6mm Mongoose
The Mongoose is a wildcat round based on the .223/5.56 case. It uses standard magazines and can run bullets from 55 grains up to 95 the 105 amax will work at 2.29 oal the heavy vld bullets won't fit.. The shoulder is 40 deg. And the case taper is blown out for case capacity so it does require fire forming.
Making 6mm Mongoose brass consists of running through the die which pushes the shoulder back and then trimming to 1.69-1.695 (the rounds will shrink a little on the first fire as they stretch to fit the chamber.) That is it load them up and shoot to fire form the case.
For data you can start with 6x45 load data a good starting point is 1 grain under max loads for the 6x45 and work up. Max loads for the Mongoose will be above that of the 6x45.
Making 6mm Mongoose brass consists of running through the die which pushes the shoulder back and then trimming to 1.69-1.695 (the rounds will shrink a little on the first fire as they stretch to fit the chamber.) That is it load them up and shoot to fire form the case.
For data you can start with 6x45 load data a good starting point is 1 grain under max loads for the 6x45 and work up. Max loads for the Mongoose will be above that of the 6x45.
6mm Mongoose by MD WS
Cartridge overall length 2.26
Max case length1.700
Trim to case length 1.69
loaded rounds the neck needs to be under .268
Here are some velocities that can be expected
18 inch barrel
80 grain federal pulls 2900-2990
68 match burner 3100-3200
20 inch barrel
87 vmax 2750-2880
90 fmj 2750-2800
105 amax 2500-2600
22 inch barrel
55 grain tipped varmegeddon 3300-3500
90 accubond 2700-2800
From Wade:
Powders between 4198 and CFE are all suitable. Faster ones for lighter bullets and slower for heavier ones. One powder that works with all bullet weights would be H-335. It would be the 1680 for the mongoose. If I could only have one 335 would be it. BLC2 gives the highest velocity for 80 and up bullets. The stick powders are more temp sensitive and forgiving, Most of them flatten out velocity wise at the top of the ladder. H-322 for the light weights, Benchmark for the heavies. LT-32 for the middle weights and lighter, Its a grain or so faster than 322.
20" barrel
95gr=2750
90gr.=2800
85tsx=3000 warm
80gr.=3000
70gr.=3100
62gr.=3200
55gr.=3300
Cartridge overall length 2.26
Max case length1.700
Trim to case length 1.69
loaded rounds the neck needs to be under .268
Here are some velocities that can be expected
18 inch barrel
80 grain federal pulls 2900-2990
68 match burner 3100-3200
20 inch barrel
87 vmax 2750-2880
90 fmj 2750-2800
105 amax 2500-2600
22 inch barrel
55 grain tipped varmegeddon 3300-3500
90 accubond 2700-2800
From Wade:
Powders between 4198 and CFE are all suitable. Faster ones for lighter bullets and slower for heavier ones. One powder that works with all bullet weights would be H-335. It would be the 1680 for the mongoose. If I could only have one 335 would be it. BLC2 gives the highest velocity for 80 and up bullets. The stick powders are more temp sensitive and forgiving, Most of them flatten out velocity wise at the top of the ladder. H-322 for the light weights, Benchmark for the heavies. LT-32 for the middle weights and lighter, Its a grain or so faster than 322.
20" barrel
95gr=2750
90gr.=2800
85tsx=3000 warm
80gr.=3000
70gr.=3100
62gr.=3200
55gr.=3300