Bullet stabilization, barrel fouling or breaking in?

[rjgonzo]

I got some interesting results with a new budget 284 Wim hunting rifle build.
The rifle is a 700 long action. I it trued with the PTG tools and adjusted the factory trigger. Bedded in a McMillan Game Warden. I picked up a Wilson barrel here from Mram10us for a very fair price.

I had two sessions of ladder tests with H4831sc, with Berger 180 VLD Hunter on the lands and Federal match primers.
It showed some promise at 2760 fps at 200 yards so I loaded up 10 rounds to check what it would do at a little longer ranges.
On a clean bore I shot 4 rounds at 200 (1 fouler and 3 shot group. Shots 2, 3 and 4 were a little disappointing at 2.9". At 300 yards it was 2.6 and 400 was 1.6 !!!
My assumption was that the bullets were continuing to stabilize at 300 & 400.
So, I went home and loaded up 20 more but didn't clean the bore.
I went directly to 500 and shot a two 3 shot groups. The first was 4.22 and the second was 1.3" !!
The wind kicked up so I went home.

I haven't had a chance to get out again since then but I plan to soot more at 500 without cleaning. I wish I could go to 600 but I haven't established a trail up the mountain any further than 500 yet. It's a bunch of work due to the thick desert thorny brush.

What do you think about these results? I've been building my own guns since 2003 and never had this kind of thing happen. I had a 6.5 284 that shot MOA at 200 but did very well at 1000 yard Benchrest matches. (5" at 1000) but nothing like this.

 

[rjgonzo]

I'm using a LongShot camera system. At 500 I made an adjustment in between the two groups.

 

[Huntnful]

I think you're just seeing dispersion from small samples is all it is. Gun and load are probably a 1 MOA combo, that just occasionally shoots smaller 3 shot groups.

 

[rjgonzo]

Interesting. How do you come up with 1 moa? All of the groups were sub moa.

 

[Huntnful]

Interesting. How do you come up with 1 moa? All of the groups were sub moa.

Just talking in generalities. A .8 3 shot group is telling that the rifle will eventually shoot larger than that. Like it did at 200 yards, where it shot over 1 MOA.

Your load is likely bigger than 1 MOA in a large sample honestly. And shooting 3 shot groups you'll see it vary from .2 to 1.2 I'd guess.

It's just dispersion of that specific load and rifle.

 

[Huntnful]

This gun shoots 3 shots touching all the time. It can also shoot a 1" group on occasion. Your load would likely look like this if you shot it a decent amount at the same aim point if I had to guess.

 

[rjgonzo]

Ok, thanks for the input. I'll try some 5 and 10 shot groups. I shy away from that due to the cost and availability of the components.

 

[Huntnful]

Ok, thanks for the input. I'll try some 5 and 10 shot groups. I shy away from that due to the cost and availability of the components.

Yeah totally understandable! It just helps learn the true cone of what the rifle is capable of shooting in general, instead of chasing three shot groups that keep varying.

If the gun is actually going to shoot lights out, it'll do it repeatedly with 3 shot groups as well. There won't be a 200-300% variance from group to group.

It's just easier and faster to see with a 10
shot group. Or three 3 shot groups shot over top of each other.


This is five 5 shot groups. I'm certain some of the consecutive 3 shot groups were 1/4 MOA. The first 5 were under 1/2 MOA for sure.

I'm not saying you HAVE to base your rifles accuracy off this. Changing position 5 times and the environmentals and mirage changing over the course of an hour can certainly increase the group size. So the rifle may definitely be capable of shooting smaller.

But I can say, "whenever I lay behind this rifle, there's a high likelihood I'll shoot MOA or smaller"

 

[waveslayer]

Nothing wrong at all. Based on your title, no the bullets are stabilized and don't stabilizer farther it goes, has never been proven, could be fouling, break in won't effect the geoup size, more velocity.

But it looks fine, shoot away, could be scope, mirage, parallax

 

[rjgonzo]

Nothing wrong at all. Based on your title, no the bullets are stabilized and don't stabilizer farther it goes, has never been proven, could be fouling, break in won't effect the geoup size, more velocity.

But it looks fine, shoot away, could be scope, mirage, parallax

Thanks waveslayer. I'm just getting started with this rifle and was just perplexed by how it behaves.

More shooting sessions will reveal…

 

[waveslayer]

Thanks waveslayer. I'm just getting started with this rifle and was just perplexed by how it behaves.

More shooting sessions will reveal…

If you are getting MOA or Sub at those distances, normal dispersion. How are the SD and ES of your loads?

 

[rjgonzo]

ES 16.6, SD 5.4

 

[waveslayer]

Try and get that SD below double digits, you will see better results

 

[Mike D Texas]

IME single digits SDs are great for bragging rights. Not so much on targets.