Pulling 20mm projectiles

One constant concern of mine is the amount of propellant in the collection, primarily in medium and large cartridges. It doesn’t take very many rounds and the quantities of powder add up quickly. A couple of years ago I teamed up with an IAA machinist friend to build as couple of bullet pullers, modelled after some that I watched in used many years ago on large caliber rounds. I have one for 37-40mm and one for 20mm. Both can be used for many different sizes, but may need different projectile clamps and extractor groove clips.
It is a slow process, and when you have hundreds of 20-30mm it takes time to work your way through different rounds. Yesterday I was finishing up on 20mm Madsen type rounds, when I got a bit of a surprise.



I’m guessing that based on the headstamp - and the oatmeal propellant - that this was a factory handout piece? I don’t see any other indication.

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One of their breakfast rounds.

I’d be very interested to see the puller. I helped a friend of mine build an inertia puller for .50x99 and 12.7x108.

hello
there are oats flakes mixed with powder ???
so nice late 20x120 madsen round

Reduced load?
I reload a lot and it is common to use inert filler in reduced loads, mainly to hold the powder up against the primer to secure optimum ignition.

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Can I ask why you used “.50x99” instead of .50 BMG or 12.7x99?

Ole

Hmm, good question!

@USSubs would love to see pictures of the pullers.

I’ve seen all sorts of stuff used on top of powder loads to keep the powder stack near the primer.

Was the Madsen originally cordite and moved to Nitro, hence the smaller fill and need for filler?

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Madsen never used Cordite to what I saw.

I think here is some confusion. The oatmeal was surely not mixed with the powder.
The image above is showing contents of 2 different cartridges that were pulled.
Maybe Jeff can confirm?

A tired brain and being unable to decide between .50 BMG and 12.7x99 :man_facepalming:

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Sorry for the confusion, it was perfectly clear to me as I was doing it…
Alex is correct, that was my powder dumping container, there is powder from three previous 20’s. then the oatmeal off to the side. If you look carefully there are at least two slight powder variations.

Personal preference, I’m not a big fan of inertial bullet pullers for calibers .50 and up. We have all seen the pictures of mistakes that have been made with German and Argentine rounds at the .30 level, the penalties get progressively worse as you go up in caliber. That and in regard to 20mm and up, it seems that the more I learn the less I know. So many of the variations are poorly documented, or the documentation is so poorly distributed that surprises are common. Even with periodic access to X-ray equipment I am seldom comfortable with submitting many of these rounds to shock energy, especially in a forward motion.
Instead, completely lacking in any practical skills of my own, I convinced a friend to build the following -

On the left is the bottom plate, with a hole for insertion of the cartridge. Two threaded rods are secured to the bottom plate and further up have nuts and a pusher plate dropped on from the top. The pusher plate has an opening for the projectile to extend through, and fitted clamp is attached to the projectile. this clamp covers the full length of the projectile, giving the most surface area to grab while doing the least possible amount of damage to the body, paint and markings.


A fitted key is slipped over the extractor groove of the case to hold the cartridge is place. The bottom plate is then secured into a vise and using a suitable wrench the nuts are simply “unscrewed”, slowly pushing the plate upwards and extracting the projectile.
One late addition was a rotating metal “tab” on the bottom of the puller. It was discovered the hard way that some cartridges (i.e. 20x102) are crimped heavily enough that the projectile/case may release suddenly, allowing the case and powder to ricochet about the room. Rotating the tab before unscrewing prevents this from happening.

Years ago we used a similar device for large caliber rounds - 75mm, 105mm, Flak 88 etc. In that case guide rods replaced the threaded rods and the upward pressure was supplied by two hydraulic jacks.

As mentioned I also have a larger version for use with larger medium caliber rounds. It is currently set up for 40mm, but can easily handle smaller calibers. In particular I have a number of 25mm Bradley cases that still contain powder and need to be cleaned up.

This tool is still being refined and we have some improvements to still explore. In particular, since the device does such an excellent job in extraction without damage or belling the mouth of the case, it can be difficult to replace the projectile into the case once the powder is removed. In theory the process can be done in reverse, but it is slightly problematic with some rounds, with rims getting in the way, the cartridge not as stable under pressure, etc. A work in progress.

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Thanks Jeff,

This is pretty much what I had envisaged but nice to see it. The 50 cal puller was only used on known rounds.

Pretty darn cool!

After the powder is dumped, do you do anything with the primer?

Not normally. Items are not in a position where I consider primers a physical hazard, and they are not a fire hazard or a legal issue, so I generally leave them as is. In a few cases I have given the inside of the case a spray of light oil, which would kill most primers, but that is as corrosion prevention and not primer specific.

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Many years ago (1989, IIRC) I visited “Dangerous Dave”, the Old Western Scrounger (R.I.P.) at his CA home/shop.
Among the items I bought was a late 1800s cannon round. Dave said it had a live warhead with a blackpowder charge. I am OK with propellant, but didn’t want a live projo around.
“No problem” said Dave, and gently removed the projo from the brass case.
His method was to use a hand operated pipe cutter with a third roller replacing the cutting disc.
As he gradually applied more pressure with each turn, the brass at the case mouth began to expand, allowing the bullet to come out easily.
HTH.

Where did he put the cutter/roller, just behind where the base of the projectile would be?
Was the case not deformed, at least somewhat?

I met Dave when he walked into the gun shop I worked at, (Potomac Arms in Alexandria, Va.), then again a couple years later at the Antique Arms show in Timmmonium, Md.
He was a pretty cool character!

The three roller setup acted on the case neck.
It would very slightly thin the neck area, as the bullet didn’t allow the neck to collapse.
This would enlarge the neck diameter as the brass flowed ahead of the roller.
(Hopefully that makes sense! )

Yes, perfectly- now!
I just could not picture it in my mind.
Thanks!

Great bullet puller!

Some decades ago i came into possession of three cases of MG151/20 rounds. Charlie Yust (rest his soul) sent me the deactivation instructions he had developed during WWII when he was in the Army. A gunmaker at H&H made me a great set of fuse wrenches and I deactivated all the projectiles. Then I had to figure out how to remove the powder. I bought a section of common iron pipe big enough that a 20mm round, wrapped in a number of sheets of old newspaper to protect the bullet and case, and a big steel (or maybe iron) washer with a center hole about the diameter of the groove on the 20mms. I cut a slot in the washer so I could slide the round in, fill the empty projectile with lead shot and replace the fuse, and slam the pipe down on some concrete. the projectile popped out with one or two slams with no damage to the round. Replacing the projectile into the case was easy. With the fuse removed I gently tapped proj back in the steel cases until the crimp snapped into the groove on the ;projectile. The unloaded rounds appeared identical to the fully loaded rounds.

Fortunately, I had some excellent advise from friends. Based on their advise I would never attempt any of this on Japanese or Russian 20mm or most other 20mm. I’ve left those to the professional. like USSubs.

Cheers,
Lew

Cheers,
Lew

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