OLD Bullpup – Bushmaster M17s with MAC

I have sold few firearms that I own, but I only regret selling one, a Bushmaster M17s bullpup rifle. As such, Military Arms Channel decided it best to hit me where it hurts and highlight his own rifle (just kidding, I don’t think MAC would do that to me).

The rifle has an interesting history that involves some interesting characters like Charles St. George of modern .50 BMG bullpup fame (which many would recognize as being externally similar to the 5.56 rifle cousin. Ultimately the result of the Australian army’s search for a new rifle where the ended up with the AUG, the weapon hopped through a few companies before ultimately ending up with Bushmaster in the United States.

Internally, the weapon is very similar to the AR-180, using a AR-style rotating bolt. It is further a short-stroke gas piston operation, driving the bolt carrier back on two rails with two recoil springs, one on each rail. It uses a few AR parts like the magazine catch, but is predominantly a proprietary platform.

Parts diagram courtesy of K&M Arms.

Parts diagram courtesy of K&M Arms.

The Bushmaster M17s is not made anymore, but fortunately they are still available on the used market. Recently, K&M arms has been making a revival of the platform with their modernized version of the weapon the M17S556 and the big-bore cousin the M17S308. For those who love the original, K&M arms will machine various patterns and even has a new lower receiver with a vastly improved trigger compatible with the old extrusions.

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • Ron

    I had one in the 90s, it would randomly fire bursts on the pull of the trigger

  • I never could get over the damn ugly extruded aluminum receiver. It looked to me like it was stolen from some shower door or 60s shelving unit manufacturer. i had no idea it competed against the AUG for the Aussie rifle contract. Compared to the AUG the finished/ergonomics design elements is not even in the same century of design. The Aussies have always been known though for designing strange unpolished designs for the market, just look at the leader guns, not too bad of a design but not very pretty.

    • Edeco

      It’s a pleasant look for me. Makes me think above ground pool, truck running boards, chalk holder for a chalk board*, other middle-class family-oriented 70’s stuff. Not that I was in that zeitgetst myself. Ah, feels trip.

      *primitive form of whiteboard that relied on grinding minerals together to firm crude pictograms.

  • MPWS

    Anyone with ambition to design BP is first bound to study human body before even knowing gun dynamics. Here is case in point.
    Look at the angle between forearm and hand – this is unnatural position. Besides, pistol grip being at such radical angle further restricts space between it and magazine. This is in addition impossible to use by LH shooter. Next thing is hot aluminum receiver against face…. and list goes on. but it is ‘zechsy’, that’s for sure.
    In my view AUG is unsurpassed to this day, but for minor penalty – it is rather bulky. So at the end you need to ask yourself: is it worth of struggle? Not in my mind.

  • borekfk

    I once saw a used one for $450. Kicking myself for not picking it up.

  • Machinegunnertim

    I have 3 of them and they are fun for modification. Bushmaster should have further evolved the design. But like the AR180b it was a good concept that was squandered by it’s company.
    As well the quality of the parts was not the best. Screws rust badly, a trigger connecting rod snapped on me a few months ago, i doubt the barrels are chrome lined and there is probably more. K&M’s new M17s is close to what bushy should have done with it.

    I do like the fact that I get a 20 inch barrel in such a short package, that way I get the most out of expensive hunting rounds should i go hog or predator hunting with it.

  • Drew Wood

    m17s is a fun rifle. one point MAC missed is that the barrel is held in tension! very very accurate rifle with its 21″ barrel. balances well, but it is a heavy rifle. included iron sights are worse than most defensive pistols. the forearm getting hot from firing is a very big problem for range day and buddies. that long trigger linkage makes for a mushy trigger.

    i modded mine with a k&m double sided charging handle and hk g36 style rail and bottom pictainny rail for a foregrip before i sold it. it was a fun project gun. i’ve never seen another production gun use the tensioned barrel.