Powder Charges +/- 1gr the same???

[Shootin4fun]

Now here's a kicker that shocked me last night, off the subject of chronographs but directly related...from the famous Houston Warehouse Precision Shooting project, an excerpt of what Dave Scott wrote:

Myths Busted:

• Powder charges, as long as they were fairly consistent and bracketed within a couple of grains, were not important. He threw all of his charges with a Belding & Mull powder measure, and for one experiment he shot groups using three different powder measure settings (51, 52 & 53) … all three groups were identical.

Link to whole article-


Secrets of the Houston Warehouse - Lessons In Extreme Rifle Accuracy - PrecisionRifleBlog.com




I just find that hard to believe unless the 3 charge levels don't produce significantly different velocities. And wouldn't the effect be more or less pronounced by the burn speed of the powder? Even if you're in the middle of one of Newberry's OCW nodes, +/- 1 gr should make a significant difference, no?

I'm not Bryan Litz or Dave Scott so I don't understand how significant variances in charges don't make a difference in group size. We're not just talking groups of charge levels, we're talking random charging because they mentioned throwing charges from a powder drop vs weighing each charge results in the same accuracy. Sorry, but my mind has been blown. Why am I weighing each charge to within kernels of 4831 or Varget if I could just throw them??? (Asking myself.) My experience is that the latter decreases accuracy. For sure it affects velocity in all cases I have seen over thousands of rounds hand loaded and speedchecked and pressure monitored. After all the obsessing over charge consistency I'm not sure if insensitivity would be a good thing or a bad thing!

Please, someone explain to me if this is true...my head's about to explode!gun)

 

[Barrelnut]

Well at 100 yards with a 22 PPC benchrest rifle, and powders of that day, that may very well be. But, this is long range hunting with magnums and heavy for caliber high BC bullets, so who cares. I wouldn't work up a LR load like that. But, I have heard that lots of benchrest guys just throw charges anyway and don't worry about weight too much.

 

[PowellSixO]

Subscribed. I've wondered this myself. I weigh every charge weight 2 or 3 times, to get every charge exactly the same. How close do your charge weights need to be? Charging powder is the most time consuming part of my reloading.

 

[Shootin4fun]

Subscribed. I've wondered this myself. I weigh every charge weight 2 or 3 times, to get every charge exactly the same. How close do your charge weights need to be? Charging powder is the most time consuming part of my reloading.

Yes, charging is time consuming. But I know 1 gr variances cause speed differences easily measurable as drops at 200 or 300 yards, even in a flat shooter like a 243 spitting 85 grainers. So what, am I never in the OCW node where variances don't matter? Still scratching my head.

 

[Shootin4fun]

Subscribed. Savage 111 7mm Rem Mag
Vortex Viper HS-T 4-16x44 VMR-1 MRAD
BlackHawk 0 Moa Picatinny Rail & 30mm Rings
Rifle Basix Sav-2 Trigger
168gr Berger VLD Hunting, Win Brass, WLRM Primers, H1000 69 grains, .010" off the lands
Boyd's Pro Varmint w/ Pillars and Bed job

That must be a sweet shooter! I'm curious to try the Bergers. I've got some H1000 but never tried it yet. I have thought about replacing the stock on my Savage 114 to more of a tactical grip type. The walnut monte carlo stock on mine looks great, but offering a good consistent hold is not it's forte and with that recoil, I've found you really need your technique to be consistent. It can be very accurate. .1" x .4" vertical strings @ 100 if I do my part.

 

[Gene]

You have a lack of understanding of BR slang. 51, 52 and 53 IS NOT grains of powder. Those are the adjustment clicks on the B&M powder measure. Benchresters have used this term for years and it is confusing. It would be impossible to get 51 grains in a PPC case. I am not sure of the click value of a B&M powder measure, but it would be close to 1/10th grain.

 

[BallisticsGuy]

Subscribed. I've wondered this myself. I weigh every charge weight 2 or 3 times, to get every charge exactly the same. How close do your charge weights need to be? Charging powder is the most time consuming part of my reloading.

It's simple, you have to separate group size from velocity. At short to modest ranges like 100yrd zeroing distance group size and velocity need not have a lot to do with each other. Time of flight is tiny and vertical dispersion won't have gotten out of hand.

Regarding anything that BR guys do as comparable to anything non-BR guys do is pointless. BR shooting requires tuning things for minimum group size at a specific distance with as many variables as possible removed. The number of tricks and techniques that BR guys use is astonishing given the almost superstitious connection any one of them independently might have to do with getting those amazing group sizes. Just like a wizards spell, you get no results if you don't use the whole spell recipe.

My Dad, who taught me to handload, always said that +/-.2grains was more than sufficient for hunting ammo and he ended up correct. Experience has shown that some loads I have made with .5gn tolerances produce single digit SD's and horrid 100m groups while in others I can have .05gn charge variances and get deep double digit SD's and great 100m groups but horrid 1000m groups. Powder charge weight is just one component. Seating depth, neck tension, case fill %, etc... all can make a difference. FWIW, my LR match ammo needs to throw single digit SD's and half inch 100m groups or it just won't be competitive. Competitive is different than usefully accurate.

 

[PowellSixO]

Thanks for the responses guys. I guess I should have been more clear with my question. I realize that extreme differences in charge weight is going to make a difference, and it's going to be come a bigger difference the further you shoot. I should have asked, how close percentage wise you need to keep your charge weights, for guy's that hunt deer and elk out to let's say 1000 yards and closer? Thanks.

 

[RockyMtnMT]

I read the article and I am not sure that it was saying that inconsistent charge weight within the group wouldn't have effect on the group. But that another group shot with a change in powder weight would still group as well as the previous charge weight. It made no reference to where the group was on the target only reference the size of the group or the consistency of the rifle. I may be wrong, but I did not come away with loose technique in measuring powder was not a big deal.

Steve

 

[BallisticsGuy]

Keep in mind I'm a LR target shooter, not a LR hunter. Used to be a hunter but never liked LR hunting. I hate hiking a long way back to the car dragging meat.

If you're hunting at that distance you're going to want single digit SD's IMO and low single digits at that would be best. That will require precise powder charging and moreover you're going to probably need to adopt target shooter type handloading practices and equipment. At 1000yrds you're going to really want 10fps or less shot to shot variance. At 1000yrds for most things capable of reaching that far 10fps difference is going to be a few inches of vertical dispersion. On an elk or moose that's not as big a deal as on a deer or bear.

If you want really precise charging then look into a Dillon electronic scale, make sure you level it on a solid base and keep any air management systems from blowing on it. Oh and get ready for things to take a while. The Dillon is as close to a lab grade scale as you're going to want to own. You might also hit up the F-Class forums and check out their loading practices.

 

[Shootin4fun]

You have a lack of understanding of BR slang. 51, 52 and 53 IS NOT grains of powder. Those are the adjustment clicks on the B&M powder measure. Benchresters have used this term for years and it is confusing. It would be impossible to get 51 grains in a PPC case. I am not sure of the click value of a B&M powder measure, but it would be close to 1/10th grain.

OKAY, now that's making more sense to me, thanks Gene! I know nothing of B&M measures despite having been hand loading on and off for 40+ years. As Dan Newberry might propose, if you are at an OCW, depending on the powder +/- .1gr may have little to no effect on POI.

Still, I'm weighing my charges to +/- 2 kernels of extruded powders, or about 15 flakes of stuff like W760. It's become a habit. f I let myself get sloppy, then HOW sloppy is okay (rhetorically speaking)? So I reload by self imposed fascism. Und documenting alles!

 

[Shootin4fun]

Keep in mind I'm a LR target shooter, not a LR hunter. Used to be a hunter but never liked LR hunting. I hate hiking a long way back to the car dragging meat.

If you're hunting at that distance you're going to want single digit SD's IMO and low single digits at that would be best. That will require precise powder charging and moreover you're going to probably need to adopt target shooter type handloading practices and equipment. At 1000yrds you're going to really want 10fps or less shot to shot variance. At 1000yrds for most things capable of reaching that far 10fps difference is going to be a few inches of vertical dispersion. On an elk or moose that's not as big a deal as on a deer or bear.

If you want really precise charging then look into a Dillon electronic scale, make sure you level it on a solid base and keep any air management systems from blowing on it. Oh and get ready for things to take a while. The Dillon is as close to a lab grade scale as you're going to want to own. You might also hit up the F-Class forums and check out their loading practices.

Agreed about wanting lowest variation...despite of the fact I never get to shoot to 1000. 600 at best. Also I don't think I would ever go over 600 in hunting because I don't seem to be a Wind Whisperer and I know how far off from my expected POI that intermittent winds can cause at longer distances. It always amazes me, even more than my 300 yard bullseyes. Fun for shooting inanimate things but not animals I have to find later due to bad placement. I'm over 60.

Not sure if any reasonably priced scale or scale+charger system could improve on my weighing abilities but I do wonder what the real accuracy of the Dillon is. Needs to be better than +/- .05gr to beat me. My old scale is well made and reliably returns the same weights down to kernels.

 

[Shootin4fun]

Thanks folks, my head is no longer exploding...well about this anyway.

 

[Kansaswoodguy]

IN 223 my accuracy nodes I would say run around .6 grains wide max depending on your level of acceptable accuracy, for short range 100yard work he might be right for a larger cased caliber. For 1000yard work no way in h$&@ is that bunk going to fly your SD's would be rediculess. I do load work up at .3gr increments for 223 rem and usually .5gr increments for larger calibers. I suspect that maybe that book or article lost the Decimal in front the numbers that would make sense. Plus or minus .1gr to .3gr I could say yep he is on the money.