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Discussion Starter · #1 ·
I looked around for a couple of days and have not seen this posted anywhere, sorry if it's an old topic.

When I look at the case capacity of the 7.5 French, it has more than the 308 Winchester but the load data for the French round has a lot less in powder charges. I would think that it would at LEAST be up to around the 7.62 NATO loadings. Am I missing something?
 

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I can't answer your question. I just know that 41gr of IMR4895 pushed a 140gr Spitzer to where it needed to go with no problems. I just finished toying with 41gr of IMR4064 behind the last of my 140gr Spitzers. They're going to the range tomorrow to run through my 36. I'll let you know how it comes out.
 

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I looked around for a couple of days and have not seen this posted anywhere, sorry if it's an old topic.

When I look at the case capacity of the 7.5 French, it has more than the 308 Winchester but the load data for the French round has a lot less in powder charges. I would think that it would at LEAST be up to around the 7.62 NATO loadings. Am I missing something?
Is the 7.5 French load using a slower burning powder? Also, the pressure spec for 7.5 French is lower than for 7.62 NATO.
 

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Discussion Starter · #4 ·
I appreciate your answers and honesty. But I do think that it's odd that all that 'space' is going to waste. Not all the data is lower in the 7.5 French and I'm not trying to hotrod the 7.5 French round, just get the most out of it and to use a heavier bullet if it shows to be accurate. At a rating of 40,000 PSI, the cartridge is limited to it's usable space (IMHO). In factory ammo, I got the best accuracy in my 36/51 using the FNM 170gr FMJ ammunition. That's quite a bit heavier than the 130gr to 150gr bullets most folks are using for their handloads. So I got to thinking that maybe this is due to the velocities being kept low, because of the limited max chamber pressure. I don't know, just a question I had...thanks again for your answers.
 

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Discussion Starter · #6 ·
Thank you kg...I think that will have the answers I'm looking for! I wanted to thank you before going through all the info, a lot of it there.
 

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COTW #11 has this to say about the 7.5x54 MAS cartridge :-

150gr SP IMR4895 48gr 2800 fps 2620 ft lbs

...and the 7.62x51 NATO -

150gr FMJ-BT Mil Load 2750 fps 2680 ft lbs

...and the .308 Win -

150gr SP IMR 4895 44gr 2700 fps 2429 ft lbs

You decide.

tac
 

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Discussion Starter · #8 ·
From the information I have read here, there is no reason to not use 308win/762nato reloading data. Which is what I was thinking when I looked at case capacities. Though some loadings for the 308win pushes the pressures way higher than I would want to go. Thanks again for the information and help.
 

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The MAS 7.5 has a working pressure of 49.000 units of pressure, not 40,000. I have no idea where this figure came from. It uses the same powder as the 308, and the same dia. bullets. If you run 308 loads in a 7.5, you will have lower pressures due to increased case capacity. You may have to get the NRA book on reloading to get the real dope on this fine cartridge, but it will be worth it. I wish people would stop spouting facts and figures they got from another forum or blog, and quote them as fact. Research first, then write it down. The NRA book is a fine reference, as it has a lot of odd ball ammo listed, like the 7.5 french long, the 7.5 Nagant, and the 7.5 Swiss. just to list a few 7.5s.
 

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Discussion Starter · #10 ·
Thanks for the input, gunsmith. I have read in more than one place that the 7.5x54 has a working max pressure of 40,000 PSI. I also see that you stated "units of pressure" which I'm thinking your are talking about CUP...not PSI ? Either way, I'm not here to spread false or bad information like you are stating. Sorry I don't know everything and my collection of material may not have all the information I need. Ever think that maybe that's why I'm here?
 

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Yes, if that is where the info came from. Cartridges of the world has many errors, like the 6.5 Carcano having a 264 diameter bullet. It has a 268 in its proper form. Many of the facts that are presented in that book are just recaps of old myths. That is my opinion,taken from a life of checking many sources, and finding the truth.
 

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Dear Mr gunsmith - Are you suggesting that 'Cartridges of the World' publishes dubious figures?

tac
I have to agree COTW has many errors in it, some of that load data is years old and needs up-dating badly.
Patrick
 

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The MAS 7.5 has a working pressure of 49.000 the units of pressure, not 40,000. I have no idea where this figure came from.
The Book Of Rifles, Smith and Smith, copyright 1948, lists the M1929C at 40,000 PSI. That's the earliest reference I am aware of. I always assumed that the 40,00PSI was in deference to the M1907/15 M34 conversions which were designed for the 8mm Lebel, rated at 38,000 PSI. What is your source for the 49.000 PSI number?
 

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The 7.5x54 cartridge model 1929 was a military product, never intended to be offered on the civilian market and as such was not CIP or SAAMI approved.
The design maximum safe working pressure of the guns built to fire that cartridge is listed as 3.500 bars or 50.750 Psi by the SNPE (Société nationale des Poudres et explosifs), as a comparison the 7.62x51 Nato load is listed as 3.600 bars or 52.200 Psi by the SNPE.

kelt
 

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The Book Of Rifles, Smith and Smith, copyright 1948, lists the M1929C at 40,000 PSI. That's the earliest reference I am aware of. I always assumed that the 40,00PSI was in deference to the M1907/15 M34 conversions which were designed for the 8mm Lebel, rated at 38,000 PSI. What is your source for the 49.000 PSI number?
The modernized Berthier rifles Mle 1934 had a new barrel in 7.5 and a new bolt fitted, they were proof tested for the standard military load same as the Mas 36.

kelt
 

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I defer to Kelt- in my experience the final authority on all things French (although I've not asked him about his favorite Bordeaux)! :)
Still not sure I'd be comfortable feeding a Berthier a steady diet of 50,000+ PSI ammo, even with a new bolt and barrel.
 

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according to the CIP and the SAAMI, the 8mm Lebel round has a maximum working pressure of 51,000 units of pressure. I know that is a lot, but that was designed in the day, when pressures were not an issue. If the gun held together for 10,000 rounds in testing, and gave good barrel life, with adaquete accuracy, that did the job. It used a fast burning powder,(the first smokeless), and fired a 230 grain bullet at 2100 fps. Later it fired a 198 grain bullet at 2380. It fired the first spitzer bullet ever made. It has similar ballistics to the 303 British, and not far behind the 30-06. It uses a .330 diameter bullet,(not a 323 like some say, measure an original, and slug a bore in a Lebel. )
The 7.5 barrel having more metal around it, would be even safer fired from a Lebel, than the 8mm.
There is a lot to be learned from this, and a lot of bull to be disposed of. Lets find the truth of the matter. In everything.
 
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