It's more in the 7 - 9 inch range based on 50rounds fired sitting using sandbags. I do come from the dark side (HKs) where this is definitely out of specs.Quote:
Originally Posted by browningautorifle
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It's more in the 7 - 9 inch range based on 50rounds fired sitting using sandbags. I do come from the dark side (HKs) where this is definitely out of specs.Quote:
Originally Posted by browningautorifle
I'll need to dig out the Sten EMER but zeroing would be at 10 or 25 yards. Certainly nothing over that. I mean........ how do you zero a Mk3?
Yes sir. Note your remark on the ammo. I cannot easily source Mk2z so am going to work with what I can get.
Regarding eccentricity. Not sure if this is what you mean, but I ran a crude test on the barrel by rotating it in the trunnion and it appears to rotate evenly when sighting down the bore from above. By evenly I mean it didn't appear to the naked eye to deviate around the long. axis.
I do observe the following however: when fully seated, the base of the barrel appears to be visibly higher in the trunnion on the right side. This would - in my mind - support why it is hitting to the right. The vertical deviation I suspect is normal if the weapon is sighted in at 100 yds. Here a photo...
Attachment 81503Quote:
Originally Posted by Peter Laidler
Yes Browningauto/Jim. Good advice. Amazing how accurate instinctive shooting is. I ran 3 mags dry using short controlled bursts. Wanted to check that the mags were good, but also see if it cycled properly and using a chrono, what the cyclic rate was. All came in exactly on spec with zero malfunctions. My target results were much the same as firing supported in semi mode - high and to the right, but with obviously greater dispersion. You're exactly right, it is hard to know what happened to the gun the past 70 odd years, but she is in remarkable good condition with an excellent barrel. So remarkable that I wonder if her innacuracy spared her useful life...
It certainly looks as though the barrel is not seated squarely. There was a Canadian cutter contraption that would resurface the barrel seating square with the mechanical axis of the tube but we never had such a thing in UK service. Our EMER simply states that accuracy should be fired at 25 yards over the firing bench, forearm rested on a sandbag and using single shots. 2 warming shots into the bank followed by 7 shots at a 1" black square. 6 out of the 7 shots should fall close to the point of aim! So much for accuracy
Thank you sir. Good and bad news then I suppose. Had hoped you would have come up with a solution that involved the judicious application of a hammer blow on one of the sides of the trunnion. Just kidding. Not really. Would that work? Or ye olde Dremel to lower one side? I know, grave rolling in full swing here...
Thanks for the data on accuracy testing. Love that close to point of aim criteria. Minute of Nazi then.Quote:
Originally Posted by Peter Laidler
From my limited experience, I would agree. That seems excessive.Quote:
Originally Posted by 5 Commando
My MkV Sten is comparable to the Mk4 Sterling in accuracy. It’s not quite as good as the Sterling, but it’s close.
The Sterling instructions for zeroing also give the standard. It’s a MPI of 64mm (2.5”) at 25m. So, about 6.4cm at 25m.
It looks like you have found where the problem is. I would not hit it with a hammer or Dremel it. The first thing I would do is check the barrel fit before the barrel nut is tightened. If tightening the barrel nut is canting the barrel, you would probably want to replace the nut.Quote:
I do observe the following however: when fully seated, the base of the barrel appears to be visibly higher in the trunnion on the right side. This would - in my mind - support why it is hitting to the right.
Had hoped you would have come up with a solution that involved the judicious application of a hammer blow on one of the sides of the trunnion. Just kidding. Not really. Would that work? Or ye olde Dremel to lower one side? I know, grave rolling in full swing here...
I can’t tell how tight your barrel is in the trunnion. If it’s loose, you can knurl it lightly to get a tighter fit. A little hand knurler works well for this. Use lots of oil.
StenParts.com has new barrel nuts and bushings if you need them.
Swiss made RUAG 124gr is pretty close to the old Mk2z ammo.
Do not use any Pakistani surplus 9mm. It’s not reliable and you run the risk of damaging the barrel.
So, I pulled out my CAMT handed to me by an old SNR NCO when I was in mortar PL back in about '76. The spec for zeroing Sten is... "25 yds, 5 shots fired, group should be 2" above POA." There's more about PV but who cares? It further states that... "A trained man should be able to group all five shots into a circle of 3-1/2" radius."
We shot SMG C1 at 100 yd but it's an SMG, not really meant for distance. Group size would be x4 for 100M...
Thanks for the info Peter, as a matter of interest what would you regard as an acceptable accuracy for a MK2 Sten at 25 yds and what sort of grouping can be achieved at 50yds?Quote:
Originally Posted by Peter Laidler
Going with what our CAMT states, the group would be X2 for the acceptable size. IE, 3 1/2" X 2 is 7 inch group...or at 100 yds would be 3 1/2 X 4 =14" group...that's a lot.
Now, I don't know what the EMR states or the UK AMT for the Sten Machine Carbine...