Theskyfox Posted July 23, 2013 Report Share Posted July 23, 2013 Hi All, Got a Brocock Enigma Deluxe that I've had a number of years. I did some chronoing on it the other day, and found that when the cylinder is fully charged it gave only 8.5ftlbs. As this discharged, using 16 grain pellets, the power then increased slowly until eventually it settled at 10.5ish ftlbs before decreasing again. Has anyone else found similar results in their PCPs? I was rather disappointed with the fluctuation in power and hoped it would be a bit more consistent. Since its 8 years old now, I've sent it off back to Brocock for a service anyway, and asked them if they can reduce this curve and get the gun overall closer to 12ftlbs. Would be interesting to see if anyone else has had to do this. -Andrew Quote Link to comment Share on other sites More sharing options...
ChAoS Posted July 23, 2013 Report Share Posted July 23, 2013 As I understand it, that sort of behaviour is normal for a PCP gun with a "knock open" valve. Whether those figures are typical for *your* make and model of air rifle, I don't know. Regards, Mark. Quote Link to comment Share on other sites More sharing options...
NIGHT SEARCHER Posted July 23, 2013 Report Share Posted July 23, 2013 (edited) I have seven PCPs and only my BSA super 10 is regulated all the rest have a power curve. The worst one is my Logun professional MK1 it says fill to 200 bar on it. I have run all my guns over a chrono from full down to 70 bar. The Logun at 200 bar is only doing 7 ftlb and slowly rises to 170 bar. At 170 bar it`s doing 11.8 ftlb it stays in the 11 ftlbs down to 80 bar. So it`s simple i just fill it to 170 bar and it gives me around 90 shots in the 11 ftlb bracket. It`s easy to adjust the hammer spring or fit a new one but you must do a full run over a chrono to make sure it`s not over 12 ftlb at some point in the power curve. I have a Daystate huntsman and at 200 bar it`s doing 11.5 ftlb but at 145 bar it`s doing 11.97 ftlb it`s legal but only just. The next time i have it in bits i might back the hammer spring of a bit. The only thing you can do to your Brocock to get rid of the power curve is to have a regulator fitted. Edited July 24, 2013 by NIGHT SEARCHER Quote Link to comment Share on other sites More sharing options...
Theskyfox Posted July 23, 2013 Author Report Share Posted July 23, 2013 Thanks for the prompt responses guys. I'll let you know what the gunsmiths says...will be interesting to see if they will offer to fit a regulator -Andrew Quote Link to comment Share on other sites More sharing options...
bruno22rf Posted July 23, 2013 Report Share Posted July 23, 2013 Most PCP rifles "suffer" from this. You simply need to find the best pressure to fill to to get the best results. The best pressure is known as the "sweet spot" and gives you the most consistency and power over the most shots. On a 200 bar gun its normally around the 170 bar mark but all guns vary-even individual guns of the same model. Borrow a chrono or see if there is an owners forum where you can ask. Quote Link to comment Share on other sites More sharing options...
evo Posted July 23, 2013 Report Share Posted July 23, 2013 can I just say that 11.97ftlb would be to close to the limit for me, surely this would go over the limit with a heavier pellet, when I had my huntsman tuned at daystate I asked why it could not be tuned higher than 11.8ftlb he replied because we tune our rifles using 16gr pellets and if we go over 11.8ftlb then a heavier pellet will take it over the limit, this way we can guarantee it will not stray over the legal 12ftlb, nightsearcher I know you know your stuff mate but that is seriously dangerously too close to the limit, atb Evo Quote Link to comment Share on other sites More sharing options...
FalconFN Posted July 23, 2013 Report Share Posted July 23, 2013 As said, it is quite normal for unregulated rifles and they won't offer you a regulator I'm afraid. I fill my rifle to 175 bar after running about 60 shots through a chrono from 200 bar and found 175 to be just about the limit of the sweet spot. I still get way more shots than rabbits I can carry, so it's not a problem as long as you know the rifle. 10.5 ft/lb is ok but I would be looking to get it into the low 11's if possible. I set mine to 11.3 with medium pellets so I've still got some leeway if it is ever tested. ATB Quote Link to comment Share on other sites More sharing options...
NIGHT SEARCHER Posted July 24, 2013 Report Share Posted July 24, 2013 (edited) can I just say that 11.97ftlb would be to close to the limit for me, surely this would go over the limit with a heavier pellet, when I had my huntsman tuned at daystate I asked why it could not be tuned higher than 11.8ftlb he replied because we tune our rifles using 16gr pellets and if we go over 11.8ftlb then a heavier pellet will take it over the limit, this way we can guarantee it will not stray over the legal 12ftlb, nightsearcher I know you know your stuff mate but that is seriously dangerously too close to the limit, atb Evo I know what you are saying evo but the 11.97 ftlb is with .177 10.8 grain bisley mags. Yes it is to close for comfort and has said in my post no 3 the next time i have it in bits I will back the hammer spring off a bit. It`s one I got cheap because of the state of it. Leaking air and sprayed camo stock an-all. I have had it in bits so many times. New valve seals and springs. new hammer spring. Stripping the stock and re-finish it with true oil. And had it re-blued it looks mint now. It is deadly accurate and very quiet with a Parker & Hale whisper silencer on it. Who in there right mind would camo a huntsman stock an-all. And i got it with four pellets stuck in the barrel. I am a little reluctant to pull it apart and disturbing it and it`s zero. I will bring it down a bit when it`s ready for a service. Happy Edited July 24, 2013 by NIGHT SEARCHER Quote Link to comment Share on other sites More sharing options...
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