Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
Armory Sponsor
2/22/2025 1:25:50 PM EDT
[Last Edit: prebans][Edited]
The stamp cleared last October and it has just sat in the safe since.  Been too busy putting out fires and handling massive headaches.  Finally coming up on time to do some shooting.

Beyond a good headspace and timing gauge and knowing how to use it, any advice?  Spares to get?  Stuff/tools to have along?  (Shooting places are easily a 6+ hour drive from home.)

EDIT: I guess I should have added what I already have and explain that the gun was disassembled for weight and size while in storage.  I have half a dozen barrels, the internals, a ground mount, T&E, a motorized linker, 10k linked rounds, and probably 20-25,000 spare links, two field manuals, three technical manuals, and two well-used headspace and timing gauges.

“Don't post anything here or send anything you aren't willing to defend in court.”

-Notcalifornialegal
2/22/2025 1:37:41 PM EDT
[#1]
A linker, maybe a barrel lol
Silent Brigade 1-20-20
2/22/2025 1:44:20 PM EDT
[#2]
Get a military TM for the weapon and make sure you thoroughly understand headspace and timing. On a 50 caliber improper headspace and timing can kill you.

I say this one more time and improperly headspace 50 caliber machine gun can kill you.
2/22/2025 4:24:24 PM EDT
[#3]
As a new M2HB owner as well I would also concur you absolutely need a headspace and timing gauge in order set the gun up to be safely fired.  I would actually get two so if one goes missing at the range you always have a spare.

There are a bunch of manuals and videos online as to how the headspace and timing procedure should be done.  IMHO its not a super complicated or difficult process but does need to be done correctly.   Personally I would practice a few times at home so it becomes a bit second nature before trying to do it at the range the first time.

I don't know what you have or don't have but based off the picture you are going to need a barrel,  a tripod, and ideally a T&E.   I personally find the MK93 soft mount a really great addition as you don't have to sandbag the front leg of the tripod to keep the gun from jumping around when firing.    The MK93 also brings the gun height up a little more as well to make it easier to shoot.  You will need ammo and links as well.  Maybe invest in a linker and it pretty tiring linking 50BMG by hand. (I was fortunate as a AR15 member and former M2HB owner gave me a WW2 vintage linker for free)

I actually found this chair on amazon that works great for not sitting in the dirt but still keeps you low enough to shoot the gun and look through the sights.

https://www.amazon.com/dp/B0CJJH626L?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2&th=1

Another thing I found lacking on the M2HB are the sights.  At the distance you are usually shooting that gun at, the sights are not ideal and the front sight blade is wide enough to almost completely cover even large steel targets 250+ yards downrange.  There really isn't much in terms of optics for this gun other than the Trijicon MGRS  and its nuclear expensive at 5+ grand.  The MGRS flip to the side magnifier is only 3x and has like ~2" of eye relief so is sort of worthless.   I am actually working to make a custom magnified and red dot optic combo out of a NSN  855-01-045-5482 mount.  Once I am done I can report back how well it works.

Another new challenge for me was actually getting commensurate targets that will hold up against a M2HB.   I bought this steel target below from make-it-ring targets that has worked pretty well.  The plate weights right about 100lbs so it will lightly swap back and forth with a burst from the M2 vs. violently flipping and twisting break chains and/or the stand.

https://makeitringtargets.com/products/ols/products/34-ar500-24-50-bmg-steel-target-gong


I have not bought much in terms of spare parts other than recoil springs. The gun and parts are massive so I don't really expect much to break.  I do plan to probably pick up a spare bolt group, a spare extractor, and another stellite lined barrel at some point in the future but that is probably going to be about it.  The good news is the world has plenty of M2HB parts and its still in production so I will probably just replace stuff if/when it breaks.  Right now most of my M2HB investment dollars are going into slowly piling up a 50BMG ammo inventory with the goal to keep around 2500 rounds on hand.

If I can think of anything else I will update the post.
2/22/2025 4:26:59 PM EDT
[#4]
Originally Posted By 18B30:
Get a military TM for the weapon and make sure you thoroughly understand headspace and timing. On a 50 caliber improper headspace and timing can kill you.

I say this one more time and improperly headspace 50 caliber machine gun can kill you.
View Quote


THIS! Good headspace and timing gauges and practice.

I am assuming you have a tripod and all that.

Good mitts/gloves to change the barrel and something to sit the hot barrel on at the range.

Good earplugs and muffs type hearing protection with gel cups. Don't turn your head while firing and break the seal it sucks.

2/22/2025 4:38:30 PM EDT
[Last Edit: prebans][Edited] [#5]
Thank you, all.  I should have posted that I’ve got around half a dozen barrels, all internals, a ground mount, T&E, a motorized linker, 10k linked rounds, and probably 20-25,000 spare links.  They’re just not pictured.  The gun was stripped for weight and size while in storage which is why it’s just a receiver here.

I also have these five manuals which came with the gun:

TM9-1005-213-10 (small July 1968)
TM9-1005-213-25 (full size July 1968)
Operator’s manual (small August 1992)
FM 23-65 (full size May 1972)
FM 3-22.65 (full size March 2005)

It came with two headspace and timing gauges.  One headspace is fatter and one is thinner.  Both show signs of wear and discoloration, so I’m buying a few more.  (“Two is one and one is none.”)

@18B30 - Thank you!  The old owner actually adjusted both “by feel” without a gauge.  Based on what little I know, I’m surprised he didn’t injure or kill himself in doing so.  But apparently he was that good of a judge.  The gun is also in spec (had it checked).  I don’t have his skill, so there’s no way I’m doing it without gauges.

@jbntex - And thank you too!  I absolutely appreciate all of your information.  I’ll order one of those chairs.  Wish they had desert camo because I most often shoot fun stuff in AZ.  Any of those colors work here in WI, but down there I want as light colored as possible.  Still better than sitting on an ammo can though.  The MGRS sight looks great but makes a Hellfighter with a mount seem cheap!  Please let me know what you learn as you continue experimenting.  Targets (at least in AZ) usually aren’t too hard to find in the desert.  Someone always abandons a junk car or water heater somewhere.  I worked at a truck stop and terminal as a teen.  A junked semi truck brake drum jumps out at me.  That target you linked isn’t as bad as a MGRS, but an old brake drum with a piece of scrap welded across the center would be cheap and fun.  (Our version of skipping tin cans with a .22?)

@machinegunseabee - Solid points.  I’ll grab some heat-resistant gloves and cobble up a portable hot barrel stand.
“Don't post anything here or send anything you aren't willing to defend in court.”

-Notcalifornialegal
2/24/2025 8:19:39 PM EDT
[#6]
Get a mount and use a regular RDS.

The irons are ok but it's nice to have a red dot sitting up higher.
"Governments may think and say as they like, but force cannot be eliminated, and it is the only real and unanswerable power."
-- Lieutenant General Sir Adrian Carton de Wiart
2/24/2025 11:10:36 PM EDT
[#7]
When I got my M2 more than 20 years ago, I got advice to buy a VHS copy of the Alabama Arms video on the M2.  Fortunately, it can be found on YouTube.  It is very well done and tells you everything you need to know on how to setup your M2 for firing.

Besides the headspace-timing gauges, I would bring a ruptured case extractor.  I’ve bought commercially reloaded ammo where the used brass cases succumbed to case head separations.  Parts of the brass remained stuck in the barrel.  Just bring a spare barrel in case you can’t get it out.

If not using an M3 mount, bring some sandbags to stabilize your mount.  My M63 AA mount will dig it’s front legs into the dirt with the rear legs popping up.  

Good luck, stay safe, have fun and post the videos here.
2/25/2025 12:15:46 AM EDT
[#8]
There are a couple of red dot mounts on 1919a4 right now for cheap
2/26/2025 10:03:29 AM EDT
[#9]
Quote History
Originally Posted By M-203:
When I got my M2 more than 20 years ago, I got advice to buy a VHS copy of the Alabama Arms video on the M2.  Fortunately, it can be found on YouTube.  It is very well done and tells you everything you need to know on how to setup your M2 for firing.

Besides the headspace-timing gauges, I would bring a ruptured case extractor.  I’ve bought commercially reloaded ammo where the used brass cases succumbed to case head separations.  Parts of the brass remained stuck in the barrel.  Just bring a spare barrel in case you can’t get it out.

If not using an M3 mount, bring some sandbags to stabilize your mount.  My M63 AA mount will dig it’s front legs into the dirt with the rear legs popping up.  

Good luck, stay safe, have fun and post the videos here.
View Quote


@m-203

Thank you!  Did a bunch of searching and couldn’t find that video.  Is it on YouTube under a different title?
“Don't post anything here or send anything you aren't willing to defend in court.”

-Notcalifornialegal
2/26/2025 10:03:49 AM EDT
[#10]
Quote History
Originally Posted By SGT-Fish:
There are a couple of red dot mounts on 1919a4 right now for cheap
View Quote


Looks like someone just snagged the complete one.
“Don't post anything here or send anything you aren't willing to defend in court.”

-Notcalifornialegal
2/28/2025 7:14:57 PM EDT
[#11]
Looks like you have everything you need. So an Eotech or trijicon red dot sight, maybe a thermal, and the surefire hellfighter light is pretty awesome. You can usually get em cheap on eBay. I bought mine for $400.00 and it came with mount and cables but no IR filter. I’ve seen em as high as $1,200.00
3/4/2025 9:46:51 PM EDT
[#12]
Apparently it is not there anymore.  I have the original VHS tape that my brother converted to DVD format.  I am sure I can convert that into an Mpeg4 file.

But can anyone suggest how to post and share that file outside of using Youtube?
3/5/2025 9:16:29 PM EDT
[#13]
I know you may not want to do you tube, but it is the best

the volume of views would be so low i would not worry.

if not try drop box and have a link for here only.
3/6/2025 10:55:28 AM EDT
[Last Edit: jbntex][Edited] [#14]
This is my first attempt at an improved "recreational shooter" M2HB sighting system beyond the standard iron sights that come with the gun.  

I wanted a magnified optic for dialing in longer shots as well as a red dot for closer work or just watching the rounds in full auto go downrange and impact the target (once set up on target using the magnified optic).  

My wish list for this setup was:

1. Setup that would raise the sighting system up a bit more as its tough to look through the iron sights and shoot the gun when on an M3 tripod even when using a MK93 soft mount that also raises the gun up.
2. Variable magnification scope, with bright illumination, and with huge eye relief so I can shoot it with my arms extended off the spade grips like normal and not squish my face up to the scope.
3. Red dot for shooting closer shots or shooting auto once dialed in using the magnified optic.  
4. Have the red dot positioned so I could just shift my head to switch  between the scope and red dot.
5. Still being able to use the iron sights if I need or want to.
6. A mount that can control elevation adjustment on both optics at the same time as I didn't want to be dialing in elevation on both optics every time I wanted to change distance.
7.  Mount that comes on and off easy for storage and transport.
8.  A price point significantly cheaper than the MGRS + Magnifier which is over$6K.

I started off buying one of the surplus military M2 optic mounts (NSN  855-01-045-5482).

I then added a variable 2x7 magnified scope.   I had seen folks add magnified optics to M2s before and the MGRS also has a flip to side magnifier as well but most all of these solutions have an eye relief measured in a couple inches at best.   The idea of putting my face a couple inches away from a scope or magnifier tube on an M2, especially an M2 in a softmount where the gun moves back and forth wasn't super appealing.   So I went looking for a magnified optic that had much longer eye relief which ultimately led to me to the extremely small variable power handgun and scout rifle optic segment.  

On the market today there appears to be exactly one variable power magnified optic/scope, with extended eye relief (12+ inches), and an illuminated reticle.  

The not great news is that its made in China and is a Leapers brand scope, glass quality is about what you would expect on an inexpensive chinese made scope, and its a 1" tube so your ring/mounting choices are limited.  

The positive side is the scope is cheap (~$200), its variable 2x to 7x, the illumination is really strong, the eye relief is huge at 20" so you can see through it in a normal M2 on spade grip shooting position.   The optic was at least theoretically designed to be placed on top of some magnum revolver, so I can only hope the correspondingly more gentle recoil of an M2 in a MK93 soft mount is nothing compared to being mounted on some Smith & Wesson 500 hand cannon.  Long term durability is a question....but they are cheap so if it dies after a couple years its not a huge deal to buy another one.

The red dot I wanted mounted above the magnified optic in a piggyback style configuration so I could easily  shift my head/view between the two optics.  This arrangement meant that a traditional large format red dot like a EOTech wouldn't really work.  However there is a relatively new RMR footprint red dot with a huge window made by Cyelee.   Again the bad news...its a chinese red dot optic, and aesthetically its a bit of an odd duck.   The good news is its also cheap (~$250), its designed to go on top of a handgun slide so hopefully its tough enough for this application.   Also nice points is it  has a variable reticle type (dot, circle, or dot in circle) and the "dot" is also small at 2 MOA where a lot of the RMR type red dot optics have 4+ MOA dots which for 200+ yard shooting itsn't ideal.

The nice thing about the mount is that once its zeroed the mount itself has a built in MOA adjustment mechanism, so once zeroed at 200 yards I can use the mount itself to adjust the elevation out farther without having to mess with the optics themselves and since the mount is making the adjustment both optics will move/adjust together. The irons are also still totally useable and the whole mount goes on and off the gun with a couple levers making storage and transport a breeze.

Anyway this is roughly how it turned out.  I have not had a chance to shoot it yet and won't for a couple months until I can get back to my alternate range that allows M2s.   I think I have about ~$700 in the whole setup and at least sitting behind it in my workshop looking out the door seems to do what I wanted.

Everything was off the shelf parts with the exception of the rings which needed two more picatinny slots milled. The only 1" rings I could find with a piggyback pic rail option on top showed up with only one slot (where the online pictures showed three slots)

View from the side:



Side by side view through both optics:


8/8/2025 11:11:42 AM EDT
[#15]
You want your headspace to be Zero. Used brass will will stretch and have case head separations.

How do you set head space to zero?

Set headspace the normal way. This is about .006 inches. Gun will work with headspace of .012 to .000 inches. Long headspace will cause more case cracks and case head separations.

Turn the barrel in another 2 clicks. each click is about .003 inches. Hence zero headspace. Recheck timing because timing and headspace interact slightly.
8/8/2025 11:59:27 AM EDT
[#16]
PM inbound.
Seriously, a tractor dealer from Possum Trot, KY has to explain this to you, a lawyer? - JPL

WTB: Glock 17 gen 2. SN CAF 895

Win if you can, lose if you must, but always look good for the crowd.
2/7/2026 6:54:23 PM EDT
[#17]
OST
2/8/2026 11:52:34 AM EDT
[#18]
Quote History
Originally Posted By pevrs114:
OST
View Quote


Thank you for this.  I keep forgetting to find this thread to contact a few people and to review what was recommended here.

A number of large personal and business headaches resolved, or at least resolved as much as they can be.  It’s time to have some fun again.  
“Don't post anything here or send anything you aren't willing to defend in court.”

-Notcalifornialegal

Sign up to continue the discussion

Create a free account to share your thoughts, follow topics, and connect with the AR15.COM community.

Already a member? Sign In

Armory Sponsor