Posts Tagged ‘Ruger Air Magnum’
by B.B. Pelletier
Photos and testing by Earl “Mac” McDonald
Hopefully, I’m getting this test finished in time for a few last-minute buying decisions for the holidays. I’m sorry it takes so long, but time being what it is, it’s the best I can do without turning this blog into an infomercial.
Today, we’ll look at the accuracy Mac was able to get from this powerful new übermagnum spring rifle. I know many of you were predicting it wouldn’t be very good, given the power output.
This is also the day when Mac will show you how to adjust the parallax of a fixed-parallax scope so you don’t have to buy a new scope to get what you want from the gun. Since that’s an interesting procedure, let’s do that first.
I was exposed to this trick back when I shot field target. Many shooters were changing the parallax on scopes with fixed parallax back then.
Step 1. Remove the threaded trim ring on the objective bell. On this scope, you’re lucky, because that exposes a cross-slot on the objective lens unit that lets you insert a thin screwdriver blade. Because of the wide span that must be crossed, a thin knife blade is often the best tool for this job. By turning the objective lens assembly slowly in either direction, the entire objective lens assembly can also be turned.
Step 2. To adjust the scope for a different range, turn the objective lens assembly while checking the sharpness of the focus on an object set at the range you wish to adjust to. Turning this assembly out adjusts the focus closer — and in moves it out farther. Unless you completely remove the objective lens assembly from the scope, no nitrogen will be lost, as the extremely viscous grease on those fine threads perfectly seals the inner part of the scope. If the seal is broken, though, the scope will be compromised and will fog up unless it’s resealed.
Step 3. Once you’re satisfied the scope focuses where you want it (i.e., the parallax is set where you want it), replace the beauty ring to lock the objective lens assembly. The job is now done.
Mac tells us that the rings that come with the rifle are nice and appropriate. They have four screws per cap and each ring has friction tape inside to prevent scope movement. Don’t do what Kevin said someone did and remove the tape because it doesn’t align quite right. Keep your hands off that tape! It’s there to do a job; and if it’s removed, the hole through each ring gets bigger.
Mac noted that the nameless scope seemed to be adjusted for the 30 yards he was shooting, so there was nothing more to do but sight-in. As first tested, the rifle shot just two inches low, with no noticeable left or right deviation. That little amount is what the scope knobs can do by themselves, so there was no need to adjust the scope mounts in any way.
Next, Mac started the testing with some Crosman Premier 10.5-grain pellets. Ten of those grouped into a pattern that measured 2.7 inches at 30 yards. Mac calls this poor, and I have to agree.
Next, he tried 10 RWS Hobby pellets that we all agreed are too light for this powerplant. They held 9 in a group measuring 2 inches even. A tenth shot was a called flier that missed the target paper altogether. This is another pellet not to try.
Except for the called flier, these RWS Hobbies grouped better than the heavy Premiers, but notice the dark edges of some of the pellet holes. Clearly, this pellet is wobbling on its way downrange –something that can’t be determined from the less-precise holes of the Premiers.
Then, Mac loaded 10 JSB Exact Diabolo heavies, the 10.2-grain domed pellets that often work best in powerful air rifles; and, again, they did their thing. They gave a 10-shot group that measures 1.1 inches at 30 yards, which is acceptable hunting accuracy.
Just for the record, Mac also fired 10 RWS Superdomes and 10 RWS HyperMAX pellets at the same distance. The groups from both pellets were too poor to measure. We know that the 5.5-grain HyperMAX pellets were traveling over 1,400 f.p.s. and could not be expected to be accurate. But, why were the Superdomes also a problem?
RWS Superdomes are almost pure lead, plus their skirts are very thin. In a rifle shooting 800 to 900 f.p.s. that’s perfect, because the rear of the skirt blows out and seals the bore behind the pellet. But, in a powerhouse like the Ruger Air Magnum, it shoots them well above the sound barrier. The thin skirt is blown all the way out until the pellet resembles a cylindrical can with a slightly domed top. Since the wasp waist is where the accuracy comes from, it’s not good to lose it this way. The pellet is then free to fly wherever it wants, destroying accuracy. If Mac could recover some of these pellets without damaging them, that is what we would see.
But, that doesn’t matter, because Mac has found a good pellet for the rifle. Putting 10 shots into 1.1 inches at 30 yards is certainly good enough for hunting. At this power level and price point, I think this is one spring gun you’ll want on your short list.
by B.B. Pelletier
Photos and testing by Earl “Mac” McDonald
Today, we’re back with the .177 caliber Ruger Air Magnum Combo rifle. You’ll remember that this is a very powerful breakbarrel springer, and we want to see how close to the advertising it comes. You’ll also remember that this rifle cocks with 58 lbs. of force, so it’s meant for hunting, not for casual plinking. And, the barrel comes back farther than most breakbarrels when the rifle is cocked, giving you a short area where the cocking becomes very difficult because of how your hands have to hold it.
Right into testing
The first pellet tested was the JSB Exact heavy, a 10.2-grain domed lead pellet. Knowing up front that this rifle is a blaster, we can also predict that the heavier pellets will be better suited to the power of this powerplant because their weight will prevent them from going supersonic.
Mac recorded 10 JSBs at an average of 970 f.p.s., with a 15 foot-second spread from 966 to 981 f.p.s. At that speed, this pellet generates 21.32 foot-pounds of energy at the muzzle.
Next, he tried 8.3-grain RWS Superdomes.. These averaged 1108 f.p.s., with a 20 foot-second spread from 1092 to 1112 f.p.s. They produced an average 22.6 foot-pounds, which is really pushing it for a .177 pellet. However, at that velocity they’re also right at the sound barrier, and I doubt they’ll hold together for accuracy at range.
The lightest all-lead pellet he has are RWS Hobbys. At just 7 grains, they’re far too light for this powerplant. They averaged 1186 f.p.s., so good luck trying to keep them quiet. The spread was also large, at 36 f.p.s., running from 1169 to 1.205 f.p.s. And, at the average speed, they produced an average 21.9 foot-pounds of muzzle energy.
Next, Mac tried Crosman Premier heavies, the 10.5-grain pellet. This pellet should certainly slow down the big rifle to a useful level for accuracy. But, they averaged 1011 f.p.s., which is a little on the fast side for best accuracy. They produced a 25 foot-second spread that ran from 998 to 1023 f.p.s., and the average muzzle energy was 23.8 foot-pounds — the highest of the test.
Finally, Mac tried RWS HyperMAX lead-free pellets. In a powerhouse like this Ruger, these 5.2-grain pellets are nothing more than bragging rights. At first, Mac got velocities in the high 1300s, but he noticed a very loose fit in the bore. When he flared the skirts, the velocities went up to 1430-1435 f.p.s. and were very consistent. He didn’t give me an average string to work with, but using 1430 as an average, this pellet produced an average muzzle energy of 23.62 foot-pounds.
In the next report, Mac will show us the accuracy he saw with the test rifle, and then he has a special bonus feature. He’ll show us how to change the parallax of the scope, as I mentioned in Part 1 of this report. The 4x scope that comes with the rifle has no parallax adjustment, but an owner can select the optimum range and adjust the parallax for that one distance. It should be an interesting time.
by B.B. Pelletier
Test and photos by Earl “Mac” McDonald
Today, we’ll begin a look at a brand-new übermagnum from Ruger, the Ruger Air Magnum Combo. This is another spring-piston breakbarrel with smashing power, and I can tell you where that power comes from — in a moment.
Mac described the rifle as a Diana RWS 34P on steroids. And, then it hit him. Maybe, it’s really more of a Diana RWS 350P Magnum. Regardless of what it reminds him of, the report will focus on this new rifle, only.
Now, being both a breakbarrel and powerful is going to mean one thing for sure. This rifle will take some technique to shoot well. You’ll have to apply the artillery hold and find and use the one best pellet no matter how many tins of lead sinker larvae you can find on sale at Wal-Mart. You know, praying doesn’t make bad ammo good, and no amount of savings will ever be enough to compensate for the miss you know started out as a good shot.
The rifle comes with open sights. In this case, they’re fiberoptic, front and rear, which is probably the right choice for a hunting gun. And, the rear sight is fully adjustable.
A scoped combo
Being a combo, though, the rifle also comes with a scope. In this case, it’s a 4×32 that I’m sure you’ll want to upgrade at some time, though Mac tells me the one on his test gun is pretty darned clear. It doesn’t have parallax adjustment at this price level, but Mac will share how to adjust the parallax on this scope in part three of this report. You can set it to 25 yards, if you like, and you’ll be averaged for hunting. Or, if you just want to shoot it at 10 meters (even though this is not an indoor plinker by any means), it should be possible to set it for that range.
And, some very good news. The rifle has a Weaver base permanently attached to the spring tube. So, buy Weaver rings and forget all scope mount movement problems. Of course, if you get the combo you also get a scope mount set, so there’s nothing more to buy.
The rifle is very large, Mac says, though at 8 lbs. it isn’t a heavyweight. It’s 48.5 inches long, which makes it much longer than the average breakbarrel. The length of pull is a good 14.25 inches, which most adults will find in the right range. The barrel measures 19.5 inches, which you’re going to want for some cocking leverage.
Where the power comes from
The cocking effort on Mac’s test rifle measures 58 lbs.! Yes, I said 58 lbs. If you want to know how that would be measured, look at this video. Please, think that through before you order one, because at that level of effort you’re not going to use one of these rifles for plinking. Even bodybuilder Lou Ferrigno would soon tire of that much effort. But, hunters shouldn’t care one way or the other, because they don’t have to cock their rifles that often. Umarex, which imports the gun, lists the cocking effort at 42 lbs. Even that’s substantial.
However, it isn’t just the powerful mainspring that creates the extra power of this rifle. Mac reports that the barrel also comes back about 120 degrees from closed before the rifle is cocked. That extra stroke of the piston is where the real secret of power lies. We know today that swept volume in springers is the real secret of their power, which begs the question of why the rifle has to cock at 58 lbs. Maybe it was a poor mainspring choice and maybe an aftermarket tuner can chop out 20 lbs. of effort without losing much power, but that’s not a question we’ll address in this report.
The one note Mac added about cocking is that he cannot feel the sear set when the rifle is cocked. The safety comes on automatically, but you really have to give the barrel a hard last yank to ensure the rifle is cocked. Maybe that’ll change with break-in, like the older Gamo triggers and BSF triggers used to, but we shall see.
Mac measured the two-stage trigger at 53 oz. He says stage two is a bit vague, but you can feel it. The trigger is also adjustable, but only for the length of first-stage travel.
You can see that the butt is synthetic, and Mac noted the thick, smooth buttpad. The stock design is conventional Monte Carlo style, but without a raised cheekpiece. Note the complete ambidextrous design because of where the automatic safety is placed, at the rear of the spring tube. The metal is nicely finished medium satin and sets off the dark stock perfectly.
More toys, boys!