Happy to be corrected, but I believe P90 is a close protection weapon more suited to SPG rather than SFF. Latter is largely an airborne/scout type unit who is better off with a more general purpose SMG.
@Johny_Baba
Hmm...5.7 x 28mm FN vs 5.56 x 30mm MINSAS,which one is better ?
From now on,Let's say MINSAS = 5.56 x 30mm,similarly FN = 5.7 x 28mm
MINSAS is basically Indian made variant of Colt's 5.56 x 30mm MARS cartridge,which was actually a shortened 5.56 x 45mm M193 cartridge in 30mm case,having bullet mass of some 55-grain (3.56 grams).We manufacture M193 in OFB so my speculation is that our MINSAS is developed in same way as well i.e. via shortening M193 case to 30mm length and making its case capacity of some 19.2 grains (or ~1.25 grams) of Nitrocellulose + Nitroglycerin propellants mixture (commonly called 'double based propellants).
OFB source for M193 -
http://ofbindia.gov.in/products/data/ammunition/sc/21.htm
This MARS cartridge was meant to be used in a downscaled AR-15 variant named Colt MARS (Mini Assault Rifle System) designed as potential replacement for 9 x 19mm and .45 ACP SMGs in US Armed Forces (Mainly,MP5s and those WW-2 era M3/M3A1 'Grease guns',although the later one was limited to Special Forces and tank/APC crew members only) as it provides much better ballistic performances to limited ranges compared to these pistol cartridges.Moreover to that same cartridge was designed to achieve much better performance than FN cartridge as well.
They tested this cartridge against many others (including FN) with a and results clearly showed that MARS was better than FN.
For more details,read my post at
http://defenceforumindia.com/forum/threads/successful-user-trial-of-msmc.55979/page-10#post-1338175
Even then,these things depend on many other things as well e.g. MARS gun had 1:300mm rifling (one turn per 30cm of barrel length ) while MSMC/JVPC has 1:250mm rifling (one turn per 25cm of barrel length),MARS had barrel length of some 10 inches while JVPC has slightly longer barrel (of some 11.8 inches or 300mm) and so,but i guess performance between MARS and MINSAS is still very much similar,and since MARS was developed as better cartridge than FN,MINSAS is better than FN as well.
For more info on Colt's MARS cartridge and MARS gun,read this PDF from
https://drive.google.com/open?id=1FnK1HIZk-w7LHDFqjRN_MijvtXz8V1_Y
Now,coming to the Weapons i.e. MSMC/JVPC vs P90,i would say MSMC/JVPC still needs some revision as in a video posted by Sandeep Unnithan (link:
) he reported that during 2014 trials,only 2 out of 5 guns submitted to the army were able to clear those trials.Moreover to that in other video posted by him,(Link:
) i was able to point out two stoppages in it,one clearly being a stovepipe jam.My speculation is that they need to add 'Rate Reducer' or 'Hammer Retarder' for smooth operation of this gun since rate of fire is somewhat higher that is causing stovepipe jams in it. (Refer my post for more info on those jams at
http://defenceforumindia.com/forum/threads/insas-rifle-lmg-carbine.43826/page-152#post-1362417 )
As for FN P90,i can't say much since i don't have much information about it apart from that it being a very compact Ambidextrous gun firing smaller yet powerful cartridges that are capable of penetrating soft kevlar armors and ballistic helmets.