Big Bore Winchester! I'm puzzled??!

[helice]

Some years ago I read that the Big Bore Winchester M-94 was a stronger levergun than the Marlin. There were a few articles on line that stated that the 444 Marlin could be loaded quite a bit hotter in the Big Bore than the Marlin. Evidence of this was presented in the ability of the Big Bore to manage the pressure of the 375 Winchester load. (I thought Marlin built a levergun in the 375 on the same action as the 444. ?) Based on this information I started looking for and managed to pick up a Big Bore in 444 Marlin. I have never been disappointed with this purchase.
I have recently had the opportunity to spend some time on QuickLoad. This exerience has me puzzled.
The Big Bore Winchester was available in 307, 356, 375, and lastly the 444. Having seen the above mentioned articles I went to the 375 Winchester data and found the program listing its max pressure at approx. 63,800 PSI. This is definately more than the 51.5KPSI listed for the 444 Marlin. But my disquietness comes after looking at data concerning the other Big Bore ctgs and the ctgs from which they obviously descend. Max pressure for the 307 was listed at 60KPSI, the 308 identical at 60K, the 356 rated 52KPSI, the 358 showed 58.7KPSI.
Is there an explanation for the differences?
I thought that maybe case head dimentions might explain it but ---Well ---I'm puzzed.
I have long since stopped hot rodding the 444, being quite content with more comfortable loads, but I want to understand this information and my feeble mind does not.
I have found a wealth of knowledge on this forum an I look forward to digesting your comments.
Karl
P.S. That QuickLoad Program is amazing.

[MT Chambers]

I had not heard that the BB94 can handle more pressure then the Marlin, I keep my .356 down so as not to affect proper functioning when hunting. The loads shown for the Marlins in .444 are already as hot as I would go regardless of which lever gun I had. I think that if you need more power, get a 45/70.

[helice]

Thanks chambers but my 444 is big enough for anything I will do. As I stated above, like you and your 356, I have loaded down for comfort sake. I am seriously jealous of your 356 tho. I do like the 35s.

[MT Chambers]

Yes, my .356 loves the 245 gr. Saeco flat pt. gc, it's my only levergun that benefits from a small scope on it.

[helice]

I went back to the Quick Load program. The difference in powder charge from 51.5KPSI to 63.8KPSI amounts to about 3 grains of ReLoder 7 and about 120'/sec. I did this work up with the RCBS-GC-SWCs of 240 and 300 grains. Working with QuickLoad again has me saying there's not enough difference to matter. A 300 gr boolit will pass through a hog at either 2175'/s or 2295'/s and the trajectory doesn't change that much either.

[missionary5155]

Greetings
A 300 grainer at 1400 fps will pass through a whole lota meat. The 45-60 was doing pretty good at 100 yards to have this much velocity and it was known as a good thumper under 100 yards.
When up in ILL. I shoot a 45-60 in a 1876 and a 50-95. I would not hessitate to pop any pig I ever came across with either of those old slowboat rounds.
So a 300 grainer at 2000 plus fps would certainly be alot of cream on the cake.
Mike in Peru

[pietro]

Six & one half-dozen of the other - IIRC, The Marlin 336/444 is thinner @ the bbl threads than the Winchester 94 & BB94; but the bottom of the bbl, just about at the front of the chamber, is thinner on the Winchester's (why some have blown there).

FWIW, Of the 3 different Marlin .444's & two different Winchester BB94's, I've owned over the years (all in .444), I can say that my .444 Marlin's (One 16-1/2" bbl'd, one 24" bbl'd & one 22" bbl'd) were more accurate than my .444 BB94's ( A 20" Carbine & a 17" ported Timber Carbine). YMMV.



.

[BAGTIC]

The reason the pressure for the .375 Wincheater is higher than the .444 is because the head diameter is smaller. The klimiting factor is probably the breech pressure which is psi times the area of the case head.

The case head of the .444 is 77.6% larger than the .375 so the pressure must be proportionately to compensate. 63,800 psi x
.776 = 49,509 psi. Pretty close, the numbers were rounded a bit. Also the proper measurement should have been the maximum chamber diameter which would have been very slightly larger than the external case dimension but most people use case dimensions since that is easier to measure. Furthermore being smaller diameter the chamber walls of the .375 would be a little thicker, .0285 =/- inch.

[helice]

Been gone for a while. Thanks guys for the input.
Bagtic thanks for your post. This is about what I was thinking but couldn't prove it.
Karl

[pietro]

BTW - Food for thought.

The BB94 action is the one with the bulge, aka thicker action sidewalls, near the locking lug.

Not only was that action chambered for the .307W, .356W, .375W, & .444M - it was also chambered for the belted .450 Marlin, although by then it wasn't labelled a BigBore, just a "Timber".

.

[Doc Highwall]

The key word is P.S.I. (Pounds Per Square Inch) As an example say a cartridge has one square inch of area and you load it to 50,000 P.S.I. meaning the gun barrel is holding a force of 50,000 Lbs. of pressure. Now say you have another cartridge that has 2 square inches of area and again it is loaded to 50,000 P.S.I., the gun barrel is now holding a force of 100,000 Lbs. at a P.S.I. of 50,000 Lbs. pressure. Pressure x Area = Force applied.

Here is a video of a 55 gal. drum that is going to have a pressure of 14.7 Lbs. P.S.I. applied to it.

http://www.wimp.com/steeldrum/

http://www.youtube.com/watch?v=Uy-SN5j1ogk

[Chicken Thief]

Anyone read Veral Smiths book "Jacketed performance with cast bullets"?
Food for thought!!!
He states that optimum boolit speed at impact with a good large meplat is 1400-1700fps.
That will give the best penetrasion and wound chanal.
Faster = more smack and less penetration.
Slower = more penetrasion and less/no smack. (They put a .44 through a bison at 4-500yds back then you know!)

[Larry Gibson]

Not sure where the OP's "psi" figures come from. SAAMI lists the MAP (Maximum Average Pressure) as 62,000 psi (transducer/piezo) for the .307, .356 & the .375 Winchester cartridges. The SAAMI MAP for the .444 Marlin is 42,000 psi (transducer/piezo).

Larry Gibson

[Lloyd Smale]

for us dummys this is called bolt thrust and it is why a case with a larger head cant be loaded to the same pressure a smaller head can. limiting factor in alot of lever guns is the actions arent that rigid and flex. More bolt thrust more flex.

The reason the pressure for the .375 Wincheater is higher than the .444 is because the head diameter is smaller. The klimiting factor is probably the breech pressure which is psi times the area of the case head.

The case head of the .444 is 77.6% larger than the .375 so the pressure must be proportionately to compensate. 63,800 psi x
.776 = 49,509 psi. Pretty close, the numbers were rounded a bit. Also the proper measurement should have been the maximum chamber diameter which would have been very slightly larger than the external case dimension but most people use case dimensions since that is easier to measure. Furthermore being smaller diameter the chamber walls of the .375 would be a little thicker, .0285 =/- inch.

[EDG]

I guess I do not understand the original post.
I have a Marlin Model 375 which is in .375 Win caliber. I once owned a .375 Big Bore. I have never read where the Winchester was stronger than the Marlin. The Marlin reciever has the same configuration as the 336 in 30-30 as far as I can tell and the Winchester had to be beefed up.
I have heard that Quick Load does not accurately predict the pressure of straight walled cased ammo. That bit of information comes from Quick Load users at another site with lots of big bore shooters. I don't know if that is fact but it was coming from guys that use the program.

[Lloyd Smale]

correct answer. You allways have to factor in bolt thrust which increases with larger head size

[tgator]

Paco Kelly loads the winchester big bores hotter than the marlin rifles. "Leverguns - An American Tradition".

Tim

[helice]

Yes Tim,
It was Paco Kelly who started this search. He has loaded "his" BigBore to loads that are quite hot. Much hotter than I want to go.
Chicken Thief,
I am now loading the 444 to about 1750'/s with Veral's 300WFN and 1650'/s with his 280 LFN. At this point my 444 loads look a lot more like 44 Mag loads.

[TXGunNut]

I've always felt the Marlin was a somewhat stronger design but like you, I don't care to load my BB 94 to the point that stresses the action. Either will handle more than I wish to endure. I love my old Big Bore but she's a safe queen these days, I can't bring myself to scope a top-eject Winchester and a receiver sight just doesn't seem right on this 98% gun. Since my buckhorn sight days are over I've opted for Marlins for medium and larger bores because of the scope options. I feel a more rigid action lends itself to better accuracy so even tho I no longer stress a levergun action there is some advantage to what I feel is the stronger action of the Marlin over the BB94.
JMHO, I've never tried to get serious accuracy out of a 94 and my only goal with my Marlins is sub-2MOA with a sutable hunting boolit.

[Doc Highwall]

I always tell people that when Winchester had to beef up the Model 1894 to the 1894BB to handle the pressures, that Marlin just chambered their gun for the 375 Winchester cartridge. The again when Winchester came out with the Model 94 Angle Eject in 307 and 356 Winchester again Marlin just chambered their 336 in in them.

I would have liked to have a 356 Winchester for a cast bullet gun over the 35 Marlin. Too bad it never caught on as a cartridge.