Riddle me this Riddle me That

Status
Not open for further replies.
B

BigBlack

Member
Joined
Feb 23, 2008
Messages
103
Location
Lyons, GA
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
 
near as i can cipher, by 550 yards the hole should disappear. would you make some of that magic ammo for me? :rolleyes:

likely that more distance gives the bullet more time to stabilize. nice shooting.
 
sounds like either...

you shot better when testing the load at 200 yds.

or

the external ballistics were different do to variations in the environment (temp, humidity, wind, etc..)

that's my guess
 
I'd have to hazard a guess that it could have been the target you were using.

Perhaps the aiming point was too large for the scope reticule at 100 yards, and just right at 200.

It could also be related to scope parralax at 100 yards.
There probably is none at 150+ yards and further.

Most 3-9 variable hunting type scopes are set to be parralax free at 150 yards and beyond. Closer then that, you may have a little when set at 9x.

rcmodel
 
I have heard stories of better groups (measured in MOA, not inches) at 300 yards with large cartridges like 300 win mag due to better stabilization beyond 100 yards, but I have not witnessed it myself. Other than that, RC has some very good points.
 
I usually shoot better at 200 or 300 than I do at 100 yards. It must be a concentration thing.
 
Very often, due to the bullet's bearing surface length and diameter vs the throat geometry, the bullet will leave the muzzle in a slightly yawed attitude. As it travels, air resistance pushes the bullet back into alignment and it seems to "go to sleep" and accuracy, measured in MOA, will often be better at longer ranges than at 100 yards. Reducing distance to the lands, if possible, is the easiest way to reduce tendency toward in-bore yaw.
 
Two reasons -- the first as stated above is that it takes a while for the bullet to "go to sleep." It is more stable over the last part of the trajectory.

The second is that your scope is probably parallax-adjusted for 200 yards, which means the point of aim can shift a bit at 100 yards, but not at 200 yards.
 
I think rcmodel and Vern got it with the scope parallax supposition for the mechanical portion of the "phenomenon", and also SSN Vet with ".. .you shot better when testing the load at 200 yds." for the human portion. rcmodel's target size is a similar parallax effect caused by a different element.

I've never bought into the "bullet goes to sleep" bit. If a bullet is unstable during the initial segment of its trajectory, no amount of perfect stability is going to erase the off-course trajectory and magically get the bullet back on line. At best it will not add to going more off course after 100 yds, but it can't pull it back to the center of the target. I'd like to see empirical proof of that.

BigBlack - what constitutes a group? 3 shots? 5 shots?
 
So at 100 yards I am about 1 MOA consistently then at 200 yards .6 to .7 MOA, why not closer to 2 MOA.
Click to expand...

2MOA at 200 yards would be about 4" I wouldn't expect a 1MOA gun at 100 yards to shoot 2MOA at 200yards. I would expect groups to get bigger, but the MOA might stay about the same.

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.
Click to expand...

1" at 100 yards is 1MOA, 2" at 200yards is 1MOA, and so on...you should expect the groups to get bigger; but if you expect the groups to be 2" at 200yards you are still expecting 1MOA not 2MOA.
 
I've never bought into the "bullet goes to sleep" bit.
Click to expand...
Can I share a difference of opinion?
If a bullet is OVER stabilized, it may spin on it's own axis, as well as have a gyroscopic spin, like a spinning top and have a corkscrew like trajectory. And once the velocity falls to a stabilization level the bullet tends to 'sleep' and tightens this gyroscope effect, after a given distance.
 
Perhaps I should have been a little clearer then. I'm saying that when a bullet becomes more stable in its trajectory, and it can, it will not magically become more accurate down range. It will not, in general, be closer to the target center if it was off center at a closer range, ignoring outside effects such as wind, etc.

I am addressing only the phenomenon posted by BigBlack, not external ballistics. My first sentence should have read, "I can't buy into the "bullet goes to sleep" bit." The remainder of my paragraph bears that out.
 
Big Black- can you share a little informatiom, for aurgement sake, as to the rifle, twist rate and load information.
Sorry to mis-qoute you Mal H, I was was just trying to point out my opinion to another poster.
 
Im with EShell. Even Berger Match bullets come with a disclaimer that you will not see any accuracy improvements until your past 300 yards.
 
Rifle: Remington 700 22" Barrel 1:9.125" Twist
Ammo: Handloads
Case: Remington
Primer: BR-2
Bullet: 100gr Sierra Game King
Powder: H4350 (Its hot so I do not want to publish my weight but velocity is in the high 2800's on average according to my chrony)
 
mostly 3's few 5's thrown in. My last time I shot all ten on the same target at both the 100 and 200. On that excursion I rotated 4 rifles every 3 shots until the last 4 of each set of 20. I will gather more data and it could be a parallex as someone mention. The scope I have has a fixed parallex so it just may be a better scope at 200 than 100.

And maybe I did a better job at 200, I used the same aim point at both ranges and it was smaller and I had to concentrate more at 200.
 
then popped off a few groups at 200 yards. Surprisingly my groups were only about 1.25" to 1.5" consistently.
Click to expand...

pretty darned good! I wouldn't change that load
Click to expand...

+1
there aswell, that's nice accuracy in a hunting rifle and hunting round. The 100gr bullet will give a very flat trajectory in .243 diameter and 243win velocities. Some people often encounter difficulties to get good downrange groups with 100 grainers in 243win.

Powder: H4350 (Its hot so I do not want to publish my weight but velocity is in the high 2800's on average according to my chrony)
Click to expand...

Hodgdon list 40gr of H4350 as max, on their online data, with a MV of 2973fps, from a little digging, it appears that was from a 24" barreled rifle. And from an earlier manual i see charges that exceed that lastest data.
If your loads appear safe in your rifle and you're happy with the results it's producing. What more can ya ask for.
 
"...if my group size was..." 1.25 to 1.5 inches at 200 yards is less than 1 MOA. One MOA at 200 is 2". The bullets you're using are taking a bit if time, granted not much, to stabilize. The loading techniques you're using are working just fine too. Don't fix it.
 
Status
Not open for further replies.

Similar threads

L
How does a load/rifle go from 1 MOA to 1/2 MOA by INCREASING distance?!
Replies
20
Views
545
z7
Z
T
  • Locked
168 gr Berger Load for CZ-550 Varmint, 308
Replies
6
Views
2K
TEC
T
C
  • Locked
Sierra .224 55gr HPBT: suggested powders
Replies
8
Views
3K
JimKirk
JimKirk
N
  • Locked
LR vs. LRM primers
Replies
6
Views
1K
dirtman
D
B
  • Locked
.223 And Barnes 36 gr Varmint grenades
Replies
13
Views
3K
witchhunter
W
Back
Top