Powder Charge Doesn't Fit in Brass

[grickards]

I am new to reloading .308 Winchester, and have run into a bit of a snag. I weighed out a 40.0 gn powder charge of IMR-4064 using a Hornady electronic dispenser and loaded it into the casing. The 40.0gn charge, according to the references I have (Hornady and Lyman) is toward the low end of the safe range. The forums talk about a 44.0 gn load being a good amount for .308, but the 40.0 gn load is already up into the case neck. I tried tapping the casing to settle the powder with no success. All five casings that I loaded to 40.0 gn filled to the same level, and would be compression loads if I seated the bullets. 44 gn of powder would definitely overfill the casings. Yes, the scale calibrated fine. I dumped the powder back in the hopper, recalibrated and repeated the weigh and charge procedure for the five casings. All of the charges filled the casings to the same level, so at least it was consistent. I dumped the powder again and checked the casings to make certain they were empty. They were. I repeated the process with a bottom end charge of Varget and got substantially the same results. Where is it going wrong?

[david_r]

Someone is going to come along and ask you the headstamp on your brass.

Weigh a resized case. Fill it with water and weigh it again. The difference in grams should give you the approximate CC volume.

edit to add: How did you verify the electronic dispenser?

[TheBear]

I had this problem quiet often. Last time i used some .223rem load data from Lapua, 25.9gr of n135 with a 55gr bullet. I cant put more than 25.2gr into the case though...
There was another time when i tried a load from the lyman reloading manual for 7,62x39 using h335 and the case wasnt big enough for the max. charge too.

I have a calibrated powder scale that is checked every 2 months so i dont think the scale is the problem.

I know from friends and family that they have had this problem too, it seems to be pretty common...

[stnosc]

What is the bullet weight and manufacturer?

[Brian Pfleuger]

We need to know what bullet you're trying to use before we know if that charge is safe.

The max charge could be barely 40.0gr is it's a heavy bullet, or the starting charge could be 6.0gr higher if it's light bullet.

Anyway, every single one of IMRs max loads for 4064 is a compressed charge. That tells me that there's a good chance that some of the starting loads are very close to, if not, compressed.

Technically, just because the bullet pushes the powder down when you seat it, doesn't mean it's "compressed", it just means that the powder doesn't sit very well in the case, not uncommon with stick powders.

If your dispenser calibrates properly, and shows the correct and expected weights afterword for the calibration weights, there's no reason to think it's wrong. You can check it with coins. An average US Quarter weights about 87 grains.

[Slamfire]

Something is seriously wrong as I have loaded thousands, getting close to tens of thousands of 308 rounds with IMR 4064, and 40.0 grains does not fill the case. Neither does 42.5 or 44 grains.

I think the scale is off its calibration.

[grickards]

- The brass is headstamped "308 WIN R P"
- A quarter weighs out at 87.8 or 87.7gn
- The bullets are 150gn Sierra GameKing Spitzer Boat Tails
- The scales says the bullets actually weigh 150.0gn according to the scales
- The Hornady handbook lists the minimum charge of IMR 4064as 38.4gn and the maximum charge as 44.9gn for a 150gn bullet
- The Lyman manual gives minimum and maximum charges for IMR 4064 for a jacketed SP as 43.0 to 48.0gn with the latter being a compressed charge.
- An empty casing (not deprimed) of the same headstamp weighed 169.3 grains empty and 225.8 grains full of water. That subtracts out to 56.5 grains of water, which is about 3.66 grams. I am not sure where to go with that, as I do not know the density of the powder.

Taking into account that 43gn of powder won't even fit in the casing and that this is Lyman's recommended starting load, what do I do?

[mehavey]

I'll try some in Starline brass tonight.

But. . . .

Right now I know for a fact that my go-to load for my M1A is IMR4064/41.5gr under a 168SMK in a Winchester Case.
Not even a hint of volume max-out

WW Case 55.6gr H2O
Chrono's @ 2,500fps

[Brian Pfleuger]

See UncleNick's post here for an explanation of what you're seeing. The beginning of the thread, here.

[grickards]

I obtained the weights of coins from the US Mint web site, and the coins all weighed out correctly on the scales.

[snuffy]

Here's one example of a long(er) drop tube in combo with a powder funnel.

http://www.midwayusa.com/product/613...-to-45-caliber

Here's another one;

http://www.midwayusa.com/product/293...long-drop-tube

What I'm hearing is a reluctance to load compressed charges. It's perfectly safe, even desirable in some scenarios. Some will say the breaking of the extruded powder granules will elevate pressure, changing the burn rate of the powder. Yes it would, if you broke every one, but you're only breaking a few at the front of the powder column.

Another trick is to pour the powder from a measure pan onto the side of the funnel taper. This causes the powder to swirl into the tube, further orienting the powder to pack/stack it into a smaller space.

[TATER]

How did you acquire this powder?
Can you walk us step by step, your procedure of weighing out a charge of powder?
Something is going wrong.

[snuffy]

Using anything other than scale check weights to check a scale is a crap shoot. The weight provided with the scale is a calibration weight. Get these to check to see if your scale is on or not.

http://www.midwayusa.com/product/493...hts-605-grains

Coins, bullets and aunt Harriet's broach are fun to weigh, but not calibrated to any set standard.

[Brian Pfleuger]

Guys, he's not facing Armageddon.

He's using an electronic dispenser. It COMES with calibration weights. Weighing coins is close enough to tell you if the scale is reasonably right or wrong. A modern quarter might weigh 87.2 or 87.9 grains but that's close enough to tell you what you want to know. If the scale says it weighs 25gr or 50gr or even 80gr, you've got a problem. 87.something, good enough.

He's using a stick powder, the EXACT SAME stick powder that UncleNick uses in his demonstration in the link I provided above.

Well known issue he's facing, well known solution. Let's not make it more than it is.

[TATER]

Brian,
I just cant see 40 grains of 4064 reaching the neck..

[cvc944]

I'm confused as well. I can't get 40 grains of IMR-4064 anywhere near the top of any of my .308 cases, regardless of manufacturer. I even tried to make it happen using a trickler to fill the cases. I would probably check the insides of the cases at this point to make sure there isn't something clinging to the sides or bottom taking up space.

[Brian Pfleuger]

Well, other than that we "don't think" it sounds right, everything else matches. His case capacities are reasonable. The headstamps are correct, his case weights are reasonable. Every single IMR 4064 max load is compressed and every single Varget max load is compressed.

There are about 15.3gr of H2O per CC at 68F. So his cases are about 3.653cc.

Lee lists the VMD of 4064 at 0.07547. 40.0grx0.07547= 3.018cc

The neck of a .308 case will be about 0.369cc that leaves 3.284cc

A 40.0gr charge of 4064 would take up AT LEAST 92% of that space below the neck and that's an UNSIZED case.

[grickards]

There isn't much to tell as to the procedure I am using. I will try to find something to use as a drop tube, but the process I used to load the casings was:

0. Inspect the interior of the casings for any foreign matter.

1. Calibrate the scales using the 10 and 50 gram weights and receive the "pass" message.

2.Pour powder into the Hornady electronic dispenser up to the bottom of the clear tube, as per the instructions.

3. Zero the scales (the pan is removed for the calibration process, so replacing it gives a reading of the weight of the pan of about 147 gn).

4. Enter the target weight of a charge at the lower end of the load data spectrum, namely, 40gn.

5. Hit dispense and wait for beep indicating that the charge has been dispensed.

6. Check the readout to make certain that it reads exactly 40.0gn

7. Place the powder funnel over the neck of the casing and pour powder from pan into funnel.

8. Marvel that the casing was filled all the way up into the neck.

9. Cover the mouth of the case with a finger and gently tap on the case with the handle of a brush to try to settle the powder (to no effect).

10. Shake the case rapidly and gently to try to settle the powder (to no effect).

11. Tap the case gently on the loading table gently (while not tapping the primer on the table) to try to settle the powder (also to no effect).

12. Dump the powder back into the hopper and try again . . . and again.

All five casings loaded with powder up into the neck.

I repeated the foregoing with five undeprimed cases with the same head stamp and tapped them sharply on the bench, since the primers had all been shot.

I then got frustrated and used language inappropriate for repetition in the forum.

[gwhunran]

Is the OP sure there is nothing in the brass. It seems unlikely after the H20 capacity stuff but I have had corn cob media gum up in brass before that had to be picked out. Very dirty stuff. That would have affected case capacity.

[grickards]

Once again, I note that a 40.0gn charge is below the minimum charge recommended in the Lyman manual and there is no way I could fit anywhere near 44gn of powder into the little of the neck that remains, let alone cram a load of 48gn of the powder into the casing to achieve the maximum load specified in the current Lyman manual (not that I want to).

[grickards]

GW Hunran: No, I checked with a fiberoptic light and there was nothing in the casings. Then I checked them again, and there still wasn't anything in them. I am baffled.

[grickards]

I tried using the vibration of an electric toothbrush to settle the powder (I used my wife's as I use a manual) (don't tell her) and got a little settling. Now the powder is sitting lower in the neck. Still no room in the case to get up to the minimum load recommended in the Lyman manual.

[pathdoc]

I've just thought of the silliest, most obvious possibility in the world, but I'm going to ask it anyway:

Are you absolutely sure it's IMR-4064 and not some other powder that got loaded into that jar by mistake?

[cgaengineer]

Do you have another can of 4064 that you can check to see if the rods are the same size?

[TATER]

147 grain pan?? that seems heavy... But I don't have an electronic dispenser.
OK, Is that the Pan that came with the scale as you did not (Have to) re-zero after the pan was replaced?