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★ ReviewsPopup content startsclose Popup
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from real shoppers4.8 star rating 30627 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 rating06/30/25JJason Y.Verified Buyer5.0 star rating06/30/2518" ultramatch mod2 223 wyldeReview by Jason Y. on 30 Jun 2025 review stating 18" ultramatch mod2 223 wyldeI was pleased with the out of the box quality appearance. Immediately put on my upper and built it up with a mix of parts I had laying around the parts locker. Initial impression while doing a manifold tuning and barrel break in I was not impressed. I chalked it up to range ammo but went back out to my range and followed up with some better quality ammo. Second time a charm I guess. This barrel just rocks! Groups with middle road ammo at 100 yards in the 1. 25" range. Once I start doing load development with some hand loads I'm sure it will bee sub 1" all day.On Rainier Arms Ultramatch MOD2 .223 Wylde AR-15 Barrel - 18" NitrideJJohn 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 Cherry$550.00 - $625.00 -
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- Gas Block Diameter .750" Remove This Item
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