The following lists all of our rates for common firearms services. If you'd like to get a quote on something not listed here or have any kind of questions, feel free to contact us.

Sentinel Machine accepts all major credit cards, personal checks, cashiers checks, and cash for products and services.

Assembly Services

Sentinel Machine offers assembly services for people looking to create a firearm to meet a user's needs. Most assembly services will require a custom quote to get a good price. Below is a list of common rates applied to typical assemblies of various firearms.

AR upper receiver assembly (without FSB on new barrel) $90
AR lower receiver assembly $50
Ask-a-pro build session $50/hour

Many firearms require certain tolerances to be set during assembly of components. In some cases, Sentinel Machine may refuse to perform the assembly if we can not guarantee the minimum tolerances can be reliably achieved.

The "Ask-a-pro build session" is a special offering for people who would like to learn some of the basics of assembling a firearm with professional guidance. You get access to the tools necessary to complete the build while ensuring all parts meet minimum tolerances and the installation meets all the required assembly criteria (e.g. clearances, concentricity, head space, torque values, etc.).

It can be overwhelming trying to decide what features you will find valuable for a custom firearm. If you'd like help selecting components that suit a particular role in your training and/or application, let us know. A few minutes of consultation is free. Helping to design a complete rifle from scratch can be negotiated as a part of an assembly charge or quoted as a completely manufactured and tested firearm.

Customization Services

Many firearm platforms can be easily modified or customized to suit the user's needs. Sentinel Machine can provide a number of customization services for many types of firearms. Below is a basic list of common services.

Rifle optic or sight mounting on M1913 "picatinny" rail $20
Rifle scope install and level (no drilling/tapping) $30
Drill and tap receiver for M1913 rail installation (does not include cost of rail) $80
Drill and tap receiver for scope ring installation (does not include cost of scope rings) $120
AR platform trigger swap $20
AR platform barrel swap (no FSB swaps) $50
Threaded muzzle device swap $20
Suppressor quick-detach muzzle device install (.223/.308) $30
Remove pinned front sight block from AR barrel $40
Drill and pin (single, taper) front sight block or gas block (requires block and barrel that has not been previously pinned) $90
Drill and pin (double, taper) front sight block or gas block (requires block and barrel that has not been previously pinned) $140
Pin and weld muzzle device to barrel $50
AR upper receiver barrel extension squaring $50
AR lower receiver swap $50
Pistol dovetail sight installation (mechanically zeroed to the slide) $50
AR platform full maintenance and gauge service $180
Other accessory installation (lights, sling mounts, etc.) $40/hour
Other service work (email for estimates) $60/hour

Incoming FFL Firearms Transfers

Many people like to purchase firearms online. If you are a Colorado resident, Sentinel Machine can serve as your receiving FFL.

All incoming transfers must contact us before you have a firearm shipped here. If you purchase a firearm from another dealer, and have it sent to us without our knowledge, your firearm is likely to be returned to the other dealer.

When purchasing two or more firearms, you pay a single transfer fee. This means 2 firearms cost the same to transfer as 10.

Special: If you are a first-time gun owner, Sentinel Machine will waive the transfer fee of your first firearm you purchase for self defense. There's no way to know if it's your first firearm, so we trust that this generous service will not be abused. Also, it is expected that this firearm will be used as one of your defensive tools. Therefore, firearms that are clearly not useful in a defensive capacity or less optimal for a new gun owner will not qualify for this. In general, most AR-style rifles/pistols or typical compact/subcompact carry handguns qualify. And, yes, Sentinel Machine is covering the cost of the state-required background investigation.

NFA Transfers: If you have multiple NFA items that are approved at the same time, then it's just one transfer fee for all of them. It's also important to note that Sentinel Machine is a Powered By Silencer Shop dealer. If you purchase directly from Silencer Shop and select Sentinel Machine as your dealer, you pay no transfer fees.

Please note: These rates include the cost of the Colorado Bureau of Investigation (CBI) fee which is currently $10.50 per background check.

Single firearm transfer $25
Multiple (2 or more) firearm transfer $35
Single transfer without notice $75
Multiple transfer without notice $85
Special: New gun owner transfer $0
NFA "Form 4" transfer $85

All transfers are handled by appointment only. Once the firearm arrives, you will be contacted with available times and dates.

Person-to-person Transfers

The state of Colorado requires all firearms ownership transfers between private parties to be transferred by a licensed dealer who must perform a background check on the recipient of the firearm. Sentinel Machine can provide this service for a small fee.

Please note: These rates include the cost of the Colorado Bureau of Investigation (CBI) fee which is currently $10.50 per background check.

Person-to-person, single firearm transfer $25
Person-to-person, multiple firearm transfer $35

A person-to-person transaction requires the current owner of the firearm along with the future owner of the firearm to meet at Sentinel Machine's location with the firearm(s) to be transferred. The current owner must present the firearms being transferred so all appropriate information can be recorded. If the CBI background check system provides a fast approval, the recipient may leave with the firearms in their possession. If there is a delay in the approval, the current owner must retain possession of the firearms and reconvene at the location after approval.

All transfers are handled by appointment only. No walk-in services are available.