12 gauge chamber length

Open discussion on Tungsten Super Shot "TSS" Handloading.

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Silvius
Posts: 7
Joined: Thu Sep 17, 2020 12:16 pm

12 gauge chamber length

Postby Silvius » Thu Sep 17, 2020 1:00 pm

Hello Gentlemen,
This is probably an ignorant question but after looking about a bit, I thought I had better ask it as I wasn't sure.

Tungsten can damage tight chokes, so presumably it can damage the forcing cone too? The best way to protect the forcing cone is presumably to use a full length hull, so that shot column and wad do not expand in the chamber only to have to contract a lot suddenly at the forcing cone? -If they never expand that much to start the contraction presumably puts less force on the forcing cone?

What do you do if you have a 3.5 inch chambered 12 gauge when TSS is so small in volume? I can see 2 ounce turkey load data out there for 3.5 inch hulls but I am not looking for a turkey load. Is it possible to sensibly get a "standard 12 gauge load" of say 1 1/8 ounces into a 3.5 inch hull or is something odd going to happen with all the fillers and buffer?

Am I just getting overly worried about the forcing cone? Is it better to just load a 2 3/4 hull and not worry about it?

Do you just have to use a gun you don't value much and accept a little damage?

Or is there good data out there that I can buy for loads of the range 7/8 to 1 1/4 ounces for the 3.5 inch hulls please? If so who do I buy the data from please?

Thank you.



Dave in AZ
Posts: 174
Joined: Thu Mar 10, 2016 1:38 pm

Re: 12 gauge chamber length

Postby Dave in AZ » Thu Sep 17, 2020 6:36 pm

Overthinking. No damage. Wad protects barrel. Forcing cone not at risk from pelletized payload... if a thin choke can handle it, which it can, then forcing cone is not an issue.

Everything you wrote is a 1st time ever read worry. I would say it is 100% just you, and completely a worry you have made up for yourself.
Sorry, just telling it like it is, no intent to offend.



Silvius
Posts: 7
Joined: Thu Sep 17, 2020 12:16 pm

Re: 12 gauge chamber length

Postby Silvius » Fri Sep 18, 2020 8:29 am

Thanks Dave. That is what I was hoping to hear. "Its OK just go ahead and make some cartridges up"

Its not just me though. I wondered where I had got the idea from and looked about a bit. This is a respected dealer in reloading components in the UK https://www.claygame.co.uk/tungsten-shot-pd449 Here they saying "Always use matching case length for your gun. E.g. do not use 2 3/4 in a 3 inch magnum as the shot will damage the forcing cone"

Has anyone had this damage or can others confirm it is just over caution please?

Thanks



Greg
Posts: 39
Joined: Fri May 31, 2019 7:25 am

Re: 12 gauge chamber length

Postby Greg » Fri Sep 18, 2020 8:59 pm

I started reloading with tss maybe 2 years ago prior to that I had exactly zero experience reloading. Here are some things I learned. I started with a brand new remington 1187 20 gauge. First misstep was using bb tss pellets in an 1-5/8oz, that cut grooves in the barrel that looked like straight rifling and destroyed a factory full choke. Solution was to back down to an 1-1/8oz load and use a choke no tighter than improved modified. Second misstep was using a load that was overpressure it was a 1oz steel and tss load. I'm no expert but I believe the excess pressure caused the tss pellets to pass through the wad and cause craters in the chamber of the barrel. Solution be cautious of information that you get. That gun is now sitting disassembled waiting on a new bolt as it was damaged by the over pressure loads.

With all that said the gun still fires and patterns great but sometimes fails to eject, my personal experience.

I wouldn't start with a gun I had some attachment to or an older gun.

No disrespect to Dave as he certainly has been doing this for longer than me and is much more experienced. I have learned quite a bit from his posts.



Silvius
Posts: 7
Joined: Thu Sep 17, 2020 12:16 pm

Re: 12 gauge chamber length

Postby Silvius » Sat Sep 19, 2020 10:08 am

Thanks for the warning Greg. This is the sort of thing I was afraid of. I had probably better buy a really cheap old gun to try loads in. I have almost no experience in loading shot shells. Just a few 0.410s because they are so expensive to buy. I have loaded rifle ammunition before though, so I hope I can pick up enough to manage OK.



Dave in AZ
Posts: 174
Joined: Thu Mar 10, 2016 1:38 pm

Re: 12 gauge chamber length

Postby Dave in AZ » Sat Sep 19, 2020 4:24 pm

Greg wrote:No disrespect to Dave as he certainly has been doing this for longer than me and is much more experienced. I have learned quite a bit from his posts.

No worries Greg, that is good info.
There are always a zillion unwritten caveats to any advice. Here are a few assumptions to my post:
1. Op said he didn't want turkey load, then mentioned 7/8oz to 9/8 oz, this lead me to believe he was looking at goose or duck tyle loads.
2. I assume all loads used will be tested with correct pressures.
3. I assume folks shooting tss will be using cylinder or very light chokes, based on the overwhelming preponderance of pattern reporting that little or no constriction works best with tss.
4. I assume pellet size will be based on targets correctly, so #7 or less for goose, #9 or smaller likely for ducks. This massively affects shot ability to flow thru constriction like forcing cone.
5. I assume loaders have read and are familiar with wad restrictions on pellet size. And are complying. This is critical to keep large pellets from rubbing thru wad and scoring barrels. For example, the csd series limits steel shot to #3 or smaller in 20ga.
6. I assume that if loaders ignore manufacturers warnings for what size hard pellet their wad can protect from, they are using alternate extra protection like a mylar wrap, or a wad inside a wad like Hal does with some 28ga wads stuffed in 20ga in some loads.
7. I assume loads are properly contained within the wad after setback, and loads are not made with super hard pellets sitting above wad where they might score barrels.
8. There is zero need for extreme speed or pressures using tss, I assume all loads are reasonable sub 1400fps speeds. If mixed with steel shot in a duplex, I assume 1550fps or less.
9. If tss steel duplex, I assume tss on bottom as most all reports give better patterns this way.

10. Lastly, in this particular post, I limited my thinking to forcing cone damage risk only, not barrel or choke. In this case, the only risk is that AFTER setback into the wad, as the wad exited a 2.75" hull in a 3.5in barrel, there was an extra 0.75in of chamber length that was 2 hull thickness wider than the barrel. The risk is the shot expanding the wad to this diam as it passes thru this .75in length, then being unable to be recompressed to correct barrel diam by forcing cone. This would lead to shot being forced thru wad and scoring cone.
....with correct size shot and loads as described above for .75 to 1.125 oz duck/goose loads, the risk is virtually zero imo.

I will absolutely concur that shooting #2 or larger tss will likely exceed wad push thru protection. Even more so if used in a max or overpressure load. Even more so if shot in a massive pellet load that exceeds what is normal with lead payloads in that hull and chamber.

If shot volumes and payloads and the wad/hull vehicle used to deliver them are. Lose to what the gun was designed and tested for, there should be little risk. There is nothing extra dangerous with tss vs steel, both have the same functional pellet compression, zero, when shot. The only difference comes from pellets getting outside the wad, or THRU the wad, when the tungsten is more likely to scratch.

Hope that info helps. This is also a good example to the OP that the more specific info you provide, i.e. exact loads you plan on shooting re pellet and payload size, speed, wad, etc, the more meaningful replies can be and with less unstated assumptions.
Best regards ;)



Silvius
Posts: 7
Joined: Thu Sep 17, 2020 12:16 pm

Re: 12 gauge chamber length

Postby Silvius » Tue Sep 22, 2020 12:26 pm

Thanks Dave,
I am going to load no 7 for geese.

I do want to get it right. I don't have much experience loading for shotguns. I have loaded rifle ammunition so I get the principle that I need to do things right but the niceties of shotgun wads will be new to me. I didn't know different wads had different limits for pellets. Thanks for teaching me this.

Interestingly I ordered some shot the other day. I decided not to go for buying some off a Chinese lady who said she would give me a fake customs slip saying it was worthless. Instead I bought some of a nice guy called Mark in Scotland for only a little more. First thing he said was "Have you loaded it before?" I said "No". He then next said "You need to watch chamber length". I wonder if this concern with chamber length is a British thing?

Mark told me that the issue with chamber length was that the slits in the side of the wad can open up as the wad goes from being fat in the chamber to being squeezed in the forcing cone and then a pellet may then get out. Mylar wraps make this a much lower risk of course. I will definitely use them.



Dave in AZ
Posts: 174
Joined: Thu Mar 10, 2016 1:38 pm

Re: 12 gauge chamber length

Postby Dave in AZ » Tue Sep 22, 2020 4:29 pm

This is a good point about small TSS shot getting through the wad slits! My impression of your post was that you thought there was a problem with the wad-contained shot hitting the forcing cone and not being able to flow thru, creating a hammer effect or something--that is what I was addressing as not a problem.

Somewhere up above I mentioned that you had to be careful that no shot got outside of the wad, maybe referring to not loading shot above the top where it could sneak down there, this is the same problem but via wad slits.

I can absolutely see that if you are using fine shot, some might escape outside the slits on that brief throat expansion. I am worried about it whenever I use TSS since I load the small pellets mostly, #8 to #10. It is for this reason that I always use a mylar wrap when doing TSS. With a mylar wrap, you won't have to worry ;)



Silvius
Posts: 7
Joined: Thu Sep 17, 2020 12:16 pm

Re: 12 gauge chamber length

Postby Silvius » Fri Oct 09, 2020 2:10 pm

Thank you Dave, so its the wrap that counts. Right I will order some before having a go.



Dave in AZ
Posts: 174
Joined: Thu Mar 10, 2016 1:38 pm

Re: 12 gauge chamber length

Postby Dave in AZ » Fri Oct 09, 2020 7:16 pm

Silvius, almost all food bags are made from Mylar. Mylar is just a brand name from duPont for a particular cross-linked polymer. You can order the wraps, but I always end up having to cut them anyways... OR you can just take some potato chip bags and cut them into strips of the right size. The absolute strongest thickest bags I have ever found are the Starbucks coffee bags, I would use them if I was using say #5 TSS or larger.

Another benefit of this is you always need to take up volume in the wad/hull, the TSS takes up so little space, so a nice thick mylar wrap is good to eat up volume and you don't have to stack 4 corks or whatever.




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