I checked these new NOE BBTs in both my Hatsan AT-44 and my Disco Double (with .25 cal MRod magazine).... They fit both magazines fine and function perfectly.... That, of course was one of the design parameters, that the overall length fit the Hatsan mags.... and they are spot on .... Remember that I got the smaller NOE mould for these bullets, with a 0.250" nose and 0.252" driving band, but I don't think the larger ones will have any problem fitting the mags....

In the Hatsan I can feel a slight resistance on closing the lever, but they will feed fine into a stock Hatsan chamber without sizing.... I chambered one bullet and then pushed it back out, and the rifling marks are clear, and appear the same depth all the way to the rear of the driving band, so I would say the chamber has little or no tapered leade.... There were absolutely no marks on the 0.2535" driving band between the rifling marks, indicating the groove diameter of the Hatsan barrel is larger than that.... It is possible that for the best accuracy in a Hatsan, the larger (0.253/0.255") NOE mould may be the better choice, but could require cutting a longer, tapered chamber to reduce chambering force.... If you don't want to do any barrel work, the smaller (0.250/0.252") NOE mould, like I got, may be the better choice....The Hatsan was tuned for 70 FPE with JSB King 34.2 gr. Heavies, and shot 75 FPE with the 50.8 gr. FN BBTs (815 fps).... I did not try increasing the hammer spring preload as that is not the gun I bought them for.... I have the 41 gr. BBT mould with the larger 0.253" nose / 0.255" driving band coming for the Hatsan.... and I now know I will likely have to cut a tapered leade for them....

In the .25 ACP liner by TJ's in my Disco Double, there was a fair amount of resistance closing the bolt, indicating they are slightly large for the chamber I have.... Once sized, they fed easier than the unsized ones in the Hatsan, basically no more resistance than chambering a JSB King Mk2 Heavy, and easier than the original King Heavy pellets with the oversize skirts.... I maxed out the hammer spring preload in the Disco Double, and tethered at 2900 psi they screamed over the Chrony at 1007 fps (114 FPE).... I backed the preload out 2.5 turns, and got the following average velocities for 5 shots....

50.8 gr. FN BBT unsized - 940 fps (100 FPE)
50.8 gr. FN BBT sized - 960 fps (104 FPE)
47.8 gr. HP BBT unsized - 965 fps (99 FPE)
47.8 gr. HP BBT sized - 985 fps (103 FPE)

Note that the velocity increased 20 fps with sizing the bullets, a good indication they are a bit tight as cast.... All four 5-shot groups that I fired through the Chrony were ragged holes in the backstop at 20 feet.... They all shot tighter during Chrony testing than the .25 cal 51 gr. BBTs I cast from my LBT mould, and a lot tighter than the 52.7 gr. RN Lyman 57902, or its HP version which was 46.4 gr.... I never found a setup that grouped with the Lymans.... It may be some time before I can get to try the new NOEs at long range, unfortunately....

When I size these bullets, there is just a hint of contact with the sizing die on the nose, enough to polish it all the way around, and the driving band is definitely smaller (now the same size as the nose, of course), but slides easily through my 0.250" sizing die.... When chambered in my Disco Double, which has a tapered leade of 2* per side, the nose is evenly, but not deeply marked by the rifling, as is the driving band.... I would say that sizing to 0.250" is just about perfect in the TJ's barrel.... I plan to size all my bullets prior to any further testing....

One other thing, I tried chambering these bullets in a .25 cal Lothar Walther barrel I bought many years ago from Mountain Air.... This barrel was chambered for pellets, and I am sure could benefit from having a longer chamber and tapered leade cut for use with bullets.... I could barely chamber an unsized bullet, but sized to 0.250" it chambered smoothly until it came up against the rifling (obviously no, or very little, taper in the leade), and the last 1/8" you had to give the bolt a firm shove to chamber it.... I understand the earlier LW barrels (which mine is) are smaller than the current production, which is listed on the LW website as 0.248" land and 0.254" groove.... If the specs on the website are correct, I think the larger size NOE mould (0.253" nose / 0.255" driving band) would be the better choice....

Now what we need are more readily available sizing dies in airgun calibers.... Al, are you listening?.... ???

Bob