pardon the caps:
HAS LEVER:
Detachable Box Mag Systems - cdiprecisiongunworksstore.com
DOESN'T HAVE LEVER, NO INLETTING, BUT DOESN'T TAKE AI MAGS EITHER:
Legacy Sports International Howa Detachable Magazine Conversion Kit .308 Winchester 10 Round
APPEARS TO BE THE SAME AS ABOVE:
Detachable Box Magazine Kit | Accessories | Products | Weatherby.com
HERE'S SOMETHING A GUY MADE, NOT AI:
Home made detachable mag’ conversion for a Howa.
THESE WILL NEED INLETTING, TAKES AI STYLE MAGS AND HAS LEVER:
Pacific Tool & Gauge, Inc. - Specials Page
IF YOU HAVE A SHORT ACTION, THESE ARE ON SALE:
https://shop.pacifictoolandgauge.co...ucts_id=1603&zenid=k874fgkv7k2da7ce2dot5d3263
CHEAP ENOUGH TO EXPERIMENT WITH.
lever, and inletting but takes AI
https://www.badgerordnance.com/product-category/trigger-guards/
these are slick, don't know if they have howa:
Detachable Bottom Metal - Parts & Accessories and it looks as if there will be inletting. no lever, aics mags.
this is as close as you are going to get...no lever, aics style mags, but there's inletting involved:
Howa 308/10 Assy., WYATT'S OUTDOOR, INC.
Howa 308/5 Assy., WYATT'S OUTDOOR, INC.
Howa 223/4 Assy., WYATT'S OUTDOOR, INC.
instructions on "near drop in" DBM for wyatt, howa :
WYATT'S OUTDOOR, INC.
has lever, may need some inletting, don't know if they have something for howa:
Stillers Precision Firearms
henderson defense has some nice BM, don't know if they still make it. same as the BAD BDM, which seems not to be had anywhere.
you can trim the lever to some extent on the paddle lever ones. other than that you are SOL on what you are looking for.
for a AICS mag type conversion, this works well for me at half the price of a regular metal mag:
http://www.snipershide.com/shooting...conversion-m5-aics-type-bm-rem-700-shown.html
you can "inlet" yourself, but after further review, i'd send it off to get done:
http://www.snipershide.com/shooting/snipers-hide-d-i-y/219944-diy-ptg-stealth-dbm-install.html