top of page

Load data for 7.21 Firebird (Lazzeroni) + .284 | 140gr | Sierra SBT GameKing

Recommended Powder(s): ADI AR 2217, ADI AR 2225, Hodgdon Retumbo, ReloadSwiss RS 80, Vihtavuori N568

7.21 Firebird (Lazzeroni) + .284 | 140gr | Sierra SBT GameKing

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.284 | 140gr | Sierra SBT GameKing
Manufacturer SKU:
1905
Bullet Weight:
140gr | 9.1g
Bullet Diameter:
0.284" | 7.21mm
Bullet Length:
1.160" | 29.5mm
Caliber:
7.21 Firebird (Lazzeroni) load data
Case Length (l3):
2.800" | 71.1mm
Cartridge Length (C.O.L.):
3.497" | 88.8mm
Seated Depth:
0.463" | 11.8mm
Shank Seated Depth:
0.323" | 8.2mm
Case Capacity:
121.0 Grains of Water | 7.86 cm³
Primer Size:
Large Rifle Magnum (LRM)
Max. allowed Pressure:
66717 psi | 4600 bar
LID:
LID_B5841_C1103
Last updated:
2025-01-01
Recommended Twist Rate:
1:12 - 1:10

Load data for 92 loads in caliber 7.21 Firebird (Lazzeroni) with .284 | 140gr | Sierra SBT GameKing bullet and 46 powders such as ADI AR 2217, ADI AR 2225, Hodgdon Retumbo, ReloadSwiss RS 80, Vihtavuori N568. The key underlying parameters are shown in the table above.

  • Important Notice: DO NOT go below Minimum Charge or above Maximum Charge unless there are reasons. Since xxlreloading.com has no control over the equipment and components used by the customer and the data used in connection with the website, any responsibility and liability for the results achieved is rejected. Also see our Terms of Service

    Questions regarding the load data: Please read the information in the next tab "Explanations".

  • No data yet

  • .

    Use the Personalized Load Calculator to customize loads to your own specific requirements. Find more details in the help section.

    Our default view only displays powders/loads that fulfill certain criteria: Max pressure of a load <=90% of Max. Standardized Pressure. Fill Rate (Min FR): >80% and <100% for rife loads,  >60% and <100% for pistol loads. Min. Propellant Combustion (Min z): >90% for rifle loads , >80% for pistol/revolver loads. Relax these criteria at your own risk to potentially get more powders shown in the load tables.

Click on the desired row in the tables below to add a specific load / powder to your Diary and manage there.

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
83%
59814
90%
**05
100%
ADI AR 2213
<<locked>>
86%
59640
89%
**38
100%
ADI AR 2217 👍
<<locked>>
94%
59567
89%
**22
100%
ADI AR 2218
<<locked>>
97%
58479
88%
**10
99%
ADI AR 2225 👍
<<locked>>
96%
59727
90%
**38
100%
Accurate 3100
<<locked>>
86%
59770
90%
**27
100%
Accurate 8700
<<locked>>
97%
46673
70%
**66
95%
Accurate MAGPRO
<<locked>>
86%
59973
90%
**45
99%
Alliant Reloder-19
<<locked>>
84%
59930
90%
**05
100%
Alliant Reloder-22
<<locked>>
86%
59915
90%
**22
100%
Alliant Reloder-23
<<locked>>
86%
59611
89%
**50
100%
Alliant Reloder-25
<<locked>>
90%
59698
89%
**05
100%
Alliant Reloder-33
<<locked>>
94%
59451
89%
**71
98%
Alliant Reloder-50
<<locked>>
97%
56637
85%
**05
97%
Hodgdon H1000
<<locked>>
94%
59567
89%
**22
100%
Hodgdon H4831
<<locked>>
89%
59770
90%
**92
100%
Hodgdon H4831 SC
<<locked>>
85%
59770
90%
**92
100%
Hodgdon Retumbo 👍
<<locked>>
96%
59727
90%
**38
100%
Hodgdon TrailBoss
<<locked>>
97%
36318
54%
**57
100%
IMR 4955 Enduron
<<locked>>
86%
59524
89%
**56
100%
IMR 7828 SSC
<<locked>>
84%
59437
89%
**45
100%
IMR 7977 Enduron
<<locked>>
91%
59422
89%
**23
96%
IMR 8133 Enduron
<<locked>>
97%
56463
85%
**99
100%
[Lovex D100]*
<<locked>>
94%
59872
90%
**43
94%
Lovex S071
<<locked>>
91%
59770
90%
**27
100%
Norma 217
<<locked>>
97%
57682
86%
**15
100%
Norma MRP
<<locked>>
83%
59553
89%
**32
100%
[Ramshot LRT]*
<<locked>>
97%
58233
87%
**35
94%
Ramshot Magnum
<<locked>>
86%
59872
90%
**89
100%
ReloadSwiss RS 14
<<locked>>
96%
37289
56%
**03
100%
ReloadSwiss RS 76
<<locked>>
90%
59944
90%
**81
100%
ReloadSwiss RS 80 👍
<<locked>>
92%
59582
89%
**58
100%
Rottweil R 904
<<locked>>
83%
59901
90%
**79
100%
Rottweil R 905
<<locked>>
84%
59756
90%
**96
100%
SNPE Vectan SP 13
<<locked>>
97%
48776
73%
**86
95%
Somchem S385
<<locked>>
83%
59495
89%
**56
100%
[Vihtavuori 20N29]*
<<locked>>
97%
47123
71%
**63
92%
[Vihtavuori 24N41]*
<<locked>>
97%
58639
88%
**96
94%
Vihtavuori N165
<<locked>>
88%
59973
90%
**50
100%
Vihtavuori N170
<<locked>>
96%
59640
89%
**63
97%
Vihtavuori N555
<<locked>>
84%
59944
90%
**63
100%
Vihtavuori N560
<<locked>>
85%
59886
90%
**51
100%
Vihtavuori N565
<<locked>>
89%
59886
90%
**22
100%
Vihtavuori N568 👍
<<locked>>
92%
59466
89%
**58
99%
Vihtavuori N570
<<locked>>
93%
59727
90%
**94
98%
Winchester StaBALL HD
<<locked>>
86%
59712
90%
**25
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2209
<<locked>>
81%
55274
83%
**40
100%
ADI AR 2213
<<locked>>
81%
50517
76%
**77
99%
ADI AR 2217
<<locked>>
81%
37739
57%
**95
96%
[ADI AR 2218]*
<<locked>>
85%
37043
56%
**18
90%
ADI AR 2225
<<locked>>
81%
34940
52%
**46
98%
Accurate 3100
<<locked>>
81%
51039
77%
**89
100%
[Accurate 8700]*
<<locked>>
91%
37101
56%
**53
90%
Accurate MAGPRO
<<locked>>
81%
50792
76%
**71
98%
Alliant Reloder-19
<<locked>>
81%
54998
82%
**17
100%
Alliant Reloder-22
<<locked>>
81%
51184
77%
**68
100%
Alliant Reloder-23
<<locked>>
81%
49792
75%
**95
100%
Alliant Reloder-25
<<locked>>
81%
43874
66%
**43
100%
[Alliant Reloder-33]*
<<locked>>
81%
36201
54%
**62
90%
[Alliant Reloder-50]*
<<locked>>
86%
37449
56%
**76
90%
Hodgdon H1000
<<locked>>
81%
37739
57%
**95
96%
Hodgdon H4831
<<locked>>
81%
46543
70%
**46
98%
Hodgdon H4831 SC
<<locked>>
81%
52054
78%
**54
99%
Hodgdon Retumbo
<<locked>>
81%
34940
52%
**46
98%
Hodgdon TrailBoss
<<locked>>
81%
28979
43%
**83
100%
IMR 4955 Enduron
<<locked>>
81%
50227
75%
**95
99%
IMR 7828 SSC
<<locked>>
81%
52605
79%
**20
99%
[IMR 7977 Enduron]*
<<locked>>
81%
42728
64%
**05
90%
[IMR 8133 Enduron]*
<<locked>>
81%
32460
49%
**57
93%
[Lovex D100]*
<<locked>>
87%
45847
69%
**90
90%
Lovex S071
<<locked>>
81%
43845
66%
**48
100%
Norma 217
<<locked>>
81%
32735
49%
**74
96%
Norma MRP
<<locked>>
81%
55042
82%
**56
100%
[Ramshot LRT]*
<<locked>>
92%
48544
73%
**48
90%
Ramshot Magnum
<<locked>>
81%
49980
75%
**18
100%
ReloadSwiss RS 14
<<locked>>
81%
29863
45%
**32
100%
ReloadSwiss RS 76
<<locked>>
81%
42888
64%
**69
100%
ReloadSwiss RS 80
<<locked>>
81%
39320
59%
**44
95%
Rottweil R 904
<<locked>>
81%
55477
83%
**00
100%
Rottweil R 905
<<locked>>
81%
54636
82%
**07
100%
[SNPE Vectan SP 13]*
<<locked>>
89%
37594
56%
**40
90%
Somchem S385
<<locked>>
81%
55129
83%
**87
100%
[Vihtavuori 20N29]*
<<locked>>
94%
42032
63%
**54
90%
[Vihtavuori 24N41]*
<<locked>>
92%
48457
73%
**99
90%
Vihtavuori N165
<<locked>>
81%
47108
71%
**23
99%
[Vihtavuori N170]*
<<locked>>
83%
38566
58%
**46
90%
Vihtavuori N555
<<locked>>
81%
54911
82%
**87
100%
Vihtavuori N560
<<locked>>
81%
51634
77%
**10
99%
Vihtavuori N565
<<locked>>
81%
45455
68%
**56
98%
Vihtavuori N568
<<locked>>
81%
40422
61%
**71
95%
[Vihtavuori N570]*
<<locked>>
81%
38682
58%
**38
91%
Winchester StaBALL HD
<<locked>>
81%
49951
75%
**74
100%

Start Load - Barrel Length: 23.60''

Any powder missing? Then click here.

FR ... fill rate of the cartridge in percent

MaxP ... max. pressure of load in psi or bar

% ... max. pressure of load in percent of the maximum allowed pressure for this caliber 

V(0) ... muzzle velocity in feet per second (fps) or  meters per second (m/s)

z ... powder burnt in percent

[...] *... not dangerous but load has suboptimal powder burnt with possible characteristics such as extensive muzzle flash or inaccurate loads.

[...] ²... fill rate low - you might want to consider using a filler to ensure proper ignition.

[...] ᴾ... possible press load - work up slowly to this load while watching for signs of excessive pressure.

👍  ... recommended powder/load for this caliber and bullet combination based on its ballistic performance.

bottom of page