ATF APPROVED!!! 4/29/05
The 550 Express was designed to be the most powerful round one could legitimately fit into a
sporting/hunting Mauser. It is designed to throw a 700gr bullets 2124fps, and exceed 7000 ft-lbs. It does
this and more, and has tolerable recoil. In short, it beats the 577 Nitro!! (approaching 2200fps with 700gr)
550 Express
FINALLY- i got to finish this beast and actually light the fires!!!

Quickload can NOT handle big straight rounds. At no point did a load and pressure/vel sync up..

Some preliminary 550 Express data!!

(these loads appeared safe in my particular gun, yours WILL vary. Do NOT take this as loading data.
This is for INFORMATIONAL use only)

23" barrel bausa barrel (my custom profile)
Weatherby 416 brass, 2.65"
federal 215s
Single stack mag 3 down, 1 up
vz-24 action
boyds lam JRS stock
f-990 pad
necg front sight
intregal rear island sight (cz take off 1 up, 2 down)
intregal barrel lug under sights
brass cup holding in barrel lug
timney trigger
flag safety
ruger/brownells barrel sling mount

blc2 (pretty dull)
665 gr casts 3.2 oal
93gr 1783  4695 ft-lbs
100gr 1980  5790 ft-lbs

70gr hawks 3.325 oal
96gr 1796 5015 ft-lbs

665 gr casts (3.2 oal)
h335 (much better)
92 gr  2037 6129 ft-lbs
94gr 2120  6638 ft-lbs
96gr 2141  6770 ft-lbs
98gr 2159  6885 ft-lbs
100gr 2184  7045 ft-lbs (YES- round PROVEN)
102gr 2219  7273 ft-lbs
104gr 2234  7371 ft-lbs
106gr 2263  7564 ft-lbs
108gr 2295  7779 ft-lbs
110gr 2321  7957 ft-lbs

that's right, 8000 ft-lbs from a MAUSER vz 24 action

700gr hawks 3.325 oal
102gr 2109  6915 ft-lbs
106gr 2115  6955 ft-lbs
108gr 2144  7147  ft-lbs (MORE than a 577 nitro)
110gr 2169  7314  ft-lbs

700gr hawk, 3.25 oal
105gr 2131  7060  ft-lbs (and i think this is THE load)
110 gr 2193 7477  ft-lbs

Cases stayed "smoked neck" until around 104-105 grains, neck wrinkle didn't go away until 108 gr.

Man, my shoulder is a little tired!!! Accuracy trailed off at the end.. i think that was mostly me being punchy!!

Anyway, the primers all looked VERY reasonable... Until the ~105gr loads, I think it was low 40s kpsi. The 110
grain loads, both 3.325 and 3.25 looked about like a normal reloaded 30-06... I think that 105 should be
considered THE load. If you want more, go for it, but 7000ft/lbs and a 700gr bullet... SD of .331, gun weight,
about 11.5, recoil, about 110 ft-lbs.

And yes, the chrony survived all this!!!

If you are working on an express, 90 grains should be a reasonable starting point.

So, at this point, *I* had about a net 50 yard 10", shooting offhand, with all these loads... When i marked
several of them, it seemed to be more like a series of 3-4" groups... At 25 yards, well, it's a bunch smaller.

Feeding was "okay" for everything but the last round.. But, hey, I've already taken that mag box out and I am
working on V2.. As I can SEE what's wrong with it.