Anyone know FX suggested slug diameters for the .25 & .30?

Yeah, I agree with the .249-.250 but I disagree with the 2S ogive. I've had far better luck with a larger hollow point. You have to be careful though because different manufacturers call their ogive 2-S when in reality it is much larger. Varmint knocker and Rat Sniper have a 2S ogive that I would consider a true 2S ogive, or as close to it as you'll find in an air gun slug with a hollow point. It didn't perform nearly as well as his other slugs with a larger hollow point in my testing, why, I don't know. In a lot of testing I've done with the .25, I've found the slugs that shot the best were flat based or had a slightly dished base, had a fairly short bearing surface and a large hollow point. This is what I've found... I had poor results with the 2S ogive but maybe others have had better luck with the 2S hollow point. Testing varies! 

Below are a couple of pictures of the slugs with the large hollow point design that I've found shoot best out of the FX slug liner and another picture of a 2S hollow point. There is another picture that shows a whole bunch of slugs that vary only slightly in their design...the base, the ogive or the bearing surface. There are a lot of designs to test.

Stoti

1562124008_9410036255d1c1ee8c21e84.15063171_IMG-1380.JPG
1562124107_15579776635d1c1f4bccdc70.04062872_IMG-1278.JPG
1562124524_19058160805d1c20ec1ce125.98736825_IMG-1279.JPG
1562124582_19961453475d1c2126985528.55655449_IMG-1290 (3).JPG

 
I did most of the testing with the 600mm .25 cal. liner and a Crown with a power tune kit. The VK 30.4, 31.5, 32.8 and Nielsen 34.7 all shot really well. So did the Rat Sniper 31.9 but it's discontinued. I think most will shoot well, it just takes a lot of time and patients to get them dialed in. I posted results for 30 something slugs I tested and then I picked the best 4 and really dialed them in for that gun. It took a while! I just got the 700mm liner for my Impact a few days ago and my FX Radar today so I am going to test a few slugs that I think will shoot well when I get back from vacation next week. I think the added power and velocity of the Impact will help stabilize some of the heavier slugs like the new one Nick Nielsen is putting out or the heavier Varmint Knockers.

Stoti
 
I did most of the testing with the 600mm .25 cal. liner and a Crown with a power tune kit. The VK 30.4, 31.5, 32.8 and Nielsen 34.7 all shot really well. So did the Rat Sniper 31.9 but it's discontinued. I think most will shoot well, it just takes a lot of time and patients to get them dialed in. I posted results for 30 something slugs I tested and then I picked the best 4 and really dialed them in for that gun. It took a while! I just got the 700mm liner for my Impact a few days ago and my FX Radar today so I am going to test a few slugs that I think will shoot well when I get back from vacation next week. I think the added power and velocity of the Impact will help stabilize some of the heavier slugs like the new one Nick Nielsen is putting out or the heavier Varmint Knockers.

Stoti

Hello Stoti, have you had experience with 600mm .25 without power kit? If yes, which do you think is the best slug for 600mm .25? Thanks in advance