FX Crown Questions

L

Late Starter

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Apologies for asking more (probably basic) questions.

I'm anguishing over which FAC PCP to go for (my first PCP).
Calibre will be .22, with adjustable power & preferably regulated & used for vermin control.

My short list is - Air Arms S510; FX Crown; Brocock BRK Commander.

Questions:-
1) - According to the FX website the crown has a max energy of 54ftlbs in .22 (presumably with slugs). Can anyone who owns a Crown advise what the power would be when adjusted down to minimum?
2) - The Crown has 3 possible adjustments (hammer; air flow & regulator). If set up for full power then turned down to minimum, would it be necessary to re-adjust all 3 settings or is this not so important at lower power?
3) - The S510 & BRK only have one power adjustment as far as I know. Does having one adjustment detrimental to accuracy/performance or are multiple adjustments not really necessary for hunting?

Thanks in advance.

LS
 
I can't tell you the range of normal adjustments in ex-factory configuration for these guns but I can suggest a couple of factors you might consider. I don't know the Brocock at all.

What shot count do you need? Do you need a bottle or will a cylinder be sufficient? Are you going to be limited by the S510 capacity?
At what ranges do you intend to shoot? The FX barrels have mixed reviews whereas the LW barrels on the Air Arms are generally better. A common upgrade to the Crown is to fit a LW barrel (including machined AA spares).

As the gun will be held on licence, the reg and power adjustments are less critical: you don't have to worry about going over the 12ft.lb limit so there'smore lattitude to run with sub-optimal TP, plenum volume and reg pressure. If the settings aren't optimised you will lose air efficiency (which may not be a limitation for you) and possibly MV consistency.

@sagalout can advise on the Crown adjustments and conversion between sub-12 and FAC.
 
BallisticBill said:
@sagalout can advise on the Crown adjustments and conversion between sub-12 and FAC
Click to expand...
@Scoie runs his 0.25 Crown with 380mm barrel around the 42fpe mark and it turns down to about 11.5fpe IIRC with just the transfer port and hammer adjusters. I would advise against fiddling with the reg because of introducing creep and thus affecting consistency.
 
@sagalout
You say TP and hammer adjusters but IIRC there's also a EV spring preload adjustment. Do you change that?

I concur, changing reg pressure is inadvisable once tuned for the intended maximum power output. The initial resetting will depend on what the intended maximum may be (and whether that is significantly lower than the ex-factory tune). The OP may not appreciate that could also lower the minimum operating power available by adjusting the other parameters.
 
Craig needs to sort out a proper 500mm or more barrel for that Crown. Poor little hamstrung thing!
 
BallisticBill said:
I can't tell you the range of normal adjustments in ex-factory configuration for these guns but I can suggest a couple of factors you might consider. I don't know the Brocock at all.

What shot count do you need? Do you need a bottle or will a cylinder be sufficient? Are you going to be limited by the S510 capacity?
At what ranges do you intend to shoot? The FX barrels have mixed reviews whereas the LW barrels on the Air Arms are generally better. A common upgrade to the Crown is to fit a LW barrel (including machined AA spares).

As the gun will be held on licence, the reg and power adjustments are less critical: you don't have to worry about going over the 12ft.lb limit so there'smore lattitude to run with sub-optimal TP, plenum volume and reg pressure. If the settings aren't optimised you will lose air efficiency (which may not be a limitation for you) and possibly MV consistency.

@sagalout can advise on the Crown adjustments and conversion between sub-12 and FAC.
Click to expand...
Thanks for the information.

I’ve subsequently read the thread FIRST FAC PCP & one of the posts on there says that his Crown power range is 12 to 43ftlbs, so that’s one question answered which confirms @Sagalout’ comments which refer to .25.

I have thought about shot capacity & the S510 has the lowest of those on my list. For vermin control (the main use) 30 shots should be sufficient. If setting up or target practice, then more would be an advantage but on those occasions I could lug a bottle.

Initially I had thought around 30ftlbs based on the theory that power levels approaching .22 rimfire would have a similar safety range (dangerous up to 1 mile). However, from reading on here & playing with a ballistic app this isn’t the case. Increased power doesn’t really increase range, there is just higher power retention at range.

Ideally, I’d like to be able to make clean kills out to 100yds, but this may be a bit of a stretch at 30ftlbs, so may have to settle for say 75 yds.



Thanks for the information on Crown barrels. I’ve read various comments on FX, some negative, but thought that the Crown was less prone to problems.

LS
 
sagalout said:
@Scoie runs his 0.25 Crown with 380mm barrel around the 42fpe mark and it turns down to about 11.5fpe IIRC with just the transfer port and hammer adjusters. I would advise against fiddling with the reg because of introducing creep and thus affecting consistency.
Click to expand...
Thanks for your reply. If I go for a Crown, I won't adjust the regulator.
In my ignorance, I had assumed that rifles with a single adjuster like the S510 adjusted the regulator but it would appear this is not the case.
Just for information, does anyone know what they do adjust (transfer port or hammer??)?

LS
 
Late Starter said:
I had assumed that rifles with a single adjuster like the S510 adjusted the regulator but it would appear this is not the case.
Just for information, does anyone know what they do adjust (transfer port or hammer??)?
Click to expand...
Air Arms adjuster is on the transfer port. I'm not sure what the effect will be on MV consistency at low power setting (min 7ft.lb I believe). The large plenum and low pressure drop may cause some irregularity in reg cycling but I think it will be irrelevant for your use as I guess you are only going to be using low power at short range so you won't see much change in POI.

32ft.lb is going to give you just short of 900fps with 18gr pellets. 40ft.lb will in theory give you a bit more range (920fps with 21.4gr) but the limiting factor is likely to be accuracy and which pellet suits each gun.
 
Late Starter said:
Thanks for the information.

I’ve subsequently read the thread FIRST FAC PCP & one of the posts on there says that his Crown power range is 12 to 43ftlbs, so that’s one question answered which confirms @Sagalout’ comments which refer to .25.

I have thought about shot capacity & the S510 has the lowest of those on my list. For vermin control (the main use) 30 shots should be sufficient. If setting up or target practice, then more would be an advantage but on those occasions I could lug a bottle.

Initially I had thought around 30ftlbs based on the theory that power levels approaching .22 rimfire would have a similar safety range (dangerous up to 1 mile). However, from reading on here & playing with a ballistic app this isn’t the case. Increased power doesn’t really increase range, there is just higher power retention at range.

Ideally, I’d like to be able to make clean kills out to 100yds, but this may be a bit of a stretch at 30ftlbs, so may have to settle for say 75 yds.



Thanks for the information on Crown barrels. I’ve read various comments on FX, some negative, but thought that the Crown was less prone to problems.

LS
Click to expand...
Hi for 100 yd range you need .25 pellets my impact does 20mm groups at 100 yd shooting 25.4 grn pellets at 46 ft lb 912 fps/ .Retained energy is 33 ft lb at 50yd 22 ftlb at 100 yd. Any higher velocity is pointless as the pellets go unstable. 33grn pellets are supposed to be stable at higher velocity but i havent tried them. You can shoot at 100yds with .22 IF you can find compattable slugs!
 
keithy said:
Hi for 100 yd range you need .25 pellets my impact does 20mm groups at 100 yd shooting 25.4 grn pellets at 46 ft lb 912 fps/ .Retained energy is 33 ft lb at 50yd 22 ftlb at 100 yd. Any higher velocity is pointless as the pellets go unstable. 33grn pellets are supposed to be stable at higher velocity but i havent tried them. You can shoot at 100yds with .22 IF you can find compattable slugs!
Click to expand...
My crown .22 will do 100+ yards no problem
 
BallisticBill said:
Air Arms adjuster is on the transfer port. I'm not sure what the effect will be on MV consistency at low power setting (min 7ft.lb I believe). The large plenum and low pressure drop may cause some irregularity in reg cycling but I think it will be irrelevant for your use as I guess you are only going to be using low power at short range so you won't see much change in POI.

32ft.lb is going to give you just short of 900fps with 18gr pellets. 40ft.lb will in theory give you a bit more range (920fps with 21.4gr) but the limiting factor is likely to be accuracy and which pellet suits each gun.
Click to expand...
Thanks for the details.
Yes, low power would be short range (pigeons inside a building).

LS
 
Late Starter said:
Hi, Are you also using pellets to achieve this & 43ftlbs?

If yes, have you tried slugs?

Will pellets & slugs perform OK in the same barrel?

Thanks,
LS
Click to expand...
Slugs at 43ftlbs
Pellets depending on weight up 40ish ftlbs with 20.8 gr
Pellets & slugs shoot absolutely fine in my superior heavy liner
Pellets are ok at that distance but slugs are far better . Pellets are good to 80 or so yards
 
Although I have some JTS 22 gr pellets to try , which hopefully will test in the next few days
 
Fx shooter said:
Slugs at 43ftlbs
Pellets depending on weight up 40ish ftlbs with 20.8 gr
Pellets & slugs shoot absolutely fine in my superior heavy liner
Pellets are ok at that distance but slugs are far better . Pellets are good to 80 or so yards
Click to expand...
Many thanks for the information.

I've seen a second hand Crown but it's .25 which will mean a variation - decisions, decisions!!

LS
 
Just chronod my 25 crown

380 barrel , reg at 130 bar

33.95 grain pellets

Low power 12.2 ft lb
Medium power 37 ft lb
High power 43 ft lb

Will do a test when I get my 600 liner and get some jsb 25.39 pellets but the platform is very flexible and with 33.95 grain pellets on low power it’s just over 400 fps so if you miss just run and catch the pellet :p
 
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