Cal .30 LR Inert Charge


#1

Not often seen, Cal .30 LR Inert Charge cartridges. FAT1E3 case, loaded with 49.5 grains of Sodium Carbonate and a T21 bullet. Left and center are headstamped FA 51, and right is headstamped FA 54. The FA 54 has a struck primer. I’m not sure if it was intentional or not. The other two are un-struck.

The ink stamping on the case side is weak on most examples. These three are very strong. Cartridges of this type have probably gone unnoticed through collectors hands when the stamping is especially weak and not noticed.

I’m not sure of the designation for these cartridges so if anyone knows for sure, please post it.

Ray


#2

Wow! Can’t help with the designation but nice cartridges…


#3

"LR—“Loading Registration”…usually Sodium Carbonate cartridges (Inert) are for testing and registering “loaded cartridge weight-testing machines”, and “Packaging Machines”. ( and even Link Belting machines.)

The use of Sodium carbonate or even common white refined sugar, was used in Minigun testing and as “lead-in and lead out” ( the inertia of a minigun keeps the barrels rotating even after the trigger is released, allowing live rounds to still be fed into the mechanism until its stops…
The Inert rounds would prevent "Un-Authorised’ or “Misaimed” discharges.
That could explain the struck primer.???

Regards,
Doc AV

Regards,
Doc AV
AV ballistics.


#4

Thanks Doc. I more-or-less knew that these are for testing or calibrating machinery. I was hoping that someone knew if there was a “T” designation for them.

I have a later cartridge that has no primer pocket, and is headstamped LC 77 INERT. The bullet has a dark blue tip. I’ll post a photo tomorrow.

Ray


#5

Why go to the trouble of producing these ‘loading registration’ cartridges when surely a regular dummy cartridge would serve the same purpose? I suspect that somebody will point out that these cartridges were made to an exact weight to simulate a ball round but that must then raise the question of why the weight of a regular dummy doesn’t match that of a ball round.


#6

Machinery Registration cartridges are made for several purposes, not only for correct weight of a “Loaded” Cartidge" but also variants Plus or Minus weights from Standard, to make sure that a functional Tolerance in the machinery can be set ( especial for “Check weigh” machines, which have a very small variance inbuilt to allow the majority of cartridges to pass through as “Correct load” yet still allowing for the normal production variation of Bullet and case weight. Over or under weight cartridges are pulled down and powder charge checked, as are the other components, and a decision taken whether the percentage of “rejects” is significant enough to “Reject” the entire Lot, or simply the reject/s are a “one off” defect, such as Two bullets in a case, or Bridged Powder (Impurity causing a reduction of Powder charge, or other defect in Powder delivery.)

QA is so strict in Military ammo production…you should see the list of reasons for rejection or re-inspecition of a Lot of Cartridges set down by Ordnance Corps.

As to the Weight of a dummy cartridge (Drill Inert) these are simply the Bullet and Empty case, with or without primer cup. These are not meant to be used for “checking machinery” but only for Drill use. and the difference of the missing Powder (and primer) Mass is immaterial to correct mechanical functioning of a Gun…

Regards,
Doc AV


#7

Those original Inert cartridges were not the best designed since the ink stamping would have worn off after a while, leaving a cartridge that appeared, for all purposes, to be live. My guess is that there are still some of them around without the owner realizing what they are.

The later cartridges would have served their purpose much better. Here’s one from 1977. Maybe there were others, intermediate?

Ray


#8

Nice cartridges! I have a .50 BMG with “INERT” stamped on the case, and if I recall the stamp is indeed hard to read after years of handling. The round does have a blackened primer to aid in identification though.


#9

I have from a collection I bought years ago a round that was labeled “7.62mm Ball M59 (Inert)” that has a black primer. I don’t know if it is actually inert or not but it does weigh the same as a normal M59. If it ever had a black stamp on the case it is gone now.


#10

Quote DocAV - "The use of Sodium carbonate or even common white refined sugar, was used in Minigun testing and as “lead-in and lead out” ( the inertia of a minigun keeps the barrels rotating even after the trigger is released, allowing live rounds to still be fed into the mechanism until its stops…
The Inert rounds would prevent “Un-Authorised’ or “Misaimed” discharges.
That could explain the struck primer.???”

Doc

I thought the testing of guns/links/feeding etc was done with a different form of Inert cartridge. Such as the M172 shown here. Blackened case and bullet. Primer pocket but no flash hole. 147 gr bullet. Double bullet crimp. 45.0 grains of Sodium Carbonate.

left is XM 172, hs FA 64
right is M172, hs LC (+) 69

Ray


#11

While looking through my XM172/M172 type dummies I noticed there are at least 3 different variations: 1) blackened bullet and brass case, 2) blackened bullet and blackened case and 3) GM bullet and brass case. I think the LC 64 round might have originally had a blacken case and the finish has worn off with use. The primer pocket is black. All the rounds are in the 372-376 grain range.


#12

Phil

I have an XM172, hs FA 64, that has a copper-washed case, blackened. Most of the black has worn off. It’s my understanding that the black was to help spot the cartridges in high-speed photos. Is that your understanding?

Ray


#13

Ray – What does a copper washed case look like? Can you post a picture? I don’t know if I’ve seen one or not.
I don’t think I have ever read why the rounds were blackened other than for sight indentification.


#14

Phil

I don’t have a photo of the copper-washed case. It is very scroungy looking. The blacking is very much worn in spots. Sorta like #2 down in your photo. The brass case was evidently given a copper wash which was then chemically blackened. Much like steel is given a copper wash prior to nickel/gold/silver plating.

Ray


#15

This thread caused a tiny bell to tinkle & finally I checked my notes. I have a 7.62 m/m NATO dummy I’ve had since 1957 which has a plated steel case, M59 bullet, and (at one time) a dented primer. Headstamp was NATO mark LC 56. A number of years ago it began to deteriorate, with heavy corrosion around the primer. Finally I pulled the bullet, removed the primer, and dumped out a bunch of white granular stuff, along with clinkers and rust. Should have taken it apart years earlier, because now the headstamp has completely disappeared. I assume this was one filled with sodium carbonate and that that chemical set up a reaction with the steel case. Jack