Which mould for casting slugs for the Huben GK1 .25(3)?

Hey here is what i have been casting. They seat very nicely with the drive bands:


I cast at lower temp to keep the size up. If you cast at higher temperature they might be loose in the GK one magazine.

I would love to have one of the .253 cal 42 grain molds but they've been out of stock for a while.

Interesting, I have both slugs in HP in the weights you are interested in.
I have tried the Huben "egg" slug years ago in something other than a Huben. They didn't shoot well. Another airgunner I still talk to said the same thing before I tried them out. Oh well, it's a exercise.

View attachment Sonnyslugs_2.0.1.xlsx

Gregor said that the MP slugs don't shoot good out of the huben. What is your groove diameter?
I've been shooting the MPs out of my sumatra.25 and I'm very happy with the results. It has a.251 diameter groove so works.
The biggest problem with the MP mold is IMHO to large. If it was only a 4 hole the slugs would come out much more consistent.

Has anyone tried the new MP Mold in there Hubens yet either the K1 or the GK1 the MP slug is the
Version 3 and casts at 50.5 grain and I sized them to .254" and there 10.70 in length , just perfect
to fit in the Huben magazines and fill it up so it will not move around

I’ll give a plus one on the Bob’s Boat Tails from NOE. I have the 250-51-FN which I picked up on a group buy a number of years ago. NOE now stocks it as an inventory item with the designation 250-50-FN BB3. It’s the same design as the one mentioned by @MrP but it’s heavier and not a hollow point.

Cast with pure lead, they literally drop out of the mold at precisely .252 and 50 grains. The mold was purchased to feed my .25 Condor SS and when sized to .250 these slugs perform very well. Nice snug fit in the chamber, very accurate and very hard hitting. In the GK1 they are way too sloppy in the magazine and can jam the gun.

But….. Right out of mold, and unsized, it’s like they were made specifically for that gun. They slide in nice and smooth right up to the rear driving band. Then with a little extra effort to full seat the slug, they fit perfectly. Both in diameter and length. No rattling, no movement.

So far they appear to be shooting good. I haven’t shot that many, maybe a hundred or so, but so far no problems. They are definitely beating the crap out of the swingers at the 50 yard mark.

I originally bought that mold for the Condor to address the more “resilient” pests around here. That would be rampaging feral roosters, their garden wrecking girlfriends and the occasional porky visitors. The Condor and the Bob’s Boat Tails have been stellar in that role. But now that I’m learning the possibilities of the GK1 and the BBTs, I’m picturing a compact, repeating carbine and some fast rooster rolling action.

I bought the Huben for a fun shooter in the backyard. And for sure it is all that. But with these slugs I may have to look into putting it to work.