September 06, 2022
OK, I don’t intend to impugn your manhood, but I have to ask a simple question: do you really need a suppressor that is full auto rated? Calm down, calm down, give me a moment and let me explain. A full-auto-rated suppressor is heavy. And it has to be, because even if you do not have a select-fire firearm to attach it to (and darned few of us do) you can still get it pretty hot. How hot? Hot enough to melt the Cordura fabric of your gun case in a few seconds. Hot enough to raise blisters on your hands or arms, should you brush up against one. Hot enough that even five minutes later you can’t handle it.
What is the weight penalty for this kind of performance? Well, let’s compare a similar suppressor to the one we are testing today. Today’s test suppressor is the SilencerCo Harvester EVO. It tips the scales at 10.8 ounces. A full-auto-rated silencer with similar capabilities from SilencerCo, the Omega 300, weighs 14.8 ounces. “Not so bad,” you say? Well, the weight may not seem like that much, but the performance comes with the price of the Omega 300 being made of titanium. Oh. So, a less-exotic materials silencer? The Chimera 300, at 15.7 ounces. We’re at half-again as much weight as the harvester EVO, so yes, weight matters. If you are a fan of SilencerCo suppressors, you are no doubt raising your hand and asking “What about the Saker ASR?” It doesn’t weigh as much as the other ones do.” You’re right. But, the list price on a Saker ASR is almost up with the others. The Saker is $900, the other full-auto-rated suppressors are nearly a grand.
All of a sudden, the $680 and the 10.8 ounces of the Harvester EVO is making it look better and better, compared to one that is full auto rated.
Then there’s the old backpacking adage: “Look after the ounces, and the pounds will take care of themselves.” If you are blind hunting, the weight of a silencer doesn’t really matter, as long as you can haul it and the rifle from the truck to the blind without being exhausted or having a heart attack. But if you are still hunting or hiking in the forests and mountains to find your quarry, then adding weight, especially to the end of the muzzle is not such a good idea. Adding more is worse. The cost-benefit ratio of taming muzzle blast, without adding too much weight, at the cost of not-full-auto-rated, starts to look a whole lot better.
Now that I’ve sold you on the imperative need to acquire a SilencerCo Harvester EVO, let’s see what it is and what it can do.
The Harvester EVO is an evolution of the Harvester 300. The 300 had a set of external baffles on the muzzle end, to be a recoil-reducing feature. It added length and weight, so SilencerCo took that off. They also shortened the EVO, and the end result is a silencer that is two-and-a-half inches shorter. By adjusting the assembly design and internals, they also managed to shave a full ounce off of the weight. The traditional way of making a silencer has been to take a seamless tube, stuff it full of baffles, (some designs welded the baffles in, others just made them a tight fit and packed in place) then weld on a front cap and some sort of mounting rear cap.
Well, that was then, and this is the 21st century. What SilencerCo does with the Harvester EVO is simple in concept, and devilish in execution. They make the baffles with side skirts, and then stack them and full-weld the edges of each baffle skirt to the next in the stack. They are proud of this (and should be) so they leave the welds there for you to see. This is hard enough to do, but they then make it even more difficult by using a mixture of materials in construction.
The blast baffle, the first one in line, and thus the one that takes the most, harshest, blast, is made of Cobalt 6. This is an alloy of mostly Cobalt (56% or so) with a large dollop of Chromium, and tungsten and carbon for strength and wear properties. It remains hard even at high temperatures and offers excellent erosion resistance. The core, the center of the baffle assembly is made of Inconel, a nickel-based alloy chosen for its ability to shrug off extreme high temperatures, while maintaining strength. The exterior, the welded sides and the mount section that you can see, are made of 17-4 stainless steel. This is a strong alloy, resistant to corrosion, and less expensive and easier to work with than exotic alloys.
So, you have the various parts made of the best alloys for the task, welded as a single unit, with yet another bonus: the base is machined for swappable mounts. The rear of the Harvester EVO is machined and threaded, and you can install a simple direct-thread mount cap there. The Harvester EVO that arrived here came with a pair of direct-thread caps, one for .30 (5/8x24) and .223 (1/2x28) so you can use it on either. SilencerCo also sent along a QD mount. To use that, you install the muzzle brake on your rifle, and make sure it is there securely. (That’s what the included Rocksett tube is for.) Then you can use the fast-pitch threads on the QD mount/muzzle brake to swap the Harvester EVO from one rifle to another.
I set the QD mount aside, as my host rifle for this project is set up for direct-thread suppressors, and I wasn’t looking to install a muzzle brake.
The rifle I used as the host is an old Remington 700, and it has been a test mule for a lot of projects. It has had a handful of scope mounts and scopes on it and has been in and out of a bunch of stocks, for this or that article. It has always been a good shooter. A long time ago, in a galaxy far, far away, I pulled the barrel and set the barrel shoulder back a couple of threads, lapped the lugs, faced the receiver, screwed the barrel back in and re-chambered it. So, Remington can’t take full credit for this accuracy level, but man they made a good barrel, and plugged it into this receiver. Some time after that, I had the muzzle threaded for a suppressor, for just this sort of testing. Some of you will wonder what the barrel nut is all about. The barrel is a lightweight profile and the resulting shoulder for suppressor was just on the small side, so we opted for an add-on shoulder nut to provide a big, square face for a suppressor to tighten to. Recently I went and dropped it into a Magpul stock, and all of a sudden it woke up and said “I’m here to shoot.” For this test it had the only scope available to be put on it, an old Trijicon 1-3X Wide, a scope I don’t think they have made for a couple of decades now. And with a mere 3X magnification, it shot like a house afire. On the one hand, I really should get it the scope it deserves. On the other hand, it is already a tack-driver as-is, with this scope, so why go and mess with a good thing?
The Magpul stock is their Hunter for the Short Action, since this is a .308 and not a .30-06. I opted for the detachable magazine version, and the chassis-bedding system of the Magpul is what this rifle likes.
Sound meter testing showed me pretty much what I expected. My test location produces sound signatures a couple of decibels higher (both before and during suppressed shots) that those SilencerCo registers. (My home range shows recorded levels a couple of dB higher with everyone’s suppressors, I just live with it.)
Since this phenomenon is an “every suppressor” thing for me, I just chalk it up to the range environment I have to work with, and that’s life. The Federal Gold match 168 grain OTM is always a really accurate round, but one-inch groups at 100 yards with a 3X scope, out of a lightweight rifle, is something to brag about. To no great surprise, the Harvester EVO did not shift group centers to any extent I could measure. It would take an absurd amount of group-shooting, both bare and with the Harvester EVO on (and remember, it has to cool between five-shot groups) to uncover a quarter-inch shift. That is, if the groups shift even that much. The groups seemed to be just a bit smaller with the Harvester EVO on, which is not unusual. Suppressors strip away the gases that can disturb the bullet’s flight near the muzzle, and this can improve accuracy. You have to have an accurate rifle/ammo combo to see it, because it is a small change.
Now, the .308 might not be the cartridge you’d select, should you be headed out to so some high-altitude hunting, with a lightweight, suppressed rifle. I’ll grant you that. But, it is the rifle I have to test with. SilencerCo lists the range as “.223 to .300 WIN” which is pretty inclusive. I asked, and yes, you can even go down to the 5.7x28, which is not surprising. However, do remember that this is a fully-welded, sealed suppressor. You do not want to be putting .22LR through the Harvester EVO, nor any non-jacketed bullets, of any caliber. If you gunk up the interior, there’s no way to properly clean it and restore its dB-reducing abilities. And while the Harvester EVO is rated for cartridges up to the .300 WinMag in performance, if you are going to be using something with a smaller bore, but not a larger case, you’re probably golden. 6.5 Creedmoor, I’m looking at you. If you have any doubts about a particular cartridge and its suitability, just ask SilencerCo. They’d be happy to answer, and you really want to know if your choice for a long-range hunting cartridge just might be too much.
Light weight, sound reduction, reasonable cost, there’s not much more you can ask of a suppressor than what the Harvester EVO delivers.
SilencerCo Harvester EVO Specifications
- Type: Multi-caliber silencer
- Barrel Length Restrictions: .223 16 in. minimum; .308 16 in. min.; .300M 20 in. min.
- Caliber: .223 to .300 WinMag
- Capacity: 5 rounds before cooling period
- Overall Length: 6.25 in.
- Diameter: 1.57 in.
- Weight: 10.8 oz
- Material: Cobalt 6, Inconel, 17-4 Stainless
- Construction: Unitized, fully-welded
- MSRP: $680
- Contact: SilencerCo.com; (801) 417-5384