on the 336 platform / 1895/444/375
we have pressure from 43000 for the 45-70 to 55000 for the 375 win, the 444 and the 450 inbetween.
could it be possible to load to a higher level for the cartridges
under that 55000 level of the 375 win?
thanks for the info guys,,m71

on the 336 platform / 1895/444/375
we have pressure from 43000 for the 45-70 to 55000 for the 375 win, the 444 and the 450 inbetween.
could it be possible to load to a higher level for the cartridges
under that 55000 level of the 375 win?
thanks for the info guys,,m71
First, we don't have "43000" for the 45-70 Gov't on the Marlin 336 platform. It is generally accepted that the safe operating pressure of the 45-70 Gov't in the Marlin 1895 is 40,000 CUP. Second, the pressure figure for the 375 Winchester is 52,000 psi. Thirdly, the pressure figure for the 444 Marlin is 42,000 psi or 44,000 CUP. Next, the pressure figure for the 450 Marlin is 43,500 psi. One has to consider that cartridges will exhibit different bolt thrust at the same pressure due to different cross-sectional area interfacing the bolt. So no, one cannot safely load a 45-70 Gov't or 444 Marlin to 50,000 psi in a Marlin lever action rifle.

the difficulty i have is the bolt thrust / diameter comment.
sounds easy but i don't understand that, if an action is good for 50,000 ,just because the case head is larger , 50,000 is still 50,000.
my question is not to do same , but to understand the principal behind your comment.
thanks for the replies

OK, let's compare a .30-30 to a .45-70. We should use the maximum inside diameter of the cases, but I don't have them handy, so I'll use the base diameter. A .30-30 has a base diameter of .421" and a base area of 0.139 square inches. A .45-70 has a base diameter of .505" and a base area of 0.200 sq.in. Now our (overloaded) .30-30 is pushing with a force of 50,000 pounds per square inch on 0.139 square inches, so the push is 50,000 X .139 = 6950 pounds. The (overloaded) .45-70 is pushing with 50,000 X 0.200 = 10,000 pounds force. The actual force is less as we should use the inside diameter, but the difference between cartridges is still significant.

Bye
Jack

Thanks Jack ; That Helps Alot .
Much Appreciated,,,m71

This raises questions.
Firstly, no one has demonstrated that bolt-thrust is the limiting factor on Marlin action strength. May be, but who knows?
Secondly, using stated figures for pressure maxes & SAAMI base diams. (granting that ID should be used), bolt-thrusts are :
.375 Win = 7204 psi
.444 Mar = 7287 psi/8639 cup
.45-70 = 8000 cup
.450 Mar = 9669 psi

IF one CAN legitimately make inferences & extrapolations, then the cartridges in question should ALL BE SAFELY LOADABLE to chamber pressures that result in equalling the BOLT-THRUST of the .450 Marlin.

In the .375, this equals 69,793 psi chamber pressure.
In the .444, this equals 55,729 psi chamber pressure.

Going farther out on this limb, comparing .45-70 cup to .444 cup, then converting this ratio to psi using the .444 figures, gives a bolt-thrust of 6748 psi, equaling 49,850 psi chamber pressure for the .45-70.

Now, I'm not advocating such loads, I simply don't see any MATHMATICAL LOGIC to the conclusions put forth in previous replies about what can or can't be loaded in a Marlin 336 "platform".

"I'm not a smart man, but I know what love is." :-)

Can anyone sort this out for us all?

regards,

GOOD TO SEE THIS IS STILL ALIVE!
HOPE to hear more.

Time to be the devil's advocate, is there a prize for loading your chosen weapon to just shy of blowing the thing up (?) . Why are we so occupied with that last 10 fps more than the guy down the street(?) . I just don't get it . A fella will destoy a .222 trying to push the envelope when he has a .22-250 in the safe.


444fitch

Hi 444 and all -

Personally, I'm not a contentious feller, so don't take offense, but the original question was simply (restated):
"If this safely, why not that safely".
Nuttin' about prizes or blowing up.
Just safety.
Seems to me a most admirable topic for discussion in a venue such as "Shooters Forum" . :-)

Also, personally, I understand & MUST accept human nature, yet it pains me to hear grown people parroting unsubstantiated assumptions & preferences as though they were FACT.
Seems the other fellow deserves AT LEAST thoughtful input if I desire/expect him to pay any attention to what I have to say.
Can I get a Amen??!!

"Conclusions are what folks reach when they get tired of thinking". ;-)

regards,