jjs,

FWIW, here are a couple of loads that I have worked up for my Lott:

---------------------------------

Cartridge Load Information
~~~~~~~~~~~~~~~~~~~~~~~~~~
Load Name: 458 Lott Softs
Bullet Mfg: Swift
Bullet Type: A-Frame
Bullet Caliber: .458
Bullet Weight: 500
Ballistic Coeff: 0.361
Powder Mfg: Hodgdon
Powder Type: Varget
Powder Weight: 0.000
Powder Lot Number: Unknown
Primer Mfg: FEDERAL
Primer Size: 215 LRM-MATCH
Primer Type:
Primer Lot Number: unknown
Case Mfg: Hornady
Case Length: 0.000
Case # Times Loaded: 0
Cartridge OAL: 0.000
Comparator OAL: 0.000
Av. Group size: 1.038
Av. Group Velocity: 2218
Cartridge Mfg Date:
Cartridge Lot Number:
Moly Coated: No
Crimped: Yes
< !--color-->



Cartridge Load Information
~~~~~~~~~~~~~~~~~~~~~~~~~~
Load Name: 458 Lott plinking load
Bullet Mfg: Hornady
Bullet Type: #4507 FMJRN
Bullet Caliber: .458
Bullet Weight: 500
Ballistic Coeff: 0.295
Powder Mfg: IMR
Powder Type: 4320
Powder Weight: 82.000
Powder Lot Number: Unknown
Primer Mfg: FEDERAL
Primer Size: 215 LRM-MATCH
Primer Type:
Primer Lot Number: unknown
Case Mfg:
Case Length: 0.000
Case # Times Loaded: 0
Cartridge OAL: 0.000
Comparator OAL: 0.000
Av. Group size: 0.693
Av. Group Velocity: 2155
Cartridge Mfg Date:
Cartridge Lot Number:
Moly Coated: No
Crimped: Yes

< !--color-->

Range was 100 yds. The groups sizes are real, but only three shot. Any more than that, they'll open up in proportion to my increasing flinch . Obviously you'll need to back off those powder weights and work up.

I still have yet to work up my woodleigh solid loads.

Take Care,

-Steve

500grains and GeorgeS

Well I went home during lunch to see what I could find out. As GeorgeS suggested, I took an unprimed case seated bullet to 4.7"+ and closed the bolt. The bullet was pushed back to 4.2"+/- so it seems that the magazine length will be the limiting factor backing off .1". So there is a significant amount of "freebore" in the CZ 458 Lott. I think I did this correctly?

I have a CZ 550 in 416 Rigby that I am using a cartridge overall length of 3.75". I think I will try seating the Lott between 3.65" and 3.7" and see what feeds and provides best accuracy.

500grains, what velocity are you getting with your load?

I used the 500 grain TSX with H4895 loaded to a nominal 2250 fps which worked very well. I did not have much time to develop loads before I went to Tanzania that was the first and only load I tried in the Lott.

I was in the process of working up to 2300 fps and may try some different powders, etc...possibly those Northfork bullets, however, I really like the Barnes TSX...any suggestions are appreciated. Thanks again for the help!