Reloading Vectan A0 in 12 gauge

[neutron619]

Hello chaps.

I just ordered my first lot of reloading kit from Clay & Game. Very excited about getting started. Before I start, I will say that C&G given me very good customer service over the course of several weeks to help me work out which bits I need to buy and I recommend using them if you can - and no, I haven't been asked to say that, but given how much time they've spent answering my amateurish questions lately, it's the least I can do.

Anyway - I've bought stuff for a 16ga load and a 12ga load. I've got the recipe for the 16ga load sorted, but I'm having trouble with the 12ga load. I'm hoping some of the resident experts can help me sift through the data and sort it out.

I've got the following for Vectan A0 in an 70mm Cheddite / CX2000-primed case:

Gualandi:
12 / 70 / 616 or CX 2000 / Plastic Wad / 1.80-1.90g / 38-39g / STAR

Folkstone Engineering Supplies:
12 / 70 / 616 / 1.85g / Fibre Wad / 36g / STAR

Nobel Sport:
12 / 70 / CX2000 / 1.80g / Plastic Wad / 40g / STAR

Clay & Game:
12 / 70 / CX2000 / 1.62g / Plastic Wad / 36g / STAR (8pt)

Ideally, I'm looking for 36-38g of shot on top of a fibre wad at 1150fps-1200fps, though none of those recipes give velocity information.

My thinking is along the following lines:

• The Clay & Game recipe seems a bit conservative, compared to the others, but it does give a pressure of 727 bar which is close to the 12 gauge limit. It also uses an 8pt crimp, which I assume is to keep the pressure down?
• The above said, the NobelSport 40g load also gives a pressure - of 700 bar. This seems contradictory.
• The use of a fibre wad as opposed to plastic should lower the pressure a bit, and maybe give me the option of a touch more powder or shot. I know the plastic wad dimensions and can substitute an over-powder card and fibre wad.

I'm sure I must be missing something here, but on the basis of the above, I'd say a middle-of-the-road approach would be something like:

12 / 70 / CX2000 / 1.80g / Fibre Wad & Nitro Card / 38g / STAR

Questions:

• Does this seem reasonable, or have I - as I suspect I might have done - missed something about the Nobel Sport and Guialandi data which means that they are for a higher pressure limit than the 740 bar I see referenced all over the place?
• Can anyone tell me what I should actually take as the "maximum load", since they seem so varied? I can then at least stay within those bounds and be safe. I'm not looking to lose eyes / fingers / my life here - just come up with a decent, heavy 12 gauge load in the 1200fps range.
• Should I risk a 6-point crimp, since the "hotter" data doesn't specify one, or stick with 8-point? I've ordered new cases, so it makes no difference to me really. Just rather be safe and keep pressures as low as possible.

Many thanks for any assistance you can give,

Adam.

Edit: Added ​comment about Nobel Sport data pressure.

​

Edited December 16, 2015 by neutron619

[Smokersmith]

What gun will you be using ... ?

 

 

The assumptions you've made seem reasonable ... especially looking at the Nobel Sport data ....

 

But I would always want a good safety margin if going off piste ....

 

So in a modern 3.5" semi I'd try it ...

 

... but I'd potentially look to make up 2 batches at 1.8, and 1.9 to send for proof if it was a standard 2 3/4" gun.

[neutron619]

What gun will you be using ... ?

 

So in a modern 3.5" semi I'd try it ...

 

... but I'd potentially look to make up 2 batches at 1.8, and 1.9 to send for proof if it was a standard 2 3/4" gun.

 

This is the hugely irritating thing. The gun is indeed a modern 3½" semi and I feel reasonably confident about making and using them in that gun. However, I'd rather have a shell - if it's possible to make one - that works for "normal" 2¾" guns too, so that I could put it down a double gun in future, if required, without fearing for my life!

 

I know we can't know for sure without sending to the proof house (how does that work, by the way?), but the fact that you've said that my logic seems reasonable is reassuring. Thanks

[MAB1954]

Hi.

 

You seem to have given this a lot of thought however I suggest you stick with a tested published recipe.

 

I think you are looking for a 12 gauge 38 gram lead load with fibre wad. If that is correct then just go with your FES recipe to start with using 36 grams however you will need the Fiocchi 616 primers but they are easy to get - well I can get CX2000 & 616's local up here takes a couple of weeks, but I doubt you live in the back of beyond like I do.

 

If you decide to use a plastic wad then C&G have a 40 gram lead load 1220fps/8400psi [580bar] using a Gualandi Super g 17 wad, if you want the recipe pm me.

 

I am sure there are other tested loads for Vectan AO maybe some will come along on here soon, the above is just what I have noted down. Good luck and be safe - tested loads only.

[hakapiken]

The italian loads allways use new hulls. Once fired hull will give more pressure. If using once fired hulls, back Down 0,10g on the powder. For a 12/70 load the Italians allways crimp/Close at 58mm when using a star crimp. If Your COL i over 58mm you will have less pressure. Under 58mm and the pressure rises 50-100bar fast. The loads from Guilandi lists two loads for both powder and shot. The higher load is winterload.

 

J.A.

[neutron619]

The loads from Guilandi lists two loads for both powder and shot. The higher load is winterload.

 

J.A.

 

Many thanks for your observations and particularly the one you've listed above - I'd been struggling to work out what the X.XX / Y.YY loads were (i.e. why are there two different loads that are equally valid) and you've just explained that to me, so thank you.

 

Thanks also to MAB1954 for his comments - I'll send a PM shortly.

[hakapiken]

Forgot to say: The Guilandi wads (Super G) gives about 30-40 bar higher pressure than B&P Z2M wads.

[Cyrus1988]

I've used the proof house a lot this year but have driven up and dropped the cartridges in myself each time. Can't find any delivery company willing to take cartridges other than TNT but then you need to set up a business account with them.

 

The proof house tests 20 cartridges in lots of 5,10 or 20. So you could load 4 sets of 5, 2 sets of 10 or 1 set of 20. Obviously the higher the sample number the more confidence in the results but I tend to use 4 sets of 5 for initial screening. You give them the recipe of each batch and I've always loaded an extra couple for each set just in case they get a misfire/technical malfunction so it doesn't mess with the final data. They usually take about two weeks but depends on how busy they are and I paid £45.60 for the last testing (20 cartridges) I had done.

Give them a call and ask for Wayne, he's the boss and loves to talk about it all.

[sitsinhedges]

Data without pressures isn't really data. If you can't get reliable data it's best to carefully make up what you want to shoot and send them to the proof house then you will have a realistic idea of the performance of exactly what you are making. Testing 20 shells currently costs £45.20 and you can do 4 batches of 5 to cover a broad range of possibilities.

[rbrowning2]

The italian loads allways use new hulls. Once fired hull will give more pressure. If using once fired hulls, back Down 0,10g on the powder. For a 12/70 load the Italians allways crimp/Close at 58mm when using a star crimp. If Your COL i over 58mm you will have less pressure. Under 58mm and the pressure rises 50-100bar fast. The loads from Guilandi lists two loads for both powder and shot. The higher load is winterload.

 

J.A.

Out of interest what factual data do you have to confirm that once fired hulls will give more pressure?

I would have thought the crimp would be weaker than for a news hull and hence less pressure as crimp plays an important part in the resulting cartridge pressure.

 

Rb

[roughshooter]

Well I will be ready to be shot down but continually sending slight variations off data to the proof house is a very expensive way to do it. Most published data has a safety margin built in and a 5% aria toon is not going to blow you up esp on 12g lead loads as pressure is rarely that high.

Just my thoughts - spent a lot of cash this year at proof house but mainly steel loads

[sitsinhedges]

I tested some A0 in 20 gauge. All the internet data, Nobelsport, Guilandi etc state 23grains for 28grams of shot. It actually failed proof at 21grains. Now it probably wouldn't have blown up a gun at 21grains even though the average pressure was 854bar and the highest 972 bar but Christ knows what the pressures would have risen to with the full stated dose of 23grains. Take nothing for granted. Dropping the powder 1 grain and the shot 1 gram brought this nicely into proof and it is a superb load at that.

[hakapiken]

I tested some A0 in 20 gauge. All the internet data, Nobelsport, Guilandi etc state 23grains for 28grams of shot. It actually failed proof at 21grains. Now it probably wouldn't have blown up a gun at 21grains even though the average pressure was 854bar and the highest 972 bar but Christ knows what the pressures would have risen to with the full stated dose of 23grains. Take nothing for granted. Dropping the powder 1 grain and the shot 1 gram brought this nicely into proof and it is a superb load at that.

 

Was this once fired hulls or new hulls? How do you crimp and to what COL?

 

J.A.

[neutron619]

Chaps,

 

Many thanks for the information on the proof house and related costs - much appreciated. Birmingham is a bit of a trek, but manageable, so when I've worked up anything I can't find a pressure value for, I'll think about sending a batch over to them.

 

I'm slightly concerned to hear sitsinhedges's experience in 20 gauge and I'll look forward to any reply he might give to hakapiken with interest.

 

One of the other members here has kindly provided me with some data for a load very similar to that which I want to manufacture - with pressure data as well. However, there does seem to be a wide range of opinion as to what pressures are produced, even amongst similar or identical data. It appears that the same powder load, shot load and primer can produce wildly varying pressures, which it is difficult to account for. Does anyone have any thoughts on why this might be?

 

Thank you again for your input - if I've forgotten anyone or missed anything I'll reply again.

 

Adam.

[hakapiken]

Proofed load data is out of interest if they say nothing about crimp length and what kind of hulls being used. Once fired or new.

That is the god thing about Italian load data. You know they always use new hulls and the crimp is allways 58mm for a 12/70. As sayd before, It is a well known fact that once fired hulls wil have higher pressure than new. The crimp length also make pressure vary wildly if it is not constant. Yes, there is differences in powder batches. Therefor it's a god idea to back down on the powder. The difference in pressure between sg and z2m wads is also a well known fact.

 

If you have profed data with a given speed (v1 or v2) I recomend using a chonograph, start low on the powder and work up the load to the desired speed (proofed speed). 0,05g powder +/- ~ 8ms.

 

J.A.

[sitsinhedges]

I tested some A0 in 20 gauge. All the internet data, Nobelsport, Guilandi etc state 23grains for 28grams of shot. It actually failed proof at 21grains. Now it probably wouldn't have blown up a gun at 21grains even though the average pressure was 854bar and the highest 972 bar but Christ knows what the pressures would have risen to with the full stated dose of 23grains. Take nothing for granted. Dropping the powder 1 grain and the shot 1 gram brought this nicely into proof and it is a superb load at that.

 

Was this once fired hulls or new hulls? How do you crimp and to what COL?

 

J.A.

 

None of the data gives a closed length for the shells and we don't generally bother with this over here. Even though I offered this information when I proofed the last lot it wasn't included on the data sheet. Instead we generally use crimp depth as a measure and 1.5mm is the generally accepted crimp depth for a standard cartridge with a deeper crimp likely to raise pressures. The shells were once fired 70mm Cheddite.

 

Personally I would expect used shells to give lower pressures. After that there are endless variables.

[rbrowning2]

, It is a well known fact that once fired hulls wil have higher pressure than new.

J.A.

Sorry to be so negative but "well known fact" is not very scientific, we get told so much miss information or myths or known facts like copper shot is better than plain shot etc but without the hard data I am with sitsinhedges I would expect the pressure to be lower with used hulls, but happy to be proved wrong.

 

Have you the data i.e two sets of cartridges test fired both identical except the fact that one lot is new hulls and the other used?

[wigeon jim]

I once put two identical loads over the chrono, one with a new case and one with a once fired case, the once fired cases were 100+ fps faster. Jim.

[sitsinhedges]

I once put two identical loads over the chrono, one with a new case and one with a once fired case, the once fired cases were 100+ fps faster. Jim.

 

Thing is one shot means nothing, you could have achieved the same result with two of the same shell, especially if the recipe wasn't an efficient one.

[Guest cookoff013]

But I'd be inclined to agree with sits. Take nothing for granted

 

What needs to be realised is that loads vary in pressure. Varying pressures cause the stats to fail. Adding more powder can increase pressures. It still may vary. Too close and over the limits of variance.

So there are good loads and bad loads. Still safe though. Bad load being it is variable in pressures and still passes specifications.

 

Gualandi data originally had a disclosure, reduce powder charges 10% for guns with weak actions.

This I took as those published loads are hot. That is very advisable !

 

I am still learning. And testing. I got some on in test at the mo.

 

Reloading is a minefield sometimes. What I'm trying to do is second guess the variability. I produced a decent load by accident once.

 

Edited because it sounded like I was bashing someone, when I wasn't. It's these new dentures.

Edited December 16, 2015 by cookoff013

[hakapiken]

This is not easy and not exact science to many variables.... Starting to Get off Topic here...

I don't have prooofed test to show this but I have done much speed testing. I use oncefired hull and a friend of mine use new hulls. Same load, same primers, cheddite hulls, same crimp dept and same length (58mm) The once fired hulls allways gives higher velocity. We have tried this test using several different powders. The result is allways the same.... And the result of higher pressure. I Get the same speed with 0,10-15g less powder. My friend has been reloading shotgun shells for allmost 40 years. I think he known what he is talking about. He also had this "fact" confirmed by a moderator on an Italian forum who own and use professional proof equipment. Crimp dept is important but if the length vary the pressure wil not be consistant.

 

I think consistant powder messuring, consistant lead messuring and the use of a chonograph is important when developing new loads.

 

Regards

J.A.

[hakapiken]

Good articles on shotshell pressure

 

http://randywakeman.com/Why_Shotshell_Published_Pressures_are_Meaningless.htm

 

http://www.shotgunlife.com/shotguns/tom-roster/important-information-about-shotshell-pressures.html

 

J.A.

[rbrowning2]

Hakapiken, you are confusing high velocity with high pressure this is not always the case, several of my loads sent to the Birmingham proof house have shown that you can get high velocity with low pressure and any mix, I do not think their is a direct relationship between velocity and pressure.

 

For example

velocity v2.5. 395.38. P1 pressure 722.17 bar

Velocity v2.5. 385.24 P1 pressure 734.62 bar

 

Wider differences are possible this was just the first report I took out of the draw.

 

Sorry to go off topic but I think safety is important.

[neutron619]

Thanks both for the further input.

 

With more load data turning up from various places I'm getting a good idea of what's hot and what's not as far as this 12 gauge load goes, so I'm currently planning to load

 

12 / 70 / CX2000 / 1.75g / Fibre Wad & Nitro Card / 38g / STAR

 

as a starting point. This is effectively the same load as my original "middle of the road" assumption, but with a slightly reduced charge (from 1.80g to 1.75g).

 

This new load comes from published data I've received for a 40g load where the shot charge has been reduced by 2g (which should reduce pressure) and where the plastic wad has been exchanged for nitro+fibre (which should reduce pressure). There are a number of loads "around" it for which I have published data, some with less shot and more powder, others with more shot and more powder, so I think I'm being appropriately cautious.

 

Many thanks to hakapiken for the interesting articles - I completely take the points about safety and about wearing out guns faster than necessary through mild overpressure - but they've set my mind at rest to some degree. 55000psi to blow up a shotgun? It doesn't surprise me at all and I'd be surprised if anything anyone here has ever loaded by mistake would have reached a third of that. Still - not a reason to be cavalier about it.

 

Since I'll be using a 3½" semi with the 12 gauge loads to start with and, in future, a 12ga Baikal SxS when I can find one that fits me the same as my 16ga (i.e. both strong, well-built guns - not posh English / Damascus steel boxlocks), I'm going to try loading some of the above carefully and seeing how they pattern. If I'm pleased with the results, I'll taken them to the proof house and adjust as necessary according to what the results might be. There is of course the possibility that they'll take half a grain or so extra powder to compensate for the reduction in pressure, but I won't be attempting that without data to back it up.

 

Thank you all again for your input.

 

Adam.

​

[Guest cookoff013]

you have assumed that nitro and fibre may reduce pressures....

the main and effective way to remove pressure is to reduce powder charges. knocking off 10% on a upper limit load probably wont change the internal ballistics that much. not only that the recipes still may fit together well.

 

hey - load safe !