[ceh383]

There have been a lot of threads regarding component swaps. That's understandable given the component situation these days.
Many of these threads have centered around using Cheddite primers. There have been comments saying in general it's a safe swap. Others have said Cheddites will raise chamber pressures, some say by 2kpsi.
This got me interested so I sent two loads to Precision Reloading for testing, one 12ga load and one 28ga load.

The 12ga load from Alliant;
Rem Gun Club hull
Win 209 primer
WAA12SL wad
1oz shot
18.4 grains Clay Dot powder
1250 fps
8,980 psi

The load sent for testing:
Rem Gun Club hull
Cheddite 209 primer (CX2000)
CB 1100-12 wad
1oz shot
18.1 grains Clay Dot powder

The powder charge was hand weighed, the shot came off the charge bar without any adjustment.

The results:

The pressure is consistent with the Alliant data, the velocity is up a tick but the SD is good.

The 29ga load from Alliant:
Win AAHS hull
Win 209 primer
CB 5034-28HS wad
3/4 oz shot
13 grains 20/28 powder
1200 fps
10,580 psi

The load sent for testing:
Win AAHS hull
Cheddite 209 primer (CX2000)
CB 5034-28HS wad
3/4 oz shot
13 grains 20/28 powder

As with the 12ga load, the powder was hand weighed and the shot came off the charge bar without adjustment.

The results:

On this load the pressure went up a little over 1500psi, but it still safe. Velocity went up nearly 50fps, but again the SD is good. For this load I think I will back the powder down to 12.5 grains and call it good.

Bottom line, if you swap components, get them tested to be sure of what you are shooting.

 

[Foxfire]

Interesting! Thanks for posting. I just picked up some Cheddite primers and I too have read they were a 1 for 1 swap.

 

[ceh383]

They seem to be in my 12ga load, not so much the my 28ga load.
I have seen other peoples data that looks like a straight swap in 28ga, just didn't work out that way for me..Perhaps wad seating or crimp differences.