Partial Mash Oatmeal Stout

CBBaron posted the following recipe which got some great feedback. Could anyone help me with a partial mash version? Thanks!

"Recipe Type: All Grain
Yeast: S-04
Yeast Starter: no
Batch Size (Gallons): 5.25
Original Gravity: 1.055
Final Gravity: 1.018
IBU: 36
Boiling Time (Minutes): 60
Color: 35
Primary Fermentation (# of Days & Temp): 14days @ 65F
Secondary Fermentation (# of Days & Temp): no

OG 1.055 (80% efficiency, adjust base malt for your system)
IBUs 36
6.75# Pale malt
0.5# roasted Barley (350l)
0.75# chocolate (330l)
0.5# crystal 40
0.5# crsytal 120
0.75# victory
1# flaked oats
2oz Willamette hops at 60
S-04 yeast

Single infusion mash at 156F for 60 min.

I threw this recipe together when I had concerns about the astringency of my previous stout.
This one is very smooth and full bodied even at 2 weeks in bottle, no problems with astringency. The roast flavors are subdued compared to most bold stouts but it tastes oh so good. "

How much grain can your mash tun hold? Even without adding any pale malt to convert the Victory and oats, you're looking at 4 pounds of non-base grains in the grist.

Here's what I'd do - the roasted and crystal malts can be steeped to get all of their goodness. I'd steep those. Then I'd mash the Victory and flaked oats with 2 pounds of pale malt. That leaves you to find an equivalent to 4.75 pounds of pale malt.

Since 1 lb pale malt = 0.75 lb extract syrup = 0.6 lb dry extract, it's easy enough to figure out: multiply 4.75 by the appropriate numbers.

Thus: 4.75 = 3.5 lbs LME = 2.85 lbs DME. Me, I'd just buy a 3 lb bag of light DME and call it a day. 0.15 lbs of DME isn't going to send the recipe so far out of whack that it'll be noticed.

Remember: When converting an All-Grain recipe to Partial Mash or Extract/Steep, leave the specialty grains alone and convert the base malt to extract thusly:

1 lb base malt = 0.75 lb extract syrup = 0.6 lb dry extract

Cheers,

Bob