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Lower Parts Kit

Lower Parts for AR-15 Builds at Western Sport

We carry triggers, stocks, buffer systems, lower parts kits, and grip panels for AR-15 lowers. The lower parts group is where most builders see the biggest performance return on investment — a quality trigger makes a bigger difference to your shooting than a premium barrel does, at most typical ranges.

For trigger upgrades, Geissele SSA or SSA-E are our standard recommendations. For stocks, Magpul CTR or MOE covers most applications. Buffer weight selection depends on your gas system, barrel length, and whether you are suppressing. We can help you dial in the right combination.

If you are building from a stripped lower, we can supply every part you need to complete it. Call us at (817) 393-4000 or come in to Roanoke.

Lower parts guide for AR-15 builders

Buffer and buffer tube selection: A standard carbine buffer (3 oz) is the starting point. If you are running a suppressor or an adjustable gas block, a heavier buffer (H, H2, or H3) reduces bolt carrier velocity and cycling aggression. The buffer tube diameter must match the stock you are running — mil-spec and commercial spec are different dimensions.

Lower parts kits: Most LPKs include everything except the trigger, hammer, pistol grip, and buffer system. Quality varies — CMMG and BCM LPKs are what we recommend over budget options. A bad disconnector or plunger spring causes more function problems than most buyers expect.

Trigger installation: Most drop-in cassette triggers (Geissele, Rise, Timney) install without modifications. Standard mil-spec triggers require pinning the trigger and hammer individually. We do trigger installs in-store — call for current labor pricing.