G3 rifle accuracy?

[knutzke]

Hello,
I have a Portuguese made FMP rifle and I would like to know
if there is a noticeable difference in accuracy compared to original
H&K rifle.My rifle has conventional rifling not polygonal like H&K have.I have found that I can shoot ca. 0,75 MOA @100m groups without optical sight.Is this good accuracy for this type of firearm?
This is my first selfloader and I`m comparing it to my bolt actions and that makes me think that FMP´s accuracy sucks!!If I remember correctly my army issue Valmet m62 shot 1,5 MOA@150m, and no one in my platoon had a rifle that could shoot
1 moa groups.

Knutzke

[Destructo6]

Your accuracy is pretty damn good.

Only a few HK 7.62x51 rifles had polygonal rifling. HK-91's imported in 1975 and 1976 were available with, and some of the sniping variants came with the poly rifling. The vast majority of HK-91's, and G3s for that matter, had conventional rifling.

[blades67]

That's on par with the German made HK91s.

[knutzke]

What are the advantages/disadvantages of polygonal rifling anyway?
Is it less expensive to manufacture with modern machinery?

I have H&K USP 9mm pistol and it has polygonal rifling,
and I have not found any difference over traditional rifling
in accuracy wise. However it seems to be easier to clean .

Knutzke

[BB]

poly rifling makes a better gas seal around the bullet, increasing pressure and velocity. A well-made poly barrel will produce higher velocities than a conventional barrel of the same length.

They are easier to get clean too.

[Destructo6]

I believe the biggest advantages to the poly barrel are ease of cleaning, as you mentioned, and barrel life. The poly barrels don't have relatively weak protrusions (lands) that will round off eventually.