How much difference does.4g make in accuracy?

[jelenko]

Interesting. I missed the changing decimal places. I read everything based on the thread title.

 

[RabbitSlayer]

I think keith glasscock said in a 284 winchester berger 180 and i think h4350 1 kernal is about .03 gr and 1 kernal changes it 1 or 2 fps. So basically .04 doesn't matter unless you are a top level competitor. Now obviously .4 grains is substantial. I should hope you are not just using a kitchen spoon to measure powder lol

 

[cameronalbrecht]

Maybe not a lot at all considering in a .308 sized case sometimes going up in powder charges by .2 & .3 tenths of a grain will show either the same speed or only a few FPS difference. And sometimes the higher charge will show a lesser FPS.

my results from earlier today in my 308, Varget powder Berger 168 hybrids. 5 shots at each grain weight. The results are pretty linear. By my math I think each .02 grain of Varget is worth about 1.5 FPS in my gun today.

42.0	2535.5
42.3	2566
42.6	2592.2
42.9	2612.9
43.2	2630.1
43.5	2644.5
43.8	2670.8
44.1	2687.2
44.4	2710.3

 

[DShortt]

my results from earlier today in my 308, Varget powder Berger 168 hybrids. 5 shots at each grain weight. The results are pretty linear. By my math I think each .02 grain of Varget is worth about 1.5 FPS in my gun today.

42.0	2535.5
42.3	2566
42.6	2592.2
42.9	2612.9
43.2	2630.1
43.5	2644.5
43.8	2670.8
44.1	2687.2
44.4	2710.3

Right. .3/grain.

NOT .004/grain.

Someone show me what scale they're using to measure out to .000/grain.

A grain is 1/7000 of a pound. It's loosely based on a single grain of wheat.

Divide that grain of wheat 1000 times?

Nope. You done lost your mind.

 

[hoz53]

Have any of you tested loads that were .004 gn off a desired load. It gets to this .02 gn zone when using a V4. ,02 gn below and .02 gn over could give .04 gn swing. I always want exact chosen load but how much difference is a potential . 04 gn swing going to make in 100 yd groups?

ive been wanting to figure this out myself so here it goes. My A&D 120 reads out down to .02 grain. so i assume Pete was talking about .02 grain on each side of zero or .04 grain total. calculating it using a 6BR at 2850 MV with 30.5 grains of powder that is 93.44 fps per grain powder. in one grain there are 50 increments of .02 so 93.44 fps per grain divided by 50 = 1.87 fps per .02 grain charge since we are going to .04 that is 1.87 x 2 = 3.73 fps for .04 grain of this powder. this is close to what others have posted here. so plug the differences into a ballistic solver and see the differance. Im using shooter.
2850 fps 100yd zero -2.8 at 200---- -332.6 at 1000 yard
2853.73 fps 100 yard zero -2.8 at 200yd - 331.5 at 1000 yd

so that .04 grains of powder made no differance at 100 yards but almost an inch difference in vertical at 1000 yd. this is why top SR benchresters used a measure and just threw their charges while 1000 yd guys are fanatics about getting it to the kernal. now though with SR matches being decided by .001 it probably matters to them also. my AD 120 will read 1 kernal of N150 or varget. it usually reads them at .02 but i wonder what it really is.

update:::: the output of the solver can change depending on atmospheric conditions ect. still i learned wat i was looking for

 

[searcher]

I go through a considerable amount of trouble to keep things within .1 of a grain.

If you guys are going to tell me that .004 grain matters......

Well. Anyone up for a game of horseshoes?

Because I'm out.

Find this difficult to believe given that, depending on the powder, 1 or 2 kernels of stick powder equate to .1/grain.

I'm with you on this. I doubt anyone reading this thread can shoot .004 of a grain difference and see it on target. Now, 4/10 (.4) grain is a different story altogether.......

 

[hoz53]

I'm with you on this. I doubt anyone reading this thread can shoot .004 of a grain difference and see it on target. Now, 4/10 (.4) grain is a different story altogether.......

not .004 but .04 yeah there are guys out there good enough at times especially at longer range.

 

[DShortt]

not .004 but .04 and down to .02. my A&D 120 will read a kernal of varget and show .02 but we dont know exactly what side of .02 that is. for that we need a scale to read .002 and i dont see one out there. at least that i could afford.

Well, as I said earlier. When I decide I need to weigh charges out to .00/grain is one day before I change hobbies.
You all do whatever you like. But that's just beyond my level of OCD.

Cutting a single grain of wheat into 100 pieces and using 2 of them......

Nope. Not this guy.

 

[hoz53]

Well, as I said earlier. When I decide I need to weigh charges out to .00/grain is one day before I change hobbies.
You all do whatever you like. But that's just beyond my level of OCD.

Cutting a single grain of wheat into 100 pieces and using 2 of them......

Nope. Not this guy.

i understand for sure—-didnt think id be doing it for many moons —. its fairly easy with a auto trickler and scale setup. i dont cut kernals though. one kernal is the best it gets for me. now if im loading for ar-15 or pistols or any large volume—they get thrown from the measure.

 

[jelenko]

Well, as I said earlier. When I decide I need to weigh charges out to .00/grain is one day before I change hobbies.
You all do whatever you like. But that's just beyond my level of OCD.

Cutting a single grain of wheat into 100 pieces and using 2 of them......

Nope. Not this guy.

Right.
It all depends on the discipline. For us cross the course guys, we measure to .1 grain [in 223/556] for our 600 yard stuff shooting at 1 MOA X ring/2 MOA 10 ring.
For 200 yard stuff, it almost doesn't matter - the X ring is 1 1/2 MOA.

I've never shot PRS, but from my understanding of their targets, .1 grain accuracy would be fine also.