Tuning Is this normal for a Huma regulator?

Gun Benjamin Bulldog modified to be pitbull AKC with huma regulator at 2700 psi by Pitbull airguns.



When I got it, it showed this for a regulated pressure after filling to 4500 PSI.



guage.1647117390.jpg




I've read these gauges can be off by as much as 400 psi (looks like off by 450 psi based on 3150 psi and 2700 PSI setting from pitbull factory).



Anyway, today, I take the gun to shoot, and this is what I have (3450 psi):



gg2.1647117497.jpg




I take a shot, and then the gauge has this (3300 psi or so):

gg3.1647117595.jpg




All together I have about 30-50 shots through the gun. Pitbull had told me long ago that I need to get about 100 shots total before I know if I have an issue. I hand pump and have other stuff going on in my life hence the reason I am only at about 30-50 shots so far. It's a good workout hand pumping to 4500 psi.:)



Also Paul at Pitbull airgun told me that it is not user adjustable as it requires a special tool made just for them, but I see this video: 



https://www.youtube.com/watch?v=RKSX6Hqvx7c



So this confuses me too. (I do have outstanding emails to airgunnation, but I'm guessing they are at some event or something since I am getting radio silence--hoping somebody here more experienced than me can give me guidance or assurances.).



Also, it looks like it might just be this regulator: https://www.huma-air.com/Benjamin-Bulldog-Tuning-Regulator-Set-With-Quickfill (for reference, see here: https://www.pitbullairguns.com/product-page/regulator-kits). 

I can find nothing on Huma's website that says a special adjustment tool is necessary.

On the other hand, pitbull air says:

>A VERY BIG SHOUT OUT!!!! To Huub at Huma Air for making us this Custom regulator made specifically for us here at Pitbull Airguns.

So maybe they are two different regulators?


 
I doubt that it takes a special tool to adjust it, but I know nothing of this conversion, and it might take a special tool to get it out. Gauges are always questionable. Have you done any chrono runs to check its consistency? It appears the reg may be creeping up a bit at rest. If it continues, they should take it back for evaluation.
 
I just installed a HUMA gauge port regulator in my Gen I Marauder.

The regulator is set for 1500psi.

The gauge will never read higher than that even when I load 3000psi…

If it's reading at the plenum, then it will never read higher than the reg set point, regardless of the the cylinder/bottle pressure. But, it should not vary from that reading at rest. In this case, it seems to be creeping up. 
 
Thanks guys for you help. Do you have a chronograph that you recommend? I am thinking about the FX radar picket wireless chronograph.

The behavior I am seeing today is about the same as when I first got the gun, except I have more shots and it seems to be getting worse. It looks like the advertisement on the site claims 6 regulated shots (it had something different before--I'll have too find the screenshot I took when I bought it). Even if the gauge is inaccurate, unless it is also random, it looks like I get about 4 regulated shots, with the regulated pressure reported by the gauge being mostly consistent after the first 3. At least that is how I am interpreting the gauge readings below. Let me know if I have a misunderstanding.

So I am trying to put more slugs through in any event. I have a pellet trap from shreadded rubber and am doing it without the benefit of a chronograph. 

This phenomenon is the same as when I first got the gun. I described it to Paul at Airgun, but he responded that I need to get 100 shots through the gun. Being a newb, I took his advice and waited. I'm still not at 100, but I just counted my pellets and I am at 80 at least 80. I have made no adjustments to the hammer or regulator.

But this doesn't seem right even if I am a newb.

So after pumping:

pumped.1647137863.jpg


after first shot

a1.1647137878.jpg


After second shot

a2.1647137894.jpg


After third shot

a3.1647137905.jpg


After fourth shot

a4.1647137916.jpg


After 5th shot

a5.1647137926.jpg





 
Looking at the huma reg on the pit bull website, it looks to be adjustable like every other huma reg. No special tool needed. Unless you consider a flat head screwdriver special.

Thanks for that. This is a direct quote though:

>Without disassembling your rifle, and by way of a special tool to adjust the pressure, this is not recommended. Disassembling your rifle will void our warranty

>...

>If you have the proper tools, such as a reliable Chronograph, you can adjust the hammer spring to get the velocity you desire.

But I have not picked up a chronograph yet.
 
It looks like the gun and regulator gauge are fairly close after the fourth shot where it has fallen off the regulator. Being a new gun and with a Huma installed that regulator pressure may actually be that high. It's possible that it was originally set at 2700psi but has settled at 3300psi. As mentioned a chronograph is really needed to find out how it's tuned. If the velocity goes up when increasing the hammer spring tension there is a good chance that the regulator is set higher than 2700. I didn't know a thing about the Bulldog/Pitbull conversion until I watched this video. I use a high quality digital test gauge to check the accuracy of these guns gauges. Some are close and some are not. The regulator gauge is the one that really needs to be.

https://www.youtube.com/watch?v=g0j17bpiA8A

The regulator looks very serviceable to me. Just a matter of de-pressuring the gun unscrewing the air tube, remove the plenum spacer, remove the fill adapter from the other end of the air tube, push the regulator out towards the receiver, re-adjust the regulator, re-assemble the air tube and pressure it up with out fully assembling the entire gun. If the regulator pressure is not where you want it de-pressure the gun and repeat. It may be a real pain pumping it back up though during this procedure though.

Reminds me of my earlier days with a Marauder and AA S510's. Sure makes you appreciate externally adjustable regulators.

Good luck

jking
 
> Well, you can't do much without a chronograph. I may be wrong, and with all respect, it seems you're being fed some BS by your dealer. True that the HST will adjust velocity, but that seems irrelevant to your problem.

I should have followed my gut, but I'll leave the pre-purchase inconsistencies for my close personal friends in real life. 

Hopefully I am wrong and pitbull airguns will respond to my emails in a way that indicates they understand the problem.

But first, when I first got the gun, I contacted them because out of the box it looked like this:

outoutobox.1647204209.JPG


And this:

scuff.1647204239.jpg


To which I got this:

>the regulator requires a break I'm period of at least 100 rounds. if you are not satisfied with your purchase please return it for a full refund. 

Which seemed nuclear, since I wasn't looking for an all or nothing solution. In fact I was just providing feedback, seeking guidance, and hoping they had a less drastic remedy. 

By the way, the gun was very well boxed and protected in foam, and the box did not have undue damage--certainly none in the area where the scuff was, which made me conclude that the scuff was there when they packaged it. As far as I was concerned, and I admit I did not specify what remedy I was asking for, was they would offer to send me a new part to replace the scuffed part, and give me reasonable guidance on the gauge.

After I clarified I wasn't looking for a nuclear option, pitbull air responded with:

>the 2600 psi indicated on the gauge on the side of the rifle is the regulator pressure of 2700. they are very close, but not 100 % accurate until its broken in.

Apparently, he was too busy to carefully read and respond to the whole email with photographs I sent, and was commenting on a video I had also linked to in the email.

To which I replied:

>But it is over 3000 (see original photo at bottom)

So he instead picked up on the scuff photo not the photo with the gauge reading, and wrote:

>a tiny streak of cleaning oil on the side of the shroud is not something to be concerned about. it is not a sealing point. Fill pressure is indicated on the 5k gauge, regulator pressure is on the side gauge. unless the box was beat up, opened, or otherwise damaged, we have never had concerns of rifles damaged in shipping.

He also (probably reasonably) indicated:

>please fill the rifle to [possibly unsafe] or [possibly unsafe] psi, and use a chronograph to measure the Velocity. it should be in the 925 fps range with 127 gr ammo. 

I still don't have a chronograph. I have had and enjoyed quite a few very expensive hobbies in my life and I am still testing the waters here in the the domain of PCP.

But a gauge is a gauge. It has units. It can have two significant forms of error, offset and slope. I was clearly most concerned about the gauge.

I also got this after I clarified yet again:

>we have never encountered a HUMA regulator to fail. it employs mechanical stacked steel Belville washers for regulation. like any mechanical device, it has a break in period. 

It doesn't look like a failure to me. Just an incorrect setting. There are lots of possible explanations, such as the gun was a return, and shipped to me without them doing a full quality control check, to something happened in shipment (not sure if sending a fully charged airgun via USPS air is smart are not), to their or my own ineptitude. 

My feeling is that pitbull airguns comes off as a little shady, not great at troubleshooting, certainly not great at reading or dealing with a lot of information and customer confusion, and not a good ambassador to the hobby.

Don't get me wrong, he did spend time, did ship the gun promptly, did package it well, and did provide an airgun that killed a coyote. But the time that was spent always seemed to be reluctant.

In any event, if I don't hear back from pitbull on my emails and phone calls, I'll either make a stab and fixing it myself, or find another airgunsmith that works on pitbull to evaluate and fix it.

I should note too, pre-emptively, this has been going on since November, and Paul at Pitbull did refer me to forums (I guess because dealing with newbs isn't exactly the type of dayjob he wanted). I could be wrong, and I hate to say this is the case, but this is the feeling I am getting. When I asked for instructions on adjusting the hammer spring using the special tool they sent fo that purpose, I got: 

>We do not offer manuals for any of our custom rifles, the stock Users Manual will give you much of what you need as far as Basic Operating Procedure to start shooting and enjoying your new airgun. There is a large community of Bulldog users from around the world on YouTube and the various forums online. 

So I am at the forums. And I am getting more help from strangers with no stake in pitbull air, and I appreciate it.

I like supporting American companies, American industry, and really would just like to get to the bottom of this before I decide to spend more money on a compressor, chronograph, and other PCP guns. Hopefully other vendors are watching this and will reach out to me. I did buy a western/U.K. made airpump from Pyramyd Air, and have purchased ammo from Griffen and NSA...and in all other cases, I have absolutely no reason to complain. They sent what I wanted, and it worked as advertised, and any questions I had were dealt with professionally, with attention to comprehension, and politely.

> Good rule of thumb in life…..never do business with any company that has “pitbull” in their name.

Funny. In this case I was just thinking Pitbull was a play on bulldog, and that dangerous and tenacious pitbulls were good at killing wild pigs and coyotes. In general, I would not want a pitbull as a pet, but to kill coyotes, sure. My rule of thumb is to stay away from companies with "integrity" or "honest" in their name....because they are always anything but. Honest companies build up reputations, they don't need to name themselves that.

I wonder if this situation with pitbull might just be stress due to whatever pressures they have around the shop coupled with what looks to me to be poor troubleshooting skills basded on information (and sometimes too much information and conjecture on my part) coupled with an "oh no not again another pain in the ass customer who doesn't appreciate how hard we work." 

Spending $2400 on a custom modified bulldog is appreciation in my book. Not taking them up on the full refund is also not only appreciation, but also a willingness to work with them reasonably. 

I am still hoping for a reasonable solution. I was even willing to buy a digital pressure gauge and install it myself but I have failed to get help from them on that, too.

Trust me, while $2400 is a lot of money, I would be a happy camper if I got $2400 worth of value in an airgun that performed and looked as it was advertised and one would expect.

If I were in business (and I am) I always try to work with customers, even though I am not the most charasmatic person in the world. Customers are money, and money is the lifeblood of a business. Repeat and referral customers can't be beat. And one thing I am, is a repeat customer (which is probably why if I buy other PCP equipment like a chronograph and pump, it will probably be from Pyramid air so long as they continue to perform and treat me with integrity). poop happens, it is how a company handles it that matters, and also how they work to prevent it from happening again.

But it may be like going to a restaurant where they screw up your order and you get an odd sense it wasn't exactly an accident. Sometimes it is just best to eat elsewhere. 

I do wonder if it is safe to send a gun pumped up to [possibly unsafe] psi through overnight air, though, and if that could cause undue stress on the regulator? I would have guessed that tanks would need to not have so much air to be cargo on an airplane (but I am a newb) That is probably ridiculous, but it's all I can come up with while assuming good faith.

Edited per mod caution to [possibly unsafe] psi
 
This is by no means an insult to you because you are just starting out in PCPs but that is absurd that they are selling modified bulldogs for $2400 AND people are actually buying them! If you decide to stick around the pcp hobby you will find MUCH better options for that kind of money. For $400 more you could have a AAA .457 Slayer that is better than a modified bulldog in every way. I would return it and get the slayer. 
 
Gun is tested by FACTORY to be safe when filled to 3000 PSI and with that spec a % of safety margin is established.

Filling to 5000 psi is BEYOND STUPID and very similar to a thread months ago ( may be the same folks ) doing so is IRRESPONSIBLE at an epic level !!!

Do it for personal use it's your life at risk ... Sell such having others take that safety risk in is .. well, i already said it above.



Now as to Q ... Plenum pressure stays put until at such time HP storage side drop below regs set pressure & gauge moves lower. NORMAL