Before I Jump

[wymberley]

Could anyone kindly tell me what real life velocity/energy they get from an unadulterated (other than on-board factory fitted adjustments) FX Crown Mk 2 .25 FAC with a std. plus barrel using slugs of which make and weight?

MTIA

[Ultrastu]

I use a .25 mk1 wildcat .with 25 .4 grn jsb grn pellets I get 880 fps .

26 grn fx pellets were slower around 800 fps if I remember .performance  wasn't as good as pellets . So I stick to pellets now I gave up on slugs in all my fac airguns and went back to much more reliable pellets .

[wymberley]

Many thanks, all good info.

I've got some slug samples to try on the off-chance, but also some JSB Kings and King Heavy and because of the BC, the latter is looking to be the best option in theory. Can't do anything else now but wait until my variation comes through.

[Mice!]

@villaman

[Ultrastu]

The thing I found with .25 cal .

Is even with 24 grn pellets at around 45 +fpe . You already have enough power ,bc and  retained energy  do do virtually  anything you want to quarry and targets . But if you use a slow heavy projectile like the 33 grn pellet you give away essential  velocity and trajectory  for more power , when you already have more than enough.

[wymberley]

11 hours ago, Ultrastu said:

The thing I found with .25 cal .

Is even with 24 grn pellets at around 45 +fpe . You already have enough power ,bc and  retained energy  do do virtually  anything you want to quarry and targets . But if you use a slow heavy projectile like the 33 grn pellet you give away essential  velocity and trajectory  for more power , when you already have more than enough.

Yep, Agree that enough is enough - you know what they say is wasted if there's more than a handful. 

With the slug samples I topped out at 30gr except for one recommended at 33.

Do disagree possibly about the 25.4 and 33gr pellets though. The 33 at 845 ft/sec outdoes the 25 at 880 downrange except for bullet path which it matches. My interest here is wind drift which is my marksmanship weak point.

Over the years, the Sierra Infinity Suite has saved me a fortune in time and money by being able to compare up to 5 trajectories at once on the one graph and has just done it again. I didn't realise it could run rad's as I've never needed it to until I got the Hawke FFP Airmax and which is a bonus.

 

EDIT: Peanuts; as you end up dropping many of them. 

Edited November 21 by wymberley

[Ultrastu]

I thought the trajectories  of the 2 pellets would be similar also with the lighter 24 grn being just a bit flatter .

I tried it and was horrified  at the amount of drop with the 33 grn compared to the 24 .it was so much it was like shooting a sub 12 airgun .

Not what I want from a fac airgun. Also accuracy  was a bit worse especially  at plus 70 yds where any bc difference would have started to show ..

[wymberley]

49 minutes ago, Ultrastu said:

I tried it and was horrified  at the amount of drop with the 33 grn compared to the 24 .it was so much it was like shooting a sub 12 airgun .

We've got something funny somewhere. Just checked again and am getting the same result. Zero for both is 70 yards. If I remember correctly, in the past my Sierra and your Chairgun have a always pretty much agreed.

[Ultrastu]

So putting the correct info chairgun.the 33 grn pellet with a .038 bc  and 24 grn with .035 bc  (about correct for what I've found ) with no zero altering  between pellets  the 33 grn will drop around 10 inch more at 100 yds compared to the 24 grn .with the 33 grn optimised for pbr  at 45 yds (the 24 grn is zeroed at 50 yds in my bullpup gun . The drop at 100 yds is still around 5 - 6 inches more than the 24 grn pellet. This is too much in my book for a fac gun .my .177 fac doesn't drop that much with a 8.4 grn jsb .at 16 fpe .

Unless your gonna push those 33 grn pellets at 60 - 70 fpe you won't see a flat trajectory  .and that's gonna drink air  so bad .also those heavy slug like pellets bounce like a 40 grn .22 lr . So you have to be very mindful of back stops and fallout . Might as well just have a .22 lr  they are cheaper and easier to work with than a 70 fpe puffgun. 

Let me correct that to 57 fpe for the 33 grn pellet .it's still a lot more energy than 44 fpe of the 24 grn . With probably around double the air usage.  

If your fx is actually  capable of getting that high . Mine is only possible by changing the reg out for a bigger one .

Yours may be different I don't know .

[wymberley]

55 minutes ago, Ultrastu said:

Yours may be different I don't know

Nor do I, but it'll be fun finding out. 

[villaman]

Shooting my .25 @ 970-980 fps with 33 gr  still getting about 60ish shots per fill . Slugs are the way to go after 100 yards or so . Yes they can bounce, but most slugs have a nice big cavity which helps to deform nicely. . Even pellets will bounce around as well , I say more so than most slugs 

[wymberley]

12 hours ago, villaman said:

Shooting my .25 @ 970-980 fps with 33 gr  still getting about 60ish shots per fill . Slugs are the way to go after 100 yards or so . Yes they can bounce, but most slugs have a nice big cavity which helps to deform nicely. . Even pellets will bounce around as well , I say more so than most slugs 

Cheers.

With what rifle is  that? It sounds a bit much at c70ftlbs  for the Crown. Mind you, I won't complain if it is the Crown, but I was realistically expecting something around the 50+ mark dependent upon the choice of pellet/slug.

[Kev1gun]

Depends what length barrel your Crown has, My friend has the .25 with a 500mm barrel and using 33.95 JSB kings running @850 fps so around 55ft/lb it shoots one hole groups at this speed and he's getting 50 shots before coming off reg

we set the reg pressure to 130 bar, and turned up the hammer spring by removing the Stock to aid adjustment, he does very well with it, Hes using a Pard dS35 - 70 Scope with the BC s'o no need to worry about drop etc, it works very well if setup properly.

[villaman]

2 hours ago, wymberley said:

Cheers.

With what rifle is  that? It sounds a bit much at c70ftlbs  for the Crown. Mind you, I won't complain if it is the Crown, but I was realistically expecting something around the 50+ mark dependent upon the choice of pellet/slug.

That is with my .25 impact sniper 700 mm barrel 

[wymberley]

1 hour ago, Kev1gun said:

Depends what length barrel your Crown has, My friend has the .25 with a 500mm barrel and using 33.95 JSB kings running @850 fps so around 55ft/lb it shoots one hole groups at this speed and he's getting 50 shots before coming off reg

we set the reg pressure to 130 bar, and turned up the hammer spring by removing the Stock to aid adjustment, he does very well with it, Hes using a Pard dS35 - 70 Scope with the BC s'o no need to worry about drop etc, it works very well if setup properly.

Many thanks.

Looks as though I'll be home and dry with the 600 barrel which I've chosen.

I have to recognise my age and now ability and with the minimum of fiddling would like to match the 100 yard trajectory of the LR I had at 90 yards (if there's a tad more, so be it, but not essential). It looks as though the Crown will do it. Good for any vermin control session with the ability to wind things down for an  afternoon's plinking/trigger time without the need to drag the charging bottle around.

All I need now is for D&CC to pull their finger out.