S510 Ultimate Sporter XS Chronograph Chart

[GWE]

I've been participating in a thread in the States on Air Gun Nation regarding the performance of the factory regulator in the XS models offered there...I'm not an expert on the technical aspects of regulators but I've seen regulated shot charts that were nearly straight as a arrow. It seems the results I'm posting here are less than sterling but it was suggested I come over and ask for comments by one of the contributors in the SU thread. So I thought I'd post them here for general comment. I was not the individual who performed the test simply had the air gunner's results forwarded to me in CSV to convert to a graph. The individual who performed the test is an experienced air gunner and although I did not include data like the temp, BP etc I can provide them if necessary. However I don't think they're going to have much bearing when one reviews the chart.



Unfortunately the chart I created for his 60 shot 220 Bar Fill of JSB 15.89's at Power Setting 4 wasn't published to the web so I don't have a URL for it. Happy to provide that to someone for posting. If so msg please me. Ah wait I may be able to attach it...but apparently not at least not as a .pdf. Not sure if that a permissions issue or size of file issue. but again I'm happy to send it on to someone who can put it up.

Regards,
George

[pelletcaster]

By far no specialist just a shooter that likes to fettle your shotstring does not look like a regulated one.
May be the reg pressure and/or hammer spring tension are set to low.

Acc. to your figures your gun seems to output about 31 fpe / 42 Joule.
It needs about 11 shots to come from 220 bar down to slightly under 200 bar to reach the average power region.
There it remains for another 42 shoots until power starts diving.
So it seems to consume estimated 1,5 bar per shot.

My P12 is HUMA-regged and set up very similar to yours and here is a typical shot string and efficiency calculation.
https://picload.org/view/dcrgipdr/p12hu ... g.png.html
https://picload.org/view/dcrgipca/p12hu ... n.jpg.html

Hope this helps.

[tonyc]

I have no experience of AA reg so will comment only from experience of two other regs (Altaros and Weihrauch) including results of extensive testing to establish multiple causes of power variation in the Weihrauch.

This cycle is not unregulated. The variation over shots 1-11 is not normal but an increase of the first few shots (up to 4 or 5, as pelletcaster's chart) is not unusual, for reasons given below. Consistency over the rest of the string is not great, but not exceptionally poor. Depending on reg design, a small dependency on cylinder pressure (a slight downward trend) is normal, and often there is some increased irregularity as the gun comes off reg. (This irregularity is irrespective of reg pressure, so I'm not referring to increases/decreases cause by reg pressure too high/low.)

A number of questions need to be asked to establish if the variations are due to other causes:

Were all results recorded in a single session with no breaks between shots and consistent shot frequency?
Were the pellets all from the same batch and unlubed? Had the barrel been cleaned and re-leaded. Did the session start with a different pellet to those used for the previous session?
Was the gun filled immediately before the session or left filled for an extended period (overnight for example)?
Was the gun at the same temperature throughout?
Was the same chrono used for all shots, what type was it and, if reliant on an external light source (daylight or artificial) and did the light conditions change? If battery powered, were the batteries in good condition? Has it been checked/verified against another chrono? (For any serious analysis I always use two.)
Is this curve repeatable?

Changes in temperature may cause substantial power variation - more than 1fps per degree C - so any transition from warm/cold storage to cold/warm test environment, or change caused by filling can have an effect, often seen at the start of a session. Also any slow air leakage into the reg chamber can result in higher initial reg pressure (lower power) which would normally dissipate over the first few shots.

Contamination and/or sticking of the reg inlet valve can cause variations as can any contamination, dry grease or lack of lube in the hammer assembly. Sometimes this can be temporary so the action frees up after a few shots.

One afterthought..... if you increased the velocity of the first 10 shots by 16fps you would have a fairly normal profile. So was the first magazine loaded at a different time, with different batch?

[GWE]

Gentleman,

I'll try to get the air gunner himself to respond to the questions below. But for now I'll give you the answers as I understand it

Were all results recorded in a single session with no breaks between shots and consistent shot frequency?

Yes

Were the pellets all from the same batch and unlubed?

I don't know, but he did mention the same tin

Had the barrel been cleaned and re-leaded.

I dont know for a fact but given the gunners experience and rather lengthy history with air rifles I would conjecture he took his usual care in develping the shot string


Did the session start with a different pellet to those used for the previous session?

No, All are JSB Eacts 15.89 gr.


Was the gun filled immediately before the session or left filled for an extended period (overnight for example)?

I don't know, but he did say at one point the tube was holding pressure exactly in the morning as from the night before

Was the gun at the same temperature throughout?

From his data I would say yes...~69 F ambient

Was the same chrono used for all shots,

Yes

What type was it and, if reliant on an external light source (daylight or artificial) and did the light conditions change?

I'm not familiar with his chrony but my guess it was the one that uses the Blue tooth Digital Link


If battery powered, were the batteries in good condition?

I dont know

Has it been checked/verified against another chrono? (For any serious analysis I always use two.)


I understand the question from an instruction tech perspective but from a practical standpoint I doubt that many air gunners have two

Is this curve repeatable?

I don't know if he ran several strings under the same condition, again as an instrumentation tech I understand the question. I can however provide you with a file that reflects similar behavior at the same fill pressure, atmospheric conditions, and shot count, As far as I know the tests were run sequentially without a break.

Changes in temperature may cause substantial power variation - more than 1fps per degree C - so any transition from warm/cold storage to cold/warm test environment, or change caused by filling can have an effect, often seen at the start of a session.

He would certainly understand that

Also any slow air leakage into the reg chamber can result in higher initial reg pressure (lower power) which would normally dissipate over the first few shots.

This was put forward by and Australian member of the forum; a leak form the tube into the plenum as being the explanation

Contamination and/or sticking of the reg inlet valve can cause variations as can any contamination, dry grease or lack of lube in the hammer assembly. Sometimes this can be temporary so the action frees up after a few shots.

There were in excess of 500 shots through the air rifle at the point this curve was developed. I would think that would count might also address the question of leading the barrel


One afterthought..... if you increased the velocity of the first 10 shots by 16fps you would have a fairly normal profile.

He commented something the same effect when were exchanging emails

So was the first magazine loaded at a different time, with different batch?

He has two as provided with the rifle and one was defective but to answer your question. I don't know.

Bob, spends an considerable time evaluating his own air rifles and this one struck him as pretty disparate from other regulated rifles such as a regulated Daystate or FX. As I said I hope he'll come over to address the questions at hand but from the responses I'm seeing here the genreral consensus is that something is off. Its my personal opinion that the graph is more than bit jumpy when compared to say

I'd encourage any member here to check ou the thread and see other examples of his raw data as he posted, the post is ...https://www.airgunnation.com/topic/aa-s ... er-chrono/

All across the pond thank you guys for your interest and responses. I know one gentleman has returned his .177 cal XS because of very similar results over a chronograph. Bob is a phenomenal hunter and has several permission properties on which he shoots, his most recent posts from the thread above are from one of those properties, Although he has some serious concerns over having paid the price for this air gun its not holding him back from enjoying it and getting some great results...He and I as well as many others who contributed to the thread feel the regulator should definitely be perofong better. I'm currently in Belize with my own .22 cal XS still in the box...to my mind there are not many better looking heirloom quality air guns in this price range and may simply keep the rife, deal whites foibles and hope that Air Arms can address the situation. IN fact I may simply send my now back to the US AA tech center at Pyramyd Air to have them go through the regultor thouroughly With the Miss Clair recently offering a three (3) year warranty on any of their rifles (that have nt been "monkeys" with I may simply hold off trying to correct anyting myself and if the regulation becomes worse then I will take advantage of that warranty. Please feel free to ad to this thread. I personally will be following this issue up and if need be actually calling Air Arms in England. I've already sent an email to their Export Manager Sheila Cooper to forward on to their tech support staff for a response. I guess I just expected more from a the first regulated air rifle offered by a company as reputable and enduring as Air Arms.

My best regards to you all,
Geogre

[GWE]

By far no specialist just a shooter that likes to fettle your shotstring does not look like a regulated one.
May be the reg pressure and/or hammer spring tension are set to low.

Acc. to your figures your gun seems to output about 31 fpe / 42 Joule.
It needs about 11 shots to come from 220 bar down to slightly under 200 bar to reach the average power region.
There it remains for another 42 shoots until power starts diving.
So it seems to consume estimated 1,5 bar per shot.

My P12 is HUMA-regged and set up very similar to yours and here is a typical shot string and efficiency calculation.
https://picload.org/view/dcrgipdr/p12hu ... g.png.html
https://picload.org/view/dcrgipca/p12hu ... n.jpg.html

Hope this helps.

Hello Pelletcaster

Thank for the reply. I'd simply point out that the S510 XS's full capacity is a 250 Bar, as per manufacturers recommendations...that recommendation was marketed as the fill pressure that could be used because the rifle was regulated. In the case I've presented the air gunners fill is starting out 30 Bar below the recommend fill of 250 Bar or 220 Bar, about 12% less than the manufacturers recommendation. Yet he is still having to shoot more than a dozen shots to get it to even begin to be in the average power region you mention. So yes I'd agree with your first statement the shot-string doesn't not seem to be a regulated one. It certainly is not even close to the ones you linked here.

Personally I doubt the shot string I presented is one influenced significantly by some of the more obscure chronograph testing issues raised by the other gentleman. Since I have no way of displaying the second shot-string at the XS's Power Setting 4 due to issues with uploading the graph up to the website, I'm afraid you'll have to accept my word that his "regulated" shot string at the same fill pressure and the lower power setting is performing in a similar fashion. That shot-string too was started with a fill of 220 Bar (12% low), shot in the same chronograph session, and used the same tin of pellets under the same atmospheric conditions. As was once said in the Gilbert and Sullivan* operetta, :The King and I"... "Its a puzzlement". Meanwhile I'm waiting to see if AA will respond to our inquiries. Thank you again and kind regards.

*Apologies ----> Rogers and Hammerstein!

[pelletcaster]

Hi George,

Thanks for your feedback.
I'm looking forward too to the news from AA to you.

And thanks to tonyc for his highly appreciated input.

[TenMetrePeter]

Rogers and Hammerstein.

[GWE]

Rogers and Hammerstein.

Ha! No wonder I failed music appreciation...

[tonyc]

Just a follow up on the reply to my questions. A slow leak into the plenum chamber is not going to cause a noticeable drop in the cylinder pressure but will result in that initial climb over first 4-5 shots. Easy to check this by shooting a full charge in two sessions with an overnight break in the middle.

I do think there is something else going on. If you are saying there were only 500 shots from new before the gun was tested, too much grease in the hammer assembly could be an issue. Other owners have criticised AA for this. I'd recommend a clean and polish of the hammer rail and a light lubrication with gun oil not grease. Too much grease will mobilize over a few shots and migrate when left unused. Also some lubricants can have viscosity/temperature dependency (Weihrauch had this) or can be prone to drying out giving some erratic results.

Just to clarify use of two chromos. I have a Combro4 (attaches to end of barrel, has own internal light source) and a ProChrono digital (external light source - daylight or non-flickering tubes). So, if I have any reservations, I shoot through both and check they track each other. This puts an end on any manufacturer's arguments that it's the chrono or lighting giving bad readings. I found this very helpful in tracking down the cause of power drift and occasional dropped shots from my Weihrauch - with both chromos registering a corresponding 50fps drop. It took me 20 full strings recording and 3 returns under warranty to finally get this sorted - with some really crazy profiles along the way!

Using the two chromos, I've found the types where you shoot through wire hoops (ProChrono, Chrony F1, etc.) are prone to giving the odd dodgy result, which could account for the occasional drop in your profile (after shot 10 onwards).

[GWE]

Tony, George here.

Thanks for the clarification about the chronographs and why that could be important if that data were to be questioned by the techs at Pyramyd Air, (AA's authorized service center here in the states). I have the ProChrono myself but I'm considering the new Labradar chronograph in addition to the Pro. Your muzzle mounted chronograph sounds interesting. I like the concept.

We defintley appreciated the tip about the possibility of excessive grease in/on/around the hammer assembly. I say "we" because mine ( alas a.22 in the walnut Minelli stock) is still in its box awaiting my return home.

As I told Bob, the owner of the rife we're discussing, the gun is so good looking with such a smooth action and customizable cheek piece I'm willing to keep it. He said that despite the strange regulator behavior it shoots like a dream. I do get concerned that that an unexpected drop in velocity and subsequent POI could result in a nonlethal shot and unnecessary suffering on the animals part. Guess I need to get better at headshots and suffer a miss versus the other outcome!

Should there be issues that remain after a decent period of break in I can work with AA to correct those under the terms of their recently announced three year warranty. I'm just glad I wouldn't have to ship it to England!

Bob, the owner of this particular XS, said he may make the journey over to this board and add a few comments. I told him there were some good people populating AAOC and contributing to the thread. Hope he does.

Oh by the way , Re: the leaking regulator aspect you clarified, he did top off the rifle to its full 250 Bar and it held that pressure overnight.

Regards,
George