Powder thrower variance

[colinbentley]

I have just started using a Lee Perfect Powder Measure and as a reloading tool I'm thrilled with how much quicker it makes then process. I was loading 222 Remington with 18 grains of powder. It varied however between 17.9 and 18.1 grains. Do members consider this an acceptable variance for a powder measure ?

[Rikta]

depends what you want it for.... cutting wads at range and top scores its not going to be good, otherwise using the triple deuce for hunting it shouldn't bother you too much

[bladeracer]

I have just started using a Lee Perfect Powder Measure and as a reloading tool I'm thrilled with how much quicker it makes then process. I was loading 222 Remington with 18 grains of powder. It varied however between 17.9 and 18.1 grains. Do members consider this an acceptable variance for a powder measure ?

That is way more accuracy than you need, even for target shooting.

[brett1868]

Tolerance on most of the electronic throwers is quoted as +/- 0.1Gr so you're well within tolerance. Case volume and seating depth will have just as much an impact as 0.2gr so I wouldn't worry about it for general hunting. If you're getting way out there 500+ then I'd be doing a lot more work with the brass, projectile and then the powder.

[Gamerancher]

Unless you are a World Champion benchrest shooter with perfect trigger control, super-human wind and mirage reading abilities, I doubt you will be able to tell the difference in real world shooting.

[Gwion]

Unless you are a World Champion benchrest shooter with perfect trigger control, super-human wind and mirage reading abilities, I doubt you will be able to tell the difference in real world shooting.

I have none of those talents and I am far more fussy about powder charge than that. I throw the charge low and trickle up to weight. But then I always look for the smallest group I can as I figure I need all the help I can get from my rifle!

As Brett says, brass and seating depth are more critical than a minor variance in powder charge. As long as you are loading on a true node and not some random accuracy point that you sometimes find between nodes; found this out early on in my hand loading!!!

Only way to know if it produces acceptable ammo is to shoot a few groups and decide for yourself if they are good enough for you. Personally, for hunting, I'd be looking 1moa as a minimum standard from a 222 or 223. My trail boss load shoots about that or a little more out to 120m and my full load with BM8208 shoots a true 0.5moa or better with every charge weighed exactly.

Come to think of it, maybe that's why I find reloading so bloody tedious! Maybe I should just take the lucky dip with the thrower next time and see what difference it make to the end product!

[bladeracer]

...and my full load with BM8208 shoots a true 0.5moa or better with every charge weighed exactly.

Try loading some with a variation of 0.1gn each side of the load and see how well it shoots.

[marksman]

if you start taking shortcuts with one thing you will with others
weigh low and trickle up to weight and you will know if there is a problem its not that
there are plenty of other things that that would be more important eg: concentricity
the more fussy you are with everything the better your loads are going to be

[bladeracer]

if you start taking shortcuts with one thing you will with others
weigh low and trickle up to weight and you will know if there is a problem its not that
there are plenty of other things that that would be more important eg: concentricity
the more fussy you are with everything the better your loads are going to be

I sort of agree with the concept, but I don't agree that 1% accuracy in the powder charge is a shortcut. If your load shoots poorly with that sort of variation I would think you need to work up a better load, one that is more forgiving of variation in all sorts of aspects of shooting. There's little point in working up a super accurate load that only shoots well in the specific environment you worked it up in, but falls apart when humidity, temperature or powder lot change.

[Gwion]

...and my full load with BM8208 shoots a true 0.5moa or better with every charge weighed exactly.

Try loading some with a variation of 0.1gn each side of the load and see how well it shoots.

I have during load development and it makes little difference as that is why I chose that load: it is on a true node and not too hot, not too soft. Problem is, I don't trust my powder thrower as I can see when I weigh and load each charge that while the majority are kind'a consistent it does throw a regular low charge and an occasional heavy charge. I'm talking maybe upto 0.5gn low and there is no way of knowing when that will happen so I don't just throw the charge into the cases as some do.

[bladeracer]

I would have to disagree nearly all the target shooters I know are using milligram scales and are down to measuring each kernel of powder. To take a kernel off or put one more on with tweezers and weigh the load at least twice and often three or four times using progressively more accurate scales is not uncommon. Some of these guys are happy to spend a few thousand dollars on the scales alone. Its not that the load is super accurate in itself it is that it is consistent every shot needs to be predictably repeatable.

Now for a hunting load sure it is fine if the POI changes 10mm over a 500m distance you still get a kill.

I would expect these people to do exactly this, but it does not necessarily follow that it makes any difference to their results. I'm sure there are at least some shooters that don't fall into the same trap of believing every grain makes a difference.

[colinbentley]

Thank you to everyone who took the trouble to reply to my question. With regards to using a powder trickler or tweezers , the whole idea behind getting a powder thrower was to avoid resorting to these measures and speed up the process. I have been using both a trickler and tweezers but it takes forever. I think I can live with the variance I now have but thanks for all the comments.

[marksman]

if you start taking shortcuts with one thing you will with others
weigh low and trickle up to weight and you will know if there is a problem its not that
there are plenty of other things that that would be more important eg: concentricity
the more fussy you are with everything the better your loads are going to be

I sort of agree with the concept, but I don't agree that 1% accuracy in the powder charge is a shortcut. If your load shoots poorly with that sort of variation I would think you need to work up a better load, one that is more forgiving of variation in all sorts of aspects of shooting. There's little point in working up a super accurate load that only shoots well in the specific environment you worked it up in, but falls apart when humidity, temperature or powder lot change.

I do agree with what you are saying 100% about .2 grains of powder and other variations being more important eg: concentricity
but my point is to do as much and as good as you can with everything you have an influence on to be consistent with what you are doing

[bladeracer]

Thank you to everyone who took the trouble to reply to my question. With regards to using a powder trickler or tweezers , the whole idea behind getting a powder thrower was to avoid resorting to these measures and speed up the process. I have been using both a trickler and tweezers but it takes forever. I think I can live with the variance I now have but thanks for all the comments.

I learned to load as a kid and thought an extra grain would blow up my rifle
I never trusted throwers at all, even though I got one included in my Lee Breechlock kit.
I finally caved and decided to at least try it when I had to load a few hundred rounds for my milsurps. I load these a little short of full-power loads anyway so even 2-3gn variance wouldn't be a big deal. I was loading 6.5x52mm, .303 and 7.62x54R so I threw three different charges of AR2206H. I started out by dumping every charge into the tray and checking it on the Gempro250, but after a dozen or more it was obviously a waste of time. The loads were all the same, but I still checked every fifth one anyway. I was really impressed with its accuracy. Like most things, finding and maintaining a rhythm is vital. I run the lever firmly, a bit like running a milsurp bolt action, with a solid knock at both ends of the stroke. And I keep the reservoir above half full to maintain consistent head pressure.

I haven't tried it with Trailboss yet. Being one-third the density of most grain powders, the loads are very light and the donuts flow with difficulty, so I think Trailboss will really test it.

[Gwion]

I would have to disagree nearly all the target shooters I know are using milligram scales and are down to measuring each kernel of powder. To take a kernel off or put one more on with tweezers and weigh the load at least twice and often three or four times using progressively more accurate scales is not uncommon. Some of these guys are happy to spend a few thousand dollars on the scales alone. Its not that the load is super accurate in itself it is that it is consistent every shot needs to be predictably repeatable.

Now for a hunting load sure it is fine if the POI changes 10mm over a 500m distance you still get a kill.

Have you checked out the Houston Warehouse Accuracy Project?

Over a number of years shooting in ideal conditions, the conclusion was drawn that precision gun smithing then brass prep and seating depth were the only real factors in ultimate precision shooting. They found with all else perfect and loading on a node, then upto a grain or two difference made no difference to precision.

Check it out. Very interesting reading.

[marksman]

I would have to disagree nearly all the target shooters I know are using milligram scales and are down to measuring each kernel of powder. To take a kernel off or put one more on with tweezers and weigh the load at least twice and often three or four times using progressively more accurate scales is not uncommon. Some of these guys are happy to spend a few thousand dollars on the scales alone. Its not that the load is super accurate in itself it is that it is consistent every shot needs to be predictably repeatable.

Now for a hunting load sure it is fine if the POI changes 10mm over a 500m distance you still get a kill.

Have you checked out the Houston Warehouse Accuracy Project?

Over a number of years shooting in ideal conditions, the conclusion was drawn that precision gun smithing then brass prep and seating depth were the only real factors in ultimate precision shooting. They found with all else perfect and loading on a node, then upto a grain or two difference made no difference to precision.

Check it out. Very interesting reading.

your dead right it is very interesting reading, I base a lot of my theory on what is in the text, but if you go into it further and read more about it you will see that how good they did in perfect conditions only worked at the ware house consistently, they did not do well in comp I think (by memory) that the other variants, wind, climate ect upset everything
and when we are talking brass prep they polished the inside of the case neck for a smooth and consistent release
a lot of comp shooters do not weigh the powder charge at all but are not using a lee thrower,
definitely no offence to lee throwers I own and use one myself from my first reloading kit

[Gamerancher]

Gwion, quoting from the Houston Warehouse tests, "They found with all else perfect and loading on a node, then up to a grain or two difference made no difference to precision"

Was exactly the point I was making, If those guys found that powder variance was not the be-all and end-all of accuracy, I'm sure there 'aint no-one on this forum that can tell the difference 0.2 of a grain will make.

Sight picture, breathing technique, trigger control, mounting the gun, type and quality of rest used, wind and mirage reading and whether the planets are in the right alignment ( ) are all variables that will have more effect on group size than worrying about a 0.2 grains of powder.

Also, try weighing your projectiles, even "match" quality can vary by a grain or two. Just throwin' in another "curve" ball for y'all.

[Gamerancher]

We're talking about 0.2 grains here mate.

[Gwion]

Also, try weighing your projectiles, even "match" quality can vary by a grain or two. Just throwin' in another "curve" ball for y'all.

Yep, i do that too, as well as weight sort my brass. Like i said, i need all the help i can get!

Actually, as someone else pointed out, i like to know my rifle & ammo are shooting as consistently as possible so i have nothing to blame but my need to improve my skills if (when) i am not performing to scratch. It's not a popular attitude with all but i like my hunting/pest control rounds to shoot well inside 1MOA when testing; if it is bigger/worse than 0.8MOA over 3 Groups of 5 i keep tweaking it. For my target rounds i aim for 0.4moa or better.

I get that all those other things play more of a role in a shooter's performance but it's good to at least remove the variable of rifle and ammo from the equation. It gives you confidence in your gear and confidence in your gear makes for a better performance and trouble shooting of your technique.

I do agree that when loading on the right node, a small variation in powder charge makes little difference but in the past i have chosen a rather toasty load that shot 0.5moa but 0.3gn more made it open up to 1.5" (and flatten primers). I soon gave up that load and sacrificed FPS for a more stable load that will only be affected slightly by small variations. I now look for a load that shoots very similarly within 0.6gn (0.3gn+/-) and load bang in the middle as much as possible.

If you are confident that your thrower is +/- 0.1 or 0.2 gn, then why not use it to speed up the process but i have found that either my thrower or my operating technique is not that consistent so i still weigh all my loads, ie: throw light and trickle up to charge. Yes, i have been known to add or remove a few granules of powder when loading for target work... (kind'a embarrassing when i go to such lengths but still only manage a 50-52 on an average 500-600yd F-class shoot! As i said, still working on all my techniques and wind reading so want to remove my gear as a variable as much as possible. Next step is getting a stock specifically set up for prone shooting, not my FrankenStock that has been "modified" from a Boyds thumb hole hunting stock (not designed to ride a bag very well or consistently).

[Gwion]

Here is a quote from a "cliff notes" of the Houston Warehouse Project:

" - 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.
- Lot variation in powder didn’t seem to have any effect on accuracy, even on when using IMR 4198, which has a reputation for varying considerably from lot to lot. He would just buy powder as he needed instead of laying in a big supply, because he found no evidence to support that powder lot variance affected accuracy in the least."

http://precisionrifleblog.com/2013/10/1 ... -accuracy/

From this, my statement of "one or two grains either side" is incorrect and should have been "a variance of +/- 1grain".
This is a sticky point that i do have trouble getting my head around but that was the findings of the experiments.

[bladeracer]

I spent $300 on the Gempro250, on top of what I spent on several other devices in search for the ultimate accuracy.
What it taught me is that that level of accuracy is not required.
If we only had the technology to weigh our charges to a quarter of a grain we would be no worse off.

[Gwion]

A Lamborghini is not really required either but it's nice to have if you can get it.


Some people just enjoy chasing the best accuracy they can attain.

[Gamerancher]

What is underlined says 2 grains. Thats what I am referring to

And, what I am referring to is the original post.

My comments are in relation to his inquiry about whether the 0.2gr variance he has found with his powder thrower is going to have a large bearing on accuracy.
For the average shooter, that amount of variation 'aint going to be noticable taking into account all of the other factors that affect "perceived" accuracy that I mentioned.