Change the book.
The Lyman manual is an antique. My Hornady Manual stops at a MAX of 44.9.
Lyman manual, an antique? You believe? Not for a second!
Taking the Hornady load at face value, with a 2.800" (SAAMI) COAL (assuming that's just right for the chamber throat which is dubious with factory rifles, their freebore usually being MUCH longer these days), and fairly heavy (Lapua or RWS) brass, QuickLOAD says that you get all of 50,233 psi PMax with 44.9gn IMR-4064 and the 150gn Hornady Interlock SP #3031, compared to the cartridge's SAAMI MAP (maximum
average pressure, ie peak is allowed to exceed that) of 60,191 psi - not quite an efficient load, even though it'll suffice for any British deer at short ranges and may give excellent results in terms of precision etc. However, a typical factory rifle typified by Remington 700s is usually given a large amount of freebore these days which further depresses pressures and velocities, so you'd be unlikely to achieve that modest 50,000 psi taking pressures back into what was regarded as the norm in the early days of smallbore military rifles and crude smokeless propellants around 120 years ago!
A point which is constantly made in handloading manuals, and constantly ignored by most users, is that the combinations only apply when all listed components are used. In the Lyman data, that's a Remington case which comes from the factory pretty thin-walled and therefore with an enhanced internal capacity. For normal calculations and comparisons, as used for example in QuickLOAD, the exact case capacity is determined by weighing a fireformed unsized case empty followed by level-full with water to obtain the 'overflow water capacity', this then converted to volume in CCs. In my 'minimum-SAAMI' (ie 'tight') .308 match rifle chambers, the water capacity of fired cases varies from 56.0 to 57.4gn depending on make. In a relatively 'slack' factory rifle chamber, the Remington case capacity will be at least 57gn, possibly as high as 57.5gn, it being one of the thinnest on the market.
Stick those values into QuickLOAD, and you get a 105.8% charge fill ratio (with seated bullet at 2.800" COAL) and 59,323 psi with a 57gn H2O capacity case, 104.8% charge fill ratio and a computed 58,113 psi for a 57.5gn case. With a decent length drop tube on the powder funnel, allied to a slow charge pour and obtaining a swirl motion in the funnel top, I would expect the actual powder compression to be modest in both examples.
However, use the Lyman load with a heavy Lapua case, worse an IMI model at 56.0gn H2O capacity or less and things get a bit hairy with 108% fill-ratio and a PMax that exceeds the maximum allowed.
If anything in this mix can be described as 'antique', it's the powder as IMR-4064 was introduced by DuPont Industries in 1935 for military smallarms cartridges (hence its name
Improved Military Rifle) and has changed little since. It's one of the most versatile propellants in its class and usually gives superb results in cartridges with similar characteristics to .308 Win - that's why it's been around for nearly 80 years and still sells well.
Right, what to do about powder up to the case-mouth? Mike, as JCS says use a modest length drop funnel - MTM does a reasonably priced multi-calibre kit incorporating a 4-inch funnel.
http://www.mtmcase-gard.com/products/reloading/powder-funnel-AF7.php
Forster does a longer (and considerably more expensive) metal drop tube model
http://www.forsterproducts.com/catalog.asp?prodid=700677
Both are available from Hannams Reloading Limited. The Forster funnel plus a slow / swirl pour will take the powder level down to the bottom of the neck. However, as noted, if you're using any case other than Winchester or Remington, drop that maximum load to 47gn anyway to take account of case volumes. As always, start well below and work up and look for good results rather than velocity for its own sake, unless you intend to take up 1,000 yard FTR match competition.