Table:
text: AR-15 variants
R series models
R series models
Colt_model_no_ Name_ Stock Fire_control Rear_sight Forward_assist Case_deflector Barrel_length Barrel_profile Barrel_twist Hand_guards Bayonet_Lug Muzzle_device
R6551 Sporter Target A2 S-1 A2 Yes Yes 20 in. A2 1:7 Ribbed No A2
R6600 AR-15A2 HBAR A2 S-1 A2 Yes Yes 20 in. HBAR 1:7 Ribbed Yes A2
R6601 Sporter Match HBAR A2 S-1 A2 Yes Yes 20 in. HBAR 1:7 Ribbed No A2
R6700 Sporter Competition HBAR A2 S-1 Flattop Yes Yes 20 in. HBAR 1:9 Ribbed No A2
R6721 AR-15A3 Tactical Carbine 4th Generation S-1 A2 Yes Yes 16 in. HBAR 1:9 Short Ribbed Yes A2
R6724 Sporter Competition HBAR A2 S-1 Flattop Yes Yes 24 in. HBAR 1:9 Ribbed No A2
R6731 AR-15A3 Competition HBAR A2 S-1 A2 Yes Yes 16 in. HBAR 1:9 Short Ribbed No A2

Question: In the AR-15 variants, what are all barrel lengths named ar-15a3 Competition Hbar among the R series models?

Question: What is the sporting aim fire control for the R-series models of the AR-15 variants?