284 accuracy issues

[Erik Cortina]

There is nothing wrong with the 284 Winchester. Just because there is one or two that don't shoot doesn't mean the caliber is not accurate!

 

[distantfoe]

Well Gentlemen I've spent a lot of time and money over the 5 days trying to narrow the situation down. So far I've checked for stress by using an indicator on the stock with only .001 worth of jump when breaking the front action screw loose. Also, changed the scope out for a 42x nightforce with no indications of improvement.

I'm going to try 162gr amax's to see if they shoot. I've received a lot of recommendations to try them as it seems to shoot well in several rifles that I know of locally.

 

[BoydAllen]

What seating depth and neck clearance?

 

[Maurice]

Maccao09

I started at touching the lands - could just see land marks on the projectile - with .030 shims on a Wilson seater, then simply changed the shims to give .010. .015 etc.
I had already found the "best" pwder load - 57 gns, as it happened, using the Hybrid & Lapua cases, but then I could not get more lapua, but Win brass was off the shelf, so as I had used the full pack of 100 hybrids, I went to SMK.
Then I found I could not get 57gns into the Win case, & had to go down to 55 which still gave me a lightly compressed load, but I was in the velocity range I was looking for.
Since then I have shot at ranges from 500yd to 900 yds with excellent trajectory & incidentally, some competition wins.

cheers

M

 

[distantfoe]

I'm running 2.5 thou of neck clearance. Had to neck turn as a loaded round would not chamber.

As for seating depths, I've tried +.020, +.010, +0, -.010, -.020, -.050, and -.130 with the smk's. To date I've tried berger 168s, 180s, smk 175's, and a few 162 amax.

 

[Erik Cortina]

I'm running 2.5 thou of neck clearance. Had to neck turn as a loaded round would not chamber.

2.5 thou neck clearance is not enough. Turn down to .004" clearance and you will see the difference.

 

[bozo699]

Erik,
Are you saying .004 total or per side?
Wayne.

 

[LongRanger]

Some, like Bill Ballard, will have success with the 284, some won't. There does not seem to be that "inherently accurate" quality about the 284 as there is with its 6.5-284 variant. If there was, I'm sure that you would find the US F Class team switching to the straight 284.

If I were just now getting into the 7mm game and looking for ultimate 1000y accuracy, I would hold off until the Team fixes upon a cartridge and load. For the present, just to have some fun with a 7mm that seems to have none of the downside of the 284, I'm going with the straight 7 RemMag for being less fussy with high pressure loads that work.

Frank B.

 

[Erik Cortina]

Erik,
Are you saying .004 total or per side?
Wayne.

No Wayne, .002" per side, .004" total.

 

[distantfoe]

I apologize, .005" total.

 

[bozo699]

Erik,
Are you saying .004 total or per side?
Wayne.

No Wayne, .002" per side, .004" total.

I figured so Erik but just checking.
I have a 6*284 that had .0075 clearance per side, it was working the brass way to much so I re chambered it, had my ream ground down to have a .269 neck, I turned the necks but must have been tired as I miss read it and had .0005 per side for clearance, it shot okay but had sticky bolt lift, took a while to figure it out, realized I had miss measured or calculated so I re turned the necks, for the next 10 re loads or so I had sticky bolt lift, couldn't figure it out then someone one here told me to trash the brass and start over,...start over?...... Yep that's all it took, new brass with about .002 per side clearance and I now have 4 or 5 loads on this brass with no issues, some times it's something that simple that can through you off
Wayne.

 

[Erik Cortina]

I'm running 2.5 thou of neck clearance. Had to neck turn as a loaded round would not chamber.

As for seating depths, I've tried +.020, +.010, +0, -.010, -.020, -.050, and -.130 with the smk's. To date I've tried berger 168s, 180s, smk 175's, and a few 162 amax.

Looking at the seating depths you posted, you can't poke around hoping to hit on the correct seating depth or powder charge for that matter. Move the bullet .005" at a time until you find a sweet spot.

 

[distantfoe]

My typical load development starts with powder charges in .5gr increments seated at the rifling. I then vary the seating depths of the best shooting/low es loads until a load is found. Never had a problem but I'm definately open for suggestions. I do appreciate and utilize all recommendations.

This will be a hunting rifle so I had to change my method a bit as I prefer not to jam bullets. I somewhat followed Berger's recommendations for seating depth.

 

[Baron B58]

Distantfoe are you using necked down Lapua brass; if affirmative have you taken care of the doughnut. I am sure that will cause accuracy issues if the bullet bearing surface goes past the shoulder /neck junction.

 

[distantfoe]

I'm actually using winchester 284 brass. I always use lapua when I can, but figured winchester would work as I'll probably lose some while hunting.

 

[Erik Cortina]

I'm actually using winchester 284 brass. I always use lapua when I can, but figured winchester would work as I'll probably lose some while hunting.

Not if you lose your mind first trying to get Winchester brass to work!

What is your chamber neck diameter?

 

[distantfoe]

The reamer is supposed to be .316 yet fired brass is .315, my loaded rounds are .310-.311.

I ran a few more 168 smk's with h4350. Groups were approximately moa but really tightened up with heavier charges. At 54gr H4350 the rifle settled to around .3 -.5 moa.

 

[bozo699]

The reamer is supposed to be .316 yet fired brass is .315, my loaded rounds are .310-.311.

I ran a few more 168 smk's with h4350. Groups were approximately moa but really tightened up with heavier charges. At 54gr H4350 the rifle settled to around .3 -.5 moa.

distantfoe,
Your spot on then,.316 chamber neck then spring back puts your brass neck at .315,...perfect
Wayne.

 

[bootlaceb]

My Dasher went south over a period of time. I looked at the stock for touching parts, different lot 108's, different lot of powder, primers etc etc etc. It eventually came out to be my stock had shrunk over 3 years and my action screws started touching the bottom of my action. Something worth looking for. When I bedded the rifle initially, everything was clear as required. Now with the small amount of shrinkage of the laminate, it all went bad. Bolts ground back to size and she is back on track! Sometimes the small things can make you mad!

 

[Rope2horns]

Hopefully the OP has figured it out after 5+ years.