What difference does a 10th of a grain make?


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harbinger_j
April 24, 2007, 05:33 PM
Yes I am a new reloader.
I bought all my equipment and have made my first rounds.
I am loading 180gr TCFM 40S&W w/Unique powder.
I started at the minimum load recommended(from my Lee dies) 5.8gr. I have shot about 73 of those rounds so far.
Then it has a do not exceed amount of 6.4

Will/Should a greater powder charge be more accurate?
Should I "work up" to the higher load? a 10th of a grain at a time?
Do I need a ransom rest, chronometer, etc. to notice the difference?

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Shoney
April 24, 2007, 06:08 PM
Welcome harbinger j!
Should I "work up" to the higher load? a 10th of a grain at a time?
With this bullet and powder, and since you are a novice, I would suggest that you load in 0.2 gr increments with the Unique. Load 10 each of the three loads and fire 5 at a target, making sure to note the target accurately with the load. Shoot min loads first up to the max. This will give a good idea of the accuracy.

Generally I cannot tell much difference with 0.1 or even 0.2 grain increments with pistols, but you may be able to see a trend in group size and/or point of impact vs point of aim.

Loading over max is never a good idea. However, some powder measures can routinely vary by 0.2 grains, depending on measure and powder used. You did not mention the method you use to throw the charge. To develope loads, I always weigh each charge.

Also remember that OAL is important, as setting a bullet too deep can cause a pressure spike. Load data max ammounts are well below SAAMI specs, and slight accidental overloads by 0.1 grains will most often not be a problem.
Do I need a ransom rest, chronometer, etc. to notice the difference?
Although it would be nice to have a Ransom & chrono, you can shoot off a sandbag, making sure that the weapon does not thouch anything but your hands. Shoot slowly concentrating on trigger control and the front sight. Let each shot surprise you.
Will/Should a greater powder charge be more accurate?
Only shooting will tell. Each weapon has it own likes and dislikes

Ol` Joe
April 24, 2007, 06:15 PM
Will/Should a greater powder charge be more accurate?


Possibly, then it may not be every firearm is different in how it reacts to a load or change. The only way to know is try it.

Should I "work up" to the higher load?

Only if you are not happy with the one you have.

a 10th of a grain at a time?

I would personally go in 0.2 gr steps but 0.1 gr is fine. More shooters would likely go with your increment then mine.

Do I need a ransom rest, chronometer, etc. to notice the difference?



Unless you are a very good shot you will probably see any difference in accuracy with a machine rest much easier then by hand.
The speed difference will only be honestly known if you cronograph it. You might guess a load is faster by recoil or POI change but a croney is needed to verafy it.

wcwhitey
April 24, 2007, 07:00 PM
A very good question. The answer, who knows! Seriously, sometimes that 1/10th will just bring you to the sweet spot that a gun likes. Load development is fun and when you find a sweet load it makes hand loading very rewarding. Personally, I stay away from any max listed load. I don't want to put my guns or body at risk. I load for accuracy and enjoyment. It allows me to shoot more by keeping the cost down. Once I find an accurate load, I load a bunch and go shooting. Bill

Walkalong
April 24, 2007, 08:15 PM
What difference does a 10th of a grain make?

Sometimes nothing and sometimes everything. Like wcwhitey said. It may be that sweet spot you are looking for. :)

It can also make the difference between a safe load and an unsafe load with some powders and calibers. :eek:

Not to worry you, just work up slow and stay under the maximum recommended load. :)

GaryL
April 24, 2007, 08:31 PM
With the right powder and the right load, 1/10th gr won't make any discernable difference. That's the ideal case anyway. When I'm trying to decide on a powder to use for a given application, I like to look through the manuals to find which powder has the smallest change in velocity over a .2-.3gr range. That indicates the powder is more forgiving of charge weight, and if the gun likes it I usually see really good results.

Unfortunately, some guns don't seem to like anything you put through them.

harbinger_j
April 25, 2007, 03:47 PM
Thanks for all the advice.
I already loaded up 10 of each 10th grain increment.
So I think I will do 2 tests one with 5.8, 6.0, 6.2 and the other with 5.9, 6.1, 6.3.

I did weigh every charge that I loaded, and I seated them all the same so it should be consistent.

Any further advice is apperciated

Walkalong
April 25, 2007, 04:26 PM
You are off to a good start. Unique is also pretty forgiving as pressure goes up, unlike some powders. Universal Clays is another good one to try here. My .40's loves it and it is cleaner than Unique.

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