View Thread: fn49 not chambering heavy ball Yugo???


bounce19712
I bought some yugo from J&G for my 'new old fn49 with a new barrel' on it.

took it shooting today with some rommy light ball on strippers from aim and the heavy ball from J&G.

long story short: the yugo ammo stops the bolt and carrier from completely chambering when firing and feeding the second round.

the Yugo heavy ball bullet is visually bigger in (diameter) and binds up on the Rifling as shows on the copper jacket of the bullet.

the yugo ammo, when hand fed into the chamber stops about 2mm before the cartridge seats as completely as the Romy ammo does.

both ammo types display rifling scraping on the copper jacket after chambering and removing but the rommy ammo is very much less pronounced.

A guy at the range mentioned there should be space between the chambered bullet and the rifling for pressure's sake...does that ring true?

this FN49 was rebarrelled by a good gunsmith I was told.

I was told it shot fine with all ammo by the seller....did I get a bad batch of yugo ammo from J&G?

adjust the gas valve for more pressure to bounce off the rear of the receiver?? that doesn't sound like the thing to do...but is it?

it did cycle the first round I chambered of the heavy stuff...

cycled all the romy ammo I fed it fine. I'm not sure what the gas setting is but my buddie said they were flying twenty feet, but then one casing was right beside the bench I was sitting at so I rely on him for 100% .

talk to me.... :)

bounce19712
rommy ammo 8mm compared to yugo 8mm rifling scrapes..

http://i137.photobucket.com/albums/q224/Bounce19712/romybullet.jpg

http://i137.photobucket.com/albums/q224/Bounce19712/rifling.jpg

http://i137.photobucket.com/albums/q224/Bounce19712/headstamp.jpg

bounce19712
the marks left on the yugo bullet are on one side mostly.

here's my measurements with a cheap mic:

yugo ammo:

empty casing length: 57.11
bullet diameter avg of 5 rounds: 8.23
OAL of five cartridges: 80.21 80.22 80.34 80.11 80.05

rommy ammo:
empty casing length : 55.95
bullet diameter avg of 4 rounds: 8.20
OAL: 79.92 79.85 79.77 80.09

I zeroed the mic after every measurement...but if you push on the scroll wheel on the mic it does flex and change measurements... I just lightly brought it to a bunch of times.

some of the yugo ammo of live rounds does have the same weird edges on the mouth of the casing..

bounce19712
after chambering a few more live rounds it the same on all the ammo...

the rommy ammo gets one tiny scrape

while the yugo gets nearly circumnavigated with scrapes...very harsh on one side (the little shaving on one scrape and lighter till just shined up a bit on the opposite side of the bullet.

allesennogwat
The Yugo 8mm specs are slightly different but nothing great. The Egyptian 8mm is also heavy ball. It sounds like the barrel is a bit in the chamber. The gunsmith would set the headspace which doesn't have anything to do with the rifling in the barrel and only sets the shoulder distance.

6526
was the bbl a stock one or turned from a blank?

John@JCDLESales
The Ogive of the Yugo is much longer than the Romy 8mm and has caused problems in FA 1919's to the extent of blowing off and twisting Top Covers. This was due to OBF "Out Of Battery Firings".

The Ogive on the Yugo Just starts sooner and ends longer compared to the Romy 8mm. You could have your chamber Lead In Lengthened but accuracy will fall of with Std. Length 8mm ammo.

bounce19712
that's positive news....

bounce19712
I bought some privi partizan 8mm mauser at a gun shop in tuba city yesterday...17$ for a box of 20!!! ouch!!!

but anyways....the round slid right into the chamber like butter on the rim of a steaming pile of mashed taters...no marks whatsover on the bullet.