O/U shotgun fix chokes modification

[DGY]

Good day all, I have a set of Brno 301 shot gun barrels that seem to have fix full chokes and I would like to get them opened up to half choke or improved, so I can shoot steel shots with it! Who is a good gun smith that can do the work? I’m in the Yukon and no one I know up here can do the work, so I guess BC and or Alberta would be my next choices!
Thanks!!

 

[guntech]

SHOTGUN BARREL ALTERATIONS FOR STEEL SHOT

Forcing Cone Alteration:

Factory shotgun barrels usually have a fairly short and abrupt forcing cone. The forcing cone is the tapered area just ahead of the chamber where the shell is contained. Altering the forcing cone, so it is one and one half or two inches in length, reduces recoil and improves the pattern density. Trap shooters and skeet shooters have been doing this for many years. It is a good benefit to the steel shot user as well.

Choke Alteration:
Choke designation from the tightest to the most open are:
Extra Full, Full, Improved Modified, Modified, Skeet II, Improved Cylinder, Skeet I, and Cylinder Bore.

Steel shot does not require the constriction that lead shot needs, to produce good patterns. In fact too much constriction, causes poor, erratic patterns, and in some cases, permanently damages the barrel. I have seen barrels bulged at the choke, I have seen barrels where the choke split right open, from using steel shot.

For steel shot, with thin barrels, chokes should be altered to at least Skeet II. Often, over & under, and side-by-side shotguns, are best altered to Skeet I and Skeet II chokes. Heavier barrels can be left at Modified choke but may see an improvement in the pattern if opened slightly.

 

[DGY]

SHOTGUN BARREL ALTERATIONS FOR STEEL SHOT

Forcing Cone Alteration:

Factory shotgun barrels usually have a fairly short and abrupt forcing cone. The forcing cone is the tapered area just ahead of the chamber where the shell is contained. Altering the forcing cone, so it is one and one half or two inches in length, reduces recoil and improves the pattern density. Trap shooters and skeet shooters have been doing this for many years. It is a good benefit to the steel shot user as well.

Choke Alteration:
Choke designation from the tightest to the most open are:
Extra Full, Full, Improved Modified, Modified, Skeet II, Improved Cylinder, Skeet I, and Cylinder Bore.

Steel shot does not require the constriction that lead shot needs, to produce good patterns. In fact too much constriction, causes poor, erratic patterns, and in some cases, permanently damages the barrel. I have seen barrels bulged at the choke, I have seen barrels where the choke split right open, from using steel shot.

For steel shot, with thin barrels, chokes should be altered to at least Skeet II. Often, over & under, and side-by-side shotguns, are best altered to Skeet I and Skeet II chokes. Heavier barrels can be left at Modified choke but may see an improvement in the pattern if opened slightly.

Thanks, that is awesome info!! So if I want to get those barrels improved for steel shots(thinking waterfowl here), first is it worth it? Second what am I looking at for cost? And third do you do that kind of work?
Thank you

 

[Potashminer]

Good day all, I have a set of Brno 301 shot gun barrels that seem to have fix full chokes and I would like to get them opened up to half choke or improved, so I can shoot steel shots with it! Who is a good gun smith that can do the work? I’m in the Yukon and no one I know up here can do the work, so I guess BC and or Alberta would be my next choices!
Thanks!!

Not to dissuade you from the project - I can not help about that. But since you are in Yukon, I suspect not more than $5 or $10 difference to mail to Vancouver or to Saint John. Do not assume that - will likely want to verify at your Post Office. Canada Post pricing is interesting - $15 to mail a parcel to a town 20 miles down the highway, $20 to mail same thing across Canada - not my fault or problem if they decide the parcel first goes 500 miles one way, and then 480 miles back to get to the town just down the highway. As if the first $13 or $14 just to get it into their system, then miles after that do not seem to matter so much. So your mailing cost - there and back - might not be a whole pile of difference whether the place to do the work is 100 miles away or 2000 miles away. If possible, keep your package less then 1 meter in length to avoid a very healthy surcharge that they apply.

 

[cosmic]

Well - I believe those guns have chrome lined barrels. That makes the mods more difficult, you may have trouble finding someone with adequate tooling.

 

[DGY]

Well - I believe those guns have chrome lined barrels. That makes the mods more difficult, you may have trouble finding someone with adequate tooling.

The barrels are marked “Poldi Special Steel”

 

[guntech]

Thanks, that is awesome info!! So if I want to get those barrels improved for steel shots(thinking waterfowl here), first is it worth it? Second what am I looking at for cost? And third do you do that kind of work?
Thank you

I used to do this... but never on chrome lined barrels...

 

[DGY]

I used to do this... but never on chrome lined barrels...

So these are chrome lined ?

 

[guntech]

So these are chrome lined ?

I don't know if they are...

I never did chrome lined barrels as that requires considerably more expensive tooling. Not that many smiths have it...

 

[DGY]

I don't know if they are...

I never did chrome lined barrels as that requires considerably more expensive tooling. Not that many smiths have it...

Ho ok, is there a way to know if they are? And if they are do you know of a smith that does the work?
Thanks for the info, I really appreciate it!

 

[mbogo3]

Did you try Casey @ Tactical Ordnance?

 

[DGY]

Did you try Casey @ Tactical Ordnance?

No, I’m just inquiring at the moment!

 

[cosmic]

Aside from the chrome issue, those guns have 2 3/4 inch chambers. Unfortunately, this imposes payload or velocity limitations on steel shot, as it requires more volume in the hull compared to lead. Let us know how it goes...

 

[Why not?]

So these are chrome lined ?

I don't know if they are...

I never did chrome lined barrels as that requires considerably more expensive tooling. Not that many smiths have it...

Dennis,

Is there a way to determine if a barrel is chrome-lined or not? I have never seen any reference to this, but there must be some way to do so.

Ted

 

[guntech]

Dennis,

Is there a way to determine if a barrel is chrome-lined or not? I have never seen any reference to this, but there must be some way to do so.

Ted

Clean the inside of the muzzle with lacquer thinner... dry, then apply cold blue... chrome lined stays bright and shiny...

 

[Why not?]

Thank you. The only reference I have seen to the ZH guns being chrome-lined is here on this thread, and I have read a lot about them over the years.

We're going to find out.

Appreciate your help,
Ted

 

[DGY]

Clean the inside of the muzzle with lacquer thinner... dry, then apply cold blue... chrome lined stays bright and shiny...

Thank you! I just did and it turned blue so I guess not chrome lined!! Maybe Ted can post the picture I sent him!

 

[Potashminer]

Well - I believe those guns have chrome lined barrels. That makes the mods more difficult, you may have trouble finding someone with adequate tooling.

Reading previous threads - maybe you might reveal from where that you got your information about the "chrome lined" thing????

 

[Why not?]

Thank you! I just did and it turned blue so I guess not chrome lined!! Maybe Ted can post the picture I sent him!

As you wish, Sir.



Looks pretty blue to me. So, ream choke to cylinder bore and you have steel shot comfort, AND ideal choke for using slugs.

Let me know who you are going to get to do it, and we'll send mine along too.

Ted

 

[DGY]

Thank you Ted!! And really I think you are better placed than me to choose a smith!!