8mm vs 7.62 x 54r

[ted65]

My brother has a mosin M38 and I have a turk 1938, we both thought that the 7.62 would be more accurate and powerful until we took them out the other day and fired some rounds through them. We both used FMJ military surplus ammo. Very hot. It would seem that my 8mm was more powerful and even more accurate. 2 1/2 in @ 100 yards (even with the terrible  sights)  His 7.62 was getting 5-6 in at 100 yards. Is this just our rifles or is this normal?

[torpedoman]

something is wrong with the 762 , it should be a lot better than that , is the blt matching no's or electro penciled? Stack masking tape on the rear of a spent case until the bolt gets hard to close ,measure the thickness of the tape to get a rought idea of the headspace. check for damaged crown.

[ted65]

Yes matching no's and perfect headspace and crown...we will take them out again tomorrow with different ammo. I think my brother may have been flinching due to the kick and how loud his light m38 is. that mosin sure packs a punch with hot ammo!..and wow it is loud! Is the 8mm more powerful? I was able to shoot clean through a pretty large tree and the 7.62 was not.

[Spanky]

Yes matching no's and perfect headspace and crown...we will take them out again tomorrow with different ammo. I think my brother may have been flinching due to the kick and how loud his light m38 is. that mosin sure packs a punch with hot ammo!..and wow it is loud! Is the 8mm more powerful? I was able to shoot clean through a pretty large tree and the 7.62 was not.

Maybe the 7.62 hit a knot!!


Spanky

[ted65]

Not ten times.

[Mikey]

The 7.62x54R and the 8mm are both on par for accuracy and power.  Both have used a 195-200 gn slug at somewhere around 2400-2500'/sec and both sound like a cannon from the shorter barrels. 

Regarding accuracy - I have played with a couple of the Moisons and found that one thing necessary to improve accuracy is to remove the bayonet and bayonet lug - those two things really throw off accuracy.  If your Moison does not wear either then I would check to see how the action and barrel sit in the stock - I have seen some where the barrel literally sits on the edge of barrel channel and others where the action would almost float in the stock even when the stock screws were tightened down.

Also, the Turk has a longer barrel which might help with its accuracy but the Moison can easily be treated to a 'accuracy enhancing' session or two that might well make it a great woods rifle. 

As for power levels - the 8mm normally fires a 195-200 gn (323 dia) slug at around 2500'/sec and the 7.62x54R takes a 200 gn (30 caliber) slug at around 2300'/sec from the shorter barrel.  The safety on the Moison is a bit difficult in a hunting/field scenario.

Treat your brother to a shoulder pad to help dampen the recoil and don't forget hearing protection - might make the session go a bit better..................... HTH.   Mikey.

[1911crazy]

The short barreled mosins do jump and kick a tad more than the longer barrels do.  I would try to benchrest it down tighter to test and compare it.  I like to adjust it so i'm pulling it straight down into the rests when i'm sighting it on the bull.  I adjust the rear rest to bring the sights on plane with the target.

It does take some getting use to the gun too.  I do find myself not shooting enough when the gun is in error its really me doing it not the gun. My own rules are shoot more, practice more by shooting more often......

Now its been said before that the longer barreled mosins were a tad more accurate over the 8mm mausers.  I'd like to see a 91/30 compared to the turk 8mm.

[Larry Gibson]

Given equal condition rifles, equal ability shooters and equal quality ammo there wouldn't be much if any accuracy difference between them.  What you and your brother found was some good shooting 8mm ammo and some poor shooting 7.62 ammo.  It's really nothing to do with either of the rifles or cartridges being better than the other. It is simply the qualitiy of the ammunition.  There are some 7.62x54R ammo out there that shoots every bit as good as that 8mm ammo you shot. Conversly there is some 8mm ammo out there that will shoot every bit as poorly as that 7.62 ammo you shot.  Simply the difference in quality of those lots of ammunition.  Not to worry, try other ammo and the results may be the reverse.

Larry Gibson

[Spanky]

Yes matching no's and perfect headspace and crown...we will take them out again tomorrow with different ammo. I think my brother may have been flinching due to the kick and how loud his light m38 is. that mosin sure packs a punch with hot ammo!..and wow it is loud! Is the 8mm more powerful? I was able to shoot clean through a pretty large tree and the 7.62 was not.

Maybe the 7.62 hit a knot!!


Spanky

Not ten times.

Maybe you missed the tree with the 7.62!!



Spanky

[30-30man]

Another thing to consider is many surplus rifles have different bores and will shoot very differently with different types of ammo. I have one Mosin that has a .309 and many others that range from .312 to .314.  There are just too many variables to determine what went wrong.  The worst group I had with my Mosins came from Wolf Gold and that is suppose to be the best ammo out there for these surplus rifles. It came with a .310-.311 bullet.  The Barnual mostly measure around .312+ so I guess that is why it is more accurate in my guns.   Another point is during war production, most countries could care less about accuracy.  They just wanted enough rifles to give to every other soilder.  I've had 6-8 inch groups with a Yugo Mauser that was in pristine condition, so who knows.....

[ted65]

After learning more about these rounds I have come to see that it was the ammo...The 7.62x54R is every bit as powerful as the 8mm. I love both, by the way...very powerful calibers indeed!

[fastbike]

I'm not so sure it was an ammo difference. There is some opinion (it's the internet, so who can say) that most of the available M38's have beeen pretty well "shot out". This is certainly the case with my son's M38. It's from 1944 and clearly has worn rifling. His 1941 M91/30, on the other hand is a much better shooter (and better rifling).

[cbxboy]

30-30 is onto the trick in my opinion.  I have 1 M-38 which shoots tight as heck and the other 2 are not so hot.  I have never slugged anything for dimension but am suspect this is the issue. 

You have self answered your question, the 7.62x54r and the 8mm are "comparable" and differing ammo and loads can alter the outcome of course.  Both are very nice and reasonable in milsurp loads --even after the price increase.  Hey if you have a few bucks grab some of the Yugo 7.62x54 that is out now again.  GREAT ammo and non magnetic to boot!  Is corrosive however as is most euro block ammo.

Play with ammo and that M-38 will be a blast....literally.  You may check stock option as mentioned above as well as many M-38's were restocked into M-44 stocks and poorly fit at that.  I have also found that if you lengthen your distance you may find you bring it close again......most ALL my Mosins shoot on at 200 yds not 100.