BAM B26
The BAM XS-B26 is a Chinese copy of the Beeman R9. It is available in two calibers: .177 and .22. It is a break barrel type air rifle. The 26 in B26 is for 26 mm chamber, but it never went into production at 26 mm. It has a 25 mm chamber. The Beeman R9 has 26 mm, where the B26 does not have the 26 mm chamber. Now Bam B26 is 26 mm chamber. References

Air guns