Your CAR-A3 HBAR Elite model CR6724 came out later in the late 90s while the Match Target Competition HBAR model MT6700 was in the market earlier if I'm not mistaken early to mid 90s probably around 1992.
The HBAR Elite is mainly for varmint and accuracy shooting while the Match Target Competition HBAR could be used in CMP (Civilian Marksmanship Program) rifle matches (formerly as DCM which means Office of the Director of Civilian Marksmanship 1916-1996).
CMP target competition have different rules some are very restrictive that only allows semi auto AR-15 version of the M-16 service rifle (or older US military issued rifles) which does not allow heavy barrels, 4.5 lb trigger pull limit, and only issued military ammo, however there are other rules that allows match heavy stainless barrels of no more than 20", free floating handguards as long as it looks like the standard military issue rifles, match triggers (check the rules for trigger pull limit), match sights, and additional front and rear ballast weights.
I used my (older preban model than yours) Colt model R6600 AR-15A2 HBAR Sporter (with fixed carry handle upper A2 receiver) which I bought new when they were first available in 1986 and I just practiced with it for slightly over 600 rounds and I took it to my first DCM match in the summer of '86, my purpose to complete the match was so I could qualify in buying a DCM USGI M1 Garand rifle.
I was surprised at the result of my first rifle match and I'm using the improper light weight 55 grain (I wish I had the heavier 62 grains or more match ammo) surplus ammo Winchester white box Q3131 XM193, using my unmodified factory Colt HBAR rifle, I ended up 20th place for the two day weekend match of about 400 shooters.
My result would have been better if I have not had failure to feed twice both during the prone rapid fire stages, I managed to clear and fire all my rounds before the cease fire both times, later on I traced the failures to a bad factory Colt 20 round magazine body.
After several months later after the match I got my 50s International Harvester brand M1 Garand rifle.
After my first match I continued competing for several more years averaging two match per year, and I slowly upgraded my factory rifle with match sights (narrower front post and finer rear sight adjustments), had my trigger worked by a local gunsmith to 4.5 lb and very smooth feel, added front and rear ballast lead weight, and when I worn out my original factory barrel at 20K rounds I replaced it with a stainless match grade Douglas 20" barrel.