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StevieLaner7777 · Moderator

Hi all

Well today (Saturday) I finally decided to get a QB78 (SMK XS78CO2 in .22 to be precise) after being inspired by my Bro's one that He got a month or two before.

So after choosing the one that I liked the look of in the Gun shop I bought it and took it home, When I got it home I had a very good look at at and realised that the barrel was slightly out of line with the Co2 tube, so I simply loosened the barrel band realigned it and tightened it back up again, Whilst I was doing this I wiped it over with an old rag with some gun oil on it to get rid of the gritty texture that was on all the metal, I also took the stock off as well and ran the rag over all the hidden metal too, After that I used some wood polish to clean the stock up and bring it to a satin sheen, Lastly I reattached the stock and added some molly lube to the Bolt probe O-ring to keep it from wearing out too quickly.

After cleaning up the Rifle I removed the open sights and attached the Simmons 4x23 8-point scope off my Crosman 1077W on to it, I will be using the Simmons Scope on my QB78 until I can save up enough cash to get a 3-9x40 scope for it.

Here's a Photo of my New XS78:

Next I took the Rifle out side to zero in the scope and do some proper shooting with it, After getting the windage adjustments zeroed I found it difficult to zero the elevation as the pellet would either impact too high or too low by about 1cm either way, I was sightly concerned about this though I carried on as normal getting through about 20 more pellets before concluding that I wasn't going to get the elevation any tighter than that, I was tempted to have a quick peep down the barrel to see if there was any imperfections down there, but as the Rifle was already charged with Co2 I decided to have a look later on after I emptied the Rifle, So I continued with a bit of 35M shooting at an inch thick piece of Hi-carbon Steel "PING"! Cool.

Target results from the XS78:

After retrieving one of the flat spent pellets from near the thick Hi-carbon Steel target I noticed a little indent on the skirts of the pellet, I looked for another one and this one also had the little indent on the skirt and the next one etc... So I decided to try and recover some pellets that haven't been deformed too much, I used a old wet towel to do this (Let me know it there is a better way of doing this without shooting into the sky and waiting for it to fall back down), After I recovered the pellets from the wet towel I checked to see if the indents was on these pellets as well and surely enough there they were on the side of the head of the pellets and the skirt, Obviously something was not quite right in that barrel!

Bisley Magnums with the indents on the side of each pellet:

So After the Co2 had ran out I took the QB78 back into the house and used a white LED and a battery to light up the barrel so I could see down it to look for any imperfections, and with no real surprise I noticed there was a small bulge in the riffling on the roof of the barrel about 3/4 of the way down the barrel from the muzzle in the exact location of where there are two small holes that are drilled and threaded to hold the rear sight, It seems some clumsy "Gunsmith" used the wrong length bolt to fasten the rear sight on to the Rifle and ended up bulging out the riffling in the barrel Rolling Eyes

Looks like this ones going back to SMK via my Gun shop on Monday, Though I'm keeping the same stock because I like it too much to swap for another one.

Stevie Thumb Up!

Alstone · Moderator & Site Supporter

Congratulations Stevie on getting a QB .22 although it' not a very officious start, had the screws punched through the barrel or just dented it, apart from that it looks very tidy.

I should get my QB back a bit quicker as I'm not away till the end of the week now, so thats somthing I shall have to look out for, but when I tried it the grouping seemed OK

Anyway I hope you get sorted out soon.

AL

StevieLaner7777 · Moderator

Hi Al

Thanks for the 'grats! It's a good thing I didn't buy it from an Internet site or I would have a lot more aggro to go through to take it back yet keep the nice stock, John will probably just swap the stock with another one that He's got and send that one back, The only problem being is that he doesn't open his shop until Tuesday so I got a long wait.

I think the bolt has just dented it though it's hard to tell but there is not Co2 leaking up though the top of the barrel so it probably haven't punched through the barrel.

Here's a photo of the inside of the barrel, Notice the dark spot on the roof of the barrel about 3/4 of the way down:

Anyways I look forward to hearing from you on your new QB78 soon!
So the leak on yours was slow enough to get a few shots then, The groupings will probably improve when there's not any Co2 leaking out cooling it all down.

Stevie Thumb Up!

AirGunEric · Site Admin

Looks good.

Too bad about that bulge damaging the pellets- that's got to be affecting their ballistic coefficient and flight path. I would have expected the spread of your shot groups to be even worse. Try a longer-range target and I bet it will start to open up significantly.

I guess you were thinking ahead by getting the gun from a local retailer and not 'online'? Good show! Brilliant! and all that. Very Happy

StevieLaner7777 · Moderator

Hi Eric

I used two different pellets to get the 5-shot groupings in the pic, I used Bisley Magnums (on the left in the pic) and RWS Superdomes (on the right), It seems the Bisley Magnums were more affected by the defect in the barrel than the RWS Superdomes as the Mugnums spread more vertically this may be due to there weights.

The problem with trying with a longer Rang is that my Garden is only 35M long so I can't do any longer range shooting than that at the moment Neutral

I really need to get that shooting permission from the Farmer so I can do some Long range shooting now that I have an Air rifle that's capable of delivering shots reasonably accurately even with a defect in the barrel, I'm still going to get it changed though, think of all the power loss with the pellets not sealing against the barrel for 3/4 of the way down.

I usually buy from local retailers if possible if I'm not too sure about how it will be when I get it, Just good thinking I suppose Wink

Stevie

Alstone · Moderator & Site Supporter

Stevie! Does your QB have a Plastic or steel barrel band ?, I think mine has plastic but I'm not sure, and the only photo I took was with an old camera I had in the car, and it's not very clear.

Al

StevieLaner7777 · Moderator

Hi Al

Both my Bro's and mine are plastic at the moment, Though I am looking around for aftermarket parts that are sold in the UK.

broommaster2000 · Moderator

There was a QB78 (or something like a QB78) conversion somewhere that was converted to a PCP. It was called "the long one". It was quite long. I like that. A very long air rifle is something I think is quite fancy. It's only that you need a very long case to get it into the club. Especially when the shooting range isn't that big. (As a matter of fact, the shooting range where I am shooting is quite small).

StevieLaner7777 · Moderator

Hi Broom!

I know this isn't the one one that you were talking about, though it is Converted to PCP and the HPA tube is pretty long:
Clicky Click!

How long would you say your local Gun range is Broom?
I think the one near to me is only 10M for Air pistols, 20M for Air Rifles, I think ~50M+ for Small bore Rifles and ~100M+ for Full bore Rifles.

Considering I can already achieve 10-20mm Groups at 30M with my Bro's XS78 I think I would have to use the Small bore range or I might get bored with the Air Rifle Range Mr. Green

Stevie

Alstone · Moderator & Site Supporter

Stevie have a look at this site, http://www.trobb.f9.co.uk/Kits%20Page.html they do black aluminium bands for £15.00.

Another thing, looking at the design of the QB it would be possible to fit any barrel you can get hold of, including springers, chop off the hinge then re-machine to fit the QB which would be a quite easy task, change it to a carbine or .177 to .22 etc.

Al

StevieLaner7777 · Moderator

Cheers Al

Interchangeable Barrels would be pretty cool but at the moment the Barrel band is highest on my list, next to the Suppressor and Stainless steel Bolt handle that I will make on the lathe.

Stevie Thumb Up!

StevieLaner7777 · Moderator

Hi all

OK so I took my faulty QB/XS78 back to the Gun shop to day to get it sorted, John seemed pretty surprised that this problem had occurred on one of the XS78's, anyways he did a "Straight swap" with another XS78 that he had in stock, He also swapped the stocks so I could keep the really nice stock off the faulty one on my new XS78, So that all worked out pretty well.

I took it back home and had another really good look over it, Checked the barrel for any defects (None this time!), Took it back out of it's stock to clean up the metal with an old rag and some gun oil, Put some oil in the Bolt slide to keep it sliding freely, Added some Molly lube to the O-ring on the bolt probe to keep it from drying and wearing out, then I polished the stock and put it back on and attached the Scope to it.

Finally I took it outside for some testing, I managed to get the equivalent 5-shot groupings to what I can get with my Bro's XS78 at the same distance So I'm pretty happy with it now!

Looks like lots of mods to come for this Rifle then! Mr. Green

Metal barrel band.
Replace stock Nut and Bolt with a flatter Bolt.
Polish Bolt handle and bolt slide.
Smothen the Gas port.
Polish the Trigger.
Thread the end of the barrel.
Make a Suppressor.
Replace the End cap with PCP version.

I think That about all I can think of so far! Though some of them should be pretty simple to do.

I'm also planing to get a 3-9x40 scope for it and a Bi-pod.

Lastly I will be posting a review on this Rifle in about a week or two, I would have posted one on it earlier but as I haven't had much chance to actually use the Rifle I feel it wouldn't be very fair.

Stevie Thumb Up!

broommaster2000 · Moderator