1/4-1/2MOA but then very poor accuracy at 300

[6BRinNZ]

I shoot consecutive groups 0.5 gr. apart at 100 yards, but once you start shooting, never touch your scope until you are done testing.

I shoot until I find two or three groups that hit the same place vertically on the target in relation to the bulls eye. Also watch you chronograph speed. The speed will not change much for those two or three groups even though the powder charge is different. Then, adjust seating depth to bring them in even closer and then pick the load in the middle of the three. That load will shoot out to 1000 yards.

Hey Eric - very useful info. Would you be prepared to go so far and post pictures and numbers up?...I'm not doubting....just asking for a bit more of a tutorial.
The new rifle will be here in about a month so I am hoping to use this process to prep it for the Nats this year.

 

[Trapper243]

From memory I think Brian Litz states the cork screw is within the diameter of the bullet, i.e. not enough of an issue for it to translate on paper as the big issue that everyone talks about. He does go on to suggest other more likely possibilities where a load shoots better further out. Interestingly I don't think he goes as far as to say it can't happen - just there are more likely explanations.

I can agree with that. Working up a new load the other day at 100, 5 shots were holding close to .5 MOA . I backed up to 400 and ran two 5 shot groups that were in the .3s. Almost no vertical at all. I repeated this the next day with almost similar results. I suppose it could be some strange phenomena, but my guess is that I don't concentrate, or execute a shot as well at close range. To verify, I put a friend behind the same rifle at 100 at it went .3s.

Trapper, by "in the .3's", you mean inches or MOA?
[/quote]

MOA. Wished I could shoot .3" at 400.

 

[Erik Cortina]

6BRinNZ, I'll try to post a target tonight with info.

 

[6BRinNZ]

6BRinNZ, I'll try to post a target tonight with info.

Awesome - thank you!

 

[savageshooter86]

Can you explain more why a load not tuned up at any distance, just shot, would should well at 600 but not 100?

I had help from a knowledgeable source, went and shot it at 600 with seating tests, found the load, brought it to 100 to shoot with some buddies and no one could get it to group

We were thinking if it shot 1/2 MOA at 600 it should shoot smaller at 100......but it appears not

 

[Erik Cortina]

I started a new thread about LR load development at 100 yards.

http://forum.accurateshooter.com/index.php?topic=3814361.msg36221455#msg36221455

 

[sailhertoo]

[quote author=CatShooter
The nature of bullets, and the laws of physics, prevent them from "stabilizing" if they are corkscrewing, yawing or precessing. Once they go off, they can never come back on axis or the original path...

Not "my opinion", just plain physics.

Anyone that argues otherwise, has no understanding of the dynamics of bullet movements.
[/quote]

How do you explain how a top on a table stabilizes?

 

[savageshooter86]

The load that shoots at 600, it should shoot at further distance too, just not at shorter distance?

Like you said before it won't matter since I won't shoot it any closer than 600, but what if I shoot it at 1000?

 

[langenc]

I fund this discussion interesting, also.

The OP mentions 'vertical' dispersion. Wouldnt that be more likely to be caused by something other than wind??

Horizontial=wind for sure but I have a lot to learn about the winds effects.

 

[Erik Cortina]

I fund this discussion interesting, also.

The OP mentions 'vertical' dispersion. Wouldnt that be more likely to be caused by something other than wind??

Horizontial=wind for sure but I have a lot to learn about the winds effects.

Horizontal can be caused by the load itself as well.

 

[VAViking]

The VMAX is also a flat base jacket; a lot of flat base rounds will have great performance at 100-200 yards, but don't hold up as well as the boat tails at longer ranges. I was reminded of this as I reread an article here:

http://www.accurateshooter.com/featured/complete-precision-case-prep/

I think a session with a chronograph is definitely in order.

Monte in VA

 

[M14AMU]

Dude.....change bullets up to a 140 or 150 and your problem will vanish!!

Chronograph? That's a joke!!

 

[JustinP]

If anyone wants more info about this issue of bullets 'going to sleep', I believe the term is 'epicyclic swerve' or 'epicyclic motion'. According to Bryan Litz, the impact of the effect is difficult to measure but there may be some credence to the idea that the pitch/yaw may not completely settle until after 100yds. Anyway, here's a link to an article and video:

http://www.longrangehunting.com/forums/f19/epicyclic-motion-bullet-video-37345/

I've also heard it discussed that shooters (even good ones) may not shoot as well at 100y/m as at longer ranges - concentration and adherence to fundamentals of marksmanship being higher as the range opens up, ergo better groups proportionally. YMMV.

Cheers, Justin

 

[M14AMU]

If anyone wants more info about this issue of bullets 'going to sleep', I believe the term is 'epicyclic swerve' or 'epicyclic motion'. According to Bryan Litz, the impact of the effect is difficult to measure but there may be some credence to the idea that the pitch/yaw may not completely settle until after 100yds. Anyway, here's a link to an article and video:

http://www.longrangehunting.com/forums/f19/epicyclic-motion-bullet-video-37345/

I've also heard it discussed that shooters (even good ones) may not shoot as well at 100y/m as at longer ranges - concentration and adherence to fundamentals of marksmanship being higher as the range opens up, ergo better groups proportionally. YMMV.

Cheers, Justin

Justin

I discovered long ago that it doesn't make much difference about how inane one may be reference reloading....there's usually someone 'out there' that's NOT....who can and will beat your azz to a fair you well regularly...no matter how many 'scare patches' you have sewn on your jacket or...what team you may be shooting with!! ;D

 

[CatShooter]

[quote author=CatShooter]
The nature of bullets, and the laws of physics, prevent them from "stabilizing" if they are corkscrewing, yawing or precessing. Once they go off, they can never come back on axis or the original path...

Not "my opinion", just plain physics.

Anyone that argues otherwise, has no understanding of the dynamics of bullet movements.

How do you explain how a top on a table stabilizes?
[/quote]

Tops on tables are NOT free spinning bullets. They are captive. That being said, the top body precesses around the tip, which is a round point (~1/10") and that tip is rolling like a small wheel in a diminishing circle, and forcing itself under the top body.

If a top it thrown off of a tall building and you film it going down, you will see that the point goes OUT and the top starts falling sideways.

Everything that spins, is not a bullet. Footballs and tops are not comparable to bullets. If you want to study spinning bullets, you need to stick with bullets and the physics that govern them... in free space, not on a table.

 

[JustinP]

If anyone wants more info about this issue of bullets 'going to sleep', I believe the term is 'epicyclic swerve' or 'epicyclic motion'. According to Bryan Litz, the impact of the effect is difficult to measure but there may be some credence to the idea that the pitch/yaw may not completely settle until after 100yds. Anyway, here's a link to an article and video:

http://www.longrangehunting.com/forums/f19/epicyclic-motion-bullet-video-37345/

I've also heard it discussed that shooters (even good ones) may not shoot as well at 100y/m as at longer ranges - concentration and adherence to fundamentals of marksmanship being higher as the range opens up, ergo better groups proportionally. YMMV.

Cheers, Justin

Justin

I discovered long ago that it doesn't make much difference about how inane one may be reference reloading....there's usually someone 'out there' that's NOT....who can and will beat your azz to a fair you well regularly...no matter how many 'scare patches' you have sewn on your jacket or...what team you may be shooting with!! ;D

Truer words were never spoken.

 

[Erik Cortina]

Shooters don't do well at 100 yards? I think many short range BR guys might disagree with that.

 

[savageshooter86]

think if you shoot at that distance only you are focused. Think he was saying LR shooters may not concentrate as much at 100 than they would at 1k. I see how that makes sense if that is what was meant

 

[JustinP]

think if you shoot at that distance only you are focused. Think he was saying LR shooters may not concentrate as much at 100 than they would at 1k. I see how that makes sense if that is what was meant

No disputing the short range BR guys are right on the money at 100/200yds. My meaning was as savage shooter explains above. The discussion I was involved in threw around the theory that many of us don't apply the same measure of concentration and the same attention to fundamentals of marksmanship at short range, as we do at the longs and this may be one factor in less than stellar results at 100yds, even amongst experienced and skilled shooters. In short, we try harder at the longs because the margin for error is so much smaller. Another factor is that load development takes time and care - but if I cite myself as an example, I know that I personally find load development not the most time efficient exercise, and that can sometimes translate to a poor effort at the 100yd line, because I'm trying to get to 'Stage B' (training with an optimal load) by hurrying through 'Stage A' (load development).

I guess what can sometimes follow is that when moving out to the longer ranges, the groups tighten up and we start scratching our heads about why the groups are proportionally smaller at longer range than they were at 100yds. That's when theories about epicyclic swerve/bullets-going-to-sleep make an appearance, when it might simply be more shooter-related.

Hope this makes sense.

 

[jmd]

I really didn't want to shoot the 120gr Vmax bullets, but I happened to try them during initial load development & they shot phenomenal so I stuck with them. The barrel was copper fouling worse than anything I had ever seen. Hornaday did suggest dropping the velocity to around 3100fps & said I was probably tearing up the jacket which was causing degrading accuracy at longer range. I ended up working on a load using 140gr Nosler ballistic tips. After getting it at 1/8-1/4 MOA at 200 I did check it at 300 & 400. It held & I no longer have horrible copper fouling. I think this confirms that I was pushing the thin jacketed Vmax too fast. Thanks for all the responses & great info.