Posts Tagged ‘SIG’

Does The FPS For Gas Ram Air Rifles Change With Temperature?

For some years after their introduction, many manufacturers promoted gas ram air rifles as being unaffected by changes in temperature. The FPS would be pretty-well the same at any temperature, they said.

Is that true? Well, on the basis of some testing I’ve undertaken, the answer is definitely “no”. At least in the cold weather we have here in up-state New York.

I’ve found that here is definitely a change in FPS for gas ram air rifles at different temperatures. And it’s more than you may have thought!

To find out what the change in FPS can be with gas ram air rifles shooting at different temperatures, we used a new .177 caliber SIG ASP20.

Does The FPS For Gas Ram Air Rifles Change With Temperature?

We shot the ASP20 at a temperatures of both 20 degrees F and at 63 degrees F. In each case, the gun was allowed to “season” at the ambient temperature for several hours before shooting. This meant that gun and ambient temperature were definitely at the same.

Also, we shot the gun slowly – about every 30 seconds – for each test. This was to avoid any effects from the ASP20 heating-up as it was fired. We took 10 shots at both temperatures for each of the six types of pellets. Total 120 shots.

So what did we find?

The answer that – taking the SIG ASP20 as a representative of gas ram air rifles – the gun shot faster, on average, by 1.28 FPS per degree F at the higher temperature.

Does The FPS For Gas Ram Air Rifles Change With Temperature?

On average, that means approximately 55 FPS difference when the gun was shot at 20 degrees F and 63 degrees F. That is very definitely enough to make the point of impact on the target very different at most ranges.

So if you’re shooting gas ram air rifles, either on the range or hunting, make sure that your gun is sighted-in at approximately the same temperature as for that critical shot. If not, you could miss the target just due to the change in temperature!

Here’s a chart showing how the Muzzle Velocities changed with temperature for different .177 caliber pellets:

Does The FPS For Gas Ram Air Rifles Change With Temperature?

And here’s the average…

Does The FPS For Gas Ram Air Rifles Change With Temperature?

So if you’re shooting gas ram air rifles, either on the range or hunting, make sure that your airgun is sighted-in at approximately the same temperature as for that critical shot.

If not, you could miss the target just due to the change in temperature!

The SIG ASP20 - A Great New Breakbarrel Air Rifle

The SIG ASP20 was one of the most-anticipated air rifles to be introduced in 2018.

I first shot it at the 2018 SHOT Show in January, then again at the formal SIG Press Launch in July 2018. Now the ASP20 is shipping in both .177 and .22 calibers and you can buy yours from Airguns of Arizona, of course!

So, what’s been happening since the July Press Launch?

Well, SIG has been making a few small tweaks and final testing to ensure that their first in-house developed airgun performs as well as the legions of SIG SAUER firearms owners would expect. SIG Air’s Development Manager Ed Schultz confirmed to me that the company has made over 200,000 shots through multiple ASP20 test guns prior to production commencing.

Yes, over two hundred thousand!

Some individual guns have exceeded 10,000 shots each, he said. And all of this durability testing has been done by hand – no testing machines. Wow! It’s a good job that the cocking effort of the ASP20 is lighter than that of most break barrel air rifles at this power level!

The SIG ASP20 - A Great New Breakbarrel Air Rifle

SIG is currently shipping the wood stock ASP20. Synthetic stock guns will follow, as will scope bundles with the SIG Whiskey3 ASP 4-12 x44 AO scope.

The gun I’ve been shooting is .177 caliber with wood stock and Whiskey3 scope. SIG mounted and sighted-in the Whiskey3 scope before shipment, so it was ready to shoot, straight out of the box.

Immediately you shoulder the ASP20, it’s clear that this is a nicely-balanced air rifle. The center of gravity lies exactly where your forward hand naturally rests to support the stock. The forend is not too wide, just comfortable, too.

The test gun weighed-in at 9 Lbs 10 Oz, including the mounted scope. I’d rate that as pleasantly substantial but not too heavy.

The SIG ASP20 - A Great New Breakbarrel Air Rifle

The wrist of the stock is nicely-dimensioned. It allowed my trigger finger to engage the blade naturally, with no strain.

Although there’s no adjustable comb to the stock, nor an adjustable buttpad, the cheek weld was immediately pleasant for me. This means that the ASP20 is a new addition to that select group of air rifles – like the Weihrauch HW100 – that feel “just right” as they come from the factory, with no need for the stock adjustments they don’t have.

However, SIG expects to have an adjustable cheekpiece available with the ASP20 synthetic stock model in the forseeable future. Just in case…

Easy, foolproof, trigger adjustment was a design goal for the ASP20. Unusually, the trigger pull weight is adjusted from the rear of the compression tube, using a click-adjustable system. You push in then rotate clockwise to increase the trigger pull weight. Anti-clockwise reduces it.

This adjustment can be made using a Phillips head screwdriver. However, if a scope is mounted, you’ll need to use the special adjustment tool provided by SIG with the gun, as the scope blocks screwdriver access.

As received from the factory, the test gun had a trigger pull weight of 2.5 Lbs. So the trigger is light. It’s also very pleasant to pull. However, there’s not that “glass break” sensation as the sear releases, it’s a softer, slightly more gentle feeling – at least as received from the factory.

SIG gives you some control over the trigger release characteristics, too. Turning the small Allen key supplied with the gun in the setscrew located behind the trigger, allows single stage operation, two stage, or somewhere in between.

The SIG ASP20 - A Great New Breakbarrel Air Rifle

Another key focus for the SIG design team was easy cocking. The test ASP20 has a cocking effort of right around 32 Lbs – that’s the SIG Glidelite cocking mechanism at work. This is definitely low for a break barrel gun of this power level.

Cocking action is smooth and even. There’s no feeling of jerkiness and no grinding or grating of the lever against the stock in operation. Again. it’s good.

Lockup is very positive and this reassuring solidity is a testament to SIG’s Keystone breech design and the match-drilling of the pivot pin holes.

H&N Field Target Trophy pellets showed-up well for accuracy. A consistent 1035 FPS – plus or minus – showed on the Chrony for these pellets at 63 degrees F. That’s 20.59 Ft/Lbs of Muzzle Energy, slightly exceeding SIG’s claim.

Our test gun also shot well with Baracuda Match and Field Target Trophy Green pellets. As SIG is an OEM customer for H&N pellets, it’s not surprising that these pellets work well in the ASP20.

It’s clear that the SIG Air ASP20 is a capable, powerful and accurate new air rifle!

With the SIG name on it, the ASP20 appeals not only to airgunners, but also firearms shooters. That’s a HUGE potential market and SIG Air is well-placed to benefit from their growing interest in non powder-burning pellet launchers!

The SIG ASP20 - A Great New Breakbarrel Air Rifle

POSTSCRIPT
Serial numbers for the SIG ASP20 all begin with the initials JDH. This unusual prefix is a memorial to Justin Daniel Heckert, one of the gun’s key design engineers. Sadly, Justin died unexpectedly before the ASP20 entered production. Serial number one of the SIG Air ASP20 was presented to Justin’s family as a mark of respect by the company.