Guys, the recoil will not be as bad as you think. The first 3" load will feel like a hot 458 Winchester Mag. The 3.5" load will make around 98ft-lbs recoil in an 8LB gun. So it will feel like a heavy loaded 458 Lott. There is better recoil efficiency in the shotgun, since it uses less than half the weight of powder as the rifle cartridges. So recoil should theoretically be a bit less per energy made.
You cannot buy loaded rounds, you must reload them yourself. If you are not familiar with slug reloading, know that it is virtually the simplest form of reloading, and I recommend you try it. Use a roll crimper bit to roll the new hulls, the rest is put in by hand. You can order the crimp bit at Ballisticproducts.com, where the sabots come from, along with everything else.
I'll post the full load data. Note that the 500 grain bullets achieve the best efficiency. 300 grains don't go 3,000FPS, for instance. But notice how it seems it's getting good at 500 grains, and they stop there. I suspect 600-700 grain cast bullets will perform very well also. Oh, and also note the 7800Ft-lb 2-3/4 load: 500gr @ 2650FPS.
One last thing, if anyone wants to develop their own loads, but wants to have pressure/FPS data first, PM me for info. There is a guy in Illinois who you can send your loaded slugs to, and he will test them in a pressure barrel to provide the transducer data. If I recall correctly, the cost is $2 per test shot, and it's recommended you fire a minimum of 3-5 rounds of each charge weight to get a sufficient average pressure.
BPI Guide: BLS-12 Ballistic Sabot
.. COPYRIGHT BALLISTIC PRODUCTS, INC. 2008
ID# Ref# Ga. Len. Hull Primer Powder Gr. Gas Seal/Wad Over Shot SLUG MFG Type PSI FPS Crimp
80929 79 12 2.75 FIOCCHI FIO-616 CLAYS 24.0 X12X+BLS12 COS12 300GR Hornady HP-XTP 10200 2200 ROLL
81001 110 12 2.75 FIOCCHI FIO-616 CLAYS 24.5 X12X+BLS12 COS12 300GR Hornady HP-XTP 11500 2400 ROLL
81006 128 12 2.75 FIOCCHI FIO-616 E3 22.0 X12X+BLS12 COS12 300GR Hornady HP-XTP 11400 2450 ROLL
80929 81 12 2.75 FIOCCHI FIO-616 CLAYS 23.0 X12X+BLS12 COS12 350GR Hornady HP-XTP 10900 2100 ROLL
81006 127 12 2.75 FIOCCHI FIO-616 E3 20.0 X12X+BLS12 COS12 350GR Hornady HP-XTP 11200 2350 ROLL
81001 112 12 2.75 FIOCCHI FIO-616 LONGSHOT 33.0 X12X+BLS12 COS12 500GR Hornady JFP MAG 10400 2600 ROLL
81002 114 12 2.75 FIOCCHI FIO-616 LONGSHOT 35.0 X12X+BLS12 COS12 500GR Hornady JFP MAG 11200 2650 ROLL
80929 82 12 3.00 FIOCCHI FIO-616 CLAYS 26.0 FS12+BLS12 COS12 350GR Hornady HP-XTP 10200 1700 ROLL
81002 116 12 3.00 FIOCCHI FIO-616 CLAYS 28.0 FS12+BLS12 COS12 350GR Hornady HP-XTP 11400 2100 ROLL
81003 123 12 3.00 FIOCCHI FIO-616 INTERNATIONAL 30.0 FS12+BLS12 COS12 350GR Hornady HP-XTP 11000 2200 ROLL
81003 122 12 3.00 FIOCCHI FIO-616 E3 24.0 FS12+BLS12 COS12 350GR Hornady HP-XTP 11200 2150 ROLL
81006 129 12 3.00 FIOCCHI FIO-616 HS6 44.0 FS12+BLS12 COS12 500GR Hornady JFP MAG 11100 2400 ROLL
81006 130 12 3.00 FIOCCHI FIO-616 LONGSHOT 38.0 FS12+BLS12 COS12 500GR Hornady JFP MAG 9700 2350 ROLL
80929 117 12 3.50 FEDERAL FED209A CLAYS 28.0 (2)FS12+BLS12 COS12 300GR Hornady HP-XTP 14000 2200 ROLL
81006 133 12 3.50 FEDERAL FED209A E3 27.0 X12X+FS12+14CORK12+BLS12 COS12 300GR Hornady HP-XTP 11200 1600 ROLL
80929 83A 12 3.50 FEDERAL FED209A INTERNATIONAL 34.0 (2)FS12+BLS12 COS12 350GR Hornady HP-XTP 13600 2600 ROLL
80929 83B 12 3.50 FEDERAL FED209A INTERNATIONAL 32.0 X12X+FS12+BLS12 COS12 350GR Hornady HP-XTP 13500 2800 ROLL
81003 125 12 3.50 FEDERAL FED209A HS6 46.0 (2)FS12+BLS12 COS12 500GR Hornady JFP MAG 11700 2400 ROLL
81006 133 12 3.50 FEDERAL FED209A HS6 50.0 (2)BPGS+FS12+14CORK12 COS12 500GR Hornady JFP MAG 12900 2750 ROLL
81002 118 12 3.50 FEDERAL FED209A LONGSHOT 40.0 (2)FS12+BLS12 COS12 500GR Hornady JFP MAG 10600 2350 ROLL
81003 124 12 3.50 FEDERAL FED209A LONGSHOT 42.0 (2)FS12+BLS12 COS12 500GR Hornady JFP MAG 11600 2450 ROLL
81006 131 12 3.50 FEDERAL FED209A LONGSHOT 44.0 BPGS+(2)FS12+BLS12 COS12 500GR Hornady JFP MAG 11400 2400 ROLL
81006 132 12 3.50 FEDERAL FED209A LONGSHOT 46.0 (2)BPGS+FS12+14CORK12 (2)COS12 500GR Hornady JFP MAG 12500 2550 ROLL
BLS-12 SLUG
*Roll Crimps: This is a rigid load requirement at this time.
WARNING: BALLISTIC PRODUCTS, INC. DISCLAIMS ALL POSSIBLE LIABILITY FOR DAMAGES, INCLUDING ACTUAL, INCIDENTAL, AND CONSEQUENTIAL, RESULTING FROM USAGE OF
INFORMATION OR ADVICE CONTAINED IN THIS AND OTHER PUBLICATIONS, LABELS, CATALOGS AND BOOKLETS. USE DATA AND ADVICE AT YOUR OWN RISK AND WITH CAUTION.
WHERE DATA LIST SPECIFIC COMPONENTS, NO CHANGES OR SUBSTITUTIONS FOR THESE COMPONENTS CAN BE MADE WITHOUT RISKING SIGNIFICANT CHANGES IN THE LEVEL OF
BALLISTIC PERFORMANCE AND/OR SAFETY OF THE LOADS SHOWN. FOLLOW LOADING DATA EXACTLY AND DO NOT SUBSTITUTE COMPONENTS. WE MAKE NO WARRANTIES
EXPRESS OR IMPLIED, LIMITED OR FULL. FAILURE TO COMPLY WITH THESE AND OTHER STANDARDS OF RELOADING MAY RESULT IN ACCIDENTS WITH SERIOUS INJURY AND/OR
DEATH TO THE SHOOTER AND/OR BYSTANDERS. KEEP OUT OF REACH OF CHILDREN. FOLLOW LOADING DATA AND WARNINGS OF RELOADING EXACTLY. WE DISCLAIM ANY
LIABILITY FOR DAMAGE OR INJURY THAT MAY RESULT FROM YOUR HANDLOADED SHOTSHELLS AS WE HAVE NO CONTROL OVER YOUR LOADING PRACTICES AND METHODS. TO
AVOID SERIOUS INJURY OR DEATH TO SHOOTER AND BYSTANDERS, THIS PRODUCT SHOULD ONLY BE USED IN GUNSMITH-INSPECTED GUNS DESIGNED FOR MODERN SHOTSHELLS.
THIS PRODUCT MUST NOT BE USED IN GUNS HAVING DAMASCUS OR TWIST STEEL BARRELS. KNOW WHAT IS BEHIND YOUR. IF GUN FAILS TO FIRE, KEEP POINTED IN SAFE
DIRECTION FOR 30 SECONDS, THEN UNLOAD CAREFULLY. WEAR EYE AND EAR PROTECTION AND OBSERVE PROPER GUN SAFETY AT ALL TIMES.