Does recoil begin before the bullet exits the muzzle?

[FIGJAM]

Let's assume a 24" barrel;

To see a 6moa change at the target, we are talking about a .042" difference at the muzzle (assuming a 24" bbl)

Do you doubt the barrel could move that much before the bullet exits @FIGJAM ?

Several years ago I bought a Rem 700 SPs varmint that had one of those super flimsy plastic stocks. POI was completely different from the bench on sand bags to the bipod because using the bipod caused the stock to contact the barrel shifting the poi. But it was like 5" at 200 yards...12" at 200 yards is crazy.

 

[bigngreen]

Without a doubt that's excessive BUT if your grouping just having a POI change then it's how the rifle is tracking or a very, very consistent flinch.
I had a 270 WSM all of the sudden start throwing shots in a group like 6 feet over a 600 yard ram target and I was like WTH, reset my position and start hammering it then up it goes. The grip of the stock was just hitting my hand during recoil while I was working the bag, it inched back a little each shot till it hit then boom up they went. Kinda made me scratch my head that a little thing would throw it so bad.

 

[codyadams]

To address the initial question, yes the rifle does move prior to bullet exit. However, it can be controlled very well with consistency and practice. However, it is harder with heavier recoiling rifles and larger projectiles because there is more movement to control and maintain consistency.

The other aspect is any unknown anticipation to recoil, put an efficient brake on your gun and you will likely see much more consistency, and will be less likely to develope bad habbits. Noone is above developing a flinch.

If you cannot get consistency out of your rifle from different positions, and won't get a brake because you don't want to wear ear protection when you hunt, or don't want to make the investment in electronic hearing protection, then zero your rifle how you will shoot in the field, and if you have to shoot from an odd position in the field that you are unaware how it will affect your POI, limit your range accordingly.

 

[FEENIX]

The physical/mechanical aspect of recoil and possible ways to mitigate it has been covered nicely. However, recoil happens long before the OP pulls the trigger because he might be anticipating the recoil.

I don't experience this with lesser recoiling rifles. I'm not an elite marksman and this rifle is a challenge to shoot (with over 50lb's of recoil). I did qualify expert marksman in basic training on my first attempt, my Grandfather was on the army shooting team and taught me well, but that was long ago and I'm just getting back into shooting a lot, so I won't rule out shooter error, but I think I've got the fundamentals down since this isn't happening with my little guns.

He might have to overcome the mental aspect of anticipating the recoil before he needs to work on the other fundamentals of shooting, but that's just me.

 

[sodakota]

The barrel vibrations and contact between the barrel and the forearm are part of the equation. The barrel should not touch the forearm when you squeeze the two together. The different types of support under the forearm will affect POI. But having the barrel touch the forearm while it's vibrating will magnify the changes.
I noticed the issue with POI changes when firing a service rifle from the bench to prone. In that case I was using a sling while prone, which pulled the forearm to the left.
The way to best resolve that issue was more relief around the barrel.

 

[dougfinn]

Another aspect of recoil is torque. As well as pushing the rifle rearward the torque of the spinning Bullet will also cause a slight amount of rotation. While maybe not perceptible, it is there and different styles of resting the rifle while shooting could make a difference on the point of impact. I shoot double rifles and they are regulated to take into account all the factors of recoil.

 

[esshup]

I dunno. I was told that not to worry about recoil affecting POI unless the bullet was moving less than 1200 fps.

Someone please shot me hard data on how much a rifle muzzle moves in the time it takes for the bullet to exit the muzzle when it's moving at "X" fps.

 

[Deleted member 107796]

When I first used shooting sticks, I found the rocking that you describe worsened my patterns and I had to develop a way to anchor the rear of the stock better to use them. I find that my pack is better than sticks, if I can support it on something high enough to shoot from it, but that is rare. As far as recoil, I use excellent recoil pads on everything with no need for a brake and as mentioned, just train as much as I can.

+1 on when something starts moving, there is a opposite and equal force.

 

[Greyfox]

Bigngreen explained it well.
Imo the proof is where the rubber meets the road, lighter recoiling rifles don't cause the same problem.
Don't punish urself with that hand cannon, get a brake on it and make it manageable to shoot.

While the brake will help with the punishment of recoil, it won't help with the effect of primary recoil effecting bullet impact. The bullet has left the barrel by the time the brake reduces secondary recoil.
Depending on the particular rifle, the muzzle can move 1/8-1/2" before the bullet exits the barrel. Last week I had an un-noticed, loose bi-pod open my typical .25MOA groups on my 6.5x284 to 2.5MOA!!! Tightened it up and it went right back to .25MOA.

 

[Buster Hemlock]

You have gotten some great advice from other members on here. Another thing worth considering is the bipod and if the legs are spring loaded. If so popping them out one click from bottom may have a effect for you if you are shooting off a fully bottomed out bipod with springs that are compressed. I've seen this have a noticeable effect myself and many others have seen the same. What makes me think this would be worth considering for you is you said off your pack is the least and prone and off the bench where you are likely using a bipod are the worst.

 

[rgmeddn]

To answer your question, yes there is recoil before the bullet exits. The opposite and equal law of physics is very clear on this. There are innumerable little components of this, but the two that account for the most recoil are the bullet (the biggest) and the air in the barrel that gets pushed ahead of the bullet acting like a little rocket.
The amount of recoil generated before the bullet exits will be exactly the same of course no matter how you support the rifle. I don't know if the amount of POI shift you are experiencing is in the "expected" range for the methods you are trying but it is well known that you should sight-in, load develop, and practice using the method you will be using when you hunt or compete or whatever you are going to do with the beast.

EDIT
Moving on to what you really are trying to figure out, you didn't mention how tight your groups are with each support method or how many shots you used to support your conclusions.

 

[Pro2A]

Your rifle recoils roughly 3/8th of an inch before exit. Getting poi the same from multiple positions at long range takes a lot of rounds down range paying attention to how the rifle tracks as it comes back and rides your rear bag and front rest.
With a bipod you want to load it so the recoil is stays at the top of the movement and does not come from the top and roll back and down a little. If you can get it tracking the same you'll maintain poi!!
This is why so many experienced long range shooter basically free recoil.

Regarding recoil/bullet movement, the bullet cannot move without equal and opposite reaction against the bolt face/rifle receiver.....cannot violate Newton's Law of Motion....For every action there is an equal and opposite reaction.

Interesting comment on bipod loading. I've never been able to get anyone to explain bipod loading benefit.....including military trained shooters. They seem do it because they were taught to load the bipod.....without understanding why. I always questioned effect due to foreshortening the vertical height component under loading....like a clock hand moving toward one o'clock from straight up 12 o'clock. The "lost" height from foreshortening loading, has to be regained under recoil raising the bore equal to the lost height. I understand your comment to mean to account for the height change via consistency of height (recoil) at instant of bullet exit from bore. Am I understanding your point correctly?

 

[Pacecount]

Since you asked... LMAO... are you holding a good group with the change in medium?

If not, Work on your position behind the rifle and loading it appropriately regardless of the medium.

If you are holding a good group and just experience POI shift I suspect your cheek weld is changing every time you change positions.

I have an adjustable cheek piece on all my rifles. I raise the cheek piece until I have a solid weld which almost forces me to go back to the same position to get a good sight picture.

 

[FIGJAM]

put an efficient brake on your gun and you will likely see much more consistency

This isn't always the answer - I have seen more people flinch because of the excessive noise from a brake than recoil.