Riddle me this Riddle me That

[BigBlack]

Okay new reloader still learning as much as possible. I have been working on my 243 loads and am getting MOA groups at 100 yards pretty consistently now. Preparing it for hunting I fine tuned the scope adjustments and then popped off a few groups at 200 yards. Surprisingly my groups were only about 1.25" to 1.5" consistently. So at 100 yards I am about 1 MOA consistently then at 200 yards .6 to .7 MOA, why not closer to 2 MOA. I was under the impression (remember new reloader here) that if my group size was 1" at 100 yards I could expect 2" at 200 yards and 3" at 300 yards and so on.

Wind was relatively nonexistent this trip.

Not looking for flames only instruction or enlightenment.

Thanks
BB

 

[wheelgunner]

Maybe the bullet get a better stabilization on the longer distance (200 y), and then the groups are more accurates. You are not happy ?

 

[BigBlack]

plenty happy, just curious as I am a knowledge junkie

 

[MachV]

I usually attribute it to scope parallax or the x hairs matching the target better. Either way its a good thing, try shooting it @ 300 and see what happens?

 

[MagMan]

I usually attribute it to scope parallax or the x hairs matching the target better.

I also agree.

Were you shooting at the same target both times?

If you were try shooting 100 again with 1/2 of the magnification that you were using at 200.

While I also understand the longer fight time to better stabilize certain projectiles my only experience with that was really long bullets.

 

[loaders_loft]

it could be residual oils/cleaning fluids in the barrel, that took awhile to clear out. Some barrels need a little fouling before the groups tighten up.

Before cleaning again, go back to 100 yards and you may like what you find.

Try using wipe out products for cleaning - it should reduce/eliminate fouling shots... At the very least, dry patch your barrel before you shoot to remove residual fluids from cleaning/storage.

 

[cross]

Kirby Allen wrote a good explaination of this a while back in which he explained that his understanding was that when bullets are in the bore of your rifle, they have no choice but to rotate around the axis of the bore because they are engaged in the rifling. Upon exiting, they then have the opportunity to rotate around the center of mass (centroid) of the bullet and they will wobble a bit until this is achieved. When they're revolving around their centroids, they will stabilize in flight and fly straighter. That explaination seemed the most reasonable I'd heard so that's what I've hung my hat on until I hear differently. I'd not experienced it until recently but my 338 Winchester won't deliver less than 1 1/2 to 1 1/4 inch groups at 100 yards but it gave me a 4 1/2" group at 500 and another 4 1/2" group at 700 back to back last weekend so I have no doubt that it's true. Another happy surprise!

 

[bshaw]

I think that barrel twist, speed, and bullet weight have a large factor in this. I shoot a .308 with 168 gr bullets my 100 yd. groups will be about 1/2 ", 200 yd. about 1" and so on. However go up to 180 gr. and my 100 yd. is about 1 1/2 " 200 yd. 1" and 300 yd the same. So it takes some flight time to stabilize different design and weight bullets. If your reloading, play with weights, lengths and charges to see what happens. Just my opinion based on my experience. Hope this helps in the gathering of knowledge.

bshaw