|
S |
M |
T |
W |
T |
F |
S |
|
|
|
|
1
|
2
|
3
|
4
|
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
|
26
|
27
|
28
|
29
|
30
|
31
|
|
|
|
Forums10
Topics38,547
Posts546,157
Members14,423
| |
Most Online1,344
Apr 29th, 2024
|
|
|
|
Joined: Nov 2013
Posts: 19
Boxlock
|
OP
Boxlock
Joined: Nov 2013
Posts: 19 |
these are the choke markings on brno sxs 17.6 and 17.8. what chokes they refer to? actually i donot want very tight chokes bcz i rarely go for waterfowling ,.. and i need chokes to be at least modified. i am to buy a brno sxs ,.. gun is very good ,.i like its balance and it swings great, but only problem is it may be choked tighter i think. i need your help for determination of chokes from picture 
Last edited by Khan; 12/06/13 01:50 PM.
|
|
|
|
|
Joined: Jan 2011
Posts: 199
Sidelock
|
|
Sidelock
Joined: Jan 2011
Posts: 199 |
You need to also find the bore size for each barrel. Subtracting the choke size from the bore size will give you points of choke. If for example you find 18.4 marked somewhere (on both barrels) that would give you 24 thou in one barrel & 32 thou in the other. Somewhere around 1/2 & 3/4 or Imp & Imp Mod.
The 17.6 & 17.8 are mm, likewise my imagined 18.4. You convert these figures to Thous of an Inch to arrive at the designated choke.
|
|
|
|
|
Joined: Feb 2006
Posts: 3,737 Likes: 55
Sidelock
|
|
Sidelock
Joined: Feb 2006
Posts: 3,737 Likes: 55 |
17.6 is .693 and 17.8 is .700 which would be full and mod. You do need to know what the bores are to get the correct readings.
You can figure the bores to be around .732 unless someone honed them.
The only way to find out what they really are is to pattern it with todays loads and also using different types to come up with something that is right for you.
David
|
|
|
|
|
Joined: Dec 2001
Posts: 12,743
Sidelock
|
|
Sidelock
Joined: Dec 2001
Posts: 12,743 |
Assuming the bores are close to the nominal size of .729" (18.5 mm) I would agree with 300846 & call these chokes Full & 3/4 (Imp Mod). A modified choke should go to around 18.0 mm.
Miller/TN
I Didn't Say Everything I Said, Yogi Berra
|
|
|
|
|
Joined: Jan 2002
Posts: 2,522
Sidelock
|
|
Sidelock
Joined: Jan 2002
Posts: 2,522 |
It isn't very expensive to have the chokes opened to what you need. I have done it on several shotguns as so many are factory full and modified when a skeet and light modified seems to work so much better for the upland game I hunt. I consider fitting the gun to it's use just a normal preparation for the hunt.
|
|
|
|
|
Joined: Jan 2002
Posts: 13,183 Likes: 1161
Sidelock
|
|
Sidelock
Joined: Jan 2002
Posts: 13,183 Likes: 1161 |
What are you going to use the gun for ........... quail, phez, dove, clays ?
SRH
May God bless America and those who defend her.
|
|
|
|
|
Joined: Nov 2011
Posts: 182
Sidelock
|
|
Sidelock
Joined: Nov 2011
Posts: 182 |
I'm dealing with the same issue on a couple tight-choked old European 12 bores. It's tempting to specify a desired constriction, take it to a competent chokemeister and call it good. But the fact is that while both guns do seem to be choked tight, right now I have no idea how tight and how much difference specific loads--spreaders, etc,--make. So I'm back to the advice that appears so frequently on this and other boards. I need to pattern my guns! Back when I lived in bear country, I scoped my 30.06 in at least once, sometimes twice, each year. But I've never patterned one of my own shotguns. Pretty sorry, but maybe not that uncommon.
|
|
|
|
|
Joined: Nov 2013
Posts: 19
Boxlock
|
|
OP
Boxlock
Joined: Nov 2013
Posts: 19 |
i think it should not be 18.5mm i also a brno where 18.35 was marked along with choke markings here is a pic,..so if considering 18.35 i think 17.6 and 17.8 give 3/4 and 1/2. wht you guys say? 
|
|
|
|
|
Joined: Dec 2001
Posts: 12,743
Sidelock
|
|
Sidelock
Joined: Dec 2001
Posts: 12,743 |
Khan;
Old standards were more or less a full choke had 1 mm of constriction. The other chokes were a fraction of that. Subtracting your choke diameters from bore diameter gives .55mm Right & .75mm Left. That would be essentially 1/2 & 3/4 chokes or what we usually refer to in America as Modified & Improved Modified. With modern shells it may well pattern tighter than that.
The 18.35 also indicates the bore is a bit undersize @ .7244", not at all uncommon nor anything to be concerned about. This does point out though why it is necessary to know the bore size to determine intended choke for measuring the choke. Choke is not a Size, but an amount of constriction. A "Nominal" 12 gauge diameter of .729" = 18.52mm
Miller/TN
I Didn't Say Everything I Said, Yogi Berra
|
|
|
|
|
Joined: Nov 2013
Posts: 19
Boxlock
|
|
OP
Boxlock
Joined: Nov 2013
Posts: 19 |
intended use of gun is for upland hunting,.. i will use it for partridge, chukar, sand grouse , quail ,, very little waterfowl hunting. i like the balance and fit of gun and it is ideal to carry in upland hunting ,.. it is in my budget but only problem is choke constriction,.. my friend also has a brno sxs with choke markings as 17.3 and 17.3 on both barrels and i think it is choked extra full! he only uses it for waterfowls not on partriges because it destroys meat and wastes the hunt most of the times. i wonder why old guns are choked so tight , had they been manufactured to hunt jackals?:) ,..mean why so tight ?
if i compare choke markings of one i am going to buy (being 17.6 and 17.8) with my friends sxs (being 17.3 and 17.3), can i use mine on birds on which my friend cannot due to tighter chokes? Or still chokes of mine are tighter? i donot want to open up chokes and neither here i find any skilled person who can do it neatly. so what do you guys say about this?
|
|
|
|
|
