Dear Konstantinych, from me to you, I have a vopros.Kupil shotgun 12 gauge with interchangeable chokes. Barrel length of 710 mm, drilling after the chamber – 18.2 mm, before the choke zone at the bottom of the barrel – 18.15 mm, the upper – 18.1 mm.
Included shotgun chokes have a length of 52 mm and an inner diameter at the point of connection to the main trunk and on the muzzle are:
Cylinder – 18.4 – 18.2 mm;
Cylinder pressure – 18.4 – 17,95 mm;
Poluchok – 18.4 – 17.7 mm;
Poluchok with head – 18.4 – 17.45 mm;
Chalk – 18.4 – 17.2 mm.
That is, in places of transition from the main stem to choke zone for the bottom of the barrel drop diameters of 0.25 mm for the top –
+0.3 mm. This situation is normal, or until the warranty on the gun should be made to replace it, or replace choke?
With your gun all absolutely fine. Shoot it in the health and pleasure as much as you want without fear!
Generally speaking, there is a very simple and effective way of checking the quality of manufacturing landing Places on muzzle of the barrel guns and interchangeable chokes, respectively. This method It does not require any optical or mechanical devices, since it is quite enough of your naked eye.
Correctly manufactured kit «trunk + interchangeable choke»:
1. When looking into the barrel bore from the breech, seen only one dark ring. We see the cone slug entrance, in the end zone of the chamber. And no more dark rings should not be.
2. When looking into the barrel bore from the muzzle seen only one very thin dark ring of uniform thickness. We see an end surface of the seat under the trunk interchangeable choke.
Shoot from such stem can be without fear.
There may be other pictures showing irregularities in the muzzle of the barrel, as follows:
1. When looking into the barrel bore from the breech, in addition to dark rings slug input It is seen more in the muzzle of stem or complete narrow dark ring, or incomplete, i.e. «crescent».
In the first case, it indicates that the interchangeable choke inlet diameter smaller than the diameter of the bore. Shoot from this trunk can not be categorically! Otherwise case, when the first shot just knock out a sheaf of the barrel moving charge, followed by blowing up an essential, if not break the extended barrel.
In the second case, it suggests that in addition to the just discussed above improper difference in diameter bore and interchangeable choke, you can talk more about the existing misalignment bore axis and the axis of the interchangeable choke.
Shoot the barrel of this, too, can not be said for a reason!
2. When looking into the barrel bore from the muzzle can see the complete (!), But thin gage dark ring. It can be in two instances:
• The axis of the bore misalignment of the axis of the barrel under the seat interchangeable choke when perfectly manufactured removable Choque.
• Channel axis interchangeable choke Misalignment with the axis of its seat when the barrel perfectly manufactured.
Shoot from the trunks of such combinations possible, but be sure to check the accuracy of their fight for bias midpoint results (STF) of the aiming point (TP).
If this shift is negligible, it is necessary to throw all «cockroaches» from the head and operate the gun without any doubt.
If the offset is significant, it is necessary to find out what exactly is to blame: Chalk or trunk?
Typically, shotgun with interchangeable chokes They completed their sets in the amount of 3–5 items.
This also should be used. In our case, It turns out to be a controversial choke and put it aside. This is followed in turn screwed into the barrel all other interchangeable chokes and examine the state of visible dark rings for polythickness. There can be two options:
• Gage dark rings retained. This means that chokes flawless, and the trunk, alas, worthless. From this gun should be discarded.
• Gage dark ring is no longer observed. This means that the trunk, and all the remaining chokes perfect. Thus, with such a gun all the suspicions are removed and set aside at the beginning of the test choke must be replaced.
Good luck, Igor!
Alexander Posudin17 August 2012 at 00:00