Slug speed out of 500mm barrel

[ladwict]

I shoot my Wildcat MK3.22 compact (500mm superior standard barrel) with 965 fps using 20.2 nsa slug. Grouping is is o.k. But air usage is rather high approx. 3.0 bar per shot . This makes approx. 30 shots per fill from 230- 135 (huma reg setting) . Do you guys think that with a 500mm superior barrel this speed of too high or fine or….any experience / ideas welcome.



MOD EDIT: MOVED TO PCP SECTION

 

[Long_Gun_Dallas]

I'd dial it down to 930fps. 

I use one on my crown @50fpe. Seems to be the happy place for that barrel on the high end of output without just absolutely dumping air

 

[ladwict]

I'd dial it down to 930fps. 

I us eone on my crown @50fpe. Seems to be the happy place for that barrel on the high end of output without just absolutely dumping air

Thanks for your reply. I achieve 41.5fpe with my setting and you 50fpe ? You will be shooting much heavier slugs in that case at 930fps…

 

[Long_Gun_Dallas]

Oops... Sun glare made your 20gr look like 26. Yes, I shoot 25gr @ 950fps, but am using a 480cc bottle. 

Really, you're probably going to have to try and dial down the power until you, the gun, and the projectiles are happy. But I would leave the regulator at 130 give or take. Just try and take some shots dialing down the hammer. Listen to the gun and see if you can tell where the report really settles down. If you can deal with the small loss of power, you should be able to get a good bit more shots. 

 

[qball]

I found the sweet spot speed for the 500mm barrel to be around 900fps maybe up to 920fps regardless of projectile weight. Slugs especially lighter slugs are very easily destabilized by muzzle blast so don't chase max speed if you want good/consistent accuracy. I usually target right at 900FPS for 500mm barrel and accuracy and efficiency has been very good. With much higher BC there is no need for max speed, I had fantastic accuracy even at 750fps range. Power is nothing without accuracy and you don't need power to have accuracy. 

 

[ladwict]

I found the sweet spot speed for the 500mm barrel to be around 900fps maybe up to 920fps regardless of projectile weight. Slugs especially lighter slugs are very easily destabilized by muzzle blast so don't chase max speed if you want good/consistent accuracy. I usually target right at 900FPS for 500mm barrel and accuracy and efficiency has been very good. With much higher BC there is no need for max speed, I had fantastic accuracy even at 750fps range. Power is nothing without accuracy and you don't need power to have accuracy.

Thanks for your replay. The thing is that I have better accuracy with 965 fps vs 940 fps. 1" at 940 and 0.5" at 965. At 50 yards 

Are you also using the standard superior barrel ?

 

[Long_Gun_Dallas]

Well, accuracy should come back around at a lower speed, that's just how harmonic nodes work. Just gota find the next one. 

 

[ladwict]

Well, accuracy should come back around at a lower speed, that's just how harmonic nodes work. Just gota find the next one.

Thanks I know that and will try that when I am in the mood to demontage my reg and set it 5 bar lower. In case I just use the hammerspring tension to go down in speed I get bad ES. For now all feels good but I just wonder if 965 from a 500 mm bartel is not a bit too hot in general.

 

[qball]

I found the sweet spot speed for the 500mm barrel to be around 900fps maybe up to 920fps regardless of projectile weight. Slugs especially lighter slugs are very easily destabilized by muzzle blast so don't chase max speed if you want good/consistent accuracy. I usually target right at 900FPS for 500mm barrel and accuracy and efficiency has been very good. With much higher BC there is no need for max speed, I had fantastic accuracy even at 750fps range. Power is nothing without accuracy and you don't need power to have accuracy.

Thanks for your replay. The thing is that I have better accuracy with 965 fps vs 940 fps. 1" at 940 and 0.5" at 965. At 50 yards 

Are you also using the standard superior barrel ?

You may find a good node somewhere above the sweet spot and if you do don't touch it. A good moderator that's caliber appropriate which can act as air stripper definitely helps! 



I only use superior heavy liners with carbon sleeves on .22 and .25. I also always use high reg pressure between 140-150 bars and pretty much can dial up and down the speed range at will and use just about any slugs without have to worry too much about accuracy. There is little accuracy difference between different weight NSA slugs I use between 700 -1000 fps in my crowns and impact. On my impact thanks to the valve adjustment and micro power wheel I can get just about any slugs to shoot at any speed 1 hole at 50 yards if I spend some time fine tuning. I've tried literally every single NSA weight/size between 26-38 grain in .25 and 17-28 grain in .22. 



You can achieve good accuracy above the sweet spot and superior liner with lighter slugs but just a lot harder especially with shorter barrel like the 300mm or 500mm.....I've tried.

 

[ladwict]

I found the sweet spot speed for the 500mm barrel to be around 900fps maybe up to 920fps regardless of projectile weight. Slugs especially lighter slugs are very easily destabilized by muzzle blast so don't chase max speed if you want good/consistent accuracy. I usually target right at 900FPS for 500mm barrel and accuracy and efficiency has been very good. With much higher BC there is no need for max speed, I had fantastic accuracy even at 750fps range. Power is nothing without accuracy and you don't need power to have accuracy.

Thanks for your replay. The thing is that I have better accuracy with 965 fps vs 940 fps. 1" at 940 and 0.5" at 965. At 50 yards 

Are you also using the standard superior barrel ?

You may find a good node somewhere above the sweet spot and if you do don't touch it.



I only use superior heavy liners with carbon sleeves on .22 and .25. I also always use high reg pressure between 140-150 bars and pretty much can dial up and down the speed range at will and use just about any slugs without have to worry too much about accuracy. There is little accuracy difference between different weight NSA slugs I use between 700 -1000 fps in my crowns and impact. 

You can achieve good accuracy above the sweet spot and superior liner with lighter slugs but just a lot harder. 



Good content. Thanks. The Wildcat is a different platform no so well equiped for heavier slugs. I believe with the standard superior and a few tweaks as I did ( huma reg with additiional plenum, huma dual TP ,slightly heavier hammer spring ) I should be happy for now reading your post. My WC is not protesting in any form right now and shooting nice ES from the first shot.

 

[qball]

Good content. Thanks. The Wildcat is a different platform no so well equiped for heavier slugs. I believe with the standard superior and a few tweaks as I did ( huma reg with additiional plenum, huma dual TP ,slightly heavier hammer spring ) I should be happy for now reading your post. My WC is not protesting in any form right now and shooting nice ES from the first shot.

If you have heavier hammer then you are good to go with higher reg tunes. Those are much easier to get good slug accuracy but try 920 and lower speed, your shot count will increase significantly and much easier to get a good accurate tune. If you want power just use 23 grain at the same speed, it has better BC so better performance in the wind and still very good in the superior liner, I won't use anything heavier in the superior though. The gun's action has more than enough power to over run the 500mm barrel length, speed is determined by the barrel length not the action itself in the WC and even the dreamline. 



There is no need to chase crazy speed unless you are just doing it for fun. 

 

[ladwict]

Good content. Thanks. The Wildcat is a different platform no so well equiped for heavier slugs. I believe with the standard superior and a few tweaks as I did ( huma reg with additiional plenum, huma dual TP ,slightly heavier hammer spring ) I should be happy for now reading your post. My WC is not protesting in any form right now and shooting nice ES from the first shot.

If you have heavier hammer then you are good to go with higher reg tunes. Those are much easier to get good slug accuracy but try 920 and lower speed, your shot count will increase significantly and much easier to get a good accurate tune. If you want power just use 23 grain at the same speed, it has better BC so better performance in the wind and still very good in the superior liner, I won't use anything heavier in the superior though. The gun's action has more than enough power to over run the 500mm barrel length, speed is determined by the barrel length not the action itself in the WC and even the dreamline. 



There is no need to chase crazy speed unless you are just doing it for fun.

Thanks again. The thing with WC is that they have too small plenum out of the box for higher power output than 30 fpe in .22. I do favor a short as psossible opening of the valve in short barreled rifles so quite reluctant with a heavier hammer causing langer dwell time. I installed a HUMA hammerspring that has just a tad more “pop” to open the valve fully at reg pressures on the higher end of the spectrum. I am rather convinced that 23 gr is about the highest weight for a well upgraded WC hence a standrd superior liner will do. For the real power-liking .22 shooters amongst us the Maverick and Impact are on the menu.

anyway the more I experiment the more I am aware that pcp airguns work with a very complex mix of variables differing from one platform to the other. Airflow, barrel , ammunition and harmonics are key elements that have to come together in one way or another to get a well shooting rifle. This complex mix is giving many of us joy and headaches. The development of know how and different products in the market is huge and noticing the entry of electronics and slugs gives high hopes for an exiting future. 

 

[DonaAna1]

I have the exact same gun and shoot the exact same NSA slug. Reg is at 130. I backed off of the hammer spring until it is shooting at 900 fps, You may be shooting a little fast.



Well maybe not the exact same slug. I am shooting the .218.

 

[ladwict]

I have the exact same gun and shoot the exact same NSA slug. Reg is at 130. I backed off of the hammer spring until it is shooting at 900 fps, You may be shooting a little fast.

Is your WC standard or did you do some mods ?

 

[DonaAna1]

Standard, right out of the box.

 

[ladwict]

@ Dona Ana1

Any idea what your plateau is (top speed) at that setting ?

 

[DonaAna1]

I don't really know. I did bring speeds down from 920 fps as I have those numbers on the chrono. I didn't like the group at 920. And the gun didn't feel comfortable at 920. It shoots a lot easier at 900. Seemed to settle down.

It also groups the jsb 18 grainers at this setting too. The exact heavies are at 925 on the same power level. So NSA 20 grainers at PW 7 and 900 fps and JSB at 925 on same power wheel level 7. By the way, port is on P for pellet. Not S.

 

[ladwict]

I don't really know. I did bring speeds down from 920 fps as I have those numbers on the chrono. I didn't like the group at 920. And the gun didn't feel comfortable at 920. It shoots a lot easier at 900. Seemed to settle down.

It also groups the jsb 18 grainers at this setting too. The exact heavies are at 925 on the same power level. So NSA 20 grainers at PW 7 and 900 fps and JSB at 925 on same power wheel level 7. By the way, port is on P for pellet. Not S.

Thanks for the info. I think from data I have that you have a fine tune like it is . 

 

[qball]

So guys, just to sum up: what do you recommend for a 500mm barrel in .22, .25 and .30 - which slug weight and speed for optimal accuracy and the highest power possible?

IMHO with 500mm barrels stick to 900fps and lower, if you need more power just shoot heavier projectiles. 

 

[ladwict]

I have tested over and over during this week and my 500 mm superior barrel shoots slugs very accurate .5 inch groups at 50 yards at 960 fps and can’t better that at lower velocties. 

The platform does not sound or feel “overloaded” . I keep it like this and take the higher air consumption as it is. I am amazed about the standard superior liner /barrel capability (in combi with NSA) for such high speeds. I cannot judge for other brands/types of barrels though.