.378 revisited

444shooter

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Finally got out to the range and got a chance to test the big boomer. I put together some "starting loads" with Hornady 300gr BTSP. Loaded 5 rounds of each starting at 105grs H4831 and went up to 107grs. Velocity estimated at 2825-2850fps from the 26" barrel.
I fired from the bench using my Led Sled (no additional weight added) and recoil was very fast, but not as bad as I thought it would be. I ended up firing all 15 rounds and no detached retinas or scope buried into forehead :p

I wasn't really shooting for accuracy, but these inital loads would keep in the 2" range which is not bad considering they are just starter loads.

Next up is some 270gr TSX...
 
Yeah, the 378's not as mean and nasty as it's reputation makes out. With a properly fitting stock and good technique, it's a pussycat. When I bought mine it had magnaports cut in the barrel, which also help out and surprisingly don't really increase the blast. So, as it turns out, I don't hate the ports at all (though I still can't stand muzzle brakes).

Anyway, I had mine out gopher shooting last weekend. The factory 300SP's at 2900fps decimate a gopher like you wouldn't believe, no bits left that were any bigger than a penny :D. Also had a few handloads with 115 of H4831SC and a Hornady 270 SP that pretty much did the same. Out to maybe 50 yards, it's surprisingly easy to hit a gopher with such a beast. And it leaves nice long furrows in the ground that really tell a story.

Problem is.... now I want something bigger :D :D I see tradex has a nice a-square hannibal in 500 A-Squate for $2500 which is a bargain considering the Hannibal retails for over $4k. Though my dream is still a 577 tyranno
 
I have some 270gr TSX (thanks crazy_dave), so will try them next. Then move on to the 300gr TSX. The day went very well until I got stung by a wasp. Damn, that hurt more than a heavy recoiling rifle! The little bugger flew up my right arm, and stung me on the inside of my bicep.
I wish I had brought my camera. The geyser of dirt that was thrown up at 100yds when the bullet hit the backstop was amazing. Must have been 6-8 ft in height :)
 
Put together some full throttle 300 gr loads with Retumbo, RL-25 or US869 and you will discover the reason for the 378's legacy.

300 Nosler Partitions can be driven to 3150 if you know what you are doing.
I have a bone spur on my middle finger from the trigger guard of a 378.

300's at 2900 fps is what my wife loads. :D
If you were going to load it girly style you should have bought a 375 Ultra!:D :D
 
Hah, that's what comes from the factory. I don't like playing it fast and loose with my reloading, I like my eyes and appendages so I stick to published load data ;)
 
X-fan said:
Put together some full throttle 300 gr loads with Retumbo, RL-25 or US869 and you will discover the reason for the 378's legacy.

300 Nosler Partitions can be driven to 3150 if you know what you are doing.
I have a bone spur on my middle finger from the trigger guard of a 378.

300's at 2900 fps is what my wife loads. :D
If you were going to load it girly style you should have bought a 375 Ultra!:D :D

As Prosper states, 2900fps is close to factory specs. BTW, mine is unbraked and anyone that thinks it is a girly load can have a crack at shooting it ;)

I don't shoot 30" barrelled 15lb custom rifles with mercury insert and a muzzle brake :popCorn:
 
prosper and 444shooter,

Get some US869 and try it yourselves.
I guarantee that your starting loads will be at or above 2900 fps...proceed carefully from there.
The 378 is so rare that the powder companies only offer enough load data to humor Weatherby. Using powders like the 4350's and 4831's in the 378 is an antiquated approach. One look at modern 375 Ultra loads will confirm this for you.
My favorite powder with 300gr bullets in the Ultra is RL-25. Nothing else comes close. If it is good in the Ultra then it stands to reason that it will be great in the 378.
This is just like 7828 and US869 in the 300 Ultra with 220gr bullets. 7828 gives 2770fps at 63,000 psi while US869 gives 2875 fps at 55,000 psi (starting pressure with 7828). There is no magic here just filling the case to capacity with the appropriate powder.

Have a look here http://data.hodgdon.com/cartridge_load.asp

444shooter said:
I don't shoot 30" barrelled 15lb custom rifles with mercury insert and a muzzle brake :popCorn:

Perhaps not but the 378 at 2900 is not serious recoil and if you own a 378 you may as well have the fastest 375 on the planet.....not a well loaded 375 Ultra. ;)


I consider recoil to be serious when it gets to the level that an average man has trouble mastering.
True recoil starts with an 8 pound 416 Rem (or a well loaded 378), gets very serious with a 450 Ackley, and while the 500 A-2 can knock the wind out of you (if you shoot it wrong) the 585 Nyati and above fall into Jackass stunt level stuff.

FYI the A-2 rifle (and especially the stock) handles like it was designed by amateurs because well....it was! ;)
 
My 378 shot much better with 7828 then Rel. 25. My 338/378 shot best with Rel. 25. I find the WBY stocks to handle recoil extremely well. I had a #1 Ruger in 460 WBY that was just brutal. Even full power Rigby loads in a CZ 550 were quite bad. I found the Mark V stocks no problem with 3000+ fps loads. Yes you move back a little but no pain at all. This gun had no brake. I'm heading for the range today with my 338,375 and 416 Rem. Relative pussycats. The 378 should be the ultimate long range Moose/Elk basher but a couple of things hold it back. The weight of the gun for serious backpacking( I don't mind the P/F action ) and I tripple dog dare you to torch off a 300 TSX at 3100 fps prone. You have to hold these guns such that precise long range holds can be tough. Obviously they're no good so somebody with a USA built one should sell it to me before they hurt themselves.
 
Cartridge : .378 Weath. Mag.
Bullet : .375, 300, Barnes 'TSX' 37558
Cartridge O.A.L. L6: 3.655 inch or 92.84 mm
Barrel Length : 26.0 inch or 660.4 mm
Powder : Hodgdon US 869

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 82 93.87 2022 2723 22384 7924 74.3 1.903
-18.0 84 96.22 2075 2869 23743 8279 76.0 1.860
-16.0 87 98.57 2130 3023 25201 8636 77.8 1.817
-14.0 89 100.91 2186 3184 26770 8994 79.5 1.774
-12.0 91 103.26 2243 3353 28456 9351 81.2 1.732
-10.0 93 105.61 2302 3530 30270 9706 82.9 1.690
-08.0 95 107.95 2361 3715 32223 10057 84.5 1.649
-06.0 97 110.30 2422 3908 34334 10401 86.1 1.608
-04.0 99 112.65 2484 4109 36612 10738 87.6 1.568
-02.0 101 114.99 2546 4319 39076 11065 89.1 1.528
+00.0 103 117.34 2610 4537 41746 11380 90.5 1.488
+02.0 105 119.69 2674 4764 44644 11681 91.9 1.449
+04.0 107 122.03 2739 4998 47795 11967 93.1 1.410
+06.0 109 124.38 2805 5242 51228 12234 94.3 1.372
+08.0 111 126.73 2872 5494 54974 12482 95.4 1.328 ! Near Maximum !
+10.0 113 129.07 2939 5754 59076 12707 96.4 1.284 ! Near Maximum !

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 103 117.34 2809 5257 51196 11904 97.6 1.381
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 117.34 2371 3745 33872 10111 78.8 1.619


Cartridge : .378 Weath. Mag.
Bullet : .375, 300, Barnes 'TSX' 37558
Cartridge O.A.L. L6: 3.655 inch or 92.84 mm
Barrel Length : 26.0 inch or 660.4 mm
Powder : Alliant Reloder-25

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 80 85.10 2307 3547 29274 9281 96.4 1.713
-18.0 82 87.22 2363 3718 31084 9532 97.3 1.673
-16.0 84 89.35 2418 3893 33015 9765 98.1 1.634
-14.0 86 91.48 2473 4073 35077 9980 98.7 1.596
-12.0 88 93.61 2527 4255 37275 10176 99.3 1.559
-10.0 90 95.73 2582 4441 39622 10350 99.6 1.522
-08.0 92 97.86 2636 4630 42127 10502 99.9 1.486
-06.0 94 99.99 2690 4821 44810 10631 100.0 1.452
-04.0 96 102.12 2743 5014 47677 10741 100.0 1.417
-02.0 98 104.24 2796 5209 50748 10848 100.0 1.384
+00.0 100 106.37 2849 5406 54037 10951 100.0 1.347
+02.0 102 108.50 2901 5604 57564 11051 100.0 1.309 ! Near Maximum !
+04.0 104 110.62 2952 5805 61348 11147 100.0 1.272 ! Near Maximum !
+06.0 106 112.75 3003 6008 65419 11241 100.0 1.237 !DANGEROUS LOAD-DO NOT USE!
+08.0 108 114.88 3054 6213 69799 11330 100.0 1.202 !DANGEROUS LOAD-DO NOT USE!
+10.0 110 117.01 3105 6421 74510 11416 100.0 1.169 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 100 106.37 2958 5827 66264 10533 100.0 1.244 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 106.37 2681 4788 43573 11315 98.5 1.460
 
X-fan said:
I consider recoil to be serious when it gets to the level that an average man has trouble mastering.

I have not come across too many "average" men that can handle 65ft/lbs + of recoil and master it. The average shooter that I have come across in the past 20+ years of shooting balks at 20ft/lbs.
 
MTM said:
My 378 shot much better with 7828 then Rel. 25. My 338/378 shot best with Rel. 25. I find the WBY stocks to handle recoil extremely well. I had a #1 Ruger in 460 WBY that was just brutal. Even full power Rigby loads in a CZ 550 were quite bad. I found the Mark V stocks no problem with 3000+ fps loads. Yes you move back a little but no pain at all. This gun had no brake. I'm heading for the range today with my 338,375 and 416 Rem. Relative pussycats. The 378 should be the ultimate long range Moose/Elk basher but a couple of things hold it back. The weight of the gun for serious backpacking( I don't mind the P/F action ) and I tripple dog dare you to torch off a 300 TSX at 3100 fps prone. You have to hold these guns such that precise long range holds can be tough. Obviously they're no good so somebody with a USA built one should sell it to me before they hurt themselves.

All this faster is better talk makes my head hurt.

While a 300 gr bullet will not kill anything at 3000 fps that it won't kill at 2600, there is just enough logic in the argument of flatter trajectory being an advantage to seem plausible. At least, that is, until one runs the numbers through a ballistics program and discovers that a streamlined .375 bullet will stay supersonic much further than most hunters can shoot.

The notion of long range shooting big game vanishes if you cannot shoot the rifle accurately from the only field position that is stable enough for precise shooting at long range.

I can shoot my .375 Ultra prone without serious discomfort, although when I sling-up my head is snapped back in an uncomfortable fashion. All the same, I am not shooting long strings, and slung-up and shooting prone or sitting, I do quite well at longish ranges. It was the same with my .416 Rigby and my .458. I could hold either for 3 shots prone, and 3 shots prone should be enough for any shooting associated with big game hunting, however, the rifle serves no purpose if you cannot hit your target. A .375" bore rifle will kill any game in the world with a 300 gr bullet loaded to 2500 fps, so it follows that faster velocities at close range serves only to produce bloodshot meat. To successfully make a long range shot, the marksman must fire from a stable platform, but if the piece is unmanageable from such a position, then what is it for?

I think the .378 Weatherby fills a particular niche, although it is unclear if a factory built rifle can fill that niche. If long range big game shooting is what you intend to do, then build a rifle that weighs in excess of 20 pounds, mount a high powered scope on a 20 minute base, load some custom made .375 bullets that are designed for long range game shooting, and have at it. But, if it is a sporter you own, and you are unable to shoot it from all field positions, then I suggest you load some 380 gr Rhinos to 2400 fps, and relegate the piece to a dangerous game rifle that you can shoot off your hind legs.
 
Boomer said:
until one runs the numbers through a ballistics program and discovers that a streamlined .375 bullet will stay supersonic much further than most hunters can shoot.

Well, trans-sonic speeds mean nothing. The majority of bullets fail to expand below 1800fps and only perform at peak above 2400 or so. Also, the advantages of MV do translate to trajectory advantages. Flatter point blank range (point blank being key. Say +/- 4"). Beyond that, drop and windage start to become a serious obstacle to the average shooter, and cannot be overcome by simply 'guessing' at range and hold over.
 
prosper said:
Well, trans-sonic speeds mean nothing. The majority of bullets fail to expand below 1800fps and only perform at peak above 2400 or so. Also, the advantages of MV do translate to trajectory advantages. Flatter point blank range (point blank being key. Say +/- 4"). Beyond that, drop and windage start to become a serious obstacle to the average shooter, and cannot be overcome by simply 'guessing' at range and hold over.


Agreed, although the 570 gr .510" X bullet retrieved from my buffalo expanded to the extent of the bullet's design, despite being below 2000 fps at impact. The advantage of the .378, however is lost on the rifleman who cannot hit anything beyond the range at which he can keep his bullets on target offhand if the rifle cannot be shot from a supported position. The man who can shoot a .375 H&H from any position can do very well out to 300 yards and beyond from prone. There is no point in maximizing the velocity of the .378 if it becomes so difficult to handle that it cannot be shot from a supported position.

Having said that, and having just done a computer generated recoil comparison between the .416 Rigby and the .378 Weatherby, I doubt if a rifleman used to shooting powerful rifles prone would be upset by the .378. Recoil for the .378 loaded with a 300 gr bullet over 111 grs of powder for 3000 fps, generates nearly 64 pounds of recoil from a 9 pound rifle. My .416 Rigby load (102 grs of powder behind a 350 gr bullet for 2800) generates just under 68 pounds of recoil in a rifle of the same weight, and as I said I could go 3 rounds prone with that load, although I found I was less focused on the job at hand when I fired a fourth shot. My .375 Ultra, that has a recoil of some 10 ft/lbs less recoil than the .378, I can accurately fire 5 rounds without difficulty.

I guess what I do not understand is why a person would load a rifle chambered for a general hunting cartridge beyond his personal recoil limits, which seemed to be the case when MTM "triple dog dared" anyone to shoot his loads prone. If they cannot be shot prone, they serve little purpose, as they will kill no better than a .375 H&H load at off hand ranges.
 
Boomer, thats the point I was makeing. However with a 378 I wouldn't hesitate to shoot out to 400 yds. from a seated position. This is as far as I really feel comfortable shooting in the feild, so its good for delivering major horsepower to big animals but not to turn people into 600+ yd shooters.
 
Have shot the full throttle 378 prone (at at a 400 yard target yet).....Why do you think I currently pack a 375 Ultra?


444 Shooter
Even your calculator shows 115 grains of US869 will run over 3000fps and RL-25 makes 3000fps at 64000 psi.
Plug H-4831 into your calculator (loads from a disk?) and compare the difference.
Worth a try isn't it?

My use of the phrase "average man" was inaccurate for the context. On the other hand a "determined man" can manage (with determined practice) huge amounts of recoil. 65 ftlbs is quickly managed by the determined big bore shooter. At least it was by myself and others I have helped in their quest to manage a bigger bore.

My apologies to anyone who felt I was calling them average.

The most difficult bore to manage is always the largest you own...the solution is obvious! :D :D
 
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