Charge variation with IMR 4895

[Dr. Dickie]

Okay, up to now I have been reloading .45, so only throwing about 5gr of a good ball powder (WIN 231). Using a Dillon 550.
I am now woking up some .308 and .30-'06 for Garand and M1A, and am using IMR 4895 (rod powder).
I noticed a heck (0.5 gr) variation in throws with this powder (in the 41 -50 gr area).
While proportionally similar (1%), that seems huge to me.
Do others see such variation (new powder bar on this)?

 

[30Cal]

You ought to be able to bring that inside of 0.3grs. It's all in how you stroke the press. With a nice, consistant stroke, you will see nice, consistant powder drops. If you bang the press, yeah, it's going to be about a half grain on the heavy side. Try weighing 50 consecutive and make notes of any irregularities in how smooth the press is. You'll quickly learn how to anticipate which drops are going to be way out.

Ty

 

[USSR]

Dr. Dickie,

Reloading bottle-neck rifle case is a whole 'nother ball game from straight-walled pistol cases. While you can use a progressive press like the Dillon for blasting ammo, if you want to produce accurate ammo, get yourself a single-stage press and weigh your charges.

Don

 

[Dr. Dickie]

Yeah, I hear ya.
I'm not a benchrester. Strickly interested in shoulder fire, minute of pie plate at 100 yards (the way rifles were designed to be shot! ).
Well, okay. I do use a sling
I just wanted to make sure that this is normal.
I did get a little RCBS partner (O-ring design single stage), just to punch out primers and re-size.
At a couple hundered bucks for a good dispenser, I will take a +- 0.5 grains.
I'm cheap, what can I say!
thanks

 

[GPWEAPON]

there are several things that will allow you to tighten that charger.

first to do is to take your rcbs hand champer tool and remove the
step on the top of the .308 cal sleeve that slides to drop the charge.
it should come to a sharp edge.

second is to modify and extend the travel on the powder charge
bar so when you are at the top of travel the bar will drop the
whole charge and not leave a few grains "hung up" in the powder
measure.

 

[Dr. Dickie]

"First to do is to take your rcbs hand champer tool and remove the
step on the top of the .308 cal sleeve that slides to drop the charge.
it should come to a sharp edge."

Is this the powder funnel (sleeve) that drops into the powder die? The piece that goes between the case top and the hopper?
Or are you talking about something internal to the powder drop system.
(I wish Dillon would sell a separate powder funnel as I load .308 and .30-'06 and would like to just switch the powder hopper--I have separate tool heads and dies, but fishing out that funnel while holding the hopper sucks).

"second is to modify and extend the travel on the powder charge
bar so when you are at the top of travel the bar will drop the
whole charge and not leave a few grains "hung up" in the powder
measure."

Not sure what you mean here. I have it adjusted so that I get maximun travel of the bar between the handle going up and down. What do you mean by modify?
thanks

 

[P0832177]

Boy if you could find an old style Dillon Powder Measure you could have a more consistent stroke of the powder measure. I used to have +/- 0.2gr of IMR4895 with that measure. There are several aids to using the stick powders. Some involve extensive polishing of the measure.

 

[DILLONHELP]

The Dillon powder measure should throw your powder within +/-.2 to.3 grains. It helps to pull the handle down a bit slower. It should take about one full second to move the powder bar its full travel.This allows the powder to freely fall through the funnel, instead of logjamming up on top and getting pushed through the funnel. It also helps to start with the powder hopper at least 2/3 full, throw 10-15 charges to settle the powder in the hopper, then start weighing charges. Finally, be sure the powder bar is making a complete stroke, so the powder bar goes all the way over consistantly, and that the blue wing nut at the bottom of the powder measure return rod is pulling the powder bar all the way back. IF you push forward on the handle, the coil spring above the blue wing nut should be partially compressed.

 

[GPWEAPON]

Is this the powder funnel (sleeve) that drops into the powder die? The piece that goes between the case top and the hopper?


Yes.

regarding the travel of the powder measure, I have the old style and
on the side of the charge bar is a small nylon square that the linkage pivots thruto move the charge bar.

I had to file away at the body of the measure where this bushing stops travel to get the maxium travel of the charge bar so the grains wouldn't hang up in
the measure.

I don't think I ever completly solved this problem but the unit will throw
within .1 with varget.

Just a oversite in design I suppose.