[stewartb]

Hi there. Can anybody tell me how do the chokes as described in the manual for a Silver Pigeon S match up to the decriptions I am more familiar with. i.e, full choke, 3/4's, 1/2, 1/4,1/8, Full Cylinder etc

Manual

Full (ok I get that one)
Improved Modified
Modified
Improved Cylinder
Cylinder (that one too)

So is Modified 1/4 choke or half? or is Improved cylinder 1/4 or 1/8 or is improved modified 3/4's or 1/2 choke etc.

Anyway I'm sure you know what I mean.

Many thanks

 

[MrBen]

¼ choke would have a restriction over the bore of 0.010"

½ choke would have a restriction over the bore of 0.020"

¾ choke would have a restriction over the bore of 0.030"

And full choke will have a restriction over bore size of 0.040"

The above info is from this source: http://www.trulockandharris.com/faqs.htm#howchoke

The US system, which is the same as Beretta's designations:
Skeet .005
ImpCyl .010
LtMod .015
Mod .020
ImpMod .025
LtFull .030
Full .035
XF .040

 

[0deuce0]

I put together this choke "cheat sheet"... All of the information except for the % and constriction came from my UltraLights manual. Anyone have a place I can post it to share? If you want to see a copy let me know, maybe it needs some corrections...

tom

 

[Just Bill]

MrBen,

I have been lurking and reviewing your posts on chokes. Thanks. You have helped straighten me out on the Beretta chokes. I have been shooting for years and always pattern my guns anyway, but I am still confused about one thing.

I just bought a new Silver Hawk 12 ga. with pistol grip and 26 inch barrels. The 2005 catalog says on page 44 that the 471 chokes are OCF and that the 471 has "Optima-Choke Tubes on mobilchoke barrel." I do not see how this can be. The Optima barrels are overbored to about .733 verses about .723 for the Mobilchoke barrels. Plus, I understand that the Opti-Choke barrels have a larger OD.

My choke tubes mic just about right for Opti-Choke tubes. So, if the barrel is truly a Mobilchoke barrel, the constriction will be way off. I will continue to look into this, but any help will be appreciated. By the way, the patterns are pretty well on and the forcing cones have been relieved.

Just Bill

 

[Seamus O'Caiside]

Welcome to Shotgunworld, Just Bill.

Well darn, your very first post and you have already stumped me! It must not be hard to do.

I'm not familiar with the Beretta SxS guns. I also noticed that statement "Optima-choke tubes on Mobilchoke barrel" and wondered how that was possible.

I just don't know the answer, but not knowing rarely stops me from expressing an opinion, so here goes:

My guess - and it is only a guess - is that this model has true backbored barrels. In other words, Beretta may have taken barrels designed for the MobilChoke system and bored them out to the Optima bore diameter, so they can fit Optima Chokes. The result would be thinner barrel walls and lighter barrels. This is in contrast to the Optima barrels on semi-autos, which are larger in their OD as well as ID, and therefore are heavier than the MobilChoke barrels.

It is easy to determine which kind of tubes the gun has. Just compare them to this pic from the Beretta USA website:

I assume your choke will be marked "Optima-choke". You said they pattern right, so I assume your bore is about .733, not .723. Try to find someone who has a bore gauge and can measure the bores for you.

But you know what they say about "assume": it makes an "***" out of "u" and "me". The real answer requires that you call or e-mail Beretta USA and ask them what the heck that means. You can e-mail them by going here http://www.berettausa.com/customer/support.html and hit the "ask a question" tab.

If you get an answer from them, please let me know. Thanks.

 

[Just Bill]

My chokes are definitely like the one in the center of the picture. They say Optima on them and mic (as close as I can mic them) at both ends like you say the measurements are on Optimas so my barrels must be the larger ID barrel like the Optima barrels.

I also have a problem so I will email Beretta and see what they say and let you know. Thanks

The problem is that with target loads, one ounce and 1 1/8 ounce loads, about 3 times out of 25 the left barrel (2nd barrel) will not fire after I fore the right barrel. After the first shot, I can release and pull the trigger several times and nothing happens. This wrecks havoc on doubles :>) I can switch the barrel selector to the left barrel and it will then shoot. This never happens when I fire the left barrel first (the right barrel always fires when it is the second barrel.

Just Bill

 

[Seamus O'Caiside]

From the way you describe it, it sounds like the second (left) hammer is not falling at all when you have that problem. The single selective trigger on the Silver Hawk is an inertia trigger, meaning it needs a bump to set the second trigger. That bump can come either from recoil or from bumping the butt against the ground (or with the palm of your hand). On O/U's with inertia triggers, failure to fire the second barrel is often caused by malfunction of the inertia block. The next time it happens, if you are in a situation where it is safe, try bumping the butt on the ground or your knee, etc while being very careful which way the muzzles are pointing and pull the trigger again. If a sharp rap on the butt will set the second trigger, you know it is an inertia block problem.

A thorough cleaning of the action might help, even if you haven't shot it much. They sometimes come from the factory with a gummy lubricant which can cause problems, and the factory is not always good about cleaning off bits of metal from the manufacturing operations. That model has a stock bolt to hold the buttstock onto the frame, so it shouldn't be hard to remove the stock. The O/U's use a 6mm hex (Allen) wrench to loosen the stock bolt, and I would guess the SxS does also. If you haven't already done it, remove the stock and clean the action thoroughly. You could spray it with brake parts cleaner or soak in kerosine or similar solvent. After it dries, spray with oil and either blow off the excess oil with compressed air or wipe it down thoroughly with a cloth. Don't leave enough oil to soak into the wood.

Don't let anybody tell you that you need to hold the gun tighter against your shoulder to make the inertia block work right. It is true that holding it tighter will sometimes solve the problem, but if the gun is working as designed, you can hold it any way you want to without trouble.

Let me know how it works out. Good luck.

 

[Just Bill]

I will try what you recommend tonight and see what happens. Your explanation sounds logical and was my thought at first. The thing that confuses me is that a couple of times I fired the first shot and the second barrel would not fire. I simply moved the selector switch to the left (second barrel), pulled the trigger and it fired. Now that seems weird. Usually, as you said, you have to bump it to set the hammer.

It is apparently an inertia trigger because when unloaded today, I pulled the trigger the first time, bounced the butt on the ground and heard the second hammer set then pulled the trigger again and the hammer dropped. So, how does the second hammer drop on a misfire when I simply move the selector to the unfired barrel. Sorry, lots of words and questions. I posed all this to Beretta at the address you gave me and will report the answer.

This is a great forum. Thanks for all your help.

Just Bill

 

[Seamus O'Caiside]

I can't tell you exactly how the mechanism works, but it is normal for an inertia trigger to fire after you move the barrel selector. What the inertia block does is shift a part (I don't know the correct terminology) from one sear to the other, and you do that manually when you move the barrel selector. Moving the selector is an alternative to bumping it.

I am becoming pretty convinced that your problem has something to do with the inertia block. I hope that a good cleaning will take care of it.