Author Topic: SPA still doesn't get it - Diana Chaser rifling damage (Read 11349 times))

nervoustrigger · « **on:** December 29, 2019, 11:19:16 AM »

Well, here we go again. It's been almost exactly 2 years since I bought a SPA product, this time a Diana Chaser (SPA CP2) for my boy for Christmas. Having seen shoddy barrel workmanship from them in the past, I decided I had better take a look at it. The Chaser is a convertible pistol / carbine that comes with a short barrel and a long barrel. The short barrel looks okay but the long barrel has rifling damage at the muzzle:

For comparison, this is what the last one looked like from 2 years ago:

This is no bueno for accuracy. It will go under the knife soon to correct it but this is disappointing to say the least, and it seems Diana has done nothing to correct this very basic quality issue.

SILENT SQUIRREL · « **Reply #1 on:** December 29, 2019, 11:29:34 AM »

following

Thanks, Jason

CraigH · « **Reply #2 on:** December 29, 2019, 11:53:45 AM »

Notwithstanding Diana's early statements about QC of their SPA sourced models, they appear to be identical to any other labeled SPA guns up to the point of etching the brand name. Some will be good and some will not.

Certainly not limited to SPA guns.

nervoustrigger · « **Reply #3 on:** December 29, 2019, 12:44:55 PM »

Agreed, the benefit of Diana marketing them is the price goes up and the quality stays the same. A win for us.

To be fair, they change a few ingredients in the mixing bowl to make a direct comparison difficult but the effect is undeniable in my view. The Diana Trailscout at $150, for example, is a CR600W that we used to get for $100 - $120 from Mrodair. It has the newer moderator and is capable of using 3 cartridges simultaneously instead of just one which I guess is nice (trades some efficiency for convenience of use), but also gives up wood stock for a plastic one.

Similarly, the Diana Airbug at $130 is a CP1-M with a nicer grip. Sure was a good value when it was $90 - $100.

Thanks, Diana. I know I feel better.

anti-squirrel · « **Reply #4 on:** December 29, 2019, 01:41:02 PM »

I didn't expect to see Diana do anything except polish the poop.

Tooling is older; clearly those longer barrels are either flexing during the machining process or something is misaligned during outfeed... Or something.

I'm sure it will receive the ol' Jason-treatment and the result will be a CO2-powered lead laser

I'll buy a SPA, Artemis, or Onyx-branded SPA, but my meathooks and wallet will avoid the Diana name completely. And my PP700 is still a laser without ever touching the barrel.

KnifeMaker · « **Reply #5 on:** December 29, 2019, 01:58:28 PM »

Mine too. the PP700 is punching way above it's pay grade.

anti-squirrel · « **Reply #6 on:** December 29, 2019, 04:41:54 PM »

Thinking more about this, a lot of folks have great short barrels from SPA. Once the barrel length gets up there, we're seeing some crown problems (seen these on just about every barrel known to man) as well as those insidious chatter/score/drag marks like Jason's. This seems more and more like something amiss with tooling. Vibration, torqueing, side-loading, bed flex/misalignment... Something affecting longer barrels more than shorter ones.

I know my Varmint's barrels (both .22 barrels) exhibit something similar inside the muzzle end. Sorely tempted to finally do something about it but what little free time I've had since Spring was spent doing other things. Anyway... Now I'm thinking TJ's with CF and...

Nope nope nope. I don't need projects!

nervoustrigger · « **Reply #7 on:** December 29, 2019, 05:06:57 PM »

Peter, you may be right about that. Your theory holds 100% accurate for the 5 SPA barrels I have. The two long ones had the rifling damage, the three short ones did not.

anti-squirrel · « **Reply #8 on:** December 29, 2019, 05:20:40 PM »

Quote from: nervoustrigger on December 29, 2019, 05:06:57 PM

Peter, you may be right about that. Your theory holds 100% accurate for the 5 SPA barrels I have. The two long ones had the rifling damage, the three short ones did not.

I may be a noob when it comes to guns and PCPs, but machinery operates under certain principles, always. Also helps I was a Navy machinist mate that went through Machine Tool Operator school (working ~~old~~ ~~really old~~ ancient Bridgeports and Versamills)

Anyway, one of my instructors way back when gave an object lesson in machining bores and then doing follow up passes for keyways. To put emphasis on how critical bed alignment and remoting runout on every bearing surface was, she adjusted one leg about 1/64th of an inch out of level and you could see the second keyway drag slowly out of alignment. When running a finish bore to remove toolmarks on another cylinder ID, the bore went out of round a short distance from the exit-side. The marks we're seeing in the barrels isn't exactly out of round, but those marks clearly indicate contact.

What we're seeing is just a lack of QA/tuning on the mills/machinery, I'm guessing. Or perhaps the metallurgy of the barrel is such that they're flexing or deflecting under the boring/buttoning tool. Any machinists feel free to chime in- I didn't make a career of running tool/die equipment so I may also be way off mark.

Pelletjunkie · « **Reply #9 on:** December 29, 2019, 05:40:55 PM »

Quote from: anti-squirrel on December 29, 2019, 04:41:54 PM

Thinking more about this, a lot of folks have great short barrels from SPA. Once the barrel length gets up there, we're seeing some crown problems (seen these on just about every barrel known to man) as well as those insidious chatter/score/drag marks like Jason's. This seems more and more like something amiss with tooling. Vibration, torqueing, side-loading, bed flex/misalignment... Something affecting longer barrels more than shorter ones.

I know my Varmint's barrels (both .22 barrels) exhibit something similar inside the muzzle end. Sorely tempted to finally do something about it but what little free time I've had since Spring was spent doing other things. Anyway... Now I'm thinking TJ's with CF and...

Nope nope nope. I don't need projects!

I say go for it. Most of my SPA guns wear LW’s and a TJ. Nothing wrong with a $)((# wearing a Rolex.

nervoustrigger · « **Reply #10 on:** December 29, 2019, 05:45:56 PM »

Yeah I'd love to see their process for crowning. I suspect it would be an instant cringe-inducing experience. What's interesting is that is that the rifling profile at the crown was pretty crisp. There is no smearing that would be expected from an old worn-out cutter. So apparently they are maintaining their tooling which leads us back to a process issue. And I doubt the cutter is in contact with the barrel for more than a few seconds to establish the small bevel so there must either be a massive amount of chatter or the pilot is very rough...or a bit of both. If they cared to correct it, all it would take is to put a brass sleeve on the pilot and this problem would immediately go away and there would be virtually no cost or labor increase.

nervoustrigger · « **Reply #11 on:** December 29, 2019, 05:53:15 PM »

Okay the deed is done. Took the hacksaw and removed 0.20" and faced it off on the lathe, and used a #6 screw and J-B to apply a crown:

With only a dozen pellets through it, it's already acting like a totally different gun. First attempt with H&N FTT made a bughole at 25 yards with a little 4x crossbow scope.

anti-squirrel · « **Reply #12 on:** December 29, 2019, 06:13:48 PM »

No surprise, Jason- re-crowns work miracles, and you've got a good track record.

I feel like the problem SPA has stems from soft metal for the barrels. I could be very extremely wrong. Short barrels show no problem, longer barrels do. Deflection can cause that.

Anyway, at some point I'll be making a trip to HFT to pick up one of the small cut-off saws (the tiny one) so I can make cleaner cuts instead of facing off the muzzle with a file (which I can do but gosh-darned it's time consuming!). Also need to invest in some JB paste; diamond burr cones work to a point, but a brass screw with some paste would yield cleaner results.

In the next few months I'll have more disposable income to play; OTOH, I'm considering donating the Var,mint and my Maximus to GTA for the fun-shoot raffles. And Wes has those M-11s; a better starting point than a PR900.

Pelletjunkie · « **Reply #13 on:** December 29, 2019, 09:05:36 PM »

Quote from: nervoustrigger on December 29, 2019, 05:53:15 PM

Okay the deed is done. Took the hacksaw and removed 0.20" and faced it off on the lathe, and used a #6 screw and J-B to apply a crown:

With only a dozen pellets through it, it's already acting like a totally different gun. First attempt with H&N FTT made a bughole at 25 yards with a little 4x crossbow scope.

Very nice.

Scotchmo · « **Reply #14 on:** December 29, 2019, 09:15:32 PM »

Quote from: nervoustrigger on December 29, 2019, 11:19:16 AM

Well, here we go again. It's been almost exactly 2 years since I bought a SPA product, this time a Diana Chaser (SPA CP2) for my boy for Christmas. Having seen shoddy barrel workmanship from them in the past, I decided I had better take a look at it.
...

This is no bueno for accuracy. It will go under the knife soon to correct it but this is disappointing to say the least, and it seems Diana has done nothing to correct this very basic quality issue.

Similar for my Diana Skyhawk (SPA P15). I worked with the factory barrel some, but it was never going to be "match grade". Since replacing the barrel with a LW poly, accuracy has been tops.

Long_Gun_Dallas · « **Reply #15 on:** December 29, 2019, 09:34:45 PM »

Clearly, it's not an isolated issue. But both my pp800 and bandit have been excellet on target. They'll both put up some serious competition with my LW 1322. And that's a one hole gun.

anti-squirrel · « **Reply #16 on:** December 29, 2019, 10:12:42 PM »

Quote from: Long_Gun_Dallas on December 29, 2019, 09:34:45 PM

Clearly, it's not an isolated issue. But both my pp800 and bandit have been excellet on target. They'll both put up some serious competition with my LW 1322. And that's a one hole gun.

Short barrels, right?

If so, I think we affirming something significant.

Walther · « **Reply #17 on:** December 29, 2019, 10:37:31 PM »

Quote from: nervoustrigger on December 29, 2019, 12:44:55 PM

Agreed, the benefit of Diana marketing them is the price goes up and the quality stays the same. A win for us.

To be fair, they change a few ingredients in the mixing bowl to make a direct comparison difficult but the effect is undeniable in my view. The Diana Trailscout at $150, for example, is a CR600W that we used to get for $100 - $120 from Mrodair. It has the newer moderator and is capable of using 3 cartridges simultaneously instead of just one which I guess is nice (trades some efficiency for convenience of use), but also gives up wood stock for a plastic one.

Similarly, the Diana Airbug at $130 is a CP1-M with a nicer grip. Sure was a good value when it was $90 - $100.

Thanks, Diana. I know I feel better.

Hey the trail scout is can be had from wesbob with wood stock also they have 2 stage tiger vs cr600w single stage.

Long_Gun_Dallas · « **Reply #18 on:** December 29, 2019, 11:51:38 PM »

Quote from: anti-squirrel on December 29, 2019, 10:12:42 PM

Quote from: Long_Gun_Dallas on December 29, 2019, 09:34:45 PM
Clearly, it's not an isolated issue. But both my pp800 and bandit have been excellet on target. They'll both put up some serious competition with my LW 1322. And that's a one hole gun.
Short barrels, right?

If so, I think we affirming something significant.

Yes. The barrels visually both appeared to have been machined thru a rough process. And subsequently were tossed in a bin with other barrels; rattled about for who knows how long before actually finding their way onto a gun. But I could not ask for them to shoot better. So, I've seen no need or reason to do anything to either. But i do polish the bore on any and all guns I have immediately upon reception.

anti-squirrel · « **Reply #19 on:** December 30, 2019, 12:04:34 AM »

Thanks for the info, Dallas.

I'm thinking more and more that SPA just has some type of tooling issue only evident on long barrels. Without knowing how they machine or bore their rifling or watching the tooling, I can only guess at the root cause, but with so many short barrels performing so well there has to be something going on.

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SPA still doesn't get it - Diana Chaser rifling damage

Author Topic: SPA still doesn't get it - Diana Chaser rifling damage (Read 11349 times))

Walther