Introduction of the 40mm M433 (ITP) Inert Test Projectile #masttechnologyinc

Hey All!

I hope you are all well. We developed a new round earlier in the year and I ‘announced’ on Linkedin and Facebook, however I forgot about you guys. Sorry.

A customer is developing a new M203/M320 Sighting Mechanism and needed to be more accurate to M433. They also don’t have HE range or Type 20 Explosive licenses. So we created this. I designed it and had it modified by Arrowtech and PRODAS. Our Ballistic guy Justin R. had input as well as my father, Jim Bell.

Here are some photos and Spec Sheet information. Let the questions fly!!

First 100 rounds - MAST%20Technology%20M433%20ITP

Spec Sheet - MAST Technology M433 ITP 20180910.pdf (127.7 KB)


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Jay, thank you for sharing!

Is the designation M433 ITP officially adopted by the US military or is this a “custom designation” for the industry?

I understand the M781 (TP) will not do the job as recoil behaviour of the M781 and M433 are different?

Before starting a lengthy research; the weights of the M781 and the M433 do not match?

Not adopted, yet… Not sure they will want to because the funding needed and the time.

Yes, mainly recoil. USG requirement on the program to have some testing with the M433 or M433 Inert Test Vehicle (M433 with fuze and all but inert materials) But yes they are slightly different on weight. Projos are close, the cases are way off.

Jay, thanks for the additional diagrams!

So you are also making the ITV variant?

Nice match of the M433 and the M433 ITP ballistics!

Not yet. I am working on it. Lot’s of convincing of larger businesses and equipment to set up. Then the next issue is my line would not be certified by USG to ‘Mil-Spec,’ so not sure if applications where they need Mil-Spec certified, if my rounds would 100% meet the scope of work.

I see, bureaucracy rules!

Late I noticed but has MAST a new code as seen on the M433 ITP now?

1999 MIL-HDBK gives “MTY” and now we have “MTL” here.

Or did we treat this before already?

Alex, yes, they use MTL (e.g., 20 mm, 40 mm, igniters), and also MJC (e.g., .300 Blk).

Thanks for the reminder, although we discussed this symbol in earlier posts, I forgot to add it to the “new” Mil-Hdbk-1461 list.



Hey Guys -

Those are site specific, when the site closes, the code closes.

MTY - Was for the Nevada Facility on Arville St. Circa 1992/3-2001. Stands for - Mast TechnologY (note caps)
MNB - Was for Boulder City 2001 to 2004. Stands for, Mast Nevada Boulder city

MTL - Lake City Operations 9/11/01 - Until present. Stands for Mast Technology Lake city
MJC - MAST Warrensburg - 2008 until Present. Stands for Mast Johnson County (Missouri).
DOD/Comm items (in order that I can remember with date) -

MTL - includes: M781 02+, M81 04+, 5.56 Commercial 05+, .50 cal Linked 06 for Crane + Comm 07+, 7.62 Linked 06 for Crane + Comm 07+, SMAW 07-08, M1110 for ARM 2012-3, 20mm PGU39 13+, 6.8SPC Linked 14+, 20mm M51A4N 15+, SMAW 17+,

MJC - M79 Electric Match 11+, 5.56 LSAT 13+, 556 Comm 13+, 223 Comm 13+, 7.62/308 13+, 300BO Comm 14+, 9mm Comm 14+, 40 S&W 14+, 6.5 Creedmore 17+, .50 Cal 18+,

I am probably missing a couple - short runs or whatever.

As a side note, MAST stands for the first initials of the 4 original partners names. Michelle Athena Sharlene Terri. Founded in July 1990 - Michelle was gone in 1992/3, Terri 1993/4 and Athena October 1996.


Jay, great information! Thank you very much. I’ll update the list.



Jay, this is invaluable info! Thanks a lot for clarifying all this!

In case you find more of those short runs let us know.

MAST Technology M433 ITP 20180910.pdf (127.7 KB)

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