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.
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Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver - 10.5"★ ReviewsPopup content startsclose Popup
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from real shoppers4.8 star rating 30626 Reviews- Site Reviews
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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 rating06/30/25JJohn R.Verified Buyer5.0 star rating06/29/25You will not be disappointedReview by John R. on 29 Jun 2025 review stating You will not be disappointedThe product is in built with attention to detail and it’s quality through and through! Remarkable !!!On OA Defense OA 2311 Pro 9mm Ported Pistol - High Desert SageBBrian K.Verified Buyer5.0 star rating06/29/25Radian ramjet for sig p365xlReview by Brian K. on 29 Jun 2025 review stating Radian ramjet for sig p365xlGreat stuff as usual from radianOn Radian Weapons Afterburner & Ramjet Barrel Combo For Sig P365XL 3.7" - BronzeJJarodVerified Reviewer5.0 star rating06/29/25Works!Review by Jarod on 29 Jun 2025 review stating Works!Had to try it, on a . 223 16" build first. Ended up watching many you-tube videos and all pretty much say use a heavy buffer. I tried two different buffers, and my 5. 3oz stopped the light primer strikes (bolt bounce) and allowed the mag to empty and last round locked the bolt to the rear. I paired this with a CMMG trigger having the open back as recommended from multiple users (again info from you-tube). I recommend a comp, to help reduce muzzle rise, maybe something like the Lantac Dragon, ported near its top. Will be trying my lower on other uppers soon.On Atrius Development 3 Position Super Selektor SafetyFFrancisco A.Verified Buyer5.0 star rating06/29/25A++Review by Francisco A. on 29 Jun 2025 review stating A++A++On Sharps Bros Echelon Improved Grip Module - Black / Brazilian CherryEEdwin R.Verified Buyer5.0 star rating06/28/25Great QualityReview by Edwin R. on 28 Jun 2025 review stating Great QualityGreat quality, reminds me of Mega Arms.
Definitely recommend and will buy more.On Rainier Arms Forged A4 Upper Receiver- GEN2$550.00 - $550.00 -
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