Back bored 12bore - Fibre Game Cartridge.

[wymberley]

4 minutes ago, Scully said:

Fair enough, but this is what I'd do below.....

 

 

Nah. If you need some choke for a 40+ yard pigeon with one ounce of 7s then a carp open IC isn't gouing to do it. Is it?

[TIGHTCHOKE]

24 minutes ago, wymberley said:

Nah. If you need some choke for a 40+ yard pigeon with one ounce of 7s then a carp open IC isn't gouing to do it. Is it?

I think that is possibly the most correct sentence you've ever posted!

[Scully]

1 hour ago, wymberley said:

Nah. If you need some choke for a 40+ yard pigeon with one ounce of 7s then a carp open IC isn't gouing to do it. Is it?

No, it isn't, but faced with not wanting to buy a non back bored gun, or being unable to sell said cartridges, then personally I'd just use them for close in stuff. That load through that choke would make a good bolting bunny combination. 

[wymberley]

2 hours ago, TIGHTCHOKE said:

I think that is possibly the most correct sentence you've ever posted!

Thank you, kind Sir, that's better than the, "Wymberley could do better and is below average I used to get many years ago" - still do come to think of it.

1 hour ago, Scully said:

No, it isn't, but faced with not wanting to buy a non back bored gun, or being unable to sell said cartridges, then personally I'd just use them for close in stuff. That load through that choke would make a good bolting bunny combination. 

As said, it's unfortunate that the photo's have gone. Yep, I could agree if we're just talking IC pattern, but you've failed to take into account the "abysmal" bit.

[Scully]

45 minutes ago, wymberley said:

 

As said, it's unfortunate that the photo's have gone. Yep, I could agree if we're just talking IC pattern, but you've failed to take into account the "abysmal" bit.

I'm unaware of the abysmal bit, but given the situation the OP finds himself in, personally I'd just dismiss it and carry on regardless. All my alternative suggestions have been quashed, so apparently there is no alternative. 

[wymberley]

1 hour ago, Scully said:

I'm unaware of the abysmal bit, but given the situation the OP finds himself in, personally I'd just dismiss it and carry on regardless. All my alternative suggestions have been quashed, so apparently there is no alternative. 

Or on the other hand the OP could try some of the suggestions made by Figgy in his comprehensive answer to the OP's question back on Page 1. The only suggestion I would add is that as I believe the chamber on his gun is 3" (76mm), then I'd go for anything in 2&3/4" (70mm) flavour avoiding the 2&1/2" (65mm) or 67/67.5mm in order to give himself the best chance.

[TIGHTCHOKE]

The OP needs to gain confidence in his current set-up, without it, it may mushroom in to massive self doubt!

[wymberley]

Hopefully, the answer given should assist in that and it's worth remembering that it can happen, not will. The biggest problem in this respect seems to be either the maker or the retailers - I'm not sure which. I've just read one report on the 525 Crown that says it's choked 1/2 and 1/2 to avoid the known problem of tighter chokes but another says the barrels are nominally bored to avoid a problem with poor patterns. Seems it's high time that the gunmakers and the cartridge loaders start talking to each other and if we've got to have 3" chambers as a matter of course then similarly we should also have 3" game cartridges and particularly if they're going to persist with the back-boring.

[Scully]

I'm still unconvinced this is something worth bothering about in the real world. I just don't see it as something which would make a noticeable difference anywhere but on a pattern plate. I know confidence plays a huge part of shotgun shooting, but can anyone honestly claim they missed this or that due to a felt wad cartridge in a back bored gun? 

[wymberley]

20 minutes ago, Scully said:

I'm still unconvinced this is something worth bothering about in the real world. I just don't see it as something which would make a noticeable difference anywhere but on a pattern plate. I know confidence plays a huge part of shotgun shooting, but can anyone honestly claim they missed this or that due to a felt wad cartridge in a back bored gun? 

Why do you think I persevere in posting on this topic? Getting towards the end of my Rottweil 6&1/2s I thought I'd change to 7s also in fibre - except there was no plastic obturator - and whereas I shot really well with the Maxus and the Rottweil I suddenly was making a right mess of things so reverted to the plate and bingo!

[TIGHTCHOKE]

Stop it, you're constantly making sense lately, I'm not used to this new you!

[wymberley]

3 hours ago, TIGHTCHOKE said:

Stop it, you're constantly making sense lately, I'm not used to this new you!

What you really mean is that you're finally starting to agree with me.

[TIGHTCHOKE]

I agree with your comments within this thread.

[Old farrier]

1 hour ago, TIGHTCHOKE said:

I agree with your comments within this thread.

 

So what are you exactly agreeing with? 😂

just asking as a few of us have lost track here 😏

[TIGHTCHOKE]

20 hours ago, wymberley said:

Nah. If you need some choke for a 40+ yard pigeon with one ounce of 7s then a carp open IC isn't gouing to do it. Is it?

 

20 hours ago, TIGHTCHOKE said:

I think that is possibly the most correct sentence you've ever posted!

 

14 hours ago, wymberley said:

Why do you think I persevere in posting on this topic? Getting towards the end of my Rottweil 6&1/2s I thought I'd change to 7s also in fibre - except there was no plastic obturator - and whereas I shot really well with the Maxus and the Rottweil I suddenly was making a right mess of things so reverted to the plate and bingo!

 

4 hours ago, TIGHTCHOKE said:

Stop it, you're constantly making sense lately, I'm not used to this new you!

There you go OF, all clear now?

[wymberley]

40 minutes ago, Old farrier said:

 

So what are you exactly agreeing with? 😂

just asking as a few of us have lost track here 😏

Hopefully, as we're well into three pages, the OP has all the information that he asked for and has been able to make a decision.

The whole situation is confusing. There is a consensus of opinion that back-boring can be detrimental to pattern performance when fibre wadded cartridges are used. There is an alternative view that notwithstanding the use of the word "can" as opposed to "will", because this phenomenon has not been experienced by individual shooters these shooters say it will (or does) not. To further compound the situation, the norm - even for those guns which the makers define as "game guns" - is increasingly for 3" chambers. I am not going to make any comment on the adviseability of shooting a 2&1/2" fibre wadded cartridge through a back-bored barrel having a 3" chamber. And now it gets even more complicated when one considers what might be the real reason why a manufacturer who has been very much in favour of the back-bore principal and who has made and sold many thousands of them has reinvented the wheel - it would seem - and introduced (?) a nominal bored version of one of his best selling guns specifically for use with fibre wadded cartridges and also one which is designed to overcome the known problem with the patterns from the tighter end of any choke selection. Eh?

Fortunately, having discovered that it can happen because it did beyond any shadow of a doubt about there being an alternative cause, I'm now quite content to carry on using my 2&3/4" chambered  SbS and 3" OU - which did need some fiddling to find a suitable cartridge to pattern to my needs - both of which conform to the standard 12 bore barrel diameter. As a result, one has to resist the temptation to say that as I, personally, have never seen any advantage by using a back bored gun or one with a 3" chamber when using the more standard English game loads, there isn't any.

[TIGHTCHOKE]

13 minutes ago, wymberley said:

Hopefully, as we're well into three pages, the OP has all the information that he asked for and has been able to make a decision.

The whole situation is confusing. There is a consensus of opinion that back-boring can be detrimental to pattern performance when fibre wadded cartridges are used. There is an alternative view that notwithstanding the use of the word "can" as opposed to "will", because this phenomenon has not been experienced by individual shooters these shooters say it will (or does) not. To further compound the situation, the norm - even for those guns which the makers define as "game guns" - is increasingly for 3" chambers. I am not going to make any comment on the adviseability of shooting a 2&1/2" fibre wadded cartridge through a back-bored barrel having a 3" chamber. And now it gets even more complicated when one considers what might be the real reason why a manufacturer who has been very much in favour of the back-bore principal and who has made and sold many thousands of them has reinvented the wheel - it would seem - and introduced (?) a nominal bored version of one of his best selling guns specifically for use with fibre wadded cartridges and also one which is designed to overcome the known problem with the patterns from the tighter end of any choke selection. Eh?

Fortunately, having discovered that it can happen because it did beyond any shadow of a doubt about there being an alternative cause, I'm now quite content to carry on using my 2&3/4" chambered  SbS and 3" OU - which did need some fiddling to find a suitable cartridge to pattern to my needs - both of which conform to the standard 12 bore barrel diameter. As a result, one has to resist the temptation to say that as I, personally, have never seen any advantage by using a back bored gun or one with a 3" chamber when using the more standard English game loads, there isn't any.

AKA re-inventing the wheel!

[wymberley]

14 minutes ago, TIGHTCHOKE said:

AKA re-inventing the wheel!

Pay attention, that man.

[Old farrier]

Far to complicated for me 

what gun are you talking about 

[JRDS]

Browning Crown I presume.

[Stonepark]

When reloading for my 410, the over powder card is normally almost air tight to the case (some times requiring 3 or 4 reseats to squeeze out the air) and is normally 5 or 6 thou over bore (circa 0.415/6) whilst the fibre wad is normally only 2 thou over (circa 0.412). 

Plastic wads tend to be spot on bore diameter at 0.410 or even down as far as 0.400 (i.e. slide easily onto the case) but often (but not always) have a bottom cup with a skirt which can expand to seal.

Will over boring a 12 bore to 0.735 make any difference with opc circa 0.740 and fibre wad circa 0.736?

It will take several microseconds longer to seal form the maximum seal as fibre wad has to compress as against the almost instant expansion of the plastic wad cup which is also closer to the powder pressure and therefore speed will be lower for the same powder charge but this is true of most fibre v's plastic cartridges.

It is unlikely on its own to significantly affect the performance of the cartridge/shotgun combo.

Now if your are progressing an over bore of 0.740 or greater, the cup of a plastic cartridge may prove to be effective in retaining pressure where the fibre cartridge would start to suffer due to failure of the seal.

 

[B525 LIGHT]

Ive deffinately encoutered it with Browning invector plus barrels. 

[Scully]

Too many 'may', 'can' and 'possibly' as opposed to 'will' and 'does' to make this an issue worth worrying about in the field in my opinion. A bloke in our syndicate owns a Browning but I can't recall whether it is back bored or over bored ( it is definitely one or the other ) but he's never mentioned anything untoward regarding its effectiveness on either clays or game. I will make a note of mentioning it when the new season starts. 

[super sharp shooter]

I have a Heritage with invector plus chokes so I'm assuming its back bored and to be honest can't notice any difference in it.

  

[wymberley]

Just nicked this from Guns On Pegs and it's written by Peter Schwerdt of EJ Churchill:

"For effective obturation fibre wad shells need to be matched to the length of chamber and shot in barrels that are not over bored. Most modern O/U shotguns sold today are over bored at 18.7 and have 3 inch chambers. The sooner clay shooting authorities ban plastic the sooner they will make guns that will suit the obturation for fibre wad cartridges and improve the cartridge itself to make it even more effective. Until that day plastic will always be better for high bird shooting."

Don't think I'll hold my breath, but just settle for what I've found works for me in my guns.