Hi, I got a gamo shadow 1000 for Christmas 04 (or 05 at the latest.) It didn't shoot worth beans, and I sent it back to gamo (had to pay for shipping both ways). Customer service was good, and they sent me another one which arrived in under 2 weeks. This one was as bad or worse than the first. both shot a tight group in one place, then shoot all over the paper (I mean 10" between subsequent shots, and this is at 20 feet). It will then settle into another tight group, usually a good 4-6" from the last group. I tried all different brands of pellets, scope and open sights
I administer a website about hunting upland game birds with air rifles, which is legal in California and has been since 2000. One of our favorite rifles is the early production Gamo Shadow 1000. It is a favorite because its power to weight ratio is pretty much unmatched in spring piston break barrel guns. It is accurate enough to hit the vital zone of a valley quail at 50 yards or more, and it shoots flat enough to have a maximum point-blank range of 50 yards. With the right pellets (hint: they don't have flat heads, but domed ones), it will carry 9 foot pounds of thump to the 50 yard line. That is three to four times the amount of power needed to cleanly kill a quail and double the amount needed to cleanly kill cottontail rabbits. I've shot well over two dozen of these rifles and each one of them behaved pretty much as the quoted poster described when new. Once broken in, however, they were almost all good for at least 1.5" five shot groups at 50 yards on a relatively wind-free day. Many would stick 5 of their favorite pellets into clusters at 50 yards that you could cover with a quarter.
What Gamo doesn't explain so well in the literature supplied with their rifles is that spring-piston air rifles are generally prone to "dieseling" when new. Excess lube gets past the piston seal and is combusted just as #2 diesel oil is in a Cummins B series engine. In a new spring-piston air rifle, however, this dieseling isn't uniform from shot to shot. You'll get velocity variation from shot to shot because of this. You'll also get "blown" pellet skirts coupled with exessive obturation of the pellet. This results in a pellet base that is no longer square in relation to the axis of the bore. When such a pellet reaches the muzzle, it cannot be evenly released to flight. A portion of it is released before the remainder. This introduces yaw, which is manifested in errant flight to the target.
This isn't just a Gamo problem. You can have an R-series Beeman do this right out of the box, too. I know because I've had several do so. Beeman, however, includes plenty of literature explaining what is going on, and they flat out tell you not to expect stellar accuracy until you've shot upwards of 1,000+ pellets through one of their guns.
During this break in period, two things are happening: The excess lube is getting consumed, and the piston seal is "wearing in" to make a more effecient seal with the compression chamber walls.
Aside from the issues I already mentioned, dieseling also causes more harshness and vibration in the discharge cycle, so now you get bizzare vibration eroding accuacy even more, and it can be pretty severe. It was enough on my first Gamo 1000 to destroy a Simmons Pro Air scope that cost more than the rifle did in about 50 shots.
A quick cure for this dieseling problem is what we call the "Tin of Kodiaks Tune." Beeman Kodiak pellets in .177 weigh in at 10.5-10.6 grains and are heavier than other .177 pellets. It takes more pressure to get them moving. This increased resistance forces the piston seal into doing a better sealing job. Normally, the dieseling you get while shooting these in a new springer will be less severe than if you shot lighter pellets and it won't last for as many shots before consistancy from shot to shot becomes more normalized. Once you're at that point, you can switch to lighter pellets if you wish.
, and it wasn't my shooting, I'm a very good marksman (and I tried it from a bench and a vice just in case I was completely messing up with the springer recoil). I was exasperated, and didn't want to pay for shipping again (the gun isn't expensive enough to warrant shipping back and forth for eternity). They wouldn't let me upgrade at the factory, and I gave up on it. So, It's been leaning in the corner for a couple years now.
The poster above might indeed be an excellent marksman with firearms but that doesn't automatically translate to being an excellent shot with a spring-piston air rifle, because there is a technique to shooting one which is alien to many who come from a firearms background. The quoted poster's mention of shooting off a bench and in a vice pretty much demonstrates a lack of understanding of commonly accepted proper springer shooting technique.
This is another area that Gamo doesn't address in their literature packed with their guns that is addressed in the literature that Beeman packs with its R-series models.
For a variety of reasons, spring-piston air rifles DO NOT shoot well from solid rests. They definitely don't tend to shoot well when shot from vices or off bipods, either. Accuracy is achieved by hold the rifle relatively loosely and letting it do its thing under recoil, rather than trying to restrain it. A spring piston air rifle will tend to have a "sweet spot" on the fore-end where your OPEN PALM needs to go. They tend to not like being strangled by the trigger hand with a tight grip, either. I shoot with a very loose grip and don't wrap my thumb around the wrist of the stock. I don't pull the butt super-tight off of my shoulder, either.
If you look at the trigger guard of an R-series Beeman, you'll see that it has cast-in "checkering" and that isn't there for decoration. Some of us like to support the rifle by placing the TG on the thumb of the support hand, with the wood fore-end resting on splayed index and middle fingers. That is how I usually shoot.
I will also submit that the technique for getting accuracy out of spring piston air rifles is very demanding and much more so than that sloppiness you can get away with shooting powder burners. There are many reasons for this but one of the major ones is the amount of dwell time that air rifle pellets spend in the bore. It is significantly longer than that of even the lowest powered firearms. Spring piston air rifles are capable of surprising accuracy but realizing it IS NOT easy.
Beeman makes that clear in their supplied literature that they pack with their guns. They also explain proper springer shooting technique.
One of the reasons why pre-charged pneumatic guns are so popular in the UK is because they are MUCH easier to shoot accurately, can be shot from solid rests and bi-pods accurately, and aren't as technically demanding to shoot. They also don't recoil as much and discharge cycle vibration is nill, so they are potentially even more precise than break-barrel spring piston guns are.
I've been seeing some good reviews on the shadow 1000's lately, and I'm wondering if the newer ones are more consistent? I'm not going to pay for shipping again if I am unlikely to get a decent shooter. Thanks!
The new ones aren't any more consistant from the older ones, from what I've seen. In fact, I think they're far less desireable now, and we no longer recommend them like we once did on my website. A couple of years ago, Gamo changed the lockup from the double-opposed wedge style as found on Beeman R-series guns to the cross-pin and wedge style common on older Webleys. The advantage of the double-opposed wedge lockup is that it essentially wears in rather than wearing out and barrel angle remains more constant over long-term use because of this. It is a superior system but it costs more to make, so Gamo shelved it to keep the Shadow at a price point. It's still probably better than detent ball lockup, but not by much.
You DO NOT want to use JB Bore paste or similar abrasive compounds on an air rifle barrel. They aren't normally made from chro-mo steel, but much softer stuff, and the rifleing is very shallow and, in guns like R-series Beemans or RWS Dianas, the barrels are also choke-bored. Shooting pure lead pellets, which most Haendler and Nattermann / Beeman pellets pretty much are, will make your bore mirror smooth in normal use.
You don't want to clean an air rifle bore too much, either. Remember that dieseling stuff? Well, it never really completely goes away. What it does do is become uniform and much milder, but it is always there to some degree. In shooting, there is usually enough lube getting into the bore to keep it from rusting. So unless you live in a very humid climate, you generally don't need to oil an air rifle bore, let alone clean it. You only clean when accuracy starts to degrade.
I still like the older Gamos and regret selling mine. The triggers stink but can be fixed with Bob Werner's GTX replacement. With that trigger, an older Shadow has a lot going for it as a small game hunting rifle.
-JP
