Author Topic: 50 Meters? QB78  (Read 7285 times)

Offline DeutschKSK

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50 Meters? QB78
« on: May 11, 2010, 05:38:57 PM »
How accurate are these guns @ 50 meters? Running on co2. I have been looking into getting one of these with a custom breach, bolt, seals, power kit.. and more! From Archer Airguns.

Thanks in advance.


Offline Gene_SC

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Re: 50 Meters? QB78
« Reply #1 on: May 11, 2010, 07:02:24 PM »
The man to ask is Ribbinson on the GTA. He loves them and probably has 50 of them..:) All different versions.
THE ONES I SLEEP WITH: BSA Lightning XL, AA TX-200, AA ProSport, BSA Ultra, HW-97K, Crosman NPSS .177, FX Cyclone, HW-30 Nicle Plated, AA-S200, Crosman Marauder, CZ-634, R-9 DG, Webley/Scott UK Tomahawk, Benji Kantana, Benji Marauder, Benji Discovery.....

Gene\'s Tunz n Toyz
Springer Tunin

Offline lillysdad621

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Re: 50 Meters? QB78
« Reply #2 on: May 15, 2010, 12:35:02 AM »
50 meters is stretching those rifles capabilities. it will get there but the groups may not be what you expect. I own a .22 78 that i home tuned and it shoots consistenly at 540 fps for 47 shots. it will group one hole out to 30 yards but at 45 the groups open up to a 1 to 1.5 inches. I also had a 79 in .177 that grouped similarly as it used barracudas and shot those at 570 fps. it would not group at all with light pellets, so getting to 50 yards also had a ton of drop to contend with. I own a crosman 167 that was tuned by MAC1 and that one shoots sub inch groups to 45 yards but it is also shooting crow mags at 715 fps average. I imagine that a 78 similarly tuned might shoot about the same. hope this helps. no matter which one you choose the qb are cracking little rifles that will provide you with a ton of fun. and archer is the place to get them from.

Offline ribbonstone

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RE: 50 Meters? QB78
« Reply #3 on: May 15, 2010, 02:17:10 AM »
Going to cut to the chase: buy the AR2078.  Think that would be your best bet out-the-box.  The one in the picture below has been run on 12gr., run as a bulk fill, run as a co2 tnker, and run on an HPA bottle... it's not been more or less accruate though it all.

Like any airgun, it depends on the shooter,the wind, and the pellets used.  Keeping under 1" with standard barrels  is pretty common, even when shooting at issue speeds (like 550fps in .22).
Shoot enough, and sooner or later you'll luck into one of those bragging groups, but for every one of those tine ones are blown groups 10X as large.  For me, I'll need 4 or 5 5-shot groups that average under 1" .

Are a lot of tune up hints and instructions on-line, but if accuracy is the goal, then look to do these things:
1. Really get that barrel stable to the breech.
2. Figure out what that rifle wants in the way of barrel bands... some want none, some one one, and some want two (check the pix below... seems I've ended up with nearly every combination)
3. Make sure both ends of the barrel, breech and crown, are smooth and burr free.
4. Get that trigger consistent.  Doesn't have to be super light, but it really helps to have it break the same each time.
5. Tune the gun, but not for power, look for the most consistent results.
6. Test the hell out of it at shorter range to weed out the pellets that would be a waste of time to try at 50.

Out of all that work, it's mostly the barrel.  Get the rifle consistent and stable, and if it won't shoot, pull the barrel off the rifle and start working on it (see #3).  Might shorten by 1/2" and recrown... may do that more than once...may lap the barrel...but the fact is that some of them never will make the 1" at 50yard goal.  

Two of the ones below have been rebarreled, but because I have so many QB's, were rebarreled to non-qb calibers (one is a 5mm and one is a .25).  Don't list barrel replacement as a "must do" as the other gun's barrels shoot just fine.