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Today, we’re shooting the Umarex Primal 20 big bore airgun. It’s an air rifle – or if required – an air shotgun. All you do is use different ammunition and change the barrel’s choke.
We covered most physical and operational details of the Primal 20 in this previous Hard Air Magazine post. So this time, we’ll concentrate on the shooting experience…
As a reminder, the Primal is a 20 Gauge PCP which – in its shipping configuration – is a .625-Inch caliber big bore hunting rifle. It shoots dedicated 395 Grain pointed sabot slugs from a two-shot magazine.
At 44.25 Inches long, the Primal is a large air rifle. Fitted with the Sightron S-TAC scope, the rig weighed-in at 11 Lbs 5 Oz. So it’s heavy, too.
That HPA tube up-front makes it very muzzle heavy for sure. Although some folk will like that, it’s definitely “un-shotgun like”.
Shooting The Umarex Primal 20 Big Bore As An Air Rifle
So far, the only solid ammo available for the Primal 20 is the Umarex 20 Gauge sabot slugs. In fact, they’re special 395-Grain 20 gauge slugs that are fitted with a plastic “wad” that acts as the seal within the barrel.
The combination of this unique slug and the Invector choke installed in the Primal’s barrel is claimed by the manufacturer to give excellent accuracy downrange. As you’ll see here, our testing confirmed that.
Given the two-shot magazine of the Primal, we fired a group of four shots at the HAM Soda Can target at 30 Yards range. Two shots were fired, then the magazine re-filled, the gun topped-up with High Pressure Air and two more shots fired from a rested bench position.
HAM Tester Doug Wall made a pretty good attempt at a one-hole group. We were very satisfied with that level of accuracy. Great shooting, Doug!
Based on the amount of air required to re-fill the Primal back to its full 4,000 PSI fill pressure, the gun was using about 500 PSI of high pressure air per shot.
As the Primal in not regulated, there is obviously a difference in energy between the first and second shots. The average Muzzle Velocity of our “Shot Ones” was 765 FPS, that equates to a Muzzle Energy of 513 Ft/Lbs.
The “Shot Twos” gave an average Muzzle Velocity of 738 FPS. That represents 478 Ft/Lbs.
In both cases, the Standard Deviation was very low at 3.13 FPS.
If we aggregate the “Shot Ones” and “Shot Twos”, the average Muzzle Velocity delivered by the Primal in HAM testing was 752 FPS for an average Muzzle Energy of 496 Ft/Lbs and an overall Standard Deviation of 14.4 FPS.
It should be noted that the velocity of all the “Shot Ones” and “Shot Twos” fired in this HAM test review far exceeded Umarex’s claims for the Primal 20.
The manufacturer’s claim is 700 FPS and 430 Ft/Lbs of Muzzle Energy. So, the 513 Ft/Lbs Muzzle Energy of our “Shot Ones” exceeded the claim by no less than 28%!!!
By using Labradar to track the slugs’ velocity, we found the average velocity to drop from 752 FPS at the muzzle to 667 FPS at 30 Yards.
That still represents a very healthy 390 Ft/Lbs of energy hitting the target at 30 Yards.
Given the curious shape of the Primal 20 slugs, I calculated the Ballistic Coefficient using both the GA and G1 models. In fact, it didn’t make much difference as the HAM test data gave a BC of 0.029 using the GA model and 0.030 with the G1 model.
Shooting The Umarex Primal 20 Big Bore Air Rifle
With that 11 Lbs 5 Oz weight, it came as no surprise to find that the Primal is a handful to shoot! This is a big, heavy gun that requires a strong shooter to fire it without a rest.
Filling with 393 cc of 4,000 PSI High Pressure Air was easy using a small portable compressor. The standard “Foster-type” 1/8-Inch quick disconnect was ideal.
Another good operational feature is the side-facing tube pressure gauge. No “looking down the barrel” to check pressure here!
However, it’s fortunate that most users will base their fill pressures on the larger gauge of the compressor or tank – rather than on the gun’s built-in gauge (as we did). The Primal’s gauge is small (16 mm diameter) and has a very limited angle of sweep for the indicator needle. So it’s really tough to read accurately.
More worryingly, the gauge shows the red “full pressure” indication at 4,500 PSI, not 4,000 PSI as specified. Given the +/- 10% accuracy of such gauges, inadvertent filling to the red line could actually cause a 4,950 PSI fill of HPA which might activate the 5K burst disk opposite the gauge.
Yes, all the accompanying documentation stresses that 4,000 PSI is the maximum fill pressure. But there is a clear need here for a larger pressure gauge with more angular sweep and an appropriate face plate.
Cocking the Primal requires a firm tug on the large, knurled cocking handle against the pressure of a strong hammer spring.
Once cocked, the handle is caught by a not overly-distinct catch. It stays back until flying forward when the trigger is pulled and the gun fires. So the position of the cocking handle very clearly indicates if the gun is cocked, or not.
You’ll want the cocking handle to be set on the opposite side of the action to where your cheek rests. Fortunately, this is very easy to do.
As for noise level, you guessed it. Don’t shoot this baby without ear defenders in place. It’s LOUD!
Recoil was probably best described as “stout”. But again, we were expecting this. There’s no way that a PCP air rifle generating over 500 Ft/Lbs on Muzzle Energy is going to be light on your shoulder!
Fortunately, the Primal has a very substantial rubber buttpad to help absorb some of the kick.
The trigger has a single-stage, rather heavy pull. This is definitely NOT a “target” trigger, but is OK for a big bore hunting gun. “Creepy, not crisp” is how Doug Wall described it.
There’s a manual, push across, trigger-block safety that worked well for us.
The two-shot, “slide across” magazine uses a similar concept to that used in the Umarex Hammer. It works, but is quite tight – at least on our test gun. Doug smeared a tiny amount of silicone grease on the magazine sealing rings: that made things much easier!
With the Primal, it’s necessary to activate the magazine release, push the magazine across and operate the cocking handle prior to making a second shot. Getting that second shot is a multi-step operation…
We didn’t specifically try for a fast follow-up shot, but clearly it would take some seconds to engage the target for a second time.
Shooting The Umarex Primal 20 Big Bore As An Air Shotgun
Umarex USA has introduced a second type of “ammunition” for the Primal 20. It’s a kit of shot shell components that can be used by the owner to create buckshot or birdshot loads.
This is a pack of 50 shot cups and wads that you load with between 3/4 and 7/8 of an Ounce of lead shot sized 7 1/2 or larger. Just measure out the shot, pour it into the cup and push the wad on top.
Both slugs and shot shells fit into the same, two-round, push-across magazine.
One other thing is required. It’s also necessary to use a different choke when using the Primal 20 as a shotgun.
Unfortunately we did not have the necessary choke. However, Doug Wall was able to source some Number 6 shot and we loaded that and fired a few times.
Needless to say, the pattern was not would be achieved from the correct choke. However we proved that the concept definitely does work. Above and below you can see the fired shot cups.
Below is the result of shooting one load at a 22 x 28-Inch board at 10 Yards range. 292 hits!
Please do not consider this to be a fair test of the Primal’s capabilities as a shotgun. It would need further testing with the correct choke to determine realistic patterns and ranges.
Umarex tells me that the range is 35 Yards-ish with shot. It depends on the size and number of shot in the load being fired, of course.
Although we didn't try it, we suspect that it might be a problem to have two shotshells in the magazine at the same time. Since the wad is only held in by a small amount of friction, it seems quite likely that the recoil would dislodge the wad from the shell, and dump the shot out the front.
Shooting The Umarex Primal 20 Big Bore – Summary
First the positives. In this Hard Air Magazine test, we found the Primal 20 to deliver excellent accuracy at a reasonable hunting range with its dedicated slug/sabot ammunition.
The test gun also produced considerably more power than the factory specification. Outstanding!
Muzzle Velocity was very consistent, too.
Of course the Primal is heavy, loud and kicks hard. Umarex advises re-filling with air after three shots. But we topped-up with HPA after two shots as that matched the capacity of the magazine and seemed logical.
As for negatives, we would have to identify the high cost of the dedicated Primal 20 saboted slugs. At $15.99 for a pack of 10, they’re well into .308 powder-burning ammo territory.
Overall, operation is slow and deliberate, so you’ll need to be sure before taking that first shot.
Oh and Umarex, please fit an appropriate pressure gauge to the Primal.
The Primal is selling at $729.99 and it’s built at Fort Smith, AR in the good ole’ USA!
BUY FROM PYRAMYD
Umarex Primal 20 PCP Air Shotgun 0.615
The post Shooting The Umarex Primal 20 Big Bore appeared first on Hard Air Magazine.
