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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: PackingHeat on February 27, 2013, 12:03:19 AM

Title: Is my Disco barrel defective?
Post by: PackingHeat on February 27, 2013, 12:03:19 AM
Let me start off by saying that I am a machinist and engineer with over 25 yrs. of experience. Some of the first parts I produced were the Williams peep sights that the Benji pumper guys know well. I have precision mics and calipers. I have had a hard time getting anything but JSB pellets to shoot anywhere near accurate. Groups look like a buckshot pattern. JBS are great. I pushed a couple pellets thru the bore and measured them with mics. I measured the bore and rifling with calipers as well. It appears my bore diameter is .218 and the rifling is .219 . My Benjamin 342 bore is .217 and the rifling is .221 . The extruded form is much better on the Benji 342 pellet. It is barely visible on the Disco pellet. Based on a lifetime of weapons experience I have never seen rifling this shallow. Please tell me what is typical for this barrel. I can't have a gun that will only shoot 2 pellets both from the same company. Should I call Crosman and have them pick me a barrel with deeper rifling. The Tippman and Hammerhead paintball barrels I have made have better rifling and it is mostly a marketing gimmick having virtually no effect on the paintball.
Title: Re: Is my Disco barrel defective?
Post by: Dead nuts dog on February 27, 2013, 12:18:20 AM
Well I'm just a fisherman but the common with air guns ( to my knowledge ) is that they all like one pellet over the rest. I had a disco that liked polymags and the discovery pellet. I'm pretty sure I was very lucky to have two that it would shoot.
Next rule of thumb is shoot crosman pellets threw crosman guns ----- shoot daisy pellets threw daisy guns, ........
Hope that helps
Title: Re: Is my Disco barrel defective?
Post by: Monkeydad1969 on February 27, 2013, 12:32:16 PM
After a bout with POI shift (from adding a heavy hammer spring, fixed when went back to stock spring), my Disco likes CPHP's 14.3, the JSB's Exact Jumbo Heavy Diablo 18.13, (loves) the H&N Baracuda Hunter Extremes 19.09 and Predator Polymags.  And when sighted and power adjusted for them, it likes the Skenco Newboy heavy-weight 26.2, the JSB's Exact Jumbo Monster Diablo 25.39, and the Eunjin domed 28.5/pointed 32.4.

The heavy hammer spring was great at first.  May have been a break in period with that and then when I got the new pellets.  So I will try it out again to see.  But with some conversations with others, I will be getting a second barrel band.  I still have flyers, say one out of 5-8 shots and that seems to be with the CPHP's, but not all the time.  I will be getting either the valve reworked or the B&N Max Flow and a complete tune from Dave @ addicted2airguns.com.

You never know what will happen with the Disco.  I wasn't having any POI issues when it was .177 (there was a break in period).  It was a tack driving monster at 35 yards and a bird MONSTER at 50 yards.  But I still believe my .22 conversion is still young right now, but maturing nicely.  My plan is to throw heavy lead like the Eunjins and Mr. Hollowpoint casts at 50-70fpe.  So we will see.  Hopefully by May I can give an end to this story.

Let us know what happens with your barrel situation.  I may end up getting another from Crosman, or spend a mint on a LW.  Why not?  already have a weeks worth of pay tied into it.  LOL!!!!!

Joe
Title: Re: Is my Disco barrel defective?
Post by: rsterne on February 27, 2013, 01:22:52 PM
I had one Crosman .22 cal barrel (the original one on my Disco) that had rifling so shallow you could hardly see it.... The gun actually still shot OK, but ONLY with JSB 15.9 gr. pellets, everything else was a shotgun.... I replaced the barrel with a random one ordered from Crosman, and never looked back....

Bob
Title: Re: Is my Disco barrel defective?
Post by: PackingHeat on February 27, 2013, 02:42:03 PM
I had one Crosman .22 cal barrel (the original one on my Disco) that had rifling so shallow you could hardly see it.... The gun actually still shot OK, but ONLY with JSB 15.9 gr. pellets, everything else was a shotgun.... I replaced the barrel with a random one ordered from Crosman, and never looked back....

Bob

That is how this one is. If you look at the crown the rifling is almost impossible to see and in the bore it looks more like drag marks than cut rifling. It's unlike any barrel I've ever seen. I think the broach was really worn out. I'm going to call Crosman and see if they will make things right.
Title: Re: Is my Disco barrel defective?
Post by: badredbird on February 27, 2013, 04:23:01 PM
nothing like consistent quality from crossman , clled the recently also  said they are no longer selling disco without pump
Title: Re: Is my Disco barrel defective?
Post by: rsterne on February 27, 2013, 05:08:54 PM
I figured the broach was worn out as well.... Lucky me to get one at the end of the run....

Bob
Title: Re: Is my Disco barrel defective?
Post by: PackingHeat on March 01, 2013, 06:44:38 PM
I called Crosman today and they said to send the barrel in and they would swap it for a new one. Thats means my Disco is down for  while. Hopefully the new barrel is good.
Title: Re: Is my Disco barrel defective?
Post by: woodant on March 01, 2013, 11:00:43 PM
It's good that they are letting you send it in.  Hopefully they send you a barrel with better rifling.

I am assuming you paid to ship it back?   ::)
Title: Re: Is my Disco barrel defective?
Post by: badredbird on March 01, 2013, 11:40:41 PM
at least they are decent enough to make good   but if they just stepped up qc would save folks some money aggravation and time   are these barrells made in america? i look at some of the older benjis and say wow    the qc has really slid from those days as ive had some probs also with some crosman and benji sheridan products   
Title: Re: Is my Disco barrel defective?
Post by: PackingHeat on March 02, 2013, 11:20:45 AM
The QB 79 I just bought has a good looking bore with deep and crisp rifling like all my other guns. Unfortunately in manufacturing we have a saying: Price, quality, and delivery. Pick 2. That is the general rule, not the exception. When things are too rushed quality is always the thing to suffer first.
Title: Re: Is my Disco barrel defective?
Post by: PackingHeat on March 20, 2013, 10:49:39 AM
I got my replacement barrel and this one has good rifling. I did not get any response to my letter telling them how disappointed I was at this messed up situation and the costs I incurred troubleshooting their quality control problems.
Title: Re: Is my Disco barrel defective?
Post by: Symore on March 20, 2013, 11:53:40 AM
Glad to hear you were sent a good barrel. At least they got it right the this time. I cant to wait to hear your testing results with the new barrel. Happy shooting  ;D
Title: Re: Is my Disco barrel defective?
Post by: woodant on March 20, 2013, 11:57:47 AM
Yes indeed!  Let us know how the new barrel shoots!