Thread: Changes in the impact point

Gillie, you got any plans for a Welly or Wairarapa long ranger. Be good to meet you and get some of the Welly crowd to throw lead at longer distances

Originally Posted by Rushy

Gillie / Tussock there is no way that I wish to debate rifle accuracy with the two of you as I know less than a new born babe about the subject. That said, Phillip will be with me during the roar and there will be little chance of him shooting beyond 100 metres let alone 200 with most of the shooting opportunity likely to be in the <30 to <50 metre range hence my assurance to him that it was not going to be an issue. I have not seen Phillip shoot but let's for the sake of conducting an exercise assume that he is not good and only capable of shooting a 4 inch group at 100 metres and then lets also assume that there will be another 4 inch shift in the point of impact between how he has sighted in his rifle and how it will perform when he is shooting off hand or resting against a tree. Even under these extreme (assumed) circumstances, surely he should be capable of hitting a deer at <50 metres. My council will be for Phillip to be taking shoulder or heart/lung shots anyway as if he gets a stag he will likely want to take the trophy.

Phillip, listen to and learn from the knowledge and wisdom of these far more learned members as I am no expert on the accuracy of rifles. But my comment stands, "It won't be a problem"

Awesome Rushy, at those sort of distances you are right, it won't make enough of a difference. Bush hunting roaring stags is easily some of my most exciting memories. Phillip, you are going to have some fun - and as you are thinking about POI change you might as well go and check it at the range to save you thinking about it again!

Rushy, I am afraid this topic is a pet peev with me - i like to advocate people shoot more and have rifle sighted in exactly where they expect. I like to have absolute confidence in my rifle. The downside to this is that it is always my fault!!

Originally Posted by Tussock

Why? Hope I didnt offend. Was not my intention.

No absolutely no offense taken just had nothing more to contribute to the conversation and not one to be an antagonist. All good.

Originally Posted by Gillie

Rushy, I am afraid this topic is a pet peev with me - i like to advocate people shoot more and have rifle sighted in exactly where they expect.

People like me must frustrate you then Gillie. I take a rifle out of the safe and expect it to hit where I aim and perform just like it did the last time I held it. I load, ready and fire and expect to see an animal on the ground (which is by and large always the result although some may bolt the gap for thirty metres or so) and then away the rifle goes after being cleaned, ready for the next time - same deal. Still that could all change if and when I get the rifle I am endeavouring to have imported.

Originally Posted by Rushy

People like me must frustrate you then Gillie. I take a rifle out of the safe and expect it to hit where I aim and perform just like it did the last time I held it.

Nope with that attitude it not the people "like you" that frustrate me and i expect exactly the same out of my own rifles.

The people that frustrate me say things like:
"But my mate said he sighted it in"
"Nah, as soon as i could hit the paper that was good enough"
"The shop sighted it in with their in store laser"
"Nah, i just use the cheap ammo to sight in with, not the hunting stuff"
"its just come back from the gunsmith, it'll be fine"
"Torque? WTF? Nah mate, did mine up with a screw driver, didn't need to talk to it"
Wheres it sighted in? - response "about 100 yards i'll just aim a bit high for that 300m goat"
Wheres it shooting? - response "last time i checked it, it was about 2 inches hight and 3 to the left" - At what distance? - response "I think it was about 100 yards"
"what do you mean, i sighted in on 9 power. It'll be bang on on 3 power as well"
"bit funny wounding that one, thought it was sighted in"
Done anything to your rifle since then? - response "Nah, i mean i took a tumble with it last trip but that won't do anything"
"nah never shot anything past 100m except that goat at... must have been 400 yards. Got it too, never found it but it was definately hit"

Can't think of anymore i have heard. Pretty sad i have heard all of these, several of them more than once...

Originally Posted by Gillie

Nope with that attitude it not the people "like you" that frustrate me and i expect exactly the same out of my own rifles.

The people that frustrate me say things like:
"But my mate said he sighted it in"
"Nah, as soon as i could hit the paper that was good enough"
"The shop sighted it in with their in store laser"
"Nah, i just use the cheap ammo to sight in with, not the hunting stuff"
"its just come back from the gunsmith, it'll be fine"
"Torque? WTF? Nah mate, did mine up with a screw driver, didn't need to talk to it"
Wheres it sighted in? - response "about 100 yards i'll just aim a bit high for that 300m goat"
Wheres it shooting? - response "last time i checked it, it was about 2 inches hight and 3 to the left" - At what distance? - response "I think it was about 100 yards"
"what do you mean, i sighted in on 9 power. It'll be bang on on 3 power as well"
"bit funny wounding that one, thought it was sighted in"
Done anything to your rifle since then? - response "Nah, i mean i took a tumble with it last trip but that won't do anything"
"nah never shot anything past 100m except that goat at... must have been 400 yards. Got it too, never found it but it was definately hit"

Can't think of anymore i have heard. Pretty sad i have heard all of these, several of them more than once...

I totally understand.

I've said most of whats listed

There will be an impact shift generally high or low when going from a bipod then with out. How much, depends on the marriage between barrel and stock and more importantly the strength of both.
Also, the surface you are shooting off of ie grass, sand to something harder will play a major role due to, jump. Train so you shall fight, zero so you shall shoot. Simple.
If you do not notice a change in mpi when changing thru prone, kneeling, sitting and standing unsupported you need to be in the olympics. Because the nature of the positions themselves require special technique and training in order to maintain a constant mpi thru positions and ranges. Maybe not so much within 100yrds on animals. The rifle is constant within reason, the operator is not.

Cheers for all the input guys. Its good to hear varying opinions (though it can make forming your own a little harder). I'm pretty confident that at the distances Rushy and I will be shooting, it won't be an issue. Nevertheless, its worth me taking a trip to the range at some point to sharpen my shooting and get to know my gun better.

Gillie, or anyone, can you explain the relationship between POI and varying the power on the scope? I'm afraid that one on the list would come out of my mouth if prompted at the moment haha

Originally Posted by Tussock

There should not really be one, apart from parralex error. If you keep your cheek welded to the same spot on the stock you have done all you need to. Not something you need to fret about for normal hunting.

Cheers for the clarification, I didn't think the cross hair should move at all with changing the power. Will make sure to centre the crosshairs and not be looking through the scope on an angle (just like using iron sights)

Originally Posted by R93

Train so you shall fight, zero so you shall shoot.

What does this mean pls ?

Originally Posted by R93

If you do not notice a change in mpi when changing thru prone, kneeling, sitting and standing unsupported you need to be in the olympics. Because the nature of the positions themselves require special technique and training in order to maintain a constant mpi thru positions and ranges. Maybe not so much within 100yrds on animals. The rifle is constant within reason, the operator is not.

Anything specific other than natural point of aim ?

R93, did you guys ever come across completely natural shots in the army ?

Originally Posted by Tussock

Completely natural shots are very common. They are known as "women".

yup - my wife ... night shoots where it is all instinctive - she is deadly !

Probably because women LISTEN when they are taught something!
I have a qualification as a fly fishing instructor and used to teach quite a lot back in the UK. Women nearly always picked up casting quicker than men because they listened carefully and didn't have the macho attitude that most men have with some sports.

ebf, I was more or less confirming or agreeing with Gillie. Train so you shall fight is an expression that justifies training, like you intend to operate.

Yes there were plenty of so called natural shots in the Army. Some of the best ones knew fuck all about ballistics and principles as well, funny enough.
Natural point of aim is imo, is most important, but finding it in its true form in other positions is subtle and takes a lot of practice.

I have tested the differing impact versus holding method many times over the years. The worst performers are always the softer synthetic stocked rifles. I have experienced an eight inch of impact point change at 100 yards with the worst one (AR15) when rested on a hard surface. Many other bolt guns with plastic stocks will also throw the shots all over the place particularly when shot off hard surfaces using the non tilting type Bipods. It is very easy to twist load these. Although poor fore end support (read block of wood here) will mostly result in shots going high, this is not guaranteed. Even bedded wooden stocked (including laminated) and fiberglass stocked rifles will throw shots off centre when fired in that manner, generally not as far off though.
If you want to sight in for <100 yard shots in the roar with any rifle, just do it as you intend to shoot it in the bush, with the same ammo you are going to hunt with.

For the record I use a Caldwell cradle for all load development, as this takes as much of "me" out of the process as possible. I'm only looking for tight groups here and not so fussed on point of impact. All subsequent sighting in is done in the actual shooting position I'll use when I shoot for keeps. I will often shoot a hunting rifle off my pack (as fore end support), then bipod, then sling prone, sling sitting, sling standing, and free hand standing to check differing zero points. All will usually result in slightly differing zeros. With a good hold technique the effect can me minimized. I find big, heavy, free floated, fiberglass stocked rifles usually have the least variation. They are also the least likely to be dragged through the scrub after animals.