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50 Kinks!


Tips and tricks to improving your .50

This page details improvements that can be made to / with your .50. I'll post anyone's 'kinks' (if they seem reasonable.) The ones I generate will generally be for the EDM Windrunner 96 - Some may apply to other guns, and hopefully I'll pick up enough other kinks to make this page useful to more than Windrunner owners.

The term 'kinks' in this context is patterned after the excellent 'Gunsmith Kinks' series produced by Brownell's. Consider this the missing .50 BMG chapter... Some kinks may require machining or similar work. It is assumed that you will hire somebody competent if you're not 100% capable of performing the work involved. I'd be happy to answer questions you may have, if I'm able, but I can't accept liability for any of YOUR actions.

Upgrading the Muzzle Brake
Bipod improvements
Stiffening the stock
Monopod improvements
Trigger replacement

Upgrading your muzzle brake

Probably half of the .50 BMG's sold come with a pretty crummy muzzle brake. By crummy, I mean one that does not reduce recoil sufficiently, or reduces accuracy. I'll leave it to you to decide if your brake needs replacing, but I replaced the stock brake on my Windrunner with an Armalite brake, which dramatically reduced recoil, and here's how it went:

There are essentially two ways to install the Armalite brake: with and without the 'cinch nut' (my terminology) they include. I think 'without' is a better solution if it can work for you, so the first step is to screw the brake onto your rifle barrel and see if it can screw down hand-tight, or if you run out of threaded length in the brake. If you run out of threaded length you'll have to use the nut...

Installation with the nut

Using the nut is easier, but in my opinion inferior.
  • Remove the old brake
  • Screw on the nut, all the way - but don't tighten
  • Screw on the brake, all the way - but don't tighten
  • Back the brake off until it's level with the gun - see the section on installation without the nut for some more details on levelling.
  • Turn the nut 'back' so it tightens against the brake - snug without disturbing brake alignment.
  • Swear at not having spanner wrench to tighten Armalite 'cinch nut'
  • Drive to specialty hardware store and purchase spanner wrench.
  • Tighten nut firmly - a little loctite might be good, depending on whether you like to take the brake off for cleaning or not. (I don't).
  • Swear at the 'ears' on the brake that interfere with the spanner wrench.
  • Decide installation without the nut might be the superior method after all...

    • Installation without the 'cinch nut'

  • Remove the old brake
  • Screw the new brake all the way on.
  • Back the brake off until it is level. - The easiest way to determine 'level' is to have a level on your scope, or scope mount (you do have a level on your scope or scope mount, don't you?) and another level on your brake. Set your rifle up in a cleaning cradle, workstand, sandbags, or what have you and set the receiver & scope level. Now check for level on the brake - when both are level you're set. This is where you want to end up.

    • It doesn't look level in the photo, because the camera was at an angle, but it is!!

  • Once the brake is perfectly level, a tiny witness mark scribed on the barrel and brake will help you line everything up again without much fuss.
  • Try shimstock 'washers' until you find a stack-up that fits. Brass shimstock can be cut with scissors, but Greenlee punches will make a real pro-job of it. Brass is nice because it will compress a bit, giving you extra tolerance. Find the stack up that will level your brake with moderate hand-tightening.
  • I like loctite...

    • Bipod Improvements

    Windrunner bipod is too far to the rear!

    Problem: The bipod on the windrunner is mounted too far to the rear. While this makes it break down into a 'small' (for a .50) package - it is not the most conducive arrangement to accurate shooting. (The windrunner isn't any less accurate, but the shooter will be!) Why? Well, the bipod is the pivot point when you're shooting. If the bipod is close to the stock, small disturbances at the stock cause large disturbances at the muzzle. If the bipod is close to the muzzle, small disturbances at the stock, cause even smaller disturbances at the muzzle.

    Solution A bipod mount extender! The bipod on the windrunner attaches to a 0.716" 'stub', with a 3/8"-16 button-head cap screw. Starting with a piece of 1" dia. 303 Stainless, I turned an end to 0.716" diameter for a length of one inch. I then drilled and tapped it 1" deep 3/8"-16. This readily handled the bipod, just as the factory stub had.

    You may notice that turning the rod down to 0.716" for a full inch is longer than is needed - That's to leave a little material for bipod modification #2 (coming!).


    My first stab at the mounting end, was to make the extender attach to the existing 'stub'. I bored the opposite end of the bar 0.716" diameter for 3/4", then drilled and tapped 3/8"-16 for another 1.25". Having done that I used a length of 3/8"-16 threaded rod (about 2") and mated the two. The solution was almost satisfactory, and gave me insight into the changes at hand. Whereas the Windrunner had been front-heavy, it was now rear-heavy. Virtually the entire weight was applied at the stock end. This could result in much greater stability, but more weight to move around with the monopod, or a sandbag. There was still a little too much springiness, so I decided to remove the original Windrunner stub, and make my extender fit that.

    I'd been hesitant to remove the factory bipod stub, because it was roll-pinned in place. Having concluded that the first mounting scheme was a no-go, I went for it. I knocked the roll-pin out and much to my surprise (and pleasure) the factory stub was threaded in!
    Here's the factory stub removed, with the first concept shown half-attached.

    The threaded section is 0.9" long, threaded 5/8"-18. The rear 0.125" is relieved to 0.525" diameter for the threading tool. I sawed off ~2" from my old set and threaded the end of the bipod extender the same way.

    This version worked like a champ! Locked up solid, without bounce. The finished extender is about 22" long. Someday I'll get around to putting a finish on it...


    NEXT: allowing some swivel in the bipod without unscrewing or tightening it!

    Stock Improvements

    NEXT: Stiffening the stock.

    Monopod Improvements

    There are a couple improvements that can be made to the Windrunner monopod. The first is installing it correctly. There is a 'front' and a 'back' to the Windrunner monopod. The 'back' (toward the shooter) is flat, where the 'front' is rounded. If the assembly is reversed the monopod doesn't sink into the cavity in the stock that was meant to accomodate it. This results in a wobbly monopod and marring of the stock.
    Having the monopod installed properly dramatically improves its stability!

    NEXT: preventing the monopod from 'walking' the rifle while adjusting elevation!