If you run an AR-15, your bolt carrier group (BCG) is putting in serious work. It takes the heat (literally), cycles your rounds, and deals with all that gas and carbon buildup. Taking it apart and giving it a good cleaning keeps your rifle running smooth and reliable. In this guide, we’ll walk you through how we do it in the shop — the same way we show our customers in person.
What You’ll Need:
- Your AR-15 (upper and lower separated)
- Punch, Allen key, or Pick
- Cleaning supplies: rags, CLP, small brush, Q-tips, maybe a pick
- Flat workspace
- Optional: spare parts tray or magnetic bowl
- And of course, a clear head
Step 1: Always Start with Firearm Safety
Before anything else, make sure your rifle is unloaded.
- Point the firearm in a safe direction
- Drop the magazine
- Pull the charging handle and visually and physically check the chamber
- Separate the upper and lower receivers
No ammo anywhere on the bench. Safety first, always.
Step 2: Remove the Bolt Carrier Group
With the rifle cleared and the upper receiver open, pull back the charging handle and slide the BCG out. Set the charging handle aside — we’re only working with the BCG today.
Step 3: Remove the Firing Pin Retaining Pin
Flip the carrier over and look for the little cotter pin on the side. Use your punch or tool to pop it out. It’s small and easy to lose — don’t say we didn’t warn you.
Step 4: Remove the Firing Pin
Turn the carrier upright and tap it lightly — the firing pin should slide out the back. If not, just pull it gently.
Step 5: Remove the Cam Pin
Push the bolt into the carrier a bit. This gives you room to rotate the cam pin 90 degrees, then lift it straight out.
Step 6: Pull Out the Bolt
With the cam pin removed, the bolt slides right out the front of the carrier. You’re now fully field-stripped.
You can also remove the extractor if you’re doing a deep clean, but for routine maintenance, this is plenty.
Tips on Cleaning Your BCG
Now that everything’s apart, here’s how we clean our BCGs in the shop:
Light lube: When reassembling, lightly oil the bolt body, cam pin, and firing pin. Don’t overdo it — just enough to stay slick without dripping.
Bolt body: Scrub with a nylon brush and CLP/Carbon Cleaner. Get into the lugs and wipe off all carbon.
Gas rings: Clean carefully — don’t bend or warp them. Make sure they spring back after pressure.
Firing pin: Wipe it clean. If you see pitting or mushrooming, time for a new one.
Bolt carrier (inside & out): Use Q-tips, a brush, and patches to clean the inside tunnel and carrier walls.
Extractor: You can pop this off with a punch if it’s super gunked up. Clean under the claw and spring area.
Cam pin hole & retaining pin slot: Carbon builds up here fast — use a pick gently if needed.
Reassembly Steps
Step 1: Insert the Bolt
Make sure the extractor is on the right (ejection) side. Slide the bolt into the carrier.
Step 2: Reinstall the Cam Pin
Push the bolt in slightly, drop in the cam pin, then rotate it 90 degrees to lock.
Step 3: Drop in the Firing Pin
Slide the firing pin back down into place. It should seat fully without resistance.
Step 4: Insert the Retaining Pin
Push the retaining pin back through the side of the carrier. Make sure it’s flush.
Step 5: Function Check
Pull the bolt forward and back — it should move freely. Tilt the BCG and listen for the firing pin to move. All good.
Final Thoughts
That’s it — your BCG is cleaned, lubed, and reassembled like it should be. Whether you’re prepping for your next range day or just doing monthly maintenance, this 10-minute job keeps your rifle running strong and reliable.
Got questions? Need replacement parts? Bring your rifle into Black Bayou Armory and we’ll go through it with you — no pressure, just solid advice and real help.
We run our gear like you do. Let us help you keep it ready.
– The crew at Black Bayou Armory
Products We Recommend
If you’re looking to clean, maintain, or upgrade your AR-15 BCG setup, here are the products we actually use and trust in the shop. You can check them out on our website below:
- Bore Tech C4 Carbon Remover
- TacShield AR-15 Cleaning Kit
- Extreme Duty Gun Oil – 1 oz
- AR-15 Cleaning Mat
We keep all of these in stock, both in-store and online — because if we wouldn’t run it in our own guns, we don’t sell it.
