Tag Archives: Trijicon

ACOG EREK

2016-10-23-15-10-34

I managed to purchase for my self an ACOG EREK cantilever adapter.

Now to be honest, I’m not exactly sure what EREK stands for.  I’m guessing something like Eye Relief Extension Kit.

So why did I buy it?  Because I wanted one.  Some time back, I saw some pictures of the USMC trying a cantilever mount for the ACOG on the M16A4.  Since them I have wanted to give it a try.

When you read about people complaining about the ACOG, the first complaint is always price, the second tends to be about the short unforgiving eye relief.  Once you take that short eye relief of the ACOG and have to mount a BUIS behind it, combined with a fixed stock, it can be annoying.  Personally, not only have I gotten used to it, I am rather fond of the ACOG mounted forward as I shoot nose to the charging handle.

So at some point the USMC had some adapters made up that moved the ACOG back and over the Knights 2-600m rear sight.  This makes the ACOG easier to use with the A2 fixed stock.  Now I tried to find pictures of it in use again, but I was unable too.  My guess is that the USMC tested it and for what ever reason decided not to use them.

Why?  I don’t know.  Perhaps raising the ACOG up make it more unacceptable to damage or abuse changing the zero.  It might not have been worth the cost.  Or someone might have come to their senses and said use the M4 instead.  In any event, I have one to use now, and it is rather nice.  It lifts the ACOG up enough that the charging handle is easily accessible, and moves the ACOG far enough back that you don’t need to crane your head forward for nose to the charging handle.

 

2016-10-23-15-10-45

 

RMR Glock first impressions

I recently had a Trijicon RMR mounted on a Glock 19c.  A full review will be posted later, so here are a few first impressions.

 

It will take some practice to get used to having an optic on a pistol.  If I bring the Glock up looking for the red dot I don’t see it.  If I bring it up looking for the sights, the dot is quickly visable.

The dot shows any errors in your trigger pull while your pulling the trigger.  This will make this setup an excellent practice gun, and might make it a good trainer pistol when teaching people how to shoot.

The Glock with RMR will still fit in some holsters with out modification.

I do not like having threaded holes in my Glock slide.  I think I would prefer is some sort of helicoil or similar insert was used to prevent possible damage to the threads in the slide.  Also one of the holes extends into the channel that the extractor spring/plunger runs though.

 

Having a red dot on a pistol is interesting, and I will be posting more about it after I get more trigger time with this setup.

Testing the 5.56mm MK318 MOD 0 / 5.56 SOST ammo

The 5.56 SOST  is the ammo currently being used by the USMC and other troops in the GWOT,  it has not been available for the public to buy for very long so I, like a lot of other people have been curious about how it performs. The round was designed to  have better terminal performance and accuracy from short barreled rifles with a muzzle velocity of 2925 fps from the 14.5 inch M4 barrel.  The round is a OTM,  this is important to remember as it is not the same as a hollow point.  It does however, offer up better performance and is barrier blind. The bullet itself has a thick copper base and a lead front end with the usual open tip that results from the process of making the bullet.  Also present are the rings seen around the bullet much like a barnes triple shock X.  A lot of people assumed and still do that the SOST is a barnes solid copper TSX, but it is not.

After getting my hands on some of the ammo I decided to test it for accuracy first. Since the ammo is intended for combat weapons, I chose to use my Colt 6940  with milspec barrel with 1/7 twist. I did put a Leupold 18x target scope on the carbine though so i could get all the accuracy out of it I could.  I fired 2 strings of 5 shots at 1 inch dots and one string of 10 shots of M855 to compare it to the common military load all at 100 yards. It was around 1100 AM , sunny with a  2 oclock 18 MPH wind.

Other then the normal 1st round flyer you usually get from hand cycling the action as opposed to letting the recoil operate and chamber  the next few rounds, the ammo showed some  great potential. The group on the left  was a little worse due to my own bad trigger work and lost concentration on one shot, but still pretty good considering. Now I know some claim  5 shot groups tell nothing, but if you over lay to  strings you get a pretty good idea  and you keep barrel heat down and mirage off the barrel messing with the scope.

After shooting the groups I decided to test out how the round matched the trajectory of the M855 since that is one of the things the SOST round was meant to have in common with the green tip. Out to 300and 400 yards  the SOST did match the BDC of my TA31F  ACOG and zero of other scopes and Aimpoint RDS I had on hand zeroed for the green tip. Also when comparing the position of the groups in relation to the aiming points, you can see on paper that the zero held very close for both rounds.

Now, the real surprise for me, was how good the lot of M855 I shot turned out to be!  Many gun board expurts and gun magazine expurtitions will gladly tell you how terrible green tip is in the accuracy department along with its many other flaws , makes it  slightly more useful then tits on a boar hog. After getting the carbine hot  after some drills using the SOST and playing around, I fired off 10 rounds fairly quickly  with the Colt/18x combo.  The results left me a little surprised, rarely have I seen green tip shot for accuracy  with sand bags, a table and a target scope further then 50 yards. And I do not recall having seen any pictures of it doing as well in a true 100 distance group.  I shot the green tip with all seriousness and the same concentrated effort I did with the SOST and the results were pleasing and a little surprising to me.  I have never taken the green tip seriously  enough for my own needs in the accuracy department so this will indeed lead to more testing of the M855 if for no other reason  then to see if this was a fluke.

Now I do not mean to sound like I think green tip is crap, I have seen some  good performance out of it at longer ranges on coyote size targets and even man sized targets. But on the other hand, I have seen some terrible accuracy from it too. Of course lots and different MGGs have as much to do with it as anything, not to metion the different shoots and the quality or lack of  in the guns used.

Back to the SOST, I think its a pretty good round from what I can tell. It is not MK 262 or TAP 75 gr. But for general issue to everyone, it is an iprovement in my humble opinion.  I have not shot anything living with it yet, but I will. Also, in the next few weeks I will test it though a few “barriers” like auto glass, wood, and wall paneling. Hopefully I will get to shoot through some auto doors as well.  I would not use it in my own house if over shooting is a issue, but I would use it for anything else at this point if you can find enough for SHTF bulk storing. And you have the benefit of practicing/training with M855 and still being able to shoot the SOST without a zero change. At this point I can not say it is better then any MK 262 top load in accuracy, but it is not meant to be, but, it is better then M193 by a long ways and it shows the ability to shoot a lot better the M855 and even if it just matches it in accuracy you still have the benefits of better terminal performance and barrier penetration while still holding together to hit the target behind if power point presentations can be believed. Hopefully my future testing will offer at least a tiny sample to help prove or disprove the new round.

Ranges Notes

Had a Colt 6920 with a Trijicon TA31-MRD ACOG and a Spikes 5.45 with a TA31-ECOS ACOG side by side at the range today.  Both were zeroed using the 300m point of aim at 25 meters.  Later that day, both were used to shoot at a steel target at 565 yards(about 500 meters).  The Colt using M855 ammo and the ACOG calibrated for that ammo was right on for elevation when using the 500m mark.  However when shooting at 500m with the 5.45 and an identical 5.56 Bullet Drop Chart reticle, the 5.45 corresponded to the 400 meter mark on the BDC.

It was interesting to see how much flatter the 5.45 was flying compared to the same zero at the M4.  I’ve never been able to find good data on the ballistic coefficient of the 5.45 7n6 rounds, or readable info on its trajectory.