Winchester 70 Post 64 Long Action Magnum DBM. This allows use of AICS mags in your Winchester 70 Long Action Rifle. This DBM Uses AI 300 Win Mag or 338 Lapua Magazines. Install is required, and we can provide inletting and install services as well. Installs are free at CDiPrecision, so click Install option and send your rifle in for install. Easy and fast. 3 week turnaround or faster. US Addresses only. Mags Must be purchased Separately.