Rifle Parts
Whether you're building a new rifle from scratch or looking to upgrade an existing firearm, our vast selection of rifle parts has everything you are going to need in that journey. At Rainier Arms' selection of rifle parts, you can find a wide variety of products including lower and upper parts, trigger parts, muzzle devices, and many more.
Explore our selection of high-quality parts coming from various leading manufacturers like Strike Industries, Magpul, BCM, and many more.
Also, don't forget to check our specially-made Rainier Arms barrels for your firearms.
-
Boss Barrels Carbon Fiber 300 BLK AR-15 Barrel - 16"★ ReviewsPopup content startsclose Popup
These are real reviews
from real shoppers4.8 star rating 30551 Reviews- Site Reviews
- Product Reviews
Thank you for posting a review!We value your input. Share your review so everyone else can enjoy it too.Thank you for posting a review!Your review was sent successfully and is now waiting for our staff to publish it.Verified Reviewer0.0 star rating05/13/25MMichael W.Verified Buyer5.0 star rating05/13/25Game changerReview by Michael W. on 13 May 2025 review stating Game changerThese “handstops” are great. I’m in the process of putting them on every build i have, and unless something better comes along, they will be on every build going forwardOn Emissary Development M-LOK HandbrakeSSgt O.Verified Buyer5.0 star rating05/13/25Staccato did it AGAIN!Review by Sgt O. on 13 May 2025 review stating Staccato did it AGAIN!What can you say! I have 6 already! And I have only owned my XC for a few months!! They are flat out amazing! (Don’t listen to negative reviews just because someone ordered a larger mag than they meant too) - I’m giving this a rating on how it actually performs! And it’s 5 stars- because it’s the flawless feed performance, and super quick connection. both of which a shooter/competitor/& a warfighter demand!On Staccato 2011 9mm/38 Super Magazine - 140mm/20rdSSgt. O.Verified Reviewer5.0 star rating05/13/25REAL Perfection is not CHEAP, Nor is it POLYMER!Review by Sgt. O. on 13 May 2025 review stating REAL Perfection is not CHEAP, Nor is it POLYMER!Lightning speed, YET with EVERY double tap round drill being “key-holed” -Please let me just admit right now! I’m a Marine Infantry NCO, and this UNBELIEVABLE pistol configuration (WITHOUT ANY QUESTION) actually and truly MAKES me a way more accurate, confident, and proficient side arm shooter!! That’s the most honest and humble way I can explain this superior pistol!! It honestly CHANGED my entire situation, and took away the single weakest piece of my overall “tactical proficiency”
and, Ohh yeah, for those that like to be envied …. . whether at the range, or on job… you WILL BE!!!…. That I assure you!
But for the most honest of reasons, not just because it’s as fast and double tap accurate, as a USPSA Race gun. But because I want my back up to always fire and be as accurate as possible!
Last word to sum this freaking nail driver up! BUTTER!!! 🧈
A real single finger🧈action smooth Slide!!! (That should explain enough to those who are extremely tired of industry standards!!
Now I am as accurate with my side arm as all of my “other” tactical platforms! Complete bliss! And worth more if you ask me! For the kind of total tactical safe mindedness it now provides me!
Thank You Staccato!!! I Love your company! And Rainer for making it so fast and easy to get my 1st baby to me!On Staccato 2011 XC DPO 9mm Pistol – BlackoutJJamieVerified Buyer5.0 star rating05/12/25Bang for buckReview by Jamie on 12 May 2025 review stating Bang for buckBought this upper for my son, he adores this rifle. Mated to an M4 lower with an ACOG on top, this is a top notch upper with all the bells and whistlesOn Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper ReceiverTTimothy H.Verified Buyer5.0 star rating05/12/25BCM MK 2 LowerReview by Timothy H. on 12 May 2025 review stating BCM MK 2 LowerGreat lower!On Bravo Company MFG (BCM) AR-15 Complete Lower Receiver w/ MK2RMS-M1T0 Mod 2 SOPMOD - WIDEBODY - FDE$650.00 -
Shop By
Now Shopping by
Shopping Options
- Gas Block Diameter .750" Remove This Item
- Thread Pitch 5/8x24 (.30 cal) Remove This Item
- Platform AR-15 Remove This Item
- Caliber 300 Blackout Remove This Item
- Barrel Length 16" Remove This Item
- Twist Rate 1:7 Remove This Item
My Wish List
Last Added Items
You have no items in your wish list.