Your thoughts 358/356 Marlin 336 conversions

[EsoxLucius]

now use that formula and figure both the 307 and the .356 at a realistic 50000 psi and it looks like its a wash. I dont know where the 60,900 came from for the .307 but i dont think anyone is loading any lever gun to those pressures.

The SAAMI pressure specification for the 307 Winchester is 52,000 CUP.  Cartridges with a SAAMI/ANSI specification of 52,000 CUP have corresponding PSI ratings of between 60,000 PSI and 65,000 PSI, with an average of 62,000 PSI.  A formula that gives approximate PSI values from CUP ratings yields 60,922 PSI. http://www.shootingsoftware.com/ftp/psicuparticle2.pdf  To believe that Winchester produces 307 and 356 Winchester ammunition way below (50,000 PSI) its rated pressure specification (52,000 CUP or approximately 60,900 PSI) is unwarranted.  In addition, I think perhaps the available load data for the 307 and 356 Winchester yields published pressures of no more than 46,000 CUP (approximately 51,828 PSI) because of a concern over these cartridges use in the few Marlin firearms in circulation.

[Chuck White]

Ive got a big bore .356 and use .358 dies to reload it.

Correct Lloyd!
It seems some of you guys don't realize it, but the 356 Win and the 358 Win are the same cartridge with the exception of the rim!
The 356 is a rimmed cartridge and the 358 is rimless!  They do use the same reloading die, but the load data is different!

It's the same setup as the 307 & 308 Winchester.  They use the same dies, but the reload data is different.

[Lloyd Smale]

looks like what your showing here is the 307 loaded up to 60000psi or about 50000 cup which is normal but then you have to consider that your figures for he rest of these round that are in cpsi  should be kicked up sustantialy as most are routinely loaded to the same figures in cup pressure. Put some 4570 Data in there where your loadin to 35000 cup and see where the bolt thrust goes.  Or try the 450 at realistic pressures that it runs and see where that goes.   [quote author=EsoxLucius link=topic=140308.msg1098558399#msg1098558399 date=120577298THRUST=AREA*CPSI Where:

AREA=3.1416*(HS/2)^2

HS=the diameter of the inside of the case head.

30-30 WCF HS=.375" CPSI=42,000 Thrust=4639psi
307 Winchester HS=.385" CPSI=60,900 Thrust=7090psi
444 Marlin HS=.395" CPSI=42,000 Thrust=5147psi
45-70 Gov't HS=.460" CPSI=38,000 Thrust=6315psi
450 Marlin HS=.420" CPSI=43,500 Thrust=6027psi
[/quote]

[Lloyd Smale]

now lets get realistic Hogdons loading data shows loads for the
444 up to 43000cup
4570 in a mariln to 40000cup
there was not pressure data for the .356 so i used .358 which is higher and it was 52000 cup\

now do the calculations using fair numbers and see what you come up with. Ill stand behind the fact that the 356 will work fine in a marlin lever. Im not going to even say it is because of all of these numbers and what has been said over the internet. I know that ive been shooting loads at these pressure levels in marlins for many many years and have yet to break a part that was caused by it let alone had a catastophic failure. Im talking Thousands of rounds not hundreds. Never so much as even sticky brass or flattened primers at 50000 in the smaller bores. I still stand behind the bolt thrust being the major limiting factor in these guns. thats why a guy cant load the big ones up that heavy. There suprisingly strong guns. they dont have the 3 times saftey built into them that a bolt gun does but its rare they actually fail. You can shoot one loose with to many big load in a 450 or 4570 but again i believe thats bolt thrust. Recoil limits (at least it does me) me to keep my loads down around 40000 anyway. Anymore and the recoil will even cause me to open the lever inadvertantly in recoil and that makes me nervous.

[EsoxLucius]

OK, I'll show you what happens when the 45-70 is loaded to 40,000 CUP or approximately 42,732 PSI.  In the literature there is consensus that the safe operating pressure of the Marlin 1895 45-70 is 40,000 CUP.  The figures for the 307 Winchester are valid as 60,900 PSI approximates 52,000 CUP and the figures for the 444 Marlin and 450 Marlin are valid because the SAAMI pressure specification for them is 42,000 PSI and 43,500 PSI, respectively.

THRUST=AREA*CPSI Where:

AREA=3.1416*(HS/2)^2

HS=the diameter of the inside of the case head.
CPSI=cartridge pressure in pounds per square inch.

30-30 WCF HS=.375" CPSI=42,000 Thrust=4639psi
307 Winchester HS=.385" CPSI=60,900 Thrust=7090psi
444 Marlin HS=.395" CPSI=42,000 Thrust=5147psi
45-70 Gov't HS=.460" CPSI=42,732 Thrust=7102psi
450 Marlin HS=.420" CPSI=43,500 Thrust=6027psi

So, it would appear that if the Marlin 1895/336 action can withstand the 45-70 at 40,000 CUP it should be able to withstand the 307 and 356 Winchester at 52,000 CUP.

[big medicine]

I will add my 2 cents here. I don't jack about bolt thrust, but I do know the 308MX cartridge is the real deal. I see it being around for a long time to come. It truely is a long range levergun. I used the rifle last year and it did exactly what I expected it would.

The first deer I shot with it was at 365 yards. It was a straight on shot, the deer was comming up over a slight rise and I was shooting down hill. It stood the deer up on it's hind legs and toppled it over backwards dead in it's tracks. The bullet was lodged near the left hind quarter and retained wt was 129 grains. That deer never knew what hit it.

I shot an elk at 178 yards with it in OCT and it did the job there...I posted the story here.

During regular rifle season I shot a 13 point buck at 147 yards and he was dead where he stood, fell stright to the ground front legs stretched out in front of him.

As for the ammo...well I figure I'm not so cheap that I can't spring for a box of factory ammo once a year.....and it may last me several years at one shot per animal. I'm working on a hand load to shoot year round so it will be affordable to shoot.

They must have a pretty good market for them, because the dealers around here can't keep them on the shelf. It really is a good cartridge with what I believe to be many years ahead of it.

[Lloyd Smale]

and you really cant get a fair comparison using the 60,900psi figure in your equation either. If you are using cup for one you need to use cup for all and that figure is 52000. id say a 4570 or a 444 is putting a much bigger pounding on a 336 then a .307 is. Makes you think to if the 450 is actually capable of even heavier loads then a 4570 instead of the other way as has been often said.

[EsoxLucius]

Sorry, but all calculations are using PSI equivalents.  Apples to Apples.  The formula for bolt thrust uses PSI and it wouldn't make sense to use CUP, as it is only used in internal ballistics to measure peak chamber pressure.  Have you ever seen water pressure or blood pressure measured in Copper Units of Pressure?

The 45-70 HS value is based on Winchester 45-70 brass.  If Starline 45-70 brass were used the resulting THRUST would be somewhat less due to thicker side walls above the web.

[Lloyd Smale]

  I guess im getting a headache from all of this thinking. Im more of a shooter then a scholar thanks for taking the time to do the math.

[PeterCartwright]

Wow!  You guys are making my head spin!  As far as the differences in barrel threads are concerned, one of the the Marlin factory guys that posts on another site has explained that rifles chambered in higher pressure Marlin rounds (like .450 and 308MX) have receivers that utilize square shaped threads (as opposed to the normal "v" shaped threads).  Don't know anything about physics or engineering, but as he explained it, the added surface area of the threads in the barrel/chamber created by the change in thread shape substantially increases the strength of the union.

Some of you fellas with slide rules (or computer programs) in your pocket will have to sort that out.

[Lloyd Smale]

when Rob Applegate did my 475 94 marlin he used simualar approach but said it wouldnt make much of a differnce in what the gun will handle. Him and i talked about it and couldnt ever remember a failure of a marlin in that area unless it was grossly overloaded. He was a big advocate in bolt thrust being the limiting factor to these guns. he told me from the start that my 475 woud take factory level loads but it would pound it apart after a while and to back off a couple hundred feet per second and it would last forever. We also talked about building a 50 alaskan and he told me becuase of the same problem with bolt thrust and marlins he would never build a 50 alaskan on a marlin. He said it would be a large framed winchester 86 or 95 or nothing. Now i dont doubt for a minute that the marlins work in 50 alaskan. My buddy has one and john linebaugh has one and ive shot both of the alot and my buddys has proably over 10000 rounds through his but when i tried to argue with Rob over that he made a good point. How many guys take a 50 ak and shoot that many full power loads out of it. Youd need shoulder surgery first. But he said if his name was going on it that it would need to be able to do it.

Wow!  You guys are making my head spin!  As far as the differences in barrel threads are concerned, one of the the Marlin factory guys that posts on another site has explained that rifles chambered in higher pressure Marlin rounds (like .450 and 308MX) have receivers that utilize square shaped threads (as opposed to the normal "v" shaped threads).  Don't know anything about physics or engineering, but as he explained it, the added surface area of the threads in the barrel/chamber created by the change in thread shape substantially increases the strength of the union.

Some of you fellas with slide rules (or computer programs) in your pocket will have to sort that out.

[PeterCartwright]

Lloyd:
I've no reason to NOT accept the word of those who do this kind of work on a regular basis-like your smith friend(s).  I'm out of my depth in such matters.  A .356 sure would be sweet in a 336 package.  I've always kinda had a hankering for a BLR in .358 for all the same reasons.  After playing with the 336/.35 Rem. I found a couple years ago, no one has to convince me of its effectiveness on whitetails.  (I especially like 200 gr. Core-lokts pushed a bit above factory levels with H4895).  Surely the .356/.358 is all that and more so.

PC

[Chris Potts]

Sorry I'll try to stay on topic

Chris