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Load data for 7.21 Firebird (Lazzeroni) + .284 | 150gr | Sierra SBT GameKing

Recommended Powder(s):

7.21 Firebird (Lazzeroni) + .284 | 150gr | Sierra SBT GameKing

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.284 | 150gr | Sierra SBT GameKing
Manufacturer SKU:
1913
Bullet Weight:
150gr | 9.7g
Bullet Diameter:
0.284" | 7.21mm
Bullet Length:
1.200" | 30.5mm
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:
0.503" | 12.8mm
Shank Seated Depth:
0.363" | 9.2mm
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_B5843_C1103
Last updated:
2025-01-01
Recommended Twist Rate:
1:12 - 1:10

Load data for 80 loads in caliber 7.21 Firebird (Lazzeroni) with .284 | 150gr | Sierra SBT GameKing bullet and 40 powder(s). 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".

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    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 2213
<<locked>>
84%
59350
89%
**43
100%
ADI AR 2217 👍
<<locked>>
93%
59567
89%
**36
100%
ADI AR 2218
<<locked>>
96%
59640
89%
**45
99%
ADI AR 2225
<<locked>>
95%
60017
90%
**56
100%
Accurate 3100
<<locked>>
84%
59611
89%
**38
100%
Accurate 8700
<<locked>>
97%
49226
74%
**43
96%
Accurate MAGPRO
<<locked>>
84%
59683
89%
**63
99%
Alliant Reloder-22
<<locked>>
84%
59857
90%
**46
100%
Alliant Reloder-23
<<locked>>
85%
59393
89%
**61
100%
Alliant Reloder-25
<<locked>>
89%
59901
90%
**33
100%
Alliant Reloder-33
<<locked>>
93%
59625
89%
**89
99%
Alliant Reloder-50
<<locked>>
97%
59756
90%
**69
98%
Hodgdon H1000
<<locked>>
93%
59567
89%
**36
100%
Hodgdon H4831
<<locked>>
87%
59640
89%
**10
100%
Hodgdon H4831 SC
<<locked>>
84%
60031
90%
**10
100%
Hodgdon Retumbo
<<locked>>
95%
60017
90%
**56
100%
[Hodgdon US 869]*
<<locked>>
97%
53679
80%
**15
93%
Hodgdon TrailBoss
<<locked>>
97%
36506
55%
**98
100%
IMR 4955 Enduron
<<locked>>
86%
59915
90%
**87
100%
IMR 7828 SSC
<<locked>>
83%
59466
89%
**56
100%
IMR 7977 Enduron
<<locked>>
90%
59654
89%
**54
96%
IMR 8133 Enduron 👍
<<locked>>
97%
59132
89%
**53
100%
Lovex D100
<<locked>>
93%
59872
90%
**74
95%
Lovex S071
<<locked>>
89%
59814
90%
**35
100%
Norma 217 👍
<<locked>>
96%
59582
89%
**56
100%
Ramshot LRT
<<locked>>
96%
59480
89%
**86
95%
Ramshot Magnum
<<locked>>
84%
60017
90%
**04
100%
ReloadSwiss RS 14
<<locked>>
97%
37507
56%
**41
100%
ReloadSwiss RS 76
<<locked>>
88%
59915
90%
**89
100%
ReloadSwiss RS 80 👍
<<locked>>
91%
59756
90%
**69
100%
SNPE Vectan SP 13
<<locked>>
97%
51140
77%
**72
96%
[Vihtavuori 20N29]*
<<locked>>
97%
49705
74%
**46
94%
Vihtavuori 24N41
<<locked>>
96%
59553
89%
**30
95%
Vihtavuori N165
<<locked>>
87%
59828
90%
**61
100%
Vihtavuori N170
<<locked>>
95%
59683
89%
**87
98%
Vihtavuori N560
<<locked>>
84%
59901
90%
**66
100%
Vihtavuori N565
<<locked>>
88%
59959
90%
**33
100%
Vihtavuori N568 👍
<<locked>>
91%
59872
90%
**69
100%
Vihtavuori N570
<<locked>>
91%
59640
89%
**12
99%
Winchester StaBALL HD
<<locked>>
84%
59959
90%
**27
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2213
<<locked>>
81%
52518
79%
**35
100%
ADI AR 2217
<<locked>>
81%
39378
59%
**62
97%
[ADI AR 2218]*
<<locked>>
82%
35389
53%
**03
90%
ADI AR 2225
<<locked>>
81%
36709
55%
**23
99%
Accurate 3100
<<locked>>
81%
52910
79%
**36
100%
[Accurate 8700]*
<<locked>>
88%
35172
53%
**35
90%
Accurate MAGPRO
<<locked>>
81%
53098
80%
**48
99%
Alliant Reloder-22
<<locked>>
81%
53272
80%
**25
100%
Alliant Reloder-23
<<locked>>
81%
51822
78%
**43
100%
Alliant Reloder-25
<<locked>>
81%
45948
69%
**00
100%
[Alliant Reloder-33]*
<<locked>>
81%
37855
57%
**43
92%
[Alliant Reloder-50]*
<<locked>>
83%
35781
54%
**74
90%
Hodgdon H1000
<<locked>>
81%
39378
59%
**62
97%
Hodgdon H4831
<<locked>>
81%
48443
73%
**13
99%
Hodgdon H4831 SC
<<locked>>
81%
53809
81%
**05
99%
Hodgdon Retumbo
<<locked>>
81%
36709
55%
**23
99%
[Hodgdon US 869]*
<<locked>>
93%
46311
69%
**67
90%
Hodgdon TrailBoss
<<locked>>
81%
29109
44%
**27
100%
IMR 4955 Enduron
<<locked>>
81%
52011
78%
**56
99%
IMR 7828 SSC
<<locked>>
81%
54781
82%
**77
100%
[IMR 7977 Enduron]*
<<locked>>
81%
44121
66%
**66
92%
IMR 8133 Enduron
<<locked>>
81%
34084
51%
**28
95%
[Lovex D100]*
<<locked>>
85%
43714
66%
**79
90%
Lovex S071
<<locked>>
81%
45803
69%
**12
100%
Norma 217
<<locked>>
81%
34751
52%
**67
97%
[Ramshot LRT]*
<<locked>>
89%
46238
69%
**17
90%
Ramshot Magnum
<<locked>>
81%
52286
78%
**82
100%
ReloadSwiss RS 14
<<locked>>
81%
30023
45%
**73
100%
ReloadSwiss RS 76
<<locked>>
81%
45397
68%
**46
100%
ReloadSwiss RS 80
<<locked>>
81%
41669
62%
**31
96%
[SNPE Vectan SP 13]*
<<locked>>
87%
35969
54%
**35
90%
[Vihtavuori 20N29]*
<<locked>>
91%
40074
60%
**36
90%
[Vihtavuori 24N41]*
<<locked>>
89%
46238
69%
**90
90%
Vihtavuori N165
<<locked>>
81%
48704
73%
**71
100%
[Vihtavuori N170]*
<<locked>>
81%
37463
56%
**48
91%
Vihtavuori N560
<<locked>>
81%
53693
80%
**68
99%
Vihtavuori N565
<<locked>>
81%
47384
71%
**20
99%
Vihtavuori N568
<<locked>>
81%
42308
63%
**44
96%
[Vihtavuori N570]*
<<locked>>
81%
40683
61%
**22
93%
Winchester StaBALL HD
<<locked>>
81%
52779
79%
**31
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.

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