Fx STX 600mm, 25 cal jsb knockout

[silentpop]

Hello

I recently tried 4 different slugs in fx wildcat mk2 25 cal STX, fx hybrid, h&n 28 grains in 2.50 and 2.49 sizes and jsb knockouts. Only knockouts made decent groups, rest were pretty much shotgunning with STX, even worse with slug liner A (that barrels works only with jsb heavies, ironic). So there was no point measuring hybrid and h&n groups. All these groups in pictures are jsb knockouts. 

Temperature 3c, velocity about 250m/s, wind 1.5-3m/s range 63m/69 yards. It seems that there is some hope with knockouts, groups are not great but not shotgunning atleast. 8 shot groups, few fliers, I dont know is it the wind, me or slugs doing it but atleast 5 out of 8 landed within 1.5cm so there is some hope, they seem rather good quality, little deformations and rear seems identical to jsb mk2 heavies. 

This group in second picture I shot quickly when wind calmed down

Im wondering is this result of spiraling since the group isnt any tighter at 40m(3rd picture) , nearly same size as 63m.

 

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Just for comparision this is same gun with STX barrel jsb heavy mk2 pellets, 8 shots on calm day. 

 

[jcote258]

Thanks for the info.

Your pictures don't say which groups are from what ammo, as you mentioned four types of ammo in your post. Is the last picture (the tightest group) the JSB Knockouts?

I have a few tins of the H&N .249 28 & 30-grain slugs inbound, and I'll be testing in my 500mm Superior Liner.

I'm still waiting on FX USA parts to build the rest of my 600mm Superior Heavy (the liner lock was back ordered from Sweeden). Once that's complete, I'll be doing some additional testing.

 

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Sorry for not making it clear, those are all jsb knockout groups in the post, because hybrids and h&n didnt give much hope. Here is 16 round group with 28 grain h&n.250 sized at 40m. Some tight group appearing next to the measure but rest spreading so much. There were clear inconsistency with the h&n slugs, some had some white smudge in the hollowpoint and some deformed rear domes.