opposite handed shooting is something that should be a rather rare occurence. Probably something one should practice a bit with in a self defense scenario where theres a scramble for a lost handgun or your main hand has been incapacitated.

What is considered the correct way to shoot offhand? Time the shot or slow squeeze and surprise shot? I know the correct way when shooting a compound but not an expert on rifle.

it depends on the situation

running target , squeeze through and follow through.
target stance , work the breathing and body position and break and hold back the trigger , you should know your trigger well enough it isn't a surprise but like your going for a surprise break.

Biathlon or similar out of breath and your just skied around a course and your huffing and puffing , you make a X crossing the target breath in you go up , as your exhaling your crossing down and right , breath in you go back up exhale cross down and left , after a few breaths you should be crossing the target on each exhale , break the shot on the cross .

how far and what size is the target all figures into how fast you can make or how long you need to take , experience is how you get there.

I was at an Appleseed was working it and shooting it , so I was busy while everyone was in prep helping someone , the clock started 2 minutes standing I was getting my stance and everything right and the 10 second count down started 10 rounds in 9 seconds because I was taking 2 on each breath it was a 22lr on a simulated 100 yard target I made it under the time , I hadn't started slinging up till fire was called

With a lever action 30/30 and a 357 out of a 7" barrel it's not too difficult. My style of shooting is based on off hand. I have a shotgun trigger finger and that's just the way I shoot, but I can keep my eye on the target through the scope until the recoil lifts the barrel. The entire time the rifle is going straight back I have the sight picture in focus, so I know exactly where I'm aiming when the bullet leaves the barrel. When the butt of the gun hits my shoulder I'm already pointing exactly where I need to be. 30 years of bird hunting makes for a quick shot.

Using my good eye? I need to shoot with my non-dominant eye to shoot well off-handed.

I suck at big game , except with a bow,,,, but I can kill bird or coyotes no problem,,,,,, Were do I turn in my man card..

Grampa taught me to me to aim a bit under the target. Lift up and pull the trigger when shooting off hand. Works pretty good.

Shooting offhand seemed a lot easier when I was a kid. Could whap sparrows with BB gun or 22 with shorts. Just aim and shoot. Minute of sparrow at 20 feet was not that hard. Shotguns all shot offhand.

These days would also use rifle's sling if wanting to cut down on rifle movement shooting offhand. Open sights still seem easier than thru a scope. Same movement, just not as noticeable.

lower power scopes make less noticed movement so you try and correct for less movement, but still gives a good fast sight picture

I also run slings , a lot of the WWII GI Web slings , they are infinitely adjustable and all get adjusted for hasty sling for me the day I am out hunting or shooting and what I am wearing

Hasty sling can make for a much more stable gun

typically I try to have a support.. I had some problems with my legs working correctly a few years back and they were thinking MS. I still was going to take the kids hunting if it killed me. I was having a bit of trouble getting up and down the hills and ditches( also had balance issues) so I took out my multi tool and cut a long strait tulip popular sapling off about 6.5' and used it for a walking stick. it was squirrel season and I was actually carring a .22 the boys like trying to kill more than dad. Didn't take long to discover that walking stick made a great shooting support. It made hills and ditches easier even when everything started working again. so typically I alway have a walking stick and use it as a shooting support also.

If I shoot very far and no rest available I sit on my butt with my knees up and shoot off my knees. Elbows on my knees. Not like a bench but works great for hunting

my stick is also great for knocking down spider webs walking through the woods in early season.

I'd think using a rest if needed would provide a better shot if a person isn't steady offhand.

I worked with a guy that bragged about him and two friends opened up on a deer and hit him 9 times to bring him down. Offhand.

Some people are better with one hand Musta got a lot of practice