Saturday, 6 December 2014

Crosman 1077, Smoothbore Repeating Rifle, A Review.

The Crosman 1077 air rifle is a CO2 'semi automatic' air rifle based on the famous Ruger 1022 rimfire rifle. In truth, it's not a true semi automatic as the trigger moves the circular mag onto the next round before releasing the hammer against the valve, and the barrel is (on the UK version at least) smooth bore and not rifled which really just makes it a pellet gun and not a rifle. It's great fun though, so much so that the wifey claimed it for herself! This is the ultimate seal of approval in our household and means I have as much chance at tinkering with it as a chicken enjoying a holiday at a Colonel Sanders theme park.

It's another Co2 gun that tries to look like the real thing....  good fun though.

There is no actual law stating you can't have a rifled semi automatic air rifle in the UK but it's all pretty ambigious and importers are playing it safe. G mac sell an aftermarket rifled barrel for under 20 quid to pop right in, but these have to be sent to an RDF, though can posted to your home as long as you send them your old smooth bore barrel. On the whole I reckon this is worth doing as they are fairly accurate out to 30 yards with the rifled barrel whereas with the smoothbore you're luck if you can hit a tin can at that same distance.

The rifle is mainly made from plastic with the inner and outer barrel liner, Co2 tube parts, most of the valve and most of the trigger mechanism being the only metal parts on the thing. There was once a model with a wooden stock but they are mostly made from a hollowed black plastic which makes the rifle very light and is pretty tough and sturdy. It could be filled to give the gun some substance.

The knurled rod has got to be the heaviest lump of metal on the whole gun

The trigger pull is quite heavy, as it has to not only pull the hammer back but cycle the next round as well. People have shortened the hammer spring to increase muzzle velocity, but this only makes the trigger stiffer and in my opinion isn't worth doing given that the increase in power that it achieves is minute. The trigger does get lighter in time but not by that much; a polish of the sear and some molly grease helps a little as well. 

It's upside down, but the tab on the right is hooked by the trigger to index the next shot. It's all plastic here.

Just when you think it can't get any heavier, the hammer releases and hits the valve, it fires the pellet with a fairly loud report for the 7 ft/lb of power the rifle produces. The safety is on the trigger guard and pushes over to one side stopping the trigger from moving, this is a typical Crosman design.

Plastic safety, plastic trigger, plastic trigger guard, plastic plastic plastic

There is a plastic revolving 12 shot magazine which fits into the top of a box mag that slides and locks into the underside of the gun.

Pull back the lock pin to release the 12 shot mag, push back the lock pin when replacing the mag or it tends not to work.

Press in the two tabs either side of the box mag to release it from the gun and slide back the spring loaded pin on top of that to remove the revolving mag to reload. 

Squeeze tabs either side of the mag and pull down, it just slots straight back in. A gormless expression while doing this is of course optional.

Wadcutters give the best result, and besides, you couldn't fit any longer pellets for love nor money. In case of a pellet getting jammed, the inner barrel can be slipped forward a little by lifting and unclipping two plastic tabs connected to the barrel in the receiver end.

The barrel tabs.

Push down then forward moves the barrel forward.

 One 12 gram Co2 sits in the tube below the barrel; the  Co2 is connected to the valve by a copper tube that bypasses the mag and firing mechanism. When the firing pin in the valve is struck, it moves forward allowing Co2 to shoot out the valve through the hollowed out end of the pin. This pushes the end of the valve airtight against the revolving mag, which in turn is pressed airtight against the breech end of the barrel to send a pellet merrily on it's journey to the tin can of your choice.

Hopefully you can see where the rotary mag fits and seals between the barrel and the black tip of the valve, seal being the opprative word here.

The open sights are your typical simple Crosman affair, with the front sight on a ramp with a green tru-glo rod in it, 

Tru-glo sights, you either love them or hate them. They actually work on this gun and i despise the fucking things.

and the rear sight adjusts side to side by using a screwdriver and lots of trial and error, and elevation set on a sliding notched ramp. 

Rear sights are a bit rudimentary, but then it's not exactly a competition rifle is it?

These work just fine with the smooth bore barrel and are even good fun in speed shooting games; though most people use action type replica pistols for this, I think it would be just as fun using rifles as well. If you want to mount a scope or dot sight then there is an 11 mm rail molded into the top of the receiver; having the rifled barrel would really make good use of a mounted scope.

Scope rail on top, yep they're plastic. But with no recoil they work well enough along as you don't over tighten the mounts.

I got just under a two inch group with 12 shots at 15 yards using the open sights. I think a scope would vastly improve this grouping, but don't count on it. I found that the square front post filled the square notch in the rear sight too much, so that the grouping spread out from left to right; vertically the group spread half an inch which shows promise considering I was shooting from a kneeling stance. Some extra support between the inner and outer barrel has been proven to increase accuracy by other 1077 owners, so this looks like a good route to follow in the future. 

That grouping is instant death to any beer can at 30 yards.

One 12 gram Co2 bulb will give you four mags worth of shots before there is any drop in power, that's 48 pellets. You could probably squeeze another mag, but you will really start to notice the drop in power and could even end up with a pellet stuck in the barrel. 

At around 80p a bulb it could expensive if you had a lot of Co2 guns and rifles.

When fitting a new Co2 cartridge, it is recommended to put a dab of silicone oil on the tip so that you make a better seal, and so that the oil shoots through the valve, lubricating those all important small parts of the valve and it's seals.

A smear of silicone oil is best, but grease will work. However a dab of grease may gunk the gun up, which is where I think I have gone wrong.

On firing, you can notice a good old spray of Co2 follow the pellet out of the barrel, which makes me wonder if there is a bit of wastage there. Maybe a heavy pellet might be of some use in this case, but you won't be getting any where near the advertised 620 fps.

Two years ago when I first got this rifle, i'm sure it was spitting pellets out at pretty close to Crosman's estimate, however i'm lucky to get 450 FPS with 7 grain Wadcutters nowadays.  

It should do better than this with 7 grain wadcutters.

It looks like this gun will be coming apart to see what is causing this lower muzzle velocity, not that it's a major problem at the moment, but it should be doing better. On the bright side, there was only a 20 FPS drop when I fired a full mag of 12 pellets in rapid fire mode, and taking into account that it was a cold winter's day in Britain, I wasn't too disappointed. 

I always thought that converting the rotary mag to take 10 .22 pellets and fitting a .22 barrel would be a bit of a hoot and would certainly use up a lot of that wasted Co2, but that's just a pipe dream at the moment, even though it would most likely put out 9 ft/lb and be pretty handy at short range ratting.

It's a fun gun and for £100 you can't go far wrong. There is plenty of info on the internet about them and even a detailed strip down. plus lots of info on which modifications work and which don't. So if you're bored and have a savage dislike of tin cans then I suggest you get one of these.


Fondest wishes, Wing commander Sir Nigel Tetlington-Smythe. 



  1. Does anyone know where I can get a couple of smooth bore barrels for the crosman 1077?

  2. Gmac sell replacement riflesd barrels for 22 quid but are currently out of stock it will a;so give you awesome groupings at 30 yards