Expected accuracy, Chinese PCP’s?

It has been said by some that Chinese barrels are a lottery - you get some good ones and some not so good.

I was going to say to try some softer pellets, but you have already tried the JSB 15.89's so you are covered there.

What chrono numbers are you getting?

One of the guns I have with a Chinese barrel is an Air Venturi Avenger. I bought it as a less expensive rifle to test out and see if I could recommend it to friends getting into PCPs who don't want to start out by dropping $2k on a Crown. I tested it side-by-side with a Benjamin Cayden.

Although I did not like shooting the Avenger as much as the Cayden, in my hands it shot just a little more accurately than the Cayden. Maybe I got one with a good barrel in the lottery.

As received from the shop the Avenger was shooting 18.13's just a bit too hot, and 15.9's way too hot. I lowered the reg pressure to get velocities down, especially since I decided I wanted to shoot 15.9's out of that gun to use less air and get a higher shot count. Unfortunately the hammer spring pre-load adjustment screw was frozen in the gun so it had to go back to AV for warranty repair. Just got it back yesterday so I can now hopefully continue my down-tuning of it.

So your gun may be shooting pellets with too high a muzzle velocity, which results in poor accuracy. If you don't have access to a chrono, at least maybe try some 18 or even 25gr pellets in it and see what happens with accuracy.

BTW I had one 5-shot group with the Avenger at 61 yards which measured 0.31" (18.13 gr pellets). Definitely couldn't do that every time but sometimes it could and mostly I could at least hold MOA with it. As a comparison, shooting a 5-shot group the same day and under the same conditions with that gun using the CPHP 14.3's resulted in a nearly 2" group.

Groups are in this thread: https://www.airgunnation.com/topic/testing-some-reasonably-priced-pcp-rifles-avenger-and-cayden/?referrer=1

I don't know about the Gauntlet 2, But I have a Gauntlet 1 in 22cal and the only thing I have done to that is add a moderator and a good scope and I am getting sub 1/2" at 25yds with all sorts of pellets including the cheap crossman 14.3HP and the JSB 18.1's barely shoot better, I do almost all my shooting 25yds and in so I can't give you any advice on 50yds.

But I am curious what kind of groups do you get at 10yds? At 25yds? Is it only out to 50yds you get bad groups? That might be a pellet weight or twist rate stabilization issue, you might need to go to some heavier pellets like 18.1gr-21gr. If at all ranges it might be a barrel issue. Unless you chronograph what your gun is shooting at its hard to tell. Are any of the pellets producing abnormal holes in the paper, sideways, oval, ragged? 

I have heard others mention a chinese barrel lottery and maybe there is something to that, and maybe a return or replacement might be your next step.

My best advice is buy some heavier pellets and some other brands, and get a chronograph, some guns are just picky. My little Umarex pistol only really likes those H&N barracudas to shoot well, everything else I have put in it doesn't perform near as well and with crossman 14.3HP's it shoots a 3" group at 25yds, with the H&N it shoots a 1" group.

thats about what id expect lol .. they mass produce barrels and crown them with a quick throw in a lathe with zero setup and a plunge by hand to whatever depth it comes out to with a dull chattering tool bit lol .. more or less .. and you cant get to it easily with a plastic ldc epoxied on .. so id say yeah, most of it is a gross job on the crown, and some may be a throat with sharp edges thats chewing pellets while feeding them in, that you can adress pretty easy ... that said my 177 chief 10 beers gets them in around an inch at 50 lol .. but 'expect' from a sub 200$ kungpow special, dont .. you can improve it with some work ...pellets and spring setting wont fix the base problem if its that bad ...

It sure sounds like dizzums knows his way around a barrel and machine work. Much more than I do.

But I also think you need to bite the bullet and get a chronograph if you are trying to get at all serious about tuning and accuracy - with any gun. It is an indispensable tool in the end, and you may find yourself using it more than you initially think. Especially if you get one which is portable and easy to set up (FX Pocket Chronograph, Air Chrony, etc.) 

I have never used a more 'traditional' chronograph which needed the shades to be set up over it. Figured it would be too much of a PITA to set up and take down, and I just knew that eventually I would shoot one of the support rods. But maybe I was wrong and they are O.K. They are cheaper to purchase, and they will give you the data you really need for tuning. And maybe make it easier for you to know, and therefore return the rifle if you did get a bum one.

I start more cleaning. Grab a patch worm and ballistol and really get it clean. Then lead in for 500ish pellets.

I'd try more pellet variety. I have a snow peak gun (PP700) and it is hit and miss with pellets. It dislikes 15.89 JSB's, can't group larger than a 50 cent at 30y. 16 grain Air Arms, essentially the same pellet, will shoot dime or smaller 5 shot groups if I do my part.

If I tried every pellet and still had the same results, I'd polish with some bore compound.

If it still has some issues, I would do a dremel crown.

I start more cleaning. Grab a patch worm and ballistol and really get it clean. Then lead in for 500ish pellets.

I'd try more pellet variety. I have a snow peak gun (PP700) and it is hit and miss with pellets. It dislikes 15.89 JSB's, can't group larger than a 50 cent at 30y. 16 grain Air Arms, essentially the same pellet, will shoot dime or smaller 5 shot groups if I do my part.

If I tried every pellet and still had the same results, I'd polish with some bore compound.

If it still has some issues, I would do a dremel crown.

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My PP 700 actually likes the JSB 15 grainers.Just goes to show you that every gun can be different even if it is the same model.But you are right by telling him that he probably needs to clean the Barrel better. The way he described it didn’t seem ideal. And also checking the crown.

Reading that it is your first rifle, I am thinking maybe it is not the rifle, or the barrel, or the pellets. Maybe the shooter needs to train how to shoot accurate.

Do some google and YouTube searches, there are lots of videos out there.

I have a couple of Chinese barrels that are truly superb. The only unsalvageable one was on a SPA made Mrodaire rifle where it matched Dizzum's description pretty well. The crown was very bad and the tool had used no guide, so there were lots of cut marks in the last 1/4" of the bore. I cut that off and recrowned, then went after the breech.... very poor also.

The bore ended up being a bit large and opening slightly the last 2 inches... bad combo, so nothing I could do without the means to choke it a little.

Pull the barrel off and clean it with a rod, jag, and patch. Then push a pellet through it to get a feel for uneveness and look at the pellet for signs of damage. Check the muzzle with a magnifier for uneveness or damage to the crown. You'll likely know why after that.

Bob

I recently purchased my first PCP, a Beeman Chief 2, and was having trouble with accuracy. I cleaned up the descending shot string somewhat by reducing the hammer pressure. I am still getting 2.5”@ 52 yards, at best with it, more like five inch, with crazy fliers.

I cleaned the barrel with .22cal cleaning pellets, one oiled, stacked with three dry behind it twice, then a stack of three dry. 

I’m shooting Crosman HP, Copper Magnums, and JSB jumbo 15.89’s, and I’ve got about 400 rounds through it so far.

I also purchased an Umerex Gauntlet 2, and I’m getting nearly the exact same results from both guns. 

anyone with experience, or ideas?

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I just watched STKO's new video today on the gauntlet 2 and found out some interesting information. https://www.youtube.com/watch?v=94A6vr8RSzc

It appears the new Gauntlet 2 has a 1/13.5" twist barrel vs the old Gauntlet 1/20" twist barrel. He said only the 21gr+ pellets are working well in it. I am guessing they probably made the change to shoot heavier pellets and slugs. Just thought I would share that with you as you may want to try some 21gr+ weight pellets or slugs in it. None of the other lighter weight pellets he tried seemed to group well. At 50yds he shot a dime sized group with it out of the box using 21gr. H&N barracuda's

check the crown , if you cant get it to shoot straight , messege me I put it on lather for you square it up and recrown it and polish bore , I had a cheaper p15 that sot 3 in at 50 yrds after someone got sick of it I bought it and redid barrel squaring it up and polishing it and recrowning it , and it shot 1/2 inch groups all day long at 50yds with either 15 or 18g ammo ,my guess is barrel and or crown needs to be reworked a uneven crown or dented or flawed can make gun unshootable I have seen many airguns with poor crowns and even many guns with no crown , airforce products many big bores have never been crowned ,and shoot wild groups and recrowning tightenes everything up 



as far as no crono , you can get a pretty close estimate like for example a 30fpe gun in 22 cal with jsb 18 gr if you zero at 50 yds and shoot 100 yds will drop about 4 mils so you can pick 2 known distances and zero at one ans shoot other and see drop to get idea do you understand?????

LOU

I second the accuracy of the Air Venturi Avenger. Mine in .22 is just a tad bit less accurate than my Benjamin Marauder, regulated with LW barrel and at half the price.

Give Jsb monsters 25 gr a try in your gauntlet 2. Mine loves them!