Western Airguns Rattler Test Review .357 Caliber


Testers: Stephen Archer

Caliber: .357

Test Date: July 20, 2022

Serial Numbers: WR0000003

Source of Supply: Supplied by Airguns of Arizona

Condition: Pre-production test gun

We Like

Zero cocking effort

We Don't Like

Slow loading
Can’t tell how many shots in magazine
Needs a better buttpad


  • Value for Money
  • Speed and Accuracy
  • Trigger and Cocking Effort
  • Comparison to Makers Claims:
  • Consistency
  • Noise Level
  • Sights
  • Shootability
  • Appearance and Finish
  • Buying and Owning



In this Western Airguns Rattler test review, we find an extremely capable .35 cal semi-auto big bore air rifle, It’s powerful, very accurate, reliable, consistent and beautifully-finished. It’s a great slug-shooter, too!

The fixed magazine is probably the only real weak point. With interchangeable magazine capability it would be close to perfection for many shooters.

Note that high demand means that you’ll need to wait to buy one. Then you’re sure to use a TON of (expensive) .35 caliber ammo. Plus you’ll need a robust way to keep it supplied with plenty of HPA. But the smile won’t leave your face once you start shooting…

It’s an easy HAM Gold Award winner!


In this Western Airguns Rattler test review, I found a powerful, fast-firing big bore air rifle that has no real competition in the current airgun market.

Yes, at $2,695, the Rattler is definitely not a cheap air rifle. However it gives a combination of power, accuracy, shot count and quality that blows away any other .357 airgun available today. Plus – it’s semi-automatic!

This is an airgun for shooting – not tinkering. There’s not many upgrades or accessories, just a power wheel underneath to turn, should you wish. So the Rattler’s customer base will undoubtedly self-select also on that basis. Shooters will love it and that’s the customer base this gun is aimed at.

For big bore shooters wanting a fast-firing airgun that’s sophisticated yet simple to operate, the Rattler is clearly great value. Even at this price…


Western Rattler Semi Auto .357


This Western Airguns Rattler test review was undertaken with a pre-production model – serial number 003. At that time I was able to shoot it at 20 Yards range, however it was clear that power and accuracy were accuracy definitely not wanting.

Best accuracy was achieved when firing 174 Grain Hi-Arc slugs. As can be seen from the test target here, the result was a “one hole” group for 10 shots at 20 Yards. Very impressive!


Shooting other pellets and slugs, 10-shot groups were in the half-Inch CTC range at 20 Yards. This proves that the Rattler has the inherent accuracy to out-shoot me, for sure!

This pre-production model had been set to shoot 81 Grain JSB pellets at an ideal Muzzle Velocity of 880 – 890 FPS. That represents a Muzzle Energy of around 140 Ft/Lbs. However the same power settings gave 180 Ft/Lbs and 680 FPS with the 174 Grain slugs, as we can see.

That 180 Ft/Lbs is greater than most magazine-fed big bore guns of the same caliber can manage as a maximum. But, it’s waaay below the maximum that can be achieved by the Rattler.


Having a semi-automatic action, this Western Airguns Rattler test review found it easy to conclude that the cocking effort is precisely zero!

The trigger pull averaged 2 Lbs 4 Oz, varying from a recorded low of 2 Lbs 2 Oz to a high of 2 Lbs 6 Oz. So it was definitely consistent. This pull weight seemed appropriate for the gun, being neither too heavy, nor too light.

True, the quality of the trigger pull is rather “mushy”. It’s not bad – indeed it didn’t interfere with the Rattler’s ability to shoot accurately – however this is not a trigger with “glass break” pretensions.

Trigger pull is long and the break point somewhat indistinct. However we do need to remember that this is a semi-automatic and calibrate our opinions accordingly.

One slightly unusual requirement is that it’s necessary to completely remove contact between finger and trigger after each shot. Otherwise, you can pull the trigger again and nothing happens! But once you’re used to this it’s not a big deal. Muscle memory soon kicks-in!


The Western Airguns Rattler is equipped with two safeties. One is on the right side of the action, directly above the trigger. The second is on the left side at the rear of the action.

Both safeties must be set to”Fire” in order to shoot the gun. Although this Western Airguns Rattler test review found that setting either safety to “Safe” will prevent the gun from firing, it’s obviously best that both safeties be engaged – just to be sure.



The manufacturer claims that the Rattler will group within 1 MOA with 174 Grain Hi-Arc slugs at 100 Yards. I didn’t have the opportunity to confirm this, however the 20-Yard group in the target above shows that this claim is far from impossible.

This Western Airguns Rattler test review also was undertaken with the pre-production gun generating Muzzle Energies in the 140 – 180 Ft/Lbs range. That’s not insignificant, but the gun can achieve considerably more!

The Airguns of Arizona website gives the range of Muzzle Energies for the .357 caliber Rattler as being between 90 and 270 Ft/Lbs – depending on projectile weight, power setting and the number of shots required per fill.

Oh – and they also say that the number of shots per fill of the 580 cc Carbon fiber HPA bottle varies between 15 and 75. So, the claim is between 15 shots per fill at 270 Ft/Lbs and 75 shots at 90 Ft/Lbs.

This Western Airguns Rattler test review found a very happy medium of 48 consistent shots per fill with a Muzzle Energy of  just over 140 Ft/Lbs. That fits well into the range of AoA’s claims and seemed a good compromise between power and the need for frequent refills of High Pressure Air.



In the “shoot down test” as part of this Western Airguns Rattler test review, I found very strong consistency of Muzzle Velocity. In fact, the Standard Deviation (a mathematical expression of consistency) was just 3.9 FPS across the entire 48 consistent shot string.

That is definitely outstanding performance!

The level nature of the curve below also shows that the tested Rattler had a hammer spring tension that was ideally-suited to the power output at hand – as we can see from the level portion of the chart up to shot 48.

The average Muzzle Energy for those 48 shots was 140.6 Ft/Lbs. The fall in velocity once the regulator set point was reached is very marked – as you would expect with such a large demand for air for every shot!


Incidentally, the readings of both pressure gauges on this gun proved to be very accurate when compared to “known-good” external gauges. This is a very positive finding, as such small-diameter gauges found on airguns are not always renowned for their display accuracy.



The Rattler is fitted with a fully-shrouded barrel. However – given the huge amounts of High Pressure Air used for every shot – it’s clear that this gun will not be exactly quiet. And, of course, the higher the power level selected, the more air is used for every shot and the louder it becomes.

Overall, the Rattler .357 is less noisy than I expected for a big bore air rifle of this performance. You’re not going to need ear defenders – as you do with some big bores – but it’s definitely not backyard-friendly in the way that a smaller caliber airgun can be.



Scope mounting on the Rattler is achieved using a robust Picatinny rail that’s built-in to the gun. This provides sufficient length to mount most any type of scope, even if it’s long and your requirements are for long eye relief.

To facilitate long range shooting, the Rattler’s scope rail includes a 20 MOA angle. This is to prevent the scope from running out of elevation adjustment.


In this Western Airguns Rattler test review, I found the scope mounting rail to be very solidly attached to the action. It provided a very strong support for the optic.



The Rattler has a fixed magazine that must be loaded with projectiles one-at-a-time. Pellets or slugs are loaded from the right side, after the loading gate has been raised. After loading two or three projectiles, the magazine is rotated clockwise to expose more empty chambers for filling.

In this Western Airguns Rattler test review, I found that loading is not difficult. However, the magazine requires deliberate effort to rotate and you have to watch out not to pinch your fingers while doing so.

Although I understand the technical issues involved with incorporating interchangeable magazines into a powerful semi-automatic airgun, the Rattler would approach perfection if it had such a capability. On the other hand, the fixed magazine configuration undoubtedly contributes to the 100% reliability of feeding that I found during this Western Airguns Rattler test review.

There was never any sign of a jam or hesitation to feed, no matter how many shots I fired and whatever the ammo in use. Full marks to the designer for this!


Additionally, the Rattler easily accepted long, 200 Grain, Hi-Arc slugs and Predator Polymag pellets. So it’s clear that the magazine is capable of feeding most – if not all – the .357 caliber airgun ammunition that’s available at the present time.

However, there’s no visible indication of the number of shots remaining in the magazine. The chambers are not numbered and it’s not possible to see how many shots are still available on board – if at all! So either you have to keep careful count when shooting or accept some blank shots when you reach the empty chambers.

Also be very careful about proving “safe” on a range or when you have finished shooting! To be certain, I opened the loading gate and rotated the magazine manually to ensure no chambers were still “live”. Then I fired some blank shots in a safe direction to be sure and engaged both safeties.

As expected, the Rattler .357  is not a light gun. Fitted with the Aztec Optics 5.5-25 x 50 scope, the rig weighed-in at 11 Lbs 2 Oz.

In spite of this, the gun shoulders well and can be shot successfully offhand. The balance is good and the Rattler does not feel as long as it’s 40-Inch overall length might suggest.

However bipod support and firing prone or from a bench will be necessary to bring out the full accuracy that the gun is clearly capable of delivering. In this case, the extra-long lower Picatinny rail will be appreciated, together with the support band that bears up against the shroud, relieving issues of pressure on the HPA tank that can occur from rail flexing when bipods are used with some PCPs.


I found the Rattler comfortable to shoot. However, I would definitely like to see an adjustable cheekpiece made available in future. And, yes – the buttpad works well enough. However I’d definitely investigate fitting a more ergonomic, aftermarket buttpad if this were my gun.



The Western Airguns Rattler has an unashamed, tactical, “black gun” appearance that is loved by many buyers in the current market.

Fit, machining and finish of the externally-visible parts are uniformly excellent – as is expected for a gun of this price.




The Western Airguns Rattler is available through Airguns of Arizona and Precision Airgun Distribution dealers across the USA. But demand is so high that there’s already backlog of orders!

The best way to order is to place a deposit ($200) with AoA. This reserves your place and they’ll contact you as soon as your gun is available to ship to you.


The 3,650 PSI (250 bar) maximum fill pressure of the Rattler – relatively low by current trends – makes it easy to satisfy the gun’s demands for air than were it to take 4,500 PSI. This could be another advantage for many users as it makes it easier to keep that 580 cc carbon fiber HPA bottle filled from an HPA tank in the field.

The Rattler is supplied with a comprehensive user manual. This among the most extensive manuals that’s available with any airgun, however it’s in English only.

One surprise is that the warranty to the retail consumer is just one year from date of purchase. This is below the average expected for an airgun in this price range. This warranty applies to the original retail customer.

Warranty coverage includes faulty workmanship and defective materials. Proof of purchase is required in the unlikely event that warranty support is required.

Finally, the Rattler is supplied with a high quality padded case – it’s more like a “soft box” than a traditional soft case. This provides good protection for the gun in transit and has two external pockets for storing ammo. It also accommodates the gun with a large scope mounted. Very good!







Western Rattler Semi Auto .357

This entire article including scoring, test targets etc is Copyright Hard Air Magazine and may NOT in part or in whole be reproduced in any electronic or printed medium without prior permission from the publisher.