Pakistan Ordnance Factories (POF) have unveiled projects of new domestic rifles called BW20 and BW21 7.62×51mm. Salman Ali, lead designer of the POF BW20 series, mentioned in The Firearm Blog that the BW20 rifle uses the same mechanism used in the Hecker & Koch G3, which is the standard fighting rifle of the Pakistan Army and is currently a POF product.
It appears that the Pakistani munitions factories have introduced the BW20 in accordance with the requirements of the next-generation rifle for the Pakistani army. It is a new design that saves costs by re-utilizing the existing production infrastructure of Pakistan's munitions factories dedicated to the HK G3. Although the BW20 has some commonalities with the G3 (about 30%), it is not an upgrade to the HK G3, but rather a new rifle.
For example, the G3 rifle consists of 200 parts, and the BW20 rifle uses 125 parts, which is a clear difference in design and construction. Furthermore, the BW20 uses PMF's internal trigger mechanism, which is based on the AR-15, while its feed system uses an AR10 magazine. The final version of the BW20 will have a different magazine (the latter design will be compatible with AK series magazines), a selector system, a bolt opening mechanism, and picatinny rails for accessories such as sighting systems and front handles.
The Pakistani munitions factories are also reportedly working on a version of the BW20 in 5.56×45mm and 7.62×39mm. This plant is likely to produce 7.62x39mm versions for both the Pakistan Army and Interior Ministry paramilitary units, in line with the increasing adoption of this caliber of ammunition in service.
As for the BW21 rifle, it differs in design from the BW20 except that it uses the same 7.62×51mm caliber using an AR-style roller-delayed blowback mechanism. It is unclear whether the BW21 is a continuation of the AR development of Pakistani ordnance factories, which debuted in late 2019 with the PK18, and the BW21 may be more indigenously designed and built than the BW20.
In 2015, the Pakistani army put out a tender for the purchase of a new generation assault rifle. Many designs have been tested from around the world, including the FN SCAR, Beretta ARX-200, CZ BREN, AK-103 and more. In the end, the Army chose none of the 7.62×51mm designs for domestic adoption. There have been reports that Pakistan has ordered the AK-103 from Russia, but the status of this program is unclear.
In the end, the Pakistan Ordnance Factory (POF) appears to have given the green light to a domestic rifle design, and part of the reason appears to stem from the sense that none of the foreign designs have significantly improved upon the G3 in terms of accuracy and durability. This is not to say that the other guns weren't good, but the incremental improvement they provided may not have justified the total cost of adopting and manufacturing a foreign design domestically.