Is this result reasonable and is my education in the right track

[frgood]

I'm a beginner learning, and trying to understand using my rifle.

Today, I took my Rem 783 30-06 and started my practice at 50 yds. The goal this weekend is to ensure I zeroed properly at 100 yds. and then to explore and test my hand at 200 yds. So I think this is nothing out of the ordinary.

I found myself, at 50, getting a nice small group off the bench. all within an inch. I was able to see the result of my breathing (note to self). I was using Factory ammo-Winchester 150 gr.

I ran out of the 150's and found I had only 180 gr. remaining. Upon it's usage I found my shots, all and consistently, 4 inches to the right. The group opened up slightly.

I realize the shift in POI is the weight change. I would have thought the shhift would be vertical. Is the shift to the right due to 'Harmonics' being a 2 dimensional (rotational) motion and not simply 1 dimension on the vertical plane as I might have originally (incorrectly)thought?

 

[BigBore45]

Dunno how you are holding the gun but rotational forces from the bullets contact with the rifling can cause this. The heavier the bullet the more pronounced it becomes. I have noticed this in bench testing my black hawk pistol in 45 colt anyways

 

[frgood]

I'm starting off the bench. Once drilled in I plan to focus on sitting, kneeling, and off hand (w/sling) since I can bring a bench hunting (heh heh).

 

[Llama Bob]

You can definitely get shifts in both directions when you change loads. And yes, it's related to how the barrel oscillates. It moves in many dimensions - circularly at the muzzle, longitudinally along the barrel, and even expansion/contraction of the diameter of the barrel (which has a notably impact on accuracy).

I have noticed that often the accurate loads for a given barrel in terms of group size will also have very little horizontal or vertical shift other than the vertical shift would would expect from different velocities. But this is not always the case. Sometimes you will get two loads that shoot to radically different POI but both group well.

 

[gspn]

I realize the shift in POI is the weight change. I would have thought the shhift would be vertical.

I smiled when I read this. I remember the first time I experienced that years ago. I changed bullet weight just 10 or 20 grains, same type of bullet from the same manufacturer, and I was hitting 7 inches to the right. I was shocked. My assumption at the time was that by shifting to a heavier weight I'd just be shooting a little low. It was a great experience...taught me a lot.

It reinforced the need to check my zero any time I make any adjustments to my loads.

 

[JohnhenrySTL]

It's hard to shoot a tiny group with a scope at 50 yards for me. I prefer atleast 100 yards. Also, what size targets are you shooting? What power scope?

For closer shots I lower my scope power. I aim for tiny targets. It's hard to get a tiny group with even an inch targert at 50 yards.

My holes move more because of barrel heat than anything else. Are you giving atleast 2 minutes between 2 shot groups?

Beware of the frustrating 50 yard zero.

An inch isn't bad at all for a new high powered rifle experience.

 

[jmr40]

Normally you only see elevation changes when changing bullet weights. But at only 50-100 yards most common bullet weights are close enough not to matter. While not an every day experience, what happened to you is not uncommon either. A lot of it is the individual rifle as much as the load. Most of my rifles with most of the loads I shoot through them are all pretty much the same at 50 or 100 yards. At 200 and farther the heavier bullets are predictably lower, but with certain combinations I see bullets striking left or right of where they should. It is just a quirk with that individual rifle and load.

 

[rcmodel]

Hold hard too.

The difference in recoil between a 150 and a 180 can make a huge difference if you are letting the rifle jump & squirm in your grasp each shot.

rc

 

[frgood]

I'm glad this group is here where I can check my sanity. This forum really does live up to it's name.

Now that I've used up all my factory ammo, I have enough brass to roll my own so that I can have a consistent and always available supply of ammo.

My next task is to move out to 100 yards and figure out which hunting bullet gets my the best bang.

The 'squirm in your grasp' comment really hit home. I had not realized how much you can feel that movement. There were a few shots were I'd yell "Shanked it
" or "Hooked that" before it even left the barrel.

To answer one question I was using a 100 yd. targeting target. Similar to this one:

I was considering using the 6 in bullseye targets at 100 and the 12" bulls at 200. I'm hoping to eventually get to a 4" group at 150-200 (off-bench of course).

Lastly, once I am confident my equipment is dialed in at 100. I'm curious to see if the markings on my scope (Nikon 3-9 x40) are correct. When I move to 200 yds. (or even 150) can I simply raise the elevation from 0 to 1 (or 1 to 2) and expect continue accuracy? For the moment windage is less important as my puny brain is just now realizing two dimensions.

I'm looking forward to learning all this in time for my first 'big hunt' (a deer hunt where I'm traveling from Florida to SC) in November.


Big thanks to everyone.

 

[stringnut]

Only shooting your rifle at different distances will tell how it shoots. All are indiviuals. A one inch group at 100 doesn't translate to a 2 inch group at 200. How high your scope is above the bore affects you mid range trajectory. Bullet weight and ballistic coefficient do to. At least scope adjustments stay consistent. If it is 1/4 per click at 100 yards it will be 1/2 at 200 and 3/4 at 300 etc. This may all sound complicated at first. To get started sight in about 2 inches high at 100 yards. This should get you pretty close at 200 yards. Use the smallest bullseye you can easily see with your scope. Aim small to hit small. If the target is to large the reticle tends to wander. To small and you cannot see it properly. I can shoot 1 inch or less groups at 100 yards with a 4x scope if the target is the right size! You shouldn't have a problem getting 4 inch or less groups at 200 yards. In spite of what you may read that is plenty good for deer.

 

[Bart B.]

It's normal that sometimes when changing loads then shooting them with the rifle resting atop something on a bench, the rifle isn't shouldered and held the same way. It twists a different amount horizontally and the bullets leave at a different angle because the recoil axis is not aligned with your center of mass holding it. Even though the sight was on target when you pulled the trigger, the barrel ended up pointing too far to the side when the bullets exits.

Good example of this happening is a pinwheel firework with the tiny rocket at the edge pushing it round and round about its spindle.