.284's Sweet Spot?

[Propdoc03]

So I am fairly confident that I have my powder/bullet (charge and seating depth) combo shooting as well as it can. I tested then back checked by another range test and again it shot consistently in the .5"to.6" range, double of what it shot with my last tube.

What is the most common or cheapest thing to try next? I hate to admit it but the economy, lack of work, gas prices etc.. is really starting to pinch us hard.

Is there one thing that gives more results than another such as bullets over powder?

Right now I am using 180 thin Bergers, Lapua brass with a light neck turn, .002-3" neck tension, .003" chamber/neck clearance, stiff charge of H4831SC, CCI-200's.

I have not tired any other primers but may have a few CCI-BR and Federal Match primers. Any suggestions on a different bullet.
Lynn, I know you mentioned the new Bergers, still think that might be a good way to go over a completely different bullet?

Thanks,
Dennis

 

[mike in co]

propdoc,
may i ask what your oal ?, bbl length, and velocity ??
6.5x284 lapua brass necked up ?

i have a box of the heavy 180's. when i get done testing i'll have 50 or so left. could ship them to you( no idea when i'll get my 284 built, i did testing in a 7mm win mag).

mike in co

 

[jerryhm]

284 data

Dennis,
Latest testing the 284 using the Berger 180 VLDs and the Berger 180 thick jacket.

Note: The VLDs shoot best around 2820/2840 fps and the Thicks shoot best around 2770/2800 fps in MY barrel chamber combination.

Jerry




Berger Bullets 7mm 180s VLD vs Thick June 20, 2008

Bat action , McMillian F class stock
NightForce NXS 12-42X scope.
Krieger 277/284 8.5 Twist 30” Barrel
Light Target Taper

WW 284 brass.
Case fired = 0.312”
Case sized = 0.306”
Case loaded = 0.308”

The OAL to touch the lands for the VLDs is 3.160”, loaded to 3.175” In the lands 0.015”
The OAL to touch the lands for the Thick is 3.131”, loaded to 3.115” Out of the lands 0.016”

Sacramento 100 yards, group and chronograph testing. Temp.=82 degrees, Time 08:00 to 09:30.
Five shot groups.


1. H4831 54.0 grains B180 VLD MV = 2791 ES = 16 SD = 05 GRP = 0.290”
2. H4831 54.5 grains B180 VLD MV = 2817 ES = 13 SD = 05 GRP = 0.199”
3. H4831 55.0 grains B180 VLD MV = 2827 ES = 11 SD = 04 GRP = 0.626”
4. H4831 55.5 grains B180 VLD MV = 2842 ES = 16 SD = 06 GRP = 0.219”
5. H4831 54.0 grains B180 BT MV = 2817 ES = 20 SD = 08 GRP = 0.966”
6. H4831 54.5 grains B180 BT MV = 2844 ES = 17 SD = 08 GRP = 0.782”
7. H4831 55.0 grains B180 BT MV = 2874 ES = 26 SD = 10 GRP = 1.158”
8. H4831 55.5 grains B180 BT MV = 2892 ES = 14 SD = 06 GRP = 0.634” SOME PRESSURE SIGNS


The 180 Thick BT have a high MV than the VLDs for the same powder charge.

June 21, 2008

Sacramento 100 yards, group and chronograph testing. Temp.=85 degrees, Time 08:00 to 09:00.
Five shot groups.

9. H4831 54.0 grains B180 VLD MV = 2788 ES = 23 SD = 08 GRP = 0.418”
10. H4831 53.0 grains B180 BT MV = 2776 ES = 06 SD = 02 GRP = 0.463”
11. H4831 53.5 grains B180 BT MV = 2796 ES = 17 SD = 06 GRP = 0.283”
12. H4831 54.0 grains B180 BT MV = 2818 ES = 16 SD = 06 GRP = 0.662”

 

[Propdoc03]

Jerry, thank you kindly for the data! Looks very encouraging!! I think I will give the new thick jacket Bergers a try. Very interesting that I had the same node as you with the thin Bergers. My rifle shoots best right at 2840 and pressure wise I have no room to go beyond that, might even need to back the charge off a bit. Just dropping off close to 2800 my groups opened up considerably. On seating; going into the lands anymore jumped my pressure way up. Back off a bit from where I am at and they start to open up again. I have a very little sweet spot and it is not that sweet. Nothing terrible but nothing to write home about. I know this rifle can shoot better!

Mike, my barrel is 31" and has a deeper throat than Jerrys chamber. I am at approx. 3.33 at the lands, as best as I can tell. I am going off of feel with the firing pin removed as I do not have a modified case for this cartridge. Brass is 6.5-284 necked up and turned just a tad.

Im off to call Bruno's

Dennis

 

[Propdoc03]

They Are Saying August

Well thats an easy way to save money. Brunos is all out and they are being told August. Mike, please do let me know if you end up with half a box that you might be willing to work something out with.

Thanks!,
Dennis

 

[Lynn]

Propdoc3

Dennis if you look over Jerry's data his best group with the VLD was 0.199 and his best group with the BT Match was 0.283 or roughly 0.100 just by swapping bullets.
If your powder charge and seating are good change your bullets.If the BT Match bullets aren't available get some Sierras and some Cauterucio's.Shoot whatever your gun likes best.
Lynn