M die compressing powder

[Thumbcocker]

I am loading some .308 rounds. My goal is to get 2300 to 2500 fps with decent accuracy. The boolit is the Ranch Dog 165 (170 lubed and checked). The rifle is a Tikka with 1in 11 twist.

After conferring with folks on this forum who are shooting. 308 in this velocity range I loaded some rounds with 4831. The charge fills the case pretty full. When the case goes to the M die for neck expansion the powder gets compressed to just at the base of the case neck. The boolit is seated and there is 100% load density.

Is there any potential problem with this compression by the M die?

[racepres]

Why are we flaring/neck expanding, after Charging???

[high standard 40]

Why are we flaring/neck expanding, after Charging???

This was my thought as well.

[Thumbcocker]

I'm loading on a Dillon 550b. Due to the layout of the tool head I have to put the M die after the powder measure. No problem with charge weights, they are very consistent. Usually no problem with the powder and the M die as most powders don't fully fill the case.

[USSR]

Yep, Thumbcocker, ya got it backwards. First expand the neck, then add the powder.

Don

[megasupermagnum]

No problem. Guys do it with black powder cartridge all the time.

[earlmck]

Sounds perfect to me. If the "M" die didn't do your little bit of compression then the boolit would be doing the compression when you seated it. Compressing with the boolit can give some boolit distortion. The BPCR guys are avoiding that possible distortion by using the die to compress and then dropping the boolit on top, which is essentially what you are doing.

[remy3424]

Maybe just knock them out on a single stage press, assuming you are only doing a few hundred a few times a year and have a single stage. Personally, I only load my rifle cartridges on a single stage presses. I have my 550 set-up for 9mm, it's only job.

[Winger Ed.]

Use the M die, if you need it at all---- before you prime & charge the case.

For .30 cal.- I put a fairly big inside bevel on the case mouth, and using gas checks, sized to .309,
I don't need to use a M die at all on most of the thicker walled brass.

[Larry Gibson]

I'm loading on a Dillon 550b. Due to the layout of the tool head I have to put the M die after the powder measure. No problem with charge weights, they are very consistent. Usually no problem with the powder and the M die as most powders don't fully fill the case.

I also load some cast bullets on my Dillon 550B. When the M-die will compress the powder I size all the cases (NS or FL) first and then put the M-die in stage 1. That way the case mouth is flared prior to charging with powder. An extra step but then by sizing all the cases first i can also clean the primer pockets, make sure there is no debris left in the case and inspect it for split neck before loading the cases progressively.

[vagrantviking]

Compressing the powder with the M die might reduce the pressure on the bullet if it has to compress the powder. Lessen or prevent any deformation of the bullet. Seems like a win to me. Especially if the die does all the compression.

Another thing you could try is to drop tube or vibrate the powder to get it to fall to a slightly lower level in the case. I'm guessing the press you are using wouldn't be convenient for that though.

[Shuz]

I load all of my cast boolit loads on an old Dillon 450. Stage1 has either a neck or full length die, stage2 has the M die, stage3 the powder die and stage 4 the seating die..No powder compression with this sequence.

[gwpercle]

Do all your case prep steps before charging with powder . Size , deprime , (trim & chamfer edge , if needed) , neck expansion / flare / M-Die used here for boolit seating prep .

The last 4 steps should be : Prime case , charge with powder , seat boolit and apply crimp .
This applies to both handgun and rifle ammo .
You can prime the case just before neck expansion ... it will not hurt anything .
Gary

[garandsrus]

The powder die has to go in position 2 on the 550 and 650. The easy solution is a Dillon compatible powder funnel that also expands the neck, in a similar same way the Dillon pistol powder dies work. The die can be modeled after how the M die expands, with a step.

There is a limit to how small you can go though. At some point, the hole in the die is too small and you risk powder bridging. I am not sure how small you could go, but I have done 25 cal successfully.

[USSR]

Note: The OP is using 4831 in a .308 Win. case. It takes a lot of the slow burning 4831 to generate any velocity, and their ain't much room for it in the .308 case. Compression, which could break up the kernals, could change the burn rate. While I would use a different, faster burn rate powder, I would use a single stage press for this particular reloading job. Just MHO.

Don

[Burnt Fingers]

The powder die has to go in position 2 on the 550 and 650. The easy solution is a Dillon compatible powder funnel that also expands the neck, in a similar same way the Dillon pistol powder dies work. The die can be modeled after how the M die expands, with a step.

There is a limit to how small you can go though. At some point, the hole in the die is too small and you risk powder bridging. I am not sure how small you could go, but I have done 25 cal successfully.

Umm.... no it doesn't. I've run the powder drop in station 3 with no problems at all.

[Walks]

I've had case mouths split after expanding.
If that happens in a progressive press you won't find out until your loaded round pops out. I size, decap and expand on my progressive. Then inspect and prime, charge, seat and crimp.
I hate having rounds with cracked case mouths or body splits in loaded ammo.

And I sure as Blue Blazes Would NOT Load a Maximum Charge or a Compressed Charge on a progressive press.

[garandsrus]

Umm.... no it doesn't. I've run the powder drop in station 3 with no problems at all.

Are you using the old style powder measure with the springs and no fail-safe rod? That would work in any station but isn’t offered any longer. You could manually return the powder measure at the end of each stroke, I guess.

[onelight]

I deprime before tumbling so if I want to use a separate expander , I resize when I deprime , tumble the cases , then expand on station 1 , bell and drop powder station 2 , seat bullet station 3 , and crimp station 4.

[Burnt Fingers]

Are you using the old style powder measure with the springs and no fail-safe rod? That would work in any station but isn’t offered any longer. You could manually return the powder measure at the end of each stroke, I guess.

I have both. I was running the springs.

[uscra112]

I think Larry Gibson has it right. Decap, clean and size before taking the cases to the progressive gizmo. M-die goes in station 1.

[sigep1764]

I think Larry Gibson has it right. Decap, clean and size before taking the cases to the progressive gizmo. M-die goes in station 1.

This is how I load my 223 ammo. It adds an extra step, but this is how it works for me on my Dillon with a failsafe rod. Besides, if you size bottleneck rifle cases in station one, how do you clean the lube off of the cases?

[Thumbcocker]

Loaded rounds are wiped down with a rag and alcohol before storage.

[rbuck351]

I would make a powder funnel/expander to replace the dillon one in the size I wanted and load as usual.

[uscra112]

Excellent! Would have to be hardened since he's doing quite a volume of loading. (4140 pre-hard might do?.)

[762sultan]

I have read many many posts by Larry Gibson and have not seen a single post that was wrong. If Larry said it then I believe it. Not that he can't make a mistake, but I have NEVER seen it.

[oley55]

I too have been doing it the same way Larry Gibson described on my RL450's for all of my cast boolit pistol reloads.

On the subject of compressed powder loads, I can see the advantage of compressing the powder with the M-type die and maybe preventing the loaded COAL from growing, but isn't there the chance some compressed powder will stick to the face of the die, resulting in slightly undercharged/over charged loads as it goes from case to case? Just wondering out loud.

[popper]

I run my 308W to 2700 fps (cast) and use faster powder, no problem. Don't have anything slower than LeverE. I also completely process all brass before priming - no need to load bad brass. According to GRT (QL) , you won't get there

[MOA]

Only issue I've ever had when expanding neck before priming..powder and bullets was occasionally by the time I got to the latter cases the neck has sprung back an started to shave some of the boolits, and I'm doing them in a single stage presses. Possibly a progressive press would not have this kind of issue.

[jimb16]

I do all my case prep work before I load with my 550 B. M die is used before I clean and polish the cases.

[1006]

Umm.... no it doesn't. I've run the powder drop in station 3 with no problems at all.

On the 650:Once it is on the third station, it makes you wonder why it was ever on the second station. I modified my powder measures to operate without the rod. But, you do have to make sure you observe the powder bar cycling at the appropriate times while charging case. The fail safe rod helps prevent both double charges and squib loads.