JRH reduced the rim size on the .475 Linebaugh. It became, thanks to Hornady, the industry standard sized rim.
My reasoning has been big case, low pressure, still get ballistics.
Problem is, even with minimum load, the bigger cases are giving a LOT of velocity. Last chronograph session looked like this(actual results are in bold, the rest is reloading information, and recoil calculations, or info taken from
AA reloading data. :
.475 recoil
275 grain bullet
1560 fps
28 grains of AA 9
Recoil Energy of 25 foot pounds, and Recoil Velocity of 23 fps.
Standard Loads
No. 9 325 HDY XTP 27.0 1,430 30.0 1,589 49,340 1.739
Recoil Energy of 29 foot pounds, and Recoil Velocity of 24 fps.
.500 recoil
500 Linebaugh
Barrel: 7.87" ■ Twist: 1-18" ■ Primer: CCI 350 ■ Bullet Dia: 0.511"
No. 9 350 CP WFNGC 26.6 1,337 29.5 1,485 34,120 1.737
Recoil Energy of 25 foot pounds, and Recoil Velocity of 21 fps.
Hi Andy
Results are as follows:
7-2-2010
Ammo velocity testing
500 Linebaugh
Barrel: 7.87" ■ Twist: 1-18" ■ Primer: CCI 350 ■ Bullet Dia: 0.511"
No. 9 350 CP WFNGC 26.6 1,337 29.5 1,485 34,120 1.737
Recoil Energy of 25 foot pounds, and Recoil Velocity of 21 fps.
350 grain AA9 .510"
1040
1071
1477
1242
1121
Rifle primers?
Need a wider sample, and more time to establish anything on this.
.475 Linebaugh
No. 9 325 HDY XTP 27.0 1,430 30.0 1,589 49,340 1.739
Recoil Energy of 29 foot pounds, and Recoil Velocity of 24 fps.
325’s
1544
1492
1492
1482
1519
325’ Are considerably quieter then the 275’s.
The 325's seem to burn the No.9 consistently, and in the 7.5" barrel I have. Hit of the three.
275 grain bullet
1560 fps
28 grains of AA 9?
Recoil Energy of 25 foot pounds, and Recoil Velocity of 23 fps.
275’s
1441
1534
1596
Ejector blew off gun, ending session...
Brand new chrony new battery
All that said, there is merit to fast and light. The 275's open up to the size of a two bore rifle bullet:
You want a one shot, 100% stopper? I think at 1596 fps, that bullet is it.
As for 1200 fps:
Hunting guys seem to like 1350 fps, with hard cast. Fackler's favorite anti-person round was a 18th century Swiss rifle round: .41 caliber, pure lead, 1300 fps. Ballistic gelatin showed it was more devastating then a .223 rifle.
What I'm finding is with lower pressure, bigger bullets are more consistent, and, a 425-445 grain cast or HP at 950-1200 fps isn't going to bounce off bears, or whatever, unless they start wearing Kevlar, and carrying chronographs.
Also, the heavier bullets recoil, in a 3-3.6 pound revolver starts getting REAL bad, real fast as velocity is increased.
My next batch of at least 300 .500 Linebaugh is going to be a 435 grain LFN, with 28 grains of 4227, which should move about 1100 fps. out of my max, that should recoil about like a heavy 44 magnum load, yet the hunting guys SWEAR that load hits like a .375 H&H, or heavier rifle, on big game, bison, beefalo, even;-)