+/- on measuring.

[fokai_zach]

Hi all!

I was loading 77 grain sierra mk hpbt
once fired remington pmc case,
winchester small rifle primer,
vihtavuori n-140 24.1 grain
2.260 c.o.l.
for my 18 inch 1:7 twist spr.

when i measure powder, i get +/- .1 grain diff, example 24.2- 24.0. is that normal?

also when i check c.o.l its the same as well +/- .01, example 2.261-2.259 c.o.l.

i am using a dillon rl-550 with hordany custom grade .223 dies.
measuring with dillon digital scale.

I watch and read videos about being "consistent," and this is not consistent. please help!

thank you!

 

[Rich Coyle]

Re: +/- on measuring.

Do you know how to measure OAL on the ogive? If you try this you might find you are more consistant than you think.

 

[Tripwire]

Re: +/- on measuring.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Old man now</div><div class="ubbcode-body">Do you know how to measure OAL on the ogive? If you try this you might find you are more consistant than you think. </div></div>

Yep, and if you want more consistant on your powder charges then weigh the damn shit to the exact grain weight........

 

[gunman_7]

Re: +/- on measuring.

It all depends what you are doing with it. Hunting, target practice with friends... that’s plenty accurate...

OR

600-1000yrd competition? Then your close....

You'll spend a ton getting your charges more accurate. to get much better than .010 consistency, you'll pay $300 for a scale.

 

[prestong]

Re: +/- on measuring.

My groupings on .308 spread from .1-.2" to 1.2" with 1 grain of powder. I threw away my dillon measure once I realized how bad a job it did. I still use progressive, however I use the RCBS auto-measure scale and just dump powder in at that stage. Just take the measure/tank off the top, and drop it right in when its in the up cycle.

 

[Clark]

Re: +/- on measuring.

Bart Bobbitt posted May 28, 2005:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Charge weight spread ain't all it's often cranked up to be. For
example, in 1991 when a half dozen of us were developing the load for
Sierra's then new 155-gr. .308 Palma bullet, we tried several powder
types. All charges were metered from our measures as that's how the
ammo would be loaded. Charge weight spread ranged from about 1/10th to
4/10ths of a grain. The powder that produced the most uniform muzzle
velocity and pressure (by tests at the HP White lab) was AA2520. But
it was also the worst for accuracy. IMR4895 had a 3/10ths grain charge
weight spread, average muzzle velocity and pressure spread AND produced
by far the best accuracy -sub 3-inches at 600 yards.

Consider the fact that virtually all primers cause a greater velocity
spread than a 2/10ths grain charge weight spread. And testing muzzle
velocity from a shoulder fired rifle is NOT a good thing to do because
two people will get different averages and spreads with the same
shooting gear just because they ain't holding the rifle the same way.
Reliable muzzle velocity data is only attained by shooting the rifle
from a machine rest on in absolute free-recoil (untouched by humans
during firing) from sand bags. A proper prone position is second best.
Hanging on to a double bagged centerfire rifle with one or both hands
so it won't recoil off the rest is not all that great for velocity
testing. There can be as much as 100 fps or more velocity difference
between two people shooting the same rifle and ammo.

Go figure...... </div></div>

If he talks about 3/10 ths grain spread in 308 would be like a 1.5 gr spread in 223.

 

[gcoulsey]

Re: +/- on measuring.

Read up about, and find your OCW load,

I have just finished working up a great round for my friends AR-15
1-8" twist, with 77gr bergers.

I chose 23.8 gr varget, because when I loaded a 23.6, 23.8 and a 24.0 charge,
All 3 shots clover-leaf at 100yrds.

I went on to load up x10 rounds of each charge weight,
Mixed them all up together, and then shot them all in 5 shot groups.

Every group was sub MOA, and nearly half of them were closer to .5"'s
They all stayed sub MOA out to 500yrds, so now it's up to him to start practicing with them.

That's a .4grn spread, staying under MOA.

Find your OCW and have a little more piece of mind