[Bandit67]

Can I ask what primers you swapped from and do you have the test numbers from those?

 

[gspbrowning]

I compared against the published primers from Aliant. 12 gauge Remington and 20/28 was Winchester.

 

[phatkaw]

Thanks for sharing.

 

[LowBrass366]

So what did the published data with w209 primers have the 20 gauge pressures being at?

 

[Bob_K]

Come on LowBrass366. You know how to use the Alliant website.
Alliant Powder - Reloader's Guide

 

[LowBrass366]

Come on LowBrass366. You know how to use the Alliant website.
Alliant Powder - Reloader's Guide

If I would have posted that “ I would have never guessed the results of 20 gauge “ ….. I would have included what they should have been….. So now everyone that read this far into the thread now has to go onto Alliants website and match all the components to draw a conclusion of what happened?

 

[George MT.]

I thought I would share some test data that I had performed with a cheddite primer swap. I was surprised at the 20 gauge results. Hope you folks find this useful!! I am glad I spent the money on testing.

Hull: GC 12 ga
Wad: CB1100
Shot: 1 oz
Primer: Cheddite
Powder: 18gr e3

Ave pressure: 10,260 psi
Ave velocity: 1327 fps

Same as above except 17gr e3

Ave pressure: 9662 psi
Ave velocity: 1290 fps

Hull: Win. AA HS 28 ga
Wad: CB5034-28HS
Shot 3/4 oz
primer : cheddite
Powder: 13gr 20/28

Ave pressure: 11,007 psi
Ave velocity: 1248 fps

Same as above except 13.5gr 20/28
Ave pressure: 11,906 psi
Ave velocity: 1273 fps

Now for the ass kicker:

Hull: Win AA 20 ga
Wad: CB1078-20
Shot: 7/8 oz
Primer: Cheddite
Powder: 15.7 gr 20/28

Ave pressure: 12,685 psi
Ave velocity: 1306 fps

Same as above except 16.7 gr 20/28

Ave pressure: 14,022 psi
Ave velocity: 1354 fps

Very significant increase in the 20 gauge. Glad I tested. Hope this helps answer the questions on safe primer swaps. I never would have guessed the results for the 20 gauge.

Hope this is helpful.

We will be putting up a thread that will be stuck to the top of the reloading section that will be for lab verified loads. THat way forum members will have access to this info in one spot. The posting member will be required to post their load data a long with pics/copies of the verified test done at a lab. Thanks George/Site admin.

 

[Nebs]

And the usefulness of comparing test data to published data is????

 

[LowBrass366]

And the usefulness of comparing test data to published data is????

Just to see the delta .

 

[Mt10us]

Thanks for posting, I haven’t loaded any 28 AA because of the lack of Winchester primers with 20/28 powder and no load data with cheddite primers. I can now load some up with the cheddites, AA hulls and the cb5034 hs wad.
Much appreciated!
Mike

 

[Nebs]

Just to see the delta .

It's an irrelevant data point.

 

[LowBrass366]

It's an irrelevant data point.

Maybe to you, but I would find it interesting to see if any of the data would reflect a trend within components.

 

[pheasantmaster]

Maybe to you, but I would find it interesting to see if any of the data would reflect a trend within components.

Why not look it up for yourself?

The OP has done spent his money to have the loads listed tested. My gosh, isn't that enough on his part?

 

[Mudmarshall]

Thanks for sharing, this is quite informative.

 

[Carl Brown]

Shotshell 20 Gauge 2 3/4-in. Winchester AA Plastic Shells 7/8 shot wt. Win 209 CB1078-20

Dram Equiv.​	Shot Wt. (ounces)​	Velocity (fps)​	Primer​	Powder​	Wad​	Grains​	Approx. psi​
---	7/8	1,200	Win 209	20 / 28	CB1078-20	15.7	9,370

Shotshell 20 Gauge 2 3/4-in. Winchester AA Plastic Shells 7/8 shot wt. Win 209 CB1078-20

Dram Equiv.​	Shot Wt. (ounces)​	Velocity (fps)​	Primer​	Powder​	Wad​	Grains​	Approx. psi​
---	7/8	1,250	Win 209	20 / 28	CB1078-20	16.7	10,490

Looks like a huge pressure increase over the win209 primers.

 

[Nebs]

Shotshell 20 Gauge 2 3/4-in. Winchester AA Plastic Shells 7/8 shot wt. Win 209 CB1078-20

Dram Equiv.​	Shot Wt. (ounces)​	Velocity (fps)​	Primer​	Powder​	Wad​	Grains​	Approx. psi​
---	7/8	1,200	Win 209	20 / 28	CB1078-20	15.7	9,370

Shotshell 20 Gauge 2 3/4-in. Winchester AA Plastic Shells 7/8 shot wt. Win 209 CB1078-20

Dram Equiv.​	Shot Wt. (ounces)​	Velocity (fps)​	Primer​	Powder​	Wad​	Grains​	Approx. psi​
---	7/8	1,250	Win 209	20 / 28	CB1078-20	16.7	10,490

Looks like a huge pressure increase over the win209 primers.

Yes, it "looks" that way.

 

[Carl Brown]

Yes, it "looks" that way.

Well if the OP would show a copy of the lab results then I would change the “Looks“ to it “Is”.

 

[fishrising]

Very interesting. This can matter to those of us who reload low pressure cartridges for some of our guns. Can we see the test sheets please? What was the sample size? Who did the testing? Tom Armbrust? Precision Reloading?

 

[RSVP410]

Thanks to George MT for arranging to post "verified" load data in a common fixed location. In addition, thanks to the OP for sharing the test data he had to pay for and then getting grilled on the merits of the data and presentation. I think the point was missed. While many have "done it your years", there is data that indicates substituting cheddite primers in some applications (ex. 20 ga. AA with 20/28) can significantly increase pressures. Not sure how long you can shoot a 20ga shotgun at 14,000 psi before you can't but it is wise to proceed with caution with Cheddites or any other primer unless you have published data. Your theory may vary. Cheers!