New production Zastava M57 and I can't hit the broad side of a barn. Bore size?

[Polish-Jack]

I feel the reloading section would be the best place to post this.

I need some help with a new production Zastava M57 I just bought and took to the range for the first time yesterday. I had ten rounds of leftover Norinco red box ammo and Russian Factory 38. Both of these cartridges shot all over the place like a stereotypical musket. At twenty meters I saw impacts in the dirt, over the target stand, two to three meters to the left and right. I did not land a single hit on the actual paper. I know this ammo was good because I also have a P762 that groups very well at twenty meters with both types of ammo.

I slugged the bore on the M57 and my micrometer shows a bore size of 0.3124 inch to 0.3126 inch. That seems to be a bit large for standard 7.62x25 cartridges, which technically are supposed to have a 0.311 inch bullet. My P762 slugs at 0.3092 inch and like I said, I am surprised at how well it groups.

I don't have any more ammo and I can't find any locally at the moment so I'm hoping one of you fine reloaders might have several pulled bullets that can take some measurements. I know the Norinco and Russian stuff is no good for this pistol, but what about the S&B and Prvi PPU stuff?

 

[B]

I have measured x25 bullets everywhere from .306-.312 with the vast majority sitting around .309". If your barrel is .312 I'd say most x25 is going to be undersized which could explain your accuracy issues.

 

[mbogo3]

My buddy has one with the same issues meanwhile my Polish TT33 is very accurate.Groove size unknown? Might have to run some .32/.312 cast bullets in it.

 

[Ganderite]

Campro makes a 115 gr .312 bullet. Tjhat might work well. I have loaded the CamPro 110gr M1Carbine bullet and it is excellent. The 115gr is just a fatter version.

 

[Rick911]

Zesteva lol

Orange ?

Lime ?

Lemon ?

 

[Polish-Jack]

Campro makes a 115 gr .312 bullet. Tjhat might work well. I have loaded the CamPro 110gr M1Carbine bullet and it is excellent. The 115gr is just a fatter version.

I've been thinking of getting some of the 85 grain CamPro bullets since it is closer to the 90-95 grain factory loads than 115 grains is. Why did you end up using the 115 grain bullet?

 

[Gnome75]

I had one of the 9mm versions. It shot like sh!t too. I think they are just junky guns.

 

[Ganderite]

I've been thinking of getting some of the 85 grain CamPro bullets since it is closer to the 90-95 grain factory loads than 115 grains is. Why did you end up using the 115 grain bullet?

I have the 115s. I bought them as 303 plinkers.

I have used the 110 308 Campro Carbine bullet in my 7.62 pistols and rifles. It works well. If I needed a fatter bullet, I would use the 115 gr version. Lower velocity probably means more accuracy.

 

[.30/06 FTW]

OP, have you benched the gun and shot groups with it? They’re not exactly easy guns to shoot well.

Zesteva lol

Orange ?

Lime ?

Lemon ?

I bought an M70A from my friend and when I was texting him about it my phone autocorrected Zastava to Zesty. The gun has been known as the Zesty Serb ever since.

 

[Polish-Jack]

OP, have you benched the gun and shot groups with it? They’re not exactly easy guns to shoot well.

After my first three shots and not seeing any marks on paper I pulled up a chair and a shooting rest and paid attention to where things were hitting. One of the other shooters was also watching. He's never seen anything like it.

This is also not my first Tokarev. I have a Polish Factory 11 that shoots nice, but I really like the longer grip of the M57. My pinky hangs under the Polish TT and messes with my shooting. I guess I am just going to have to reload for it.

 

[fire@will]

I have the 115s. I bought them as 303 plinkers.

I have used the 110 308 Campro Carbine bullet in my 7.62 pistols and rifles. It works well. If I needed a fatter bullet, I would use the 115 gr version. Lower velocity probably means more accuracy.

I just bought a bag of these same bullets (CamPro 110 gn. M1 Carbine). The only load I can find that references the powder I use (Longshot), is 8.3 grains, under a 93 grain bullet. This is listed as a maximum load. Do you think that 7.5 grains of this powder, under the 110 grain bullet, would be excessive ? - The pistol is a M57 Zastava.

 

[Ganderite]

I would start with 6.0 and chrony the load.

7.5 looks to be too much

 

[fire@will]

Okay. Thank you for the input.

 

[Polish-Jack]

I managed to luck into one more pack of that Russian 7.6x25 at the shop. Looks like they found one that got bumped behind some other ammo and I was in the shop just when that happened. Lucky me! I pulled one of the bullets and you will not believe it. It measures 0.3082". No wonder I can't hit the broad side of a barn in the M57. There is a gap of 0.004" between the grooves and the bullet. Only the thing that is making contact with the bullet are the lands, and they are only digging into the bullet 0.006". If the bullet was a proper size and riding the grooves at 0.312" then the lands would be 0.011" into the bullet.

 

[B]

FWIW the nominal bore size for x25 is .309 so it's really not the ammo but your barrel to blame. I have measured some Czech x25 at .306" and it shot fine from 3 different TT-33 pistols.

 

[Polish-Jack]

FWIW the nominal bore size for x25 is .309 so it's really not the ammo but your barrel to blame.

Yep. That's what I was trying to say. The M57 barrel is just oversized. I am going to either have to reload for it, or find surplus ammo that will work with the gun and buy a stockpile.

 

[B]

Yep. That's what I was trying to say. The M57 barrel is just oversized. I am going to either have to reload for it, or find surplus ammo that will work with the gun and buy a stockpile.

I guess I read too fast and failed to comprehend, my bad. It is a pretty lame situation but considering the current price of surplus let alone factory ammo you may be better off.

 

[Polish-Jack]

So I'm embarrassed to say that I think I found the problem. It's a combination of a 10lbs + trigger pull and overconfidence in my abilities. I managed to score some Czech surplus ammo, used a redneck rest, and hyper focused on taking each shot. There were decent groups to be had. I no longer believe there is anything wrong with the gun, other than a horrible trigger and a fool shooting it.