1st Customization Project Seeking advice.

[Tun_Tavern215]

I have an ArmaLite Law Enforcement Carbine, standard 16” Barrel but am interested in upgrading to an LMT 10.5" M4 Carbine Upper Receiver Group. This is my first rifle and I am new to personal weapon customization. I would appreciate both advice and input on the matter. Below I am attach my rifle full specs in order for a better recommendation.
ArmaLite LEC15A4CBK
.750 At the journal (under the gas block)
Length of Pull: (collapsed) 10 3/8" (Extended) 14 1/2"

Caliber: .223/5.56 X 45 mm NATO
Barrel: 16" Chrome Lined\Chrome Moly Vanadium MIL-B-11595-E, with M203 Step Down Barrel, Threaded 1/2x28
Rifling Twist: RH 1:9" 52-69 Grain Ammo
Muzzle Device: Flash Suppressor
Front Sight Base: A2
Upper Receiver: Forged, Flattop with Picatinny Rail & Laser Engraved Rail Numbering, 7075-T6 Aluminum
Lower Receiver: 7075-T6 Aluminum (forged)
Trigger: Tactical Two Stage, 1st Stage 3.5 lbs - 2nd Stage Approximately 5-6 lbs.
Overall Length: 35.6"
Weight: 6.5 lbs
Finish: Anodized Aluminum Upper/Lower Receiver, Manganese Phosphated Steel Barrel
Accuracy: 2 - 2 1/2" MOA


These are the specs for the LMT 10.5 M4 upper Carbine Barrel Group

M4 Feed Ramp Barrel Extension
M4 Feed Ramp Flat Top Receiver
T-Marked Upper Receivers
USGI 1/7 Twist Rates
USGI 5.56 NATO Chambers
Chrome Lined Bore and Chamber
Manganese Phosphate Barrel Finish
USGI Government Profile Barrels