In the last article I discussed lightening and modernising the old SPR build we have here. Graham from ACP Shooting (Sussex, England) kindly fitted the Rainier Evolution handguard.
Rainier Arms provided two muzzle brakes which were originally going to be used in a group test. As our SPR build was sporting a rather battered looking A2 flash hider I figured one of the brakes could find a home.
I have taken the rifle out on two allday shoots which saw around 500 rounds go through it. It has given some suprising results – I wasn’t really expecting improvements other than reduced weight and better feel.

Shoot 1 – Practical, Wales.


We made the trip to the Orion Firearms Training centre in Wales again. It is a few hours drive away but well worth it. The practical long range target set up they have is superb. Calibres up to .50BMG, targets out to 2000m and amazingly rugged scenery. The military often run excercises in the area and you can see why.. Miles of rocky hills and valleys in every direction.
Targetry is mixed – Steel plates, swingers, animal silhouettes, clays, skittles, a car and a boat in the middle of a pond! Shooting positions and scenarios are also diverse and include steep angles and some structures to shoot from. In short it is the Valhalla of practical rifle in the U.K.


I began at 200yds with the AR15 using GGG 5.56mm Nato. GGG (GIrates Ginkluotes Gamykla) are an Eastern European producer of Nato spec and match quality ammunition. I have been using there 5.56mm for a couple of years and found it to be reliable and well priced. It normally gives about 1.5-2moa accuracy in the GnZ AR.
It took 3 shots to find zero which started about 1 foot high right. I had expected a change after the barrel had been stuck in a vice and barrel nut and handguards swapped.


The gun felt a lot lighter up front which was the main aim of the new handguard. It also felt alot more comfortable to shoot. The slimmer front end sits in the hand very nicely. I took a few shots from the knee and then standing and it felt pretty good. It was certainly hitting ISPC shaped steels consistently central.

I then decided with everything working as it should be to remove the old A2 flash hider and replace it with a Rainier Arms Compensator. I had a few peel washers with me which was handy. I could not have generated enough torque to flatten the supplied crush washers without an action block and vice. “Timing” your muzzle device basically means screwing it on so that it is:

1. Facing the right way (follow manufacturers diagram).

2. Secure.

You do not want your muzzle device unscrewing as eventually a bullet may clip it and ruin a good piece of kit (not to mention safety implications).
It took a little trial and error, splitting peel washers to find the ideal thickness but pretty soon I had the device fitted. It looked the part but would it have any noticeable effect?

Rainier Arms Compensator in use.


I have heard a lot of derisory comments about muzzle devices being pointless for .223.. “There is no recoil.. Just man up” and so on.. Lets forget about ego and muscles and testosterone for a minute and consider some facts.
If a bullet flys out of your barrel then there is always going to be an opposing force – recoil. Some will be hardly noticeable (.22 rimfire for example) yet the recoil is still there. My concern is not with the recoil hurting my shoulder but its negative effects on accuracy. You can try to control the recoil – maintain a straight position behind it and absorb it to improve your accuracy or you can reduce its intensity. Surely a combination of the two methods is preferential when aiming to reduce variables?
As well as a possible negative impact on accuracy recoil can effect your ability to track your shot and the speed at which you can take another. In an ideal world you would keep the target in sight as the round strikes it and witness the impact or watch for splashes around it. If you are standing then that becomes quite hard even without recoil… Less is good in my mind..


The RAC is a a multi purpose device. The various openings are designed to redirect the escaping gases in order to reduce recoil/climb/flash. It is made of Stainless steel finished in either a black nitride of matte stainless. The barrel of this AR15 is so scratched up that either option would be passable!

The RAC is 2.3″ long and weighs 2.6oz, only a few grams more than the standard A2 birdcage (which does nothing to manage recoil).

The AR was immediately louder with the RAC in place. The guys shooting to my left and right moved away from me. While at a large range with multiple shooting positions available then this is fine. Shooting a braked rifle in cramped surroundings is pretty unpleasant and is banned in some venues.

The recoil was greatly reduced to the point I could stay on the target to watch hits and 100-200yds in the unsupported standing position. Standing and shooting off hand with no sling is pretty tough and if you are shooting at multiple targets then the ability to see your impact and move cleanly to the next target are paramount. The RAC made a big difference in terms of finding targets after each shot. The 5.56mm recoil may be small but it is enough to send your aim off when you want a quick follow up..
I also found the long range prone shots were a lot easier to scope. Shooting 4.2″ clay pigeons at 800yds requires that I see the splashes of missed shots. Thankfully I can easily and a few clays get dusted with the 77g SMKs.
The RAC muzzle device has definitely reduced recoil. As far as flash goes all I can say is that it was similar to the standard A2 flash hider and seemed fine to me.


One of the gang shooting down onto the water features.

The AR was a real joy to use and for the rest of the afternoon I used it for shooting down into the ponds across the valley. The ponds have floating targets as well as static steels. It really is fantastic fun to shoot down onto them as you immediately see where your misses are going due tothe splosh!

The RAC and Evo Hanguard were so far getting a huge thumbs up from me. Next it was onto the famous Bisley for some load testing to see if accuracy had been effected..



The Short Siberia Range at Bisley.

I met up with GnZ regular writer TurkishRaf and our good friend Sam. We all had some load testing to do so we made our way to the 100yd range (Short Siberia). I was keen to see how the AR was grouping after the barrel nut and handguard were changed. The AR used to shoot around 1moa (an inch at 100yds). Even with careful handloading I had been unable to achieve much better than just under an inch. To be fair most would be happy with that accuracy and I had found it to be fine for what I wanted. My real concern was that changes might make it worse.

The test loads were Sierra 77g SMKs and Ramshot TAC. I had rounds batched in 3s stepping up in .1g increments from 24g to 25g of TAC.


This time I decided to test the other Rainier Arms muzzle device – their Rainier arms minicomp 2.0. (also known as the RMC 2.0). The RMC is smaller and lighter than the standard A2 flash hider which fits very much with the ethos of these articles. I want to turn this heavy build into something that can be used comfortably from any position.


Sam and Raf were load testing either side of me. They would give me instant feedback if the side blast from the RMC was to vicious. I shoot 3 shot groups for load testing. I find that three shots keep me concentrating and I have less tendency to daydream and pull one.. I keep my shooting paced at around 1.5 minutes per shot to try and avoid the barrel heating up and effecting accuracy. Sure in the real world of a competition you don’t have that luxury but it is important with load testing to remove all possible variables except the powder weight.


Looks cool but will it give my shooting buddies a headache?

The first 2 groups were around 1MOA which is great for a standard AR15. The recoil was hardly noticeable with the RMC and a snug prone position (bipod up front). The guys didn’t yell at me so the side blast was ok. In comparison to the RAC the RMC 2.0 provides around the same level of recoil mitigation but with less side blast. The muzzle flash was a little more noticeable but that is not something that concerns sports shooters like us. The RMC also looks the coolest – it has a angular spiky front end. Beware though that spiky front end can rip your expensive rifle bag if your not careful. My rifle bag cost £30 from an airsoft stall at a market so I am not bothered! It looked like the RMC 2.0 would be staying on… Until the group test happens at least…


The groups kept getting better. Between 24.7gn of TAC and 25gn the groups were all below .5MOA. The 25gn group actually measure .484 of an inch from edge to edge. That is excellent accuracy from an AR15 running a mil contour DPMS barrel. I had previously run these loads with the old quad rail in place and achieved no where near this level of precision. Why the change?


It could be multiple factors. Graham at ACP shooting had to remove the old barrel nut and put a new one on. This may have effected the barrels harmonics. A more likely effect to the harmonics is probably the handguard itself. Equally possible is that the muzzle devices effect harmonics – I would bet that they remove some of the whip that can be seen on a barrel in slow motion video. Whatever it was it seems that Grahams handywork combined with a couple of excellent Rainier Arms products produced very pleasing results.


Next time I will be swapping out the old (and heavy) scope mounts for a lighter single piece mount from The mount features a quick release system and 20MOA of built in elevation and so far looks to be fantastic. I will leave a picture below as a taster.



Thanks again to Graham and Steve at ACP Shooting –

Rainier Arms –

Orion Firearms Training –

Bisley National Shooting Centre –