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Disco .22 POI Fixed

May 17 2012 at 10:50 AM
Joe Dzekevich  (Login JoeDzek)
YF12

I just wanted to share this info. I have a six months old .22 Discovery and it had three problems: a POI shift after pump-ups; a smaller POI shift as the pressure changed; and it did not like RWS Superpoint pellets. They would hit about 4-5 inches below and a couple inches to the right of round nose pellets like RWS Superdomes and Benjamin domed hollowpoints. Because it was on my list of things to do, and I am not a good mechanical type, I sent the .22 Disco to Mike at TKO for a tuning. One thing that he found was that the breech screws were loose. That could cause all three problems. The gun is great now. The POI shifts are gone and the RWS Superdomes, Superpoints and Benjamin domed hollowpoints all hit the same POI when I reshot the gun at 20 yards. It also chrony'd at 815fps using 15.9g JSBs for 23fpe. So, for folks that may be experiencing some of the POI problems and maybe some really out of wack pellet problems, one easy check would be to see that the breech screws are tight. My next step is to sight t in a 30 and then maybe 40 yards and see how things go. I am also very please with the TKO22 tuning. One theory about the Superpoints being so far out of wack was with a loose breech, the pellets were not going in far enough to pick-up the rifling, and thus had a slight yaw/wobble when fired. All is fine now.

 
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AuthorReply
Bill B.
(Login billyquest)
YC

Breech screws were loose?

May 18 2012, 12:36 AM 

What exactly did Mike do for you,and how much was it? I have a second hand Disco. I got in a trade,and it never worked right for me. The guy has a hammer spring modd.on it where I had to back the internal hex.head as far back as it would go to cock it where it didn't feel like I was going to break the bolt handle off.Cleaning my closet up I found the crumpled box with the extra .177 barrel,and a hammer,and spring setup. The hammer looked like some one ground on it to lighten it up.I was looking for some one who could adjust this modd.so I could get more than 5/10 shots from the gun,and swhich back to the .177 barrel.I put one of the brass after market triggers in it already. Once I have that done I think I'll have the stock refinished,and modded for the double tube assembly.If I could get 950fps.to a grand with a decent shot count I'll be happy.I shoot .22 all the time,that velocity isn't to wishful is it? What is the standard velocity every one shoots? I shoot 800/850 as an average for my .22's.Shouldn't the .177 be in the range I'm asking? I shoot to hunt,tree rats,rabbits,along those lines.I should be able to reach out to 40/60yards with those numbers for dove,and pigeons,right? What kind of shot count do you think I would get with that double tube attachment? Anyone? Names,and prices.

 
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Joe Dzekevich
(Login JoeDzek)
YF12

TKO Disco Tuning

May 18 2012, 10:03 AM 

The tuning costs $80 and it was another $16 return USPS shipping. Go to this link to see exactly what Mike does on the tuning.http://www.tko22.com/parts.html
I am not a mechanical type, so I had Mike do the tuning. I am very pleased with the results. I also put my 3-9x50AO Centerpoint scope onto the Disco. It just barely fit even with high mounts. The 50mm objective is so large that I had to remove the rear barrel sight in order to mount the scope. That same scope would not hold-in on my .177 Crosman Phantom springer that has a pretty good kick. It does just fine on the "kickless" .22 Discovery PCP. After the tuning the trigger pull seems better; the breech seems smoother; and with the pressure in the gauge green zone, the POIs are the same at 20 yards for the four pellet types that I tried. This week I'll use a Caldwell Deadshot Fieldpod and see how it groups to 30+ yards.

 
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Joe Dzekevich
(Login JoeDzek)
YF12

Number of Shots

May 18 2012, 10:08 AM 

While it is somewhat subjective depending about where one stops pumping around 2K psi, I would say that I get somewhere between 20-25 shots while keeping the gauge in the green zone. This is with the stock .22 Disco tank. It would be interesting to see what folks get who have modified to the dual tank.

 
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Bill B.
(Login billyquest)
YC

Good info with that website!

May 20 2012, 12:16 AM 

Thanks Mike seems like he knows what he's doing.As soon as my income tax check shows up the Disco. is getting the tune up,and shwiched back to .177.I've been trying to get a hold of Rich in Mich to see if I could get another QB79 from him.But no luck so far. I did several transactions with him,and I had his #.But due to circumstances beyond my control I lost my phone #'s.I used to call him,and talk for an hour,or so about his latest Starling hunt on one of the local dairy farms by his house. I used to tell him how jealous I was ,because he had such fertile hunting grounds.Him,and his hunting buddy would get a hundred birds ,or so a piece in one days hunting.Now that's shooting! I have a new policy,I won't by a new gun if I have one in my possesion already that isn't functional. One that's not a parts gun per say.I've been leaning more to the standard hold guns,like multi-pump,and PCP's for my sure shot go to guns.I haven't become that efficiant with the springers yet.I keep feeding them pellets though.I notice I'm getting closer to the mark,and more comfortable with them.Sooner,or later it'll fall into place.Thanks for the response.Keep slinging that lead.

 
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Joe Dzekevich
(Login JoeDzek)
YF12

33 Yards

May 20 2012, 10:58 AM 

OK Bill. Yes, I am very pleased with the TKO tuning. This week, I did set up the Champion bullet trap at 33 yards instead of my usual 20 yards. I put the .22 Disco onto a Caldwell Deadshot Fieldpod to eliminate as much of the variability of me as the shooter as possible. It's not a vise, but it does work very well. At 20 yards after the tuning, .22 Benjamin Hollowpoints, RWS Superdomes and RWS Superpoints had about the same POI. Crosman Premiere Brown Box had a slightly wider group. Big difference at 33 yards. The Benjamin 14.3g hollowpoints were great. In a 10 shot group, I hit a penny sized bullseye at 33 yards 8 of 10 times. The Crosman Premiere Brown Box pellets were second best. The RWS pellets had wider 2 inch groups. The Benjamin pellets in the .22 Disco really "shined" at the longer 33 yards. A comment on the starlings - boy, they got their exercise! If they used a PCP, that was a lot of pumping. If that was a break barrel, that was a lot of breaking. In either case, one would keep fit. :^)

 
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Bill B.
(Login billyquest)
YC

Benji. .22 cal. the same weight as Gamo Hunters.

May 20 2012, 8:02 PM 

That's what I've been using in my LE 392 ACP to thin the treerat population around here.They seem to have the extra umph that down the squirrels.Now I've been using the Cros.Premier in the brown box.They are real accurate.I'm going to see if I can chalk up as many squirrels with them.Close to 300 in about 3yrs.80 to 100 with a 2250 with skeleton stock,and the rest with the LE.There was an ocasional QB78 kill,that's why I expanded on it to the QB79 HPA that I'm shooting now.My shots are primarily 15 to 20yds.sometimes a little more.I beleive Rich shoots a springer at the starlings.He shoots in tin roofed cow barns,and doesn't want to shoot thru. That's why I had him rebuild my Crosman Quest 1000 in .177.he did a wonderful job with it. It cycles real smooth,and has lots of power.When I first got it back,I was shooting at one of those footby foot styrofoam targets with the animal pic's on.I thought I was missing at about 17yds..In reality the pellet was going thru it so fast that it wasn't making it move to where I thought I was missing it.When I looked at it after 5/6 shots I was an inch from where I wanted to hit,but they were clean thru it.He got me all enthused in springer shooting.That lasted for a while,till I couldn't drive nails with it like I could do with a standard hold air rifle. Than he was talking to me one night about what he could get the QB 79's to do,and I was a convert to the so called dark side.I hadn't been able to shoot the QB till recently,and boy what a wet dream that rifle is.Consistent,quiet,accurate,well designed.Everything you would want in a well functioning air rifle for cheap.Well I ran out of space.


    
This message has been edited by billyquest on May 20, 2012 8:06 PM


 
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Joe Dzekevich
(Login JoeDzek)
YF12

Fast Pellets

May 21 2012, 10:10 AM 

Bill, speaking of fast pellets going through things. I did an experiment with water filled dog food cans. Using my .177 Crosman Phantom springer, it would put the .177 pellet through the can and make a water spout but not knock over the can because the 7.4g pellet was fast and lite. Using a heavier .177 10.2g pellet, it would also knock over the can. Using my .22 Discovery with 14.3g pellets, it makes the water spout and knocks over the can every time. The exit holes are also large. Both guns shoot lead pellets in the 800-850 fps range. So the extra pellet weight really makes for improved knock-down power.

 
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