Distance to lands

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surfclod
Senior Member
Posts: 132
Joined: Mon Feb 19, 2007 2:53 pm
.204 Ruger Guns: None
Location: SE Saskatchewan

Re: Distance to lands

Post by surfclod »

If all the cases were loaded with the same bullets, brass and primers, you should be able to weigh them to determine which is what powder charge. Then just put them back in the ammo box by weight.
I had hoped to be able to do this but the brass weights vary to much to be able to tell what the powder weights were in unmarked cartriges.


When developing my load I weighed 428 once fired Hornady cases and found they varied in mass from 95-103 grains after resizing, trimming and deburring flash hole.

I ended up with just enough cases (about 100) that fit within 1 grain of the average.

I also weighted every bullet and picked out the ones that were exactly 32 grains, most were exact but about 25% of each box of 100 were off by .3 grains. (0.2 over, 0.1 under)

After a day of weighing and doing statistical calculations I finally had 100 brass that varied by only 1 grain and 100 bullets weighing in at exactly 32 grains. Then loaded 5 batches of 20 rounds in 0.3 grain increments from 26.3- 27.5 grains of H332. Labeled the rows in my MTM case and placed the cartidges in their respective rows.

Then dropped the MTM ammo case and watched it spill on ground at range. :wall:

Luckily enough remained in the case that I was able to shoot three 5 shot groups of each batch and find my rifles preferred load.

But what I am saying is that unless you weighed every case to have less variance in weight than the powder charges, weighing the cartridges will not tell you how much the powder weighs inside the cartridge.
Brass variance 8 Grains + Bullet Variance .3 grains vs powder variance .3 grains

or even after eliminating approx 20% of bulllets and 75% brass still
Brass variance 1grain vs powder variance .3grain

Perhaps Norma brass is consistent enough to have less than .3 grain variance I have never used Norma or other premium brass.

The best I have seen (maybe on this forum even) was a fella who had multi colored sharpies and colored the primers. The label was easy to see and removed in reloading process.



To get back on topic of post........

My Savage (factory barrel) has to much distance to allow any currently produced bullet to touch the land even single fed.
I use 32 Grain Vmax at 2.290 COAL. I have found my powder weight sweet spot but my next step would be to vary COAL but I am not even going to bother as I am very happy with 1/2 MOA in a factory rifle. My next load testing will be to find a good load for 39 Grain Sierra BK's
JD11
Junior Member
Posts: 51
Joined: Sat May 17, 2008 5:14 pm
.204 Ruger Guns: Savage 12 Varminter low profile
Location: Cody, Wyoming

Re: Distance to lands

Post by JD11 »

But what I am saying is that unless you weighed every case to have less variance in weight than the powder charges, weighing the cartridges will not tell you how much the powder weighs inside the cartridge.
Good point. I appreciated the advice, but in my case it didn't work out anyway because it turned out my wife's postage meter wasn't near sensitive enough. I shot'em up, finally reloaded more yesterday, set'em where the cat (who is on my reloading bench as I type this :) )can't tip the box over and am good to go back to the range if the wind ever quits.

I can't touch the lands either with my new Savage LPV. For starters, I'm seating my bullets equal to their diameter and doing that, my COL is right at 2.355 with 39Gr. Sierra BKs. I haven't had time to work up the perfect powder weight yet. At this point it's confusing. With Varget, the recommended loads are 25 to 28.5 grains with 39gr. BKs. Brand new out of the box (after breaking in the barrel) I loaded up about 15 rounds with only 25.6 grains to sight in my newly installed scope at the gun club. I got it sighted in then told my wife, I'm shooting a 3 shot group, then we're out'ta here, I can't get comfortable today. Looking through the spotting scope, she said, Holy Crap, go get your target. The 3 shots were one ragged hole. With the same less than quality bags, the only group that's been almost the same size was with the much hotter 27 grains. Since then I've bought the big Caldwell Tack Driver bag so hopefully that will take some of the pilot error out of the equation.
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