The Accurate Reloading Forums
Do loads ever group relatively better at further distances?
12 November 2017, 18:48
Mike_DettorreDo loads ever group relatively better at further distances?
I have heard that because a load is say 1.5 MOA at 100 yards doesn't mean it won't be a 1 MOA group at 200 yards or a 3/4 MOA at 300 yards.
Can this be true? and if so what is the "engineering" or "technical" explanation.
Mike
What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
12 November 2017, 22:09
BiebsMike, I've heard that said of the old Mannlicher Shoenauer rifles, but I can't figure it out.
12 November 2017, 23:17
INTJThe theory is that as the bullet immediately exits the muzzle it is a little wobbly. It needs to travel a little bit before the wobbling stops. Kind of like if you spin a top too hard it will wobble before spinning smoothly. I have seen slightly better MOA at 200 yds vs 100 sometimes with long high BC bullets.
I am not sure of all the physics involved but from shooting 1000 yd BR I do know that shorter lower BC bullets and slower twist rates produce better group sizes. Perhaps because such a combo doesn’t spin as fast it is less prone to wobble?
13 November 2017, 01:30
Blair 338RUMIt also can happen when you have a very tight twist rate in the barrel.
Generally it's rubbish, though.
14 November 2017, 05:31
IOWADONThe third barrel on my 7MM Weatherby was like that with 160-gr Sierra boat tailed bullets. It shot about 1.5 MOA at 100 yards and about 1.0 MOA at 200 yards. Also, my son-in-law's AR in .308 shoots about 1.25 MOA at 100 yards but about .75 MOA at 330 yards with Nosler 150 gr Balistic Tips. I haven't had that with any other rifles. The 7MM Weatherby barrel had a 1-in-9 twist and I don't the twist rate of the .308.
15 November 2017, 22:28
ZekeShikarThose bullets are pretty smart to divert their path and move back into the groups!
I KNOW its possible for bullets to settle down and not produce larger MOA's at distance but to return to the group-center, thus producing tighter and tighter MOA at longer ranges is not physically possible.
If they're moving around then we should experience the opposite effect half of the time too...which we do because of external forced.
There are way too many variables at distance for me to believe some of this stuff.
Just my 2 cents,
Zeke
16 November 2017, 06:11
youngoutdoorsZeke, Get you some really long target bullets and I'll bet you'll be a believer. I've seen it a few times.
God Bless, Louis
16 November 2017, 16:14
VaqueroAccording to Bryan Litz the groups don't get smaller at distance
16 November 2017, 23:56
Kyler HamannWith a small enough sample size I can "prove" almost anything.
Believing in magic is a wonderful thing.
17 November 2017, 06:05
lockingblockquote:
Originally posted by Vaquero:
According to Bryan Litz the groups don't get smaller at distance
This.
He discusses the various bullets he has tested and their stability in flight in his books.
The gist is...not really. Some bullets can exhibit a degree of yaw or "wobble" in flight and this can decrease as the velocity bleeds off...but it is not something that you would want overall. Select a better bullet/rifling twist/velocity would be the answer to wobbly bullets.
17 November 2017, 20:27
Bill/OregonAmong black powder cartridge rifle shooters, there is considerable faith that those big lead slugs can indeed "go to sleep" after the initial 100 yards or more and produce slightly better accuracy further downrange.
There is hope, even when your brain tells you there isn’t.
– John Green, author
19 November 2017, 20:57
SaeedIt might be more due to wind deflection.
I am not kidding.
I have fired a lot of tracer ammo in a 308 Winchester at night across the desert, and those bullets hardly ever went in a straight line, even with little wind.
In fact, the bullets seem to wobble all over the place as they go along.
The only reason we could attribute this wobble to is wind.
29 November 2017, 08:01
R.A.N.G.E.Rquote:
<…>
In fact, the bullets seem to wobble all over the place as they go along.
The only reason we could attribute this wobble to is wind.
Maybe they were skipping around more static pools of differing densities of atmosphere, not unlike an airplane gets pushed around?
“Truth is not a state of mind”
29 November 2017, 15:36
tiggertateThe tracing compound burns erratically which can alter the center of mass in the base of the bullet.
My bullets must
begin wobbling at about 100 yards...
"Experience" is the only class you take where the exam comes before the lesson.
30 November 2017, 00:54
SFRanger7GPI have seen a lot of that when firing heavy bullets in calibers such as 300 win mag, 338 Lapua and above. I would not call it getting tighter groups; I would call it less deviation with range. I have heard it credited to everything from bullet over stabilized/spin to scope parallax. All of which can be argued by people with more free time and smarts than I have. Very common to see 200gr bullets in a 300 win mag shoot 1.5 MOA at 100m but then be sub-MOA at longer ranges. I personally found the various theories interesting but did not really care as long as the load and system were consistent.
Safe shooting..............Larry