RCBS Chargemaster accuracy

[Fisky]

Re: RCBS Chargemaster accuracy

Last weekend I chrono'd some of my first loads with the CM. SD was 15. I don't know if that's acceptable to many of you?

There are many things I'm not doing that could probably bring that number down; flash hole debur, uniform primer pockets, sort brass, sort bullets, etc. And I'm currently FL sizing and shooting Rem brass. But at this time, I'm happy with the CM and the results on target. I'm sure as my shooting skills increase (and when I make the change to Lapua brass), I'll change a few things in my brass prep to try and lower that SD a bit.

 

[Notso]

Re: RCBS Chargemaster accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RAT807</div><div class="ubbcode-body">As gvanhyning has said the household current does fluctuate and will effect electronic devices. Florescent lighting and other electrical appliances will also add to the problems if sensative electronics are sharing the same electrical box/ground. I would recommend treating digital scales like it's a computer. It needs clean power. A simple solution would be to buy an uninterrupable power supply from APC or another well known company that will supply stable power.
Years back, I worked on digital scales and every scale had a UPS supplying it's power. </div></div>

Yep, I do exactly that. I have my CM on an UPS from Best Buy (it was $60 IIRC). I usually calibrate the CM when I first turn it on and it usually stays dead nuts on for the entire loading session. Occasionally it will stray, but I've never had it move more than .1 gr. If I see that happen, I'll recalibrate it.

Everybody keeps asking how do I know which scale is the correct one when comparing.... Its called "check weights". Weigh a known object on both scales and see which one is right. Check weights come with the CM but I find they are too heavy to be useful. You can buy a set of check weights in your powder weight range for cheap and then there will be now doubt.

One trick I did (because I'm not comparing between different scales) is to ahve something that I weighed as soon as I got my CM that I could use as a check weight to see if the calibration changed over time.... take a penny, wrap a piece of tape around it and weigh it in the CM and write the weight down in marker on the piece of tape. I keep mine next to my CM to throw in the pan every 25 charges or so and 99.9% of the time it reads exactly what it should (39.9 gr). The penny is a good weight because its right in-between my .223 and .308 charge weights.

Edit: BTW - I ONLY use the CM for match loads and I routinely get SDs in the single digits. For all you OCD folks - use it and love it.

 

[Leaddog]

Re: RCBS Chargemaster accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fisky</div><div class="ubbcode-body">Last weekend I chrono'd some of my first loads with the CM. SD was 15. I don't know if that's acceptable to many of you?

There are many things I'm not doing that could probably bring that number down; flash hole debur, uniform primer pockets, sort brass, sort bullets, etc. And I'm currently FL sizing and shooting Rem brass. But at this time, I'm happy with the CM and the results on target. I'm sure as my shooting skills increase (and when I make the change to Lapua brass), I'll change a few things in my brass prep to try and lower that SD a bit.</div></div>

You surmise correctly. SD's are brought down by a host of things. First thing... to bring them down.. go with Lapua brass and resize with a Redding 'S' bushing die. Check your concentricity. Should be less than 1/2 of one thousandth (.0005)

What is your powder and charge? Primer type? Barrel type and length?

My ammo is not acceptable unless the SD's are 5 and lower. I've known some shooters that will not accept anything less than an SD of 1 or 2 fps. (Benchrest weenies).

 

[Fisky]

Re: RCBS Chargemaster accuracy

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Leaddog</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fisky</div><div class="ubbcode-body">Last weekend I chrono'd some of my first loads with the CM. SD was 15. I don't know if that's acceptable to many of you?

There are many things I'm not doing that could probably bring that number down; flash hole debur, uniform primer pockets, sort brass, sort bullets, etc. And I'm currently FL sizing and shooting Rem brass. But at this time, I'm happy with the CM and the results on target. I'm sure as my shooting skills increase (and when I make the change to Lapua brass), I'll change a few things in my brass prep to try and lower that SD a bit.</div></div>

You surmise correctly. SD's are brought down by a host of things. First thing... to bring them down.. go with Lapua brass and resize with a Redding 'S' bushing die. Check your concentricity. Should be less than 1/2 of one thousandth (.0005)

What is your powder and charge? Primer type? Barrel type and length?

My ammo is not acceptable unless the SD's are 5 and lower. I've known some shooters that will not accept anything less than an SD of 1 or 2 fps. (Benchrest weenies). </div></div>

Varget
210M
Factory Rem SPS Varmint 26"

It's a decent shooting rifle as is. My shooting is still a work in progress, as is my reloading. My plan is to shoot up the Rem brass and make the change to Lapua. I'm slowly building a supply of Lapua now. When I make the change I'll probably educate my self on the "finer tuning" of brass prep. There are a lot of things I'm just not familiar with yet.