


Retired Spook said...

Had a coworker who's new SIG 1911 was shooting high with 230 gr. loads. He was worried that he'd have to find a new front sight, and get it fitted, until I suggested that he try a lighter weight bullet.

Much to his surprise (but not mine) he found that the 200 gr. JHPs hit right where he wanted them.

I explained that it's not where the muzzle is pointed when you pull the trigger, but where it's pointed when the bullet exits the barrel.

He still doesn't believe me, but he carries it with the 200 gr. JHP bullets.

Anonymous said...

You could prove this scientifically using a Ransom Rest.

Gary W. Anthony
MSgt, USAF, Ret.
Shepherd, MT.