Bad 100 yd groups but great LR load?

[rogue308]

Just wondering if this is happening to anyone else. Load is...

.308 208 AMAX
46.8 gn RL17
CCI BR2
Lapua brass
Loaded at 2.865"
2510-2520 fps out of 20" bbl

At 100 I can barely pull off a 1 moa group. It's usually .8-1.2" (5 rounds of course). Push it out to 500-600 though and I'm getting consistent .5-.75 moa groups. I guess it's taking the round awhile to stabilize. Ladder testing was done at 300 yds so I'm guessing that has something to do with it also. Anyone else experience this?

 

[sobrbiker883]

Re: Bad 100 yd groups but great LR load?

If your looking for groups at 100, is needs work, if you want to shoot at distance its fine......but you knew that.

Why is this in the "competitions" forum?

 

[rogue308]

Re: Bad 100 yd groups but great LR load?

Sorry meant to put this is the reloading forum, If a mod could move it for me that would be great. Thanks.

 

[savage110]

Re: Bad 100 yd groups but great LR load?

30-06
168 AMAX
47.8gr IMR 4064
Win brass
Wolf match primer
sub MOA, -- Gave me an .8 something today. Alot higher BC. then SMK which makes it better for LR
2760fps

Same load with 168 SMK's - I wont say what sized groups to not start another shit storm but sub .25MOA. many groups alot smaller then that.

 

[Lucks]

Re: Bad 100 yd groups but great LR load?

I'd probably do some more load development. It would bug me if my load wouldn't shoot an inch at 100y.
If it will shoot .5 MOA at 500y, I would think you should be able to find a load that will shoot sub-MOA from 100 yards and out with some tweaking.

 

[rogue308]

Re: Bad 100 yd groups but great LR load?

It bothers me a little, but not to the point where I think I want to change it. To be honest I could care less about 100 yd groups. If it performs 500 and out that's what matters to me. Just found it interesting and wondered if this has happened to anyone else. The groups really start shrinking at 300. I have shot 300 yd groups that were only about an inch bigger than some of the ones at 100.

 

[sobrbiker883]

Re: Bad 100 yd groups but great LR load?

I'd rather have a load that shoots moa or better at 300 and out than any 100yd bughole load that falls apart once it stretches its legs. My old 168gr 308 load only shot moa-ish at 100 but posted successive 3 shot in 15 second limited exposure targets that were under 1/2 minute at 500 and 600 yards at NorCal last year (then the load fell apart at 800+ of course).

There's a reason 100/200yd benchrest guys use different bullets than the 600 and 1000yd boys. If you want a tiny group to brag on try some flat based bullets at 100.
Me, I'll trade first round hits at distance for wallet card screamer groups any day!!

 

[frankythefly]

Re: Bad 100 yd groups but great LR load?

This might be one of those old man tales, but I was always told that bullets especially VLDs and the AMAXs needed longer distance of being in flight until they go to "sleep" mode (stabilized). That is why I do all my load development at 200yds instead of 100yds. Also my friend who shoots 210 jlks and Berger VLDs out of his .300 win mag groups .5-1 moa at a 100 but at 200 it is all through the same hole.

 

[Sleeper]

Re: Bad 100 yd groups but great LR load?

I don't know, several practical tactical matches I have been to lately could have been won or lost on the 100 yard line!

 

[one shot ST]

Re: Bad 100 yd groups but great LR load?

My 100 m zero, on the left and the right SMK 175, first one shot on month ago, in the center Berger 185, every groups 5 shot.
Berger 185 is always .1 MIL up and .1 MIL left versus sierra SMK 175.

till 800 m I'm always at 1/3 MOA groups.

prone position, Atlas V8, normal leg position and rear padded glove

 

[sobrbiker883]

Re: Bad 100 yd groups but great LR load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sleeper</div><div class="ubbcode-body">I don't know, several practical tactical matches I have been to lately could have been won or lost on the 100 yard line! </div></div>

Very true. I've considered working up a flat based load that matches my distance load's 100yd zero (within .1-.2 mil) for just such occasions, but I'd rather practice hitting dots than shooting for groups anyway.

 

[sobrbiker883]

Re: Bad 100 yd groups but great LR load?

rogue308- speaking of dots, how does the load do shooting one shot each at 1" to 1/2" dots at 100?

I know I can't shoot groups for shit, and for me its more mental than rifle/load.

 

[2156SMK]

Re: Bad 100 yd groups but great LR load?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: frankythefly</div><div class="ubbcode-body">This might be one of those old man tales, but I was always told that bullets especially VLDs and the AMAXs needed longer distance of being in flight until they go to "sleep" mode (stabilized). That is why I do all my load development at 200yds instead of 100yds. Also my friend who shoots 210 jlks and Berger VLDs out of his .300 win mag groups .5-1 moa at a 100 but at 200 it is all through the same hole. </div></div>

It's not an "old man tale".
The Bryan Litz book and Vaughn's Rifle Accuracy Facts book both speak about why heavy bullets that are right on the edge of being stabilized don't "go to sleep" and start shooting tight groups until after 100yds.
Both those books were written by career exterior ballisticians.

 

[ubet]

Re: Bad 100 yd groups but great LR load?

Had a 300wsm with 185vld bergers, would group 1moa @ 100yds, but at 300yds could group less than an 1 inch (on a good day) I just kept a 300yd zero on it and called it a day.