Sig RM400 Elite 5.56 16" RM400-16B-E Layaway
Factory New Condition
FFL is required
Current Bid
No Bids
BuyNow! Price Was
Starting Bid
No Reserve!
0 Bids Bid History
Time Left 15 min rule
Item has Ended
8/10/2017 3:28 PM
Item 680306725
Location Lolo, MT 59847
See Item Description
No international shipments
Payment Personal Check, Visa / MasterCard, American Express, Discover, USPS Money Order, Money Order, Certified Check, See Item Description
Checkout Yes, Immediate
Sales Tax
Seller does not collect sales tax
Inspection/ Return Policy
AS IS - No refund or exchange

The seller of this item assumes all responsibility for this listing. You must contact the seller to resolve any questions or concerns before placing a bid. Payment must be made using U.S. dollars ($) unless otherwise stated in the listing. Firearms may only be shipped to a licensed dealer (FFL Holder). Some listed items may not be legal in every state. Complete your purchase within the law.

Please read the Item Characteristics for important listing details.

Sig RM400 Elite 5.56 16" RM400-16B-E Layaway


To Hell and Back Reliability. SIG SAUER is a brand synonymous with quality firearms. Inheriting a legacy of unparalleled Swiss + German craftsmanship and engineering, the M400 is an AR-15 carbine that SIG SAUER initially developed for law enforcement, but has subsequently taken the civilian market by storm. 

The rifle has certainly raised a few eyebrows since it employs a traditional direct gas impingement system, where SIG gained an international reputation as a small arm manufacturing juggernaut building advanced gas piston platforms. The move was easy to understand when you actually stop to consider that the dominant weapons system in this county is direct gas impingement, and SIG has been in negotiations with several U.S. agencies regarding the M400.

As mentioned, at the heart of the SIG SAUER M400 Elite design lies a direct gas impingement system. It has the benefit of less moving parts, less weight, significantly less expense and typically greater accuracy. The M400 Predator is a very versatile configuration of Sig's M400. 

The bolt carrier has been chrome lined for maximum wear and corrosion resistance, while great care has been taken to ensure the carrier key is staked properly to ensure reliable gas flow. Standard upper features also include a brass deflector, ejection port cover and forward assist assembly. A small protrusion inside the barrel extension supports the extractor body when the rifle is fired, relieving stress on the extractor pin should there ever be a cartridge over-pressure issue. 

The 18- inch stainless barrel provides . With a barrel twist rate of 1:8", the rifle is capable of stabilizing heavy bullets such as .223REM 75- grain match ammo, while equally at home firing standard 55- grain 5.56mm ball. The barrel profile is close to that of the M4, with additional metal removed forward of the gas block. 

The carbine length gas system is fed through a low profile gas block. The SIG SAUER M400 Elite has a 15" MLOK handguard that provide improved handling and accuracy.

To provide maximum protection against wear or rust, the lower receiver has been hard coat anodized, while all other parts wear a tough mil-spec manganese phosphate finish. Weighing in at 6.7 pounds, the rifle accepts standard AR-15 magazines. For service or repair, it is backed by a limited lifetime warranty. Overall, the SIG SAUER M400 Elite is an innovative, rugged and reliable M4 rifle designed for years of reliable service. 


  • Caliber:  .223 / 5.56
  • Mode of Operation:  Semi- Automatic
  • Operating System:  Direct Gas Impingement
  • Lower Receiver:  7075-T6 Forged Aluminum
  • Magazine:  (1) 30- Round
  • Barrel:  16" 1:7" Black Nitride
  • Buttstock:  6- Position Collapsible Sig Stock
  • Handguard:  UTG Pro Free-Floated M-LOK
  • Grip:  Sig Overmold
  • Sights: No Sights
  • Finish:  Hard Anodized Black (Aluminum Components) & Manganese Phosphate (Steel Parts)
  • Barrel Twist:  1-in-7"
  • Weight of Rifle:  7lbs.
  • Trigger:  Mil Spec Single Stage
Visit us Online

We have gun parts, accessories, and magazines available on our website, Any magazines, accessories, or ammunition that you buy along with your firearm SHIP FREE, so give us a call and ask us about it at checkout!

Auction Terms & Conditions
  • All sales are final.
  • In store pickup for your order is available but approval is required before pickup
    • Normal shipping fees apply to cover processing from our warehouse to store.
  • We do not hold items for extended periods of time.
Buyer Responsibilities / Owner Limitations
  • It is the BUYER’S responsibility to ensure that the firearm is legal to own in your city or state.
  • Please check your local laws or call your local dealer before bidding to ensure this model meets the requirements for your state.
  • Magazines that violate capacity laws may be substituted but are subject to product availability and a $10 swapping fee.
  • Firearms that are not transferable are subject to our cancellation fees (see below)
  • Not for sale where prohibited
  • Accepted payment methods include:
    • Visa, MasterCard, Discover, American Express
    • Personal/Business Check (held for 10 business days to clear)
    • Cashier’s Check
    • Money Order
  • We do not accept trades.
  • Layaway is available! Terms and Conditions:  A nonrefundable deposit of at least 20% of the total combined price of your order including all shipping, transfer, and special charges are due when the merchandise is put into layaway. You may make additional payments at any time, but the total price of your order must be paid within sixty (60) days from the start of the Layaway contract. No service fees are applied for putting an item in Layaway.  Please request the Full Layaway Terms using the "Ask Seller a question" Link above.
Shipping & Handling
  • Shipping and handling to the contiguous US is $30
    • If shipping to Hawaii or Alaska, please call for shipping quote before bidding.
  • Small pistols are shipped UPS 2nd Day Air Mon-Wed.
    • UPS does not ship small handguns 2nd Day Air over weekends.  Our best effort will be made to ship completed orders for small handguns by Wed.  All other Small Handgun orders will be shipped following Mon.
  • Rifles and larger pistols are shipped UPS ground Mon-Fri.
  • All firearms must ship to an FFL.
  • We do not ship to PO Boxes.
  • Insurance is available to protect your shipment. Cost of insurance is based on the total cost of your order at the rate of $5.00 per $500 and is rounded up to the nearest $500 of valuation. Please contact us if you would like insurance added to your shipment.
  • Your order will be shipped upon receipt of payment and a signed, legible copy of your dealer’s FFL sent via e-mail, fax, or mail.
  • Shipping time-frames are estimated and are not guaranteed. 
Sales Tax & Fees
  • There are NO CREDIT CARD FEES!
  • Since we are located in Montana, we do not collect any sales tax.
After Auction Ends
  • After you have won an auction, please use the GunBroker checkout system to select your payment method (even mailed payment). We do accept payments over the phone, but we still ask that you use the GunBroker checkout system, this creates an invoice that allows us to automate the shipping process.
  • Please have your selected dealer send a signed, legible copy of their FFL by email at or by fax at (406)204-0415.?
    • Include Item/Order number with FFL
    • We are happy to contact them on your behalf, but we ask that you contact us with a request to do so.
  • Feedback will be left after you have posted feedback for us and after the order has shipped.
Product Availability

We run a full time retail store and online store which means that auctions are also for sale in our store. We make every effort to pull items after it receives a qualifying bid, but on rare occasion an auction item may be sold in store before we notice a bid. If this happens we will contact you immediately.

Contact & Questions
  • Contact us with any questions before bidding.
  • Use the GunBroker contact link to contact us.
  • We respond to all inquiries as fast as possible
  • Our operating hours are:
    • Monday-Friday: 9:00 AM – 4:00 PM MST
    • Saturday: Closed
    • Sunday: Closed
  • Auctions will automatically relist if not sold so DO NOT BID if you have submitted a question that has not been answered.
Auction Cancellations
  • All cancellations are subject to a 25% fee to cover our GunBroker referral costs.

Thank you for choosing Selway Armory, and enjoy your purchase.

Seller provided no "Additional Terms of Sale"
Sig Sauer
5.56mm NATO
Barrel Length
16 inch
Mfg Part Number