7.62x54R Mosin and Published Load Data

[Eddie1971]

Something that really makes me scratch my head, especially in this day in age, is why do all the reloading manuals state that 7.62x54R should be loaded with .308 bullets? Out of the 1,000's of Mosins I have come across I have seen maybe 2 Finn made examples with a .308 grove diameter. The only ones I know for sure that were in the Finn 7.62x53R, .308 grove were the M27's, which are pretty hard to come by. Even all the M28's were converted to D ball. I think Hornady is the only one that lists any loads using a .311 or .312 bullet. I was shocked that even Lyman in their manual says to use .310 diameter with cast in a Mosin. What do you think about this, and do you think they will ever change? Then again this will be wishful thinking because they still warn people about 8mm Mauser and treating all of them that they have the Patrone 88 J bore!

[ShooterAZ]

I have always used .314 cast boolits, and .312 Hornady jacketed in my Mosin's. I always work my loads up, so I've never had any problems with the data listed for .308 bullets. And no, I doubt if the manuals will ever change their data. I've also used .308 jacketed bullets with varied results. Some were quite accurate, mostly the heavier for caliber bullets. The lighter bullets not so much...

[beemer]

My Hornady manual list both size bullets. Most dies size for .308 and use different expanders for the different diameters. It can be hard on brass so I neck size with different mandrels if needed.

Other than that ShooterAZ sums it up pretty well.

[LAGS]

I have been loading the 7.62x54 since 1978.
I used the data listed for .308 bullets to load the .312 bullets.
Like you are supposed to,
I always started with the lowest load for each bullet.
Then I increased my load to find the load that shot well in MY rifle.
I only had issues when I had a rifle that had a good chamber and a Worn Bore when I shot over .312 cast Boolits.
And that was an issue with the round not wanting to slip in easily into the chamber because the neck was larger.

[winston10]

Old misinformation dies hard , Just like you talking about a military Mauser with a J bore . There is no such thing . The German military never used a J nor S as a bore size . The original Gew-88 groove was .3208 , changed to .323 in 1896 1/2 . All German S ammo was a .3208 bullet . So all post 96 8mm Mauser were .323 . The original Russian bullet was .308 changed to .3095 with the later spitzer .

[Larry Gibson]

I think it goes back to the ammunition the US loaded for the troops to train with stateside using the Westinghouse, Winchester and Remington made M91s that were not delivered to Russia after the 1917 revolution.

To quote from Philip Sharpe's Complete Guide To Handloading regarding the 7.62 MM Russian cartridge;

"Originally it used a round-nosed bullet, the round nosed type weighing 214 grains. This was changed at about the time of the World War, however, to a pointed bullet very similar to the old 30-06 but weighing 148 grains as made in Europe or 145 grains as made in this country. Essentially it was the same bullet as the 30'06 150 grain, the lighter weight being achieved through a conical cavity in the base of the bullet. Since the bullet was somewhat undersized, the idea of this conical cavity was to create the proper upset during firing, so the bullet would fill the rifling."

As he further states that following the sell off to NRA civilians after the war that "thousands upon thousands of cases of ammunition were also sold to members at the excessively low price of about $5 per case of one thousand rounds." Thus, it seems the original ammunition loaded for the US made MNs used in the country back then had .308 caliber bullets. The load data Sharpe recommends also uses .30 caliber bullets. Thus being what was done (loading the cartridge with .308 caliber bullets) originally was carried forward and recommended in some earlier loading manuals.

[Tedly]

FWIW when I was shooting handloads in my Mosins (mostly M44s) I started with .308"bullets and they shot as good as .312" bullets did , both Hornady 150 gr. sptzers over 50.0gr. IMR 4350 . Granted this was iron sight shooting at 50 and 100yds , but 2 MOA was there

[LAGS]

When I first started reloading for the Mosins,
I followed the manuals , and used .308 bullets.
Accuracy was about 5" at 100 yards.
Then I tried some Speer .309 bullets that they made in the '70s.
The accuracy went down to 2" at 100 yards.
Then I decided to try some .310 bullets.
The accuracy went down to 1"
That rifle had a .310 bore.
I still have that rifle.
It is a Finish 28-30
I had good results on a rifle that had a .312 bore if I used Hornady .312 bullets.
Now Cast Boolits.
I always shot Boolits that were .002 bigger than the rifles bore Diameter and I shoot cast Boolits up to .316"

[GhostHawk]

I can point to to the moment my 2 Mosin rifles went from shooting 8" patterns at 50 yards to shooting 3" groups at 50 yards. Primer, powder charge did not change. Only change was going from a .311 cast boolit to a .314 cast boolit.

And when I cleaned it after that range trip the last of the dark in the bottom of the grooves was gone. Whole bore was shiny silver that sparkled like glass.
(TY Ben for BLL)

All it took was a Lee .314 sizing die and a little tape work on my .312 mold to get .315 boolits. Gas checks got put on with a rubber mallet and pushed through the die.

[Eddie1971]

Old misinformation dies hard , Just like you talking about a military Mauser with a J bore . There is no such thing . The German military never used a J nor S as a bore size . The original Gew-88 groove was .3208 , changed to .323 in 1896 1/2 . All German S ammo was a .3208 bullet . So all post 96 8mm Mauser were .323 . The original Russian bullet was .308 changed to .3095 with the later spitzer .

I know all about the 8mm story, and I'm just using the J and S round as an example of how it's similar to 7.62x54R today in loading manuals.