HOT
OpticPrimary Arms
SIG Sauer Romeo MSR Gen 2 Red Dot Sight - 2 MOA
2 MOA dot · 40,000-hour battery · M1913 Picatinny mount
Check price at Primary Arms →Every shop, one board
EVERY GUN SHOP
YOU LOVE
IN ONE PLACE
Cold Bore Index pulls the shops you already trust — Palmetto State Armory and Primary Arms, with more being added — into one board. Pick the optic, slide, BCG, or a whole build, and we send you straight to the product page to check the live price and buy from the source. We just point.
20HAND-PICKED
DIRECTSHIPS FROM THE SHOP
LIVEPRICE ON CLICK
WHAT CAN I BUILD FOR…
8 PLATFORMS · REAL PARTS LISTS
7 builds in reach
Showing every build — the budget filter needs JavaScript.
Comfortably in range
In range: Ruger 10/22 In range: Glock 19 In range: Glock 17 In range: 1911Doable, but tight
Tight: AR-15 tight Tight: SIG P320 tight Tight: AK-47 tightOut of reach at this budget
Out of reach: AR-10 / .308
BUDGETS ARE PLANNING BALLPARKS · LIVE PRICE SHOWN AT THE SHOP
No Inventory. No Warehouse. Just Receipts.
Cold Bore Index is a price tracker, not a store. Here's the whole business, in three moves.
01 — TRACK
We Watch The Prices
Every morning we sweep the retailers builders actually use — checking slides, BCGs, triggers, furniture, and mags for blems, closeouts, and quiet markdowns.
02 — CLICK
You Hit "GO"
Every part on the board links straight to the retailer's own product page. No middleman checkout, no repackaged listings, no markup.
03 — BUY AT THE SOURCE
They Ship It
The retailer takes your payment, handles compliance, and ships your order like any other. Your warranty and support come from them — the people who actually made or stocked the part.
FULL DISCLOSURE: Some links on this site are affiliate links. If you buy through them, the retailer pays us a small commission. It never changes your price — it's how the lights stay on up here.
Build Sheets — Every Part, One List.
Pick a platform. We lay out every part you need to build it, with estimated prices and a running budget total. Check parts off as you buy — your progress saves on this device (needs JavaScript).
Glock 17 Build
9mm · Full-Size · parts from Brownells
PRO TIP: Building on an 80% frame ships to your door with no FFL — but finishing it is on you, and it can never be sold. A serialized OEM frame is the FFL route.
ESTIMATED TOTAL $410–560 · STILL TO BUY $410–560
Glock 19 Build
9mm · Compact · parts from Brownells
PRO TIP: Same build as the 17, just compact — the frame, slide, and barrel are shorter. A great everyday-carry first build.
ESTIMATED TOTAL $405–550 · STILL TO BUY $405–550
SIG P320 Build
9mm · Modular · parts from Brownells
PRO TIP: The P320 is built around the Fire Control Unit — that little stainless chassis IS the serialized firearm. Grip module, slide, and barrel all ship to your door, so one FCU can become a full-size, carry, or X-series gun whenever you want.
ESTIMATED TOTAL $535–725 · STILL TO BUY $535–725
AR-15 Build
5.56 NATO · Carbine · parts from Palmetto State Armory
PRO TIP: The friendliest centerfire rifle build — barrels come headspaced from the factory, so the upper is basically drop-in. Stake that castle nut and gas key.
ESTIMATED TOTAL $520–700 · STILL TO BUY $520–700
AR-10 / .308 Build
7.62 NATO · Rifle · parts from Palmetto State Armory
PRO TIP: The big-bore AR. Pattern is everything — DPMS/Gen1 and Armalite (SR-25)/Gen2 parts do NOT mix. Pick one lane, match your BCG to your barrel, and gauge headspace before you ever fire it.
ESTIMATED TOTAL $855–1,155 · STILL TO BUY $855–1,155
AK-47 Build
7.62×39 · AKM · parts from Palmetto State Armory
PRO TIP: Real kit-building means pressing a barrel and setting rivets — gunsmith territory. Most people start with a complete rifle or a barreled/riveted receiver, then upgrade the furniture and trigger. That honesty saves you a ruined receiver.
ESTIMATED TOTAL $575–775 · STILL TO BUY $575–775
1911 Build
.45 ACP · Government · parts from Brownells
PRO TIP: The 1911 is a fitting gun, not snap-together — the sear, barrel, and safeties usually need stoning and hand-fitting. Budget for a gunsmith, or go slow on your first.
ESTIMATED TOTAL $470–635 · STILL TO BUY $470–635
Ruger 10/22 Build
.22 LR · Rimfire · parts from MidwayUSA
PRO TIP: The friendliest build there is — no headspacing, no press, no fitting. Everything hand-assembles with a punch. The best possible first build.
ESTIMATED TOTAL $370–500 · STILL TO BUY $370–500
NOTE: Every price here is an estimate to help you size a budget — not a live quote and not a price we can honour. Ranges are typical street prices; the only real number is on the retailer's own page. The one part that may require an FFL transfer is flagged on every sheet.
HOT
AR-15 UpperPrimary Arms
Battle Arms Workhorse Stripped AR-15 Upper - BLEM
Forged 7075-T6 · cosmetic blem only · warranty intact
Check price at Primary Arms →NEW
TriggerPrimary Arms
MIMTAC CORE AR-15 Drop-In Trigger - 3.5lb Flat
Drop-in cassette · single stage · fits AR-15 and AR-10
Check price at Primary Arms →HOT
OpticPSA
Vortex SPARC AR 2 MOA Red Dot
2 MOA dot · 12 brightness settings · included multi-height mount
Check price at PSA →OpticPSA
Vortex Strikefire II Red Dot
4 MOA red/green dot · lower-1/3 co-witness mount
Check price at PSA →HOT
AR-15 BCGPSA
PSA 5.56 Nitride MPI Full-Auto BCG
MPI-tested · full-auto profile · nitride finish
Check price at PSA →AR-15 BCGPSA
Anderson AR-15 Nitride BCG
Black nitride · M16 profile · budget-proven
Check price at PSA →AR-10 BCGPSA
PSA PA10 .308 Nitride BCG
DPMS-pattern .308 · nitride finish
Check price at PSA →NEW
HandguardPSA
Aero Precision Atlas S-One 15" M-LOK
Free-float · 15" M-LOK · titanium hardware
Check price at PSA →HandguardPSA
Midwest Industries Combat Rail 15" M-LOK
One-piece free-float · lightweight · M-LOK
Check price at PSA →HOT
Weapon LightPSA
Streamlight ProTac HL-X Pro 1000lm
1000 lumens · rail mount · USB multi-fuel
Check price at PSA →Weapon LightPSA
Streamlight ProTac HP-X Pro 800lm
800 lm · long-throw beam · rail mount
Check price at PSA →Weapon LightPSA
Inforce WML Gen 2
Weapon-mounted light · constant / momentary / strobe
Check price at PSA →GripPSA
Magpul MOE Grip (AR15/M16)
Drop-in AR grip · anti-slip texture · storage core
Check price at PSA →NEW
GripPSA
Magpul MOE K2-XL Grip
Steeper grip angle · aggressive texture · AR-10/AR-15
Check price at PSA →HOT
MagazinePSA
Magpul PMAG 30 GEN M2 (5.56)
30-rd · 5.56 · anti-tilt follower · USA-made
Check price at PSA →MagazinePSA
Magpul PMAG 30 AK MOE (7.62x39)
30-rd · 7.62x39 · fits AK / AKM
Check price at PSA →Muzzle BrakePSA
LanTac Dragon 1/2x28 5.56 Brake
Dragon ports · heavy recoil + rise reduction
Check price at PSA →Muzzle BrakePSA
Midwest Industries 5.56 Muzzle Brake
3-chamber · 3.6 oz · 100% USA-made
Check price at PSA →Muzzle BrakePSA
Fortis RED Brake 5.56 (SS)
Stainless · full-auto tested · 2.4 oz
Check price at PSA →Field Notes
Build guides and buyer's notes — the stuff we wish someone had told us before the first order.
Build Guide
The $400 AR Build That Actually Runs
A full parts list from budget-tier options — what to save on, what to never cheap out on, and the one shortcut that keeps a first build from failing.
Read the guide → Buyer's NotesWhat "Blem" Really Means
Cosmetic scars, full function — usually. How to read a blem listing, what's actually wrong, and when it's free money.
Read the guide → Field NotesCold-Weather Lube: What Survives −20°F
Most gun oil is rated for a garage in Georgia. What actually works at twenty below — specific picks, and the mistake that freezes your firing pin.
Read the guide →Talk The Talk
New to building? Here's the shorthand you'll see on every listing — decoded.
FFL
Federal Firearms License. A serialized frame or receiver must ship to an FFL holder for transfer — unless it's an unfinished 80% part.
80%
An unfinished frame or receiver. Not legally a firearm yet, so it ships to your door — you do the final machining, and it can never be sold.
Blem
A blemished part: cosmetic marks only, full function. Usually 20–40% cheaper. Free money if you don't mind a scuff.
BCG
Bolt Carrier Group — the heart of an AR's action. Look for HPT/MPI tested and a properly staked gas key.
LPK
Lower Parts Kit. Every small part to finish an AR lower: trigger, safety, springs, and pins.
Stripped
Sold as the bare part — slide or receiver — with none of the internals. Cheaper, but you supply the guts.
Headspace
The critical fit between bolt and chamber. Some builds (AR, 10/22) are drop-in safe; others need gauging. Get it wrong and it's dangerous.
M-LOK
The standard slots for bolting rails, grips, and lights onto a handguard. Modular and everywhere.
MOA
Minute of Angle — about 1 inch at 100 yards. How sights and scopes measure adjustment and accuracy.
Nitride
A hard, corrosion-resistant black finish (aka Melonite/QPQ). Tougher and cheaper than phosphate for BCGs and barrels.
Free-Float
A handguard that attaches only at the receiver and never touches the barrel — more consistent accuracy.
Castle Nut
The notched nut that locks an AR buffer tube to the lower. Stake it so it never backs out under recoil.
Drops Don't Wait For You To Check The Site.
One short email when a tracked part actually drops. No spam, no daily digest padding — if nothing moved, you hear nothing.