80% lower AR-15 Router Jig Showdown


Easy Jig gen2 vs Modulus Arms vs 5D Tactical vs 5D Tactical Pro


NOTE: This page was updated on 11/11/17 to reflect the release of the 5D Tactical Pro jig. Information regarding the original 5D Tactical jig will remain for now.


The purpose of this router jig comparison is to do exactly that. Compare. No jig is declared a winner or a loser because that would mean certain criteria would have to be used and what I value most may not be what you value most. This is why I break down what I consider the most important criteria to consider and explain what each jig brings to the table in that regard. I think this will allow you to make decisions on what is most important to you and choose a jig solely on that basis. If you believe there are other criteria that should be consider let me know in the forum or using the Contact link at the bottom of the page and I will evaluate that.


Regarding the wording below when I write "AR-15" I mean AR-15, AR-9 or any jig that machines a standard AR-15 sized lower. When I write "AR-10" or "AR-308" I mean any jig that will machine the larger AR-10 or AR-308 pattern lower.


Price: The AR-15 only version of the Easy Jig gen2 is $170 which is the same as the Modulus jig and each have steel side plates. The $200 5D Tactical Pro jig comes with massive 1.5" aluminum side plates with replaceable steel bushings. The price of the 5D Tactical Pro jig is comparable to the Easy Jig gen2 with their $30/pair stabilizers. So Easy Jig gen2 and 5D Tactical Pro are essentially the same with the caveat that you have to pay the extra $30 with the 5D Tactical Pro while you have the option with the Easy Jig gen2. The Modulus Arms has steel side plates but does not have the option of side plate drill stabilizers.


Universality: The Easy Jig gen2 works with every lower I have available to test it with. The Modulus jig works with everything I have tried except the Genesis CNC which I don't think is even made any more. The original 5D Tactical jig works with everything except the Hybrid-80 polymer lower and that would work with some slight modification. So in my opinion it's a draw here as well. I am updating this review on 11/11/17 which is the date the 5D Tactical Pro jig is released so I can't comment on how universal it is though I would expect it to be just as universal if not more.


AR-10/AR-308 compatibility: Here is where things get more interesting. All three companies offer AR-15 only jigs. Modulus Arms offers only separate jig systems so you would have to buy a complete AR-10 jig apart from their AR-15 jig. This would cost another $220 for a total of $390.


The original 5D Tactical jig system can convert from the AR-15 to the AR-308 with their conversion kit. This costs an additional $130 and can be added after the initial purchase of the AR-15 jig or at the same time bringing the total cost to $305. The just released 5D Tactical Pro jig costs $200 but you can get a conversion kit for $60. The conversion kit only adds $60 whether you buy it separately at a later date or at the same time as your AR-15 or AR-308 jig so the total here is $260.


The Easy Jig gen2 is also available in a dual AR-15/AR-308 configuration but this is a product that is separate from the AR-15 only Easy Jig gen2. The cost of this product is $240 which is $70 more than the AR-15 only jig. This makes it $65 cheaper than the original 5D Tactical dual receiver option but you have to know at the time of purchase that you want to do both receiver types. If you buy the AR-15 only Easy Jig gen2 and then later decide you want to do AR-308 receivers then you will have to buy the complete Easy Jig gen2 dual receiver system for another $240 (or go with another brand of AR-308 jig).


So if you know, or highly expect, that you want to do both AR-15 and AR-308 lowers the Easy Jig gen2 wins on price being $20 cheaper than the 5D Tactical Pro jig. If you're unsure or don't think you will do AR-308 lowers then the 5D Tactical Pro is better on price while still giving the option of upgrading to AR-308 capability at no cost penalty in the future. The Modulus Arms jig is the cheapest of the three if you definitely know you will never want to do an AR-308 lower but the most expensive if you change your mind.


Router compatibility: The Modulus Arms jig can use either a hand held router or a full-size router. The Easy Jig gen2 can use either as well but that system requires an adapter plate. The hand held router adapter plate comes with the jig but you can get an additional full-size adapter plate at the time of purchase for an additional $30 (I don't see it available as a separate purchase but it may be). The 5D Tactical Pro (or original) jig system does not work with full-size routers. If you already own a full size router but not a hand held router this may be an issue for you. If you will have to buy a router then the hand held router is going to be cheaper for comparable quality. I like full size routers for their extra power and stability (weight) but they also take longer to spin down once turned off which increases the wait time before you can adjust the depth of cut between milling passes.


Tooling cost: The Modulus Arms, like the Easy Jig gen1, uses a standard 1/4" end mill that they sell for $30 or in a tool kit for $45. The Easy Jig gen2 uses a proprietary 1/4" shank, 5/16" cutter end mill they sell for $40 or $50 in a tool kit. The original 5D Tactical also required use of 5D Tactical's 1/4" shank, 5/16"cutter end mill they sold for $40 or $50 in a tool kit. The new 5D Tactical Pro jig system uses a unique "ReadyMILL" which uses a replaceable 5/16" end mill inside a thermally fit tool holder. This tool holder threads directly to the router and replaces the collet. The ReadyMILL sells for $45 separately or $55 in a tool kit.


So the original 5D Tactical and 80% Arms end mill and tool kits are the same price. The Modulus jig is $5 cheaper for the tool kit and $10 cheaper for the end mill. However their end mill is not proprietary and can be ordered from various other sources which is a plus. The 5D Tactical Pro ReadyMILL is the most expensive by a small margin over the 80% Arms end mill but is justified considering the unique approach it takes.


Machining philosophy: The original and Pro 5D Tactical and Easy Jig gen2 both use a 5/16" end mill and only one pilot hole to mill the fire control group pocket. The Modulus jig uses many pre-drilled holes (eight (six if you have a pre-machined rear pocket) 3/8", one 19/64") to remove a lot of bulk from the fire control group pocket. This is the same basic idea used in the Easy Jig gen1. So you either have a lot less drilling or a lot more machining, and vice versa, with the 5D Tactical and Easy Jig gen2 systems depending on if you are a glass half full/empty person. Some like to pre-drill and remove a lot of bulk. It reduces the amount of milling with the router and they'd rather replace cheaper drill bits than expensive end mills. On the other hand it could be argued that the Modulus jig has a potential flaw because the spinning end mill shank makes physical contact with the jig. Theoretically that can cause deflection of the end mill if one is not careful when following the jig surface. It could also cause some wear between the end mill shank and the jig though I doubt this as both surfaces are steel. In practice I don't see any major difference in the final product regardless of which system is used.


Speed: I'll start off by saying the speed I can machine a lower means very little to me. If anything I'm more concerned with the amount of steps I have to take between tasks. So I suppose I don't mind how long it takes as long as there isn't a bunch of nonsense/wasted steps along the way.


The easiest jig to set up in terms of the router preparation is the Modulus Arms. It requires no adapter plate so you just tighten the end mill and you're ready to go. The other two jigs require use of an adapter plate. They are fairly similar but the original and Pro 5D Tactical may require an included adapter block in addition to the plate. It should also be noted that if you use your router for more than just machining lowers the setup and takedown time will be increased with the 5D Tactical jigs and the Easy Jig gen2 jig. This is because the router adapter plates need to be removed to use the router for other purposes and later re-aligned when used with the jig. The Modulus Arms jig only needs the collet to be loosened which is standard for any router activity.


The 5D Tactical jig milling is limited in area by use of three different pin pairs that screw into the adapter plate so that will be an additional step. The Easy Jig gen2 requires an adapter plate but no additional block or depth pin pairs. However the Easy Jig gen2 does have an alignment bushing to ensure the end mill is centered.


Initial jig assembly is simplest with the Easy Jig gen2 but just barely. All three jigs are quite efficient in their steps and there isn't a lot of difference here. Probably half a dozen screws one way or the other. To attach the side plates to the top plate takes four screws for the Easy Jig gen2, six for the original 5D Tactical, eight for the 5D Tactical Pro and four for the Modulus Arms.


The original and Pro 5D Tactical jigs and Modulus Arms jig require attachment of a "tower" (facilitates attachment of the receiver front) to the top plate (two screws) while the same type of piece is integral to the Easy Jig gen2.


The drill block requires four screws with the original 5D Tactical, two with the 5D Tactical Pro, only one with the Easy Jig gen2 and two with the Modulus Arms.


The rear of the jig requires two screws for the "buffer support" on the Easy Jig gen2 and the 5D Tactical Pro, two screws on the Modulus Arms but none on the original 5D Tactical. The rear of the receiver attaches to the jig by a large "screw" with the Easy Jig gen2 and 5D Tactical Pro, a buffer support disc and two screws with both the Modulus Arms and the original 5D Tactical jig.


The original 5D Tactical and the Easy Jig gen2 use quick release "cotterless hitch pins" to secure the jig through the rear takedown and front pivot pin holes. The 5D Tactical Pro jig only uses one "cotterless hitch pin" through the front pivot pin hole.

The Modulus Arms jig uses a long screw through the rear takedown hole and recommends assembling the front pivot pin to secure the front of the receiver (I purchased a cotterless hitch pin for my jig). The Easy Jig gen2, Modulus Arms and original 5D Tactical jigs use a long, full thread screw to stiffen the side plates. The 5D Tactical Pro jig does not use this long screw and I believe relies on the use of four top plate attachment screws to keep the side plates aligned and stable. The side plate stiffening screw is by far my least favorite part of any jig as it often gets aluminum shavings on it which can bind up in the side plate holes. They're also fully threaded which means you have to screw/unscrew for what seems like an eternity and every jig that uses them requires the screw to be removed/replaced when inserting/removing a lower.