Initial adjustment and testing Crown Mk 2

[Dave]

As the title says, I did an initial tune on my rifle and tested some slugs. 

(500mm barrel, Donnyfl Tatsu, Accu-tac pc-4, Vortex Diamondback tactical 6-24x50 W/EBR-2C reticle )

I set the reg to 150bar and adjusted the hammer spring to fully utilize the pressure. and started with the NSA 17.5gr .2165, .217, and .2175. Velocity was 998 FPS, with the .2175 holding the tightest group, which was clover leafed at 12 yards. I think these might benefit from a reduction in velocity to about 950FPS. 

(The groups with the flyers had a noticeably more difficult seating of the slug for the shots that went right. I think they may have gone in with the nose angled)

I will soon have all the different diameters from .2165-.218 for the 20.2gr. However, I did have the FX hybrid 22gr on hand. 

Results from the 22 hybrids. (10 shot group)

Velocity/ HI 903/ Low 898/ Avg 900/ Muzzle energy 39.6 ft-lbs.

Definitely shows promise. I don't really want the overall length of the 700mm barrel, but I am considering moving up to the 600mm one. 

I will update with 20.2 and others as I try various slugs from a few other manufacturers as well. And once I have some good candidates for accuracy, I will test at 50 yards.

 

[Kgphotos]

Thanks for posting your info. I am “this close” to putting a deposit on a new Crown in .22. I’m trying to decide between 500mm and 600mm barrels. I know it won’t be as powerful as my Impact but I’d like a more traditional styled rifle. I’m hoping for 870 fps with either 18.3 grain or Monsters which shouldn’t be a problem. Then I’d like to be able to hit 900-920 fps with slugs in the 23 ish grain weight. I’ve been researching and it looks like the 600mm barrel should get me pretty close. I will keep following your posts with interest.

Kenny

 

[Dave]

Thanks for posting your info. I am “this close” to putting a deposit on a new Crown in .22. I’m trying to decide between 500mm and 600mm barrels. I know it won’t be as powerful as my Impact but I’d like a more traditional styled rifle. I’m hoping for 870 fps with either 18.3 grain or Monsters which shouldn’t be a problem. Then I’d like to be able to hit 900-920 fps with slugs in the 23 ish grain weight. I’ve been researching and it looks like the 600mm barrel should get me pretty close. I will keep following your posts with interest.

Kenny

I should have the rest of the 20.2gr NSA slugs I ordered on Friday, and will test them and update my post. I will also see what pellets I have, and get some numbers with them in my current tune. I know I have the 18.13 JSBs and possibly some 21gr barracuda match, not sure if I have the monsters. 

I know how it can be deciding on what exactly you want, but at least with the swappable barrels it gives us options.

I am considering holding off a little on compressor setup to pick up another pcp, probably a .25 which I will leave as a pellet only gun.

 

[ChRiSiS]

Thanks for posting your info. I am “this close” to putting a deposit on a new Crown in .22. I’m trying to decide between 500mm and 600mm barrels. I know it won’t be as powerful as my Impact but I’d like a more traditional styled rifle. I’m hoping for 870 fps with either 18.3 grain or Monsters which shouldn’t be a problem. Then I’d like to be able to hit 900-920 fps with slugs in the 23 ish grain weight. I’ve been researching and it looks like the 600mm barrel should get me pretty close. I will keep following your posts with interest.

Kenny

Kenny, the 600 mm barrel will easily get to 870 FPS with the JSB 18.3 and the Monsters. I have had a number of Crowns, and currently have two MK 2s. One is set up as a .30 and one as a .22, both with 700mm barrels. However before that I had two MK 1 Crowns (sold both on the Classifieds). The .22 was set up with a 600mm barrel. The results below are what i got with the 18.3, 21.13 and Monster pellets:

600mm Barrel

JSB 18.1

PW # TP .17/.22 TP .25/.30

FPS Ft Lb ES FPS Ft Lb ES

2 898 32.4 1.0% — — —

3 946 36.0 1.0% — — —

4 990 39.4 0.7% 1001 40.3 1.4% [01/16/21]

5 1011 41.1 0.9%



H&N Barracuda Match 21.1 gr

PW #. TP .17/.22 TP .25/.30

FPS Ft Lb ES FPS Ft Lb ES

2 848 33.7 1.9% — — — [03/25/21]

3 895 37.6 1.3% — — — [03/25/21]

4 942 41.6 1.5%* 944 41.7 1.7% [01/16/21] {3/25/21}*

5

JSB Jumbo Monster Redesign 25.39 gr

PW # TP .17/.22 TP .25/.30

FPS Ft Lb ES FPS Ft Lb ES

MAX — — — 925 48.2 1.2% [2/06/21]

5+ — — — 923 48.0 1.0% [2/06/21]

5 — — — 896 45.3 2.1% [4/06/21]

Notes: Stunningly accurate at all power levels (4/06/21 10 shots one hole @ 25 yards)

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As you can see it easily got to the power levels you want. Plus that was with the MK 1! The MK 2 is definitely more powerful.

Chris

 

[Kgphotos]

You guys are awesome. Thanks a ton. I love the people on this forum. The info you provide is really helpful when making my decisions.

Kenny

 

[richard bartley]

can anyone help ,
im looking for settings on impact mk 3 .22 slugs starting at 25 gn ZAN slugs