iPhone 6 PlusFlickr/Omar Jordan FawahliPhone 6 shipments will soar in Q4.

According to KGI Securities analyst, Apple is forecast to sell 71.5 million iPhones in Q4, Apple Insider reports.

KGI’s Ming-Chi Kuo — who has a good record as an Apple analyst because of his sources in Apple’s supply chain — says quarter-over-quarter shipments of the smartphone will grow 82% in Q4, and predicts the iPhone 6 will head the surge.

Apple Insider explains the iPhone 6 will likely make up nearly 60% of all sales over the period, quoting a figure of 41.65M units. The iPhone 6 Plus will not perform quite as well though. Apparently suppliers are having production issues with the larger phones, and Q4 sales are dependent on the supply chain.

After strong sales over the festive season, Kuo expects iPhone sales to fall dramatically to a combined 49.5 million units as off-season demand reduces. Q1 sales always tend to dip after the Q4 holiday buying season. 9to5Mac believes demand will eventually settle at a 2:1 ratio favouring the 6 over the 6 Plus. It’s worth noting the drop in quarterly sales would still be a big jump year-on-year; if Apple sells that many phones, it will be up 13%.

Kuo says older models, such as the entry-level iPhone 5C and iPhone 4S, will be discontinued in 2015 in favour of the 5S. Until that happens, promotional pricing on all those lines will reduce the average sales price of iPhones in Apple’s lineup. The iPhone 5s could eventually become free on contract, Kuo says.