Max loads 7.62x54R 150grain SP

fiddler

fiddler

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Recent ladder loads for 150gr sp using IMR 4350 powder, going from min to max (50-55gr) I had no pressure signs at all using the chart maximum. Before I continue loading another set going higher, has anyone loaded up this round to visible pressure signs using 4350 powder?



I was getting some good groupings at 53gr but I don't feel the North American charts give this round a fair evaluation for pressures. I want to test fire up to a visible max before I draw my conclusions, but my data does not approach this.
 
I have a Lyman book as well with the same info. I think its under-spec. I'm looking for someone who has actually loaded this round higher, or has a book with European charts. The brass is not working hard at all with the max load.

This load can go higher than North American charts. I'll load a few steps higher going up the ladder looking for problems. I'm curious for someone who has done this so I don't have to pull apart loads after finding the pressure max.
 
If you got decent groups at 53 gr you did better than I did. I could not get any where with that powder and a 150 gr bullet. I don't think I went right to the listed max , but I also tried H4350 and did no better. (The H4350 is the best with 180 grains though, 50 was my magic number for accuracy in an M39beyond which they start to drift). I found that Reloader 15 really liked the 150gr in both my MN's so the search ended.

On a side note, Lyman's 48th does not list any of the 4350's for the 150gr bullets.
 
"...This load can go higher than North American charts..." 55 grains of IMR4350 is max. You won't find anything about the actual pressures by looking for the signs. By the time you see 'em, the pressures are too high. In any case, it has nothing to do with the case. Has to do with the rifles.
"...with European charts..." Pressures don't change by crossing The Pond. IMR4350 is the same there.
"...Lyman's 48th does not list..." Does in the 45th. Oddly Hodgdon doesn't list 'em for a 150 on their site either.
 
commonman said:
If you got decent groups at 53 gr you did better than I did. I could not get any where with that powder and a 150 gr bullet. I don't think I went right to the listed max , but I also tried H4350 and did no better. (The H4350 is the best with 180 grains though, 50 was my magic number for accuracy in an M39beyond which they start to drift). I found that Reloader 15 really liked the 150gr in both my MN's so the search ended.

On a side note, Lyman's 48th does not list any of the 4350's for the 150gr bullets.
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I have Lyman's 45th for the specs 150gr IMR 4350, but I'm also using a .313 diameter bullet in a rifle that slugs out at .315.

The reason I want to go higher is my groups were coming in tight a second time but the loading increments topped out at 55 gr. The chronograph shows me to be under calculated velocities in both Mosin rifles, one with "as new" bore and one warn and dark.
 
Well - One issue is that the powder is somewhat too slow for the bullet weight/caliber. Hard to get the most out of that powder ... Switching powders will get more velocity with less pressure - I realize this is quite subjective, but - your're dealing with old rifles of indeterminate QA. I friend of mine had the bolt head fail on his recently, using relatively weak factory ammo.
 
cosmic said:
Well - One issue is that the powder is somewhat too slow for the bullet weight/caliber. Hard to get the most out of that powder ... Switching powders will get more velocity with less pressure - I realize this is quite subjective, but - your're dealing with old rifles of indeterminate QA. I friend of mine had the bolt head fail on his recently, using relatively weak factory ammo.
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How come its not too slow to use in a 30.06 with 150gr bullet? or .308? They are pretty much the same bullet/cartridge as x54 Russian. Either way, my chronograph indicates these charts are faulted. I think these charts were added to the books in NA to fill it up. I'm really doubting there was much research to these Communist calibers.

Does anyone have valid pressure specs for a Mosin rifle chamber?
 
I think that Cosmic is right. The 4350 powder is too slow to work well with 150 grain bullets in an MN period. On top of that is the bore diameter versus the bullet size, my guess is a faster powder will work better.

Just a note, I found that the MN's are different to work with than a 303 brit even if the bores slug a similar size. On my riffles I attributed that to the fact that the bore is .300 even if the ID of the grooves is .313 or more, (a common brit will be .303 bore and .313 groove ID) so the engraving on the bullet is deeper. Newer the barrel the more noticable this is. With a faster powder you need to be extra careful of pressure.

From my shelf I would try first, Reloader 15, next Varget, last IMR-4064. There's lots of others but those all worked for me.
 
Do you have the Lee Modern Reloading Second Edition? it gives the pressures for most loads.

Max loads with 150 gr bullets:

55 grs BL-C(2) = 3027 fps at 50241 PSI
50.5 grs Varget = 2985 fps at 50349 PSI
49.5 grs H4895 = 2938 fps at 50241 PSI
49.5 grs H335 = 2918 fps at 49806 PSI

The Lee manual doesn't list IMR 4350 but has A-XMR 4350 at 54 grs for 2673 fps at 44100 CUP.
 
How come its not too slow to use in a 30.06 with 150gr bullet? or .308? They are pretty much the same bullet/cartridge as x54 Russian. Either way, my chronograph indicates these charts are faulted. I think these charts were added to the books in NA to fill it up. I'm really doubting there was much research to these Communist calibers.
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You won't find a 30-06 or a 308 with the same barrel and bullet fit. The 303 brit is the closest and it is different so I don't expect the same powders to work. With any of the military rifles I have experienced so far, the accuracy has dropped off with max pressures. (correction; the Swiss rifle just seemed to stay good no matter).
 
commonman said:
With any of the military rifles I have experienced so far, the accuracy has dropped off with max pressures.
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I generally agree but not so in this case.

My 51.5gr (group 3) was good, then opened up a bit then started coming together on the 55gr max (group 10). Both groups were the same.
 
Well - The MN typically uses a larger area bullet than the 308 or 30-06. About 2.6% more, and that is sufficient to change the powder speed requirement. So its closer to a 303....
 
Never had much luck with IMR 4350 in my MN and 150's Best I did was 3031 and 150gr Hot-cors. Worked great.

I only took 4350 to 55 grains, that was enough for me. No pressure signs.
 
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