S510 Ultimate Sporter XS Chronograph Chart

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TenMetrePeter
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Location: Luton Beds UK

Re: S510 Ultimate Sporter XS Chronograph Chart

Wed Oct 10, 2018 9:23 pm

My 2p worth.
I dont think the reg is working at all
If it was regulating there would be no curve at the start.
That plus a lot of shot to shot variation suggests its a dirty internal action too.
A Friday afternoon gun.

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Bob_O
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Joined: Mon Oct 08, 2018 11:30 pm

Re: S510 Ultimate Sporter XS Chronograph Chart

Wed Oct 10, 2018 9:43 pm

Thanks Tony.

Here is the shot string I did for Alan of Air Arms last night....from 250bar to 150bar. As controlled a test as I could do.

The ES was 90 and SD was 22 over 75 shots. Even if one took out shot #36, which had a huge dive in velocity (856fps compared to 915fps for shot #35 and 917fps for shot #37) taken out, the ES was still worse at 76 compared to my self-established optimal fill pressure of 220 bar and stopping at 125 bar (60 shots) for an ES of 40 and SD of 8, the best I've been able to get on High power over 60 shots. The best I got on Power Lvl 4 was ES of 33 and SD of 8.

Hard to make sense out of this without a chart or graph, but I can't upload images to the site and I don't host my own.

Waiting to hear back from Alan.

Thank you.

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GWE
Posts: 17
Joined: Sat Oct 06, 2018 3:05 am

Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 6:56 am

Hi all,

Just for the record neither Bob or I ever thought or said there wasn't a regulator in the XS. Whatever regulator is in there is just giving us some petty weird results; increasingly weird to the point where I'd consider sending mine back unopened. Hopefully Bob will publish the graph I prepared for him from test data that AA requested; specifically a 250 Bar to 150 Bar shotstring with the same brand and weight pellets he used previously (i think Bob said they were even from the same tin)...If I recall correctly there were abut 70-75 shots in the string, The graph is pretty weird. Its not a Bell curve; this one is more linear gradual upward slope with progressively higher velocities as the number of shots increases. Almost sounds like some sort of hammer/pressue issue.To be honest I'd rather not conjecture; I'd rather hear what AA has to say. Bob forwarded them the data yesterday morning. Whatever happens they need to look at his and possible others rifles to see whats going on and take care of the people who trusted the brand to the tune of...damn it used to be like $US 5.25 to the £ when I was a kid in Lakenheath....any way a bunch of quids worth of air gun.
Last edited by GWE on Thu Oct 11, 2018 1:05 pm, edited 2 times in total.

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GWE
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Joined: Sat Oct 06, 2018 3:05 am

Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 12:53 pm

Greetings all, found a workaround so you can see...sorry abut the size but you'll get the drift...

Image

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TenMetrePeter
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Location: Luton Beds UK

Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 1:26 pm

Keep shooting and you'll go supersonic!

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GWE
Posts: 17
Joined: Sat Oct 06, 2018 3:05 am

Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 2:56 pm

TenMetrePeter wrote:
Thu Oct 11, 2018 1:26 pm
Keep shooting and you'll go supersonic!
The thought occurred to me Peter,

AA set the parameters for the test and Bob just did what they asked. Up until the time of their request Bobs been doing nothing but his usual pesting and shooting. Oddest damned thing I’ve ever seen. So odd in fact I need to double double check the raw data to make sure it didn’t import into the spreadsheet program in some weird kind of sorting. The date and time stamps looked good though.

George

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Archer50
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Joined: Mon Jun 20, 2016 5:06 pm
Location: Perth

Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 3:04 pm

It will be very interesting to hear what AA say. I would not expect a bell-shaped curve unless the regulator was simply not working. In the real world, a regulated shot string is hardly ever flat, and MV shows a clear trend from full to empty, normally downwards. I don't know about the regulator AA use in these guns, but in all the gun/regulator combinations I have seen an upward trend like this would indicate that either the regulator output pressure has been set far too high or the regulator is faulty and/or dirty.

However, upwards or downwards, the trend you are showing is massively too big too be acceptable - I would expect it to be no more than about 10 fps from full to empty, and usually <5 fps is easy enough to achieve.

BTW - and I mean this respectfully as one who has been there and done it :oops: - any chance you double-shotted #36 ?

Alan

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tonyc
Posts: 376
Joined: Mon May 29, 2017 10:55 am

Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 4:15 pm

I agree with Alan. The only thing I would add is that this could be the upward slope of an unregulated curve. So the reg inlet valve could be stuck partially open.

I've seen the dropped shot before - in my case the cause was the action. If you keep seeing low velocity shots try shooting through two chromos; it could just be a bad chrono reading but you'll know for sure if the chronos don't correspond.

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TenMetrePeter
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Joined: Wed Jun 29, 2016 5:40 pm
Location: Luton Beds UK

Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 6:23 pm

Another 2p worth. If a gun is regulated the firing valve should not be "aware" of the cylinder pressure until it drops below the reg setting. So a bell curve would not be expected in my opinion. Thats a naked gun sweet spot curve.
ANY curve at all with a full cylinder is because either the reg is stuck open, massive leak, or set above fill pressure.
Even a slightly leaky reg (ie where pressure builds up in the valve area over several minutes) only gives a wonky first shot, not a stream of them.
The only fluctuation expected with a regged gun is a zigzag because of simple physical random friction variation but the trend would be flat until reg setting is hit.
ANY hint of velocity being affected by fill pressure means it is simply not regulated.

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tonyc
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Re: S510 Ultimate Sporter XS Chronograph Chart

Thu Oct 11, 2018 7:24 pm

Peter, if you send me a PM with your email address I'll gladly send you some curve profiles - up then down, down then up, up and down like a snake - all with the reg working normally. Most regs are (very slightly) cylinder pressure sensitive. For example, Altaros state theirs is and by how much, though how they get it so flat is beyond my comprehension given they don't vent to atmospheric. Regarding slow leaks, if the reg chamber is relatively large, cylinder near maximum pressure and the set point low, a single shot will not exhaust the chamber so the excess lasts for more than one shot (but not many more).

Don't disagree with you this one is not working but something else is happening as, collectively, I don't think we've explained the initial increase in the first profile. BTW several of my profiles exhibit this, for known reasons, but it's a different gun and causes not directly applicable to the US.

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