Cheddite Primer pressure spikes

[Pete Lester]

From trapshooters.com. A poster had some loads tested and this stood out.

The first load with a Win 209 and 15.7 gr of 20/28 is listed on the Alliant Reloading Guide as being 1200 fps and 9370 psi.

The second load with a Win 209 and 16.7 gr of 20/28 is listed on the Alliant Reloading Guide as being 1250 fps and 10,490 psi.

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

https://www.trapshooters.com/threads/cheddite-primer-swap-test-results.918249/

[Aaron Beck]

Cheddite makes several flavors of primer. I am pretty sure we can only get the 2000 kind, but wonder if rst has access to the 1000. It seems like this might result in lower pressures but im not an engineer.

[Andrew Sacco]

Well this is fraught with all kinds of scientific holes. Did he measure the powder loads with a scale rather than just trust the bushing? I spent a lot of time measuring powder throws with an RCBS digital scale, and sure enough I varied quite a bit as much as I tried to be consistent. Chamber length compared to the manual? Hull? Temperature? How many times have we run a chronograph on our loads and we "average them" because they vary so damn much. I think we need a heck of a lot more detail before we say Cheddite cause pressure spikes. That's just MY opinion and I'm pretty new at this but I'll say we need more evidence.

[Pete Lester]

Well this is fraught with all kinds of scientific holes. Did he measure the powder loads with a scale rather than just trust the bushing? I spent a lot of time measuring powder throws with an RCBS digital scale, and sure enough I varied quite a bit as much as I tried to be consistent. Chamber length compared to the manual? Hull? Temperature? How many times have we run a chronograph on our loads and we "average them" because they vary so damn much. I think we need a heck of a lot more detail before we say Cheddite cause pressure spikes. That's just MY opinion and I'm pretty new at this but I'll say we need more evidence.

What makes the test results of reloads sent for testing by a member of Trapshooters.com more suspect then reloads tested by the members of the PGCA?

[Andrew Sacco]

It doesn’t. The list of things that affect pressure are the hull (how many reloads), powder throw, the crimp and we can go on. My point is how do you know it’s the primer that made the pressure higher or a combination of things?

[Frank Srebro]

On that Trapshooter thread; many replies but so far the OP has been reticent to reveal the lab or source that did the pressure testing. ?????

[Pete Lester]

I will continue to watch the thread and hope the OP provides that info. I doubt he is making up a story. One way or the other it would be good to know the facts.

On that Trapshooter thread; many replies but so far the OP has been reticent to reveal the lab or source that did the pressure testing. ?????

[Chuck Bishop]

I asked Alliant a couple of years ago about primer swapping, specifically swapping primers in 20 and 28 gauge guns. I wasn't concerned about 12 ga. because my pressures were in the 6k to 7k range. I asked them if using their published components, would it be safe to substitute only the primer? They didn't have the specific primer I wanted to use but they said they tested all the popular primers in their published loads and the highest pressure spike they observed was 2,500 psi. SAAMI service pressures are 12,000 psi for 20ga. and 12,500 psi for 28ga.

So, if you want to substitute a primer into their published recipe, add 2,500 psi to their data and if it's below SAAMI limits, you can substitute. They advised me not to do it in 28 ga.

[Pete Lester]

The poster on Trapshooters.com posted the following this morning.

"The testing was done at precision reloading. I didn’t post the pictures of the actual test results because I never posted pictures and need to figure out how. Just haven’t had time yet. Once I figure it out I will post on Georges thread once he creates it."

[Mike Koneski]

Cheddite makes several flavors of primer. I am pretty sure we can only get the 2000 kind, but wonder if rst has access to the 1000. It seems like this might result in lower pressures but im not an engineer.

RST buys primed hulls. I can't answer whether they can specify which primer or if they only manufacture shells with one primer (2000 vs 1000). My guess would be whatever primed hulls Cheddite produces they use one primer to keep costs down.

[Andrew Sacco]

I called Hodgon about primer swapping a few months back and he said what Chuck said. ADD or SUBTRACT 2500 psi and start with a load above 6500 psi (to avoid a squib) and below 9500 to avoid pressures too high.

[Billy Gross]

Not being able to find Win 209, I bought some new Cheddites (blue and pink box - alleged to be better that the old ones). I load Old Style Win AAs 28 Ga. with Claybuster Wads and 20/28 Powder. We contacted Alliant, and they said only load with Win 209 because the other pressures are too high. I think the real problem is they never tested anything else. Vista also owns Cheddite, and I asked why they never tested their own product - no answer. The folk law I hear in the internet is the Cheddites are OK for 12 Ga, but the pressures are too high for the small gauges. Also, a lot of guys on the interned say they load 13.0 Gr of 20/28, and all is good. So I just sent 4 sample loads to Pression Reloading to test:
13.2 Gr 20/28 with Win 209 primers
13.0 Gr 20/28 with Win 209 primers
13.0 Gr 20/28 with Cheddite primers
13.0 Gr 20/28 with CCI primers

All loads weighed on my digital scale - I will keep you guys posted when I get the results.
Billy Gross

[keavin nelson]

What Cheddite has to say about their primers:

[Pete Lester]

Vista also owns Cheddite, and I asked why they never tested their own product - no answer.
Billy Gross

Can you provide a reference, I do not see Cheddite listed among the brands owned by Vista.

https://vistaoutdoor.com/brands/

[Billy Gross]

OOPS - I meant CCI is part of Vista - They didn't list load data for 28 Ga AAs other than Win 209. Also, I sent the Cheddite CX2000 209 out to Precision Reloading for testing. Billy

[Chuck Bishop]

Thanks Billy, you saved me the trouble of having my loads tested.

[Milton C Starr]

I was looking at this chart earlier.
My 10 ga cheddites appear to have the 2000 primer as they are copper color.

[Mark Garrett]

There is too many variables to go willy nilly changing components in a published load.

Both those test show his loads increased by 3300-3500 psi , so I guess that info from Alliant to ad 2500 psi goes right out the window in this case.

In every case that I have had loads tested with Win 209 vs Ched cx2000 primers, the Ched primers have always had more pressure.

[Aaron Beck]

Hearsay has this increase as nominal, though that likely varies with powder type and other variables. Is that generally what you have seen Mark or is it more in line with the increase in the thousands?

[Billy Gross]

Mark - Can you post the results of your test data. I agree that we should not be making up our own recipes. But because of the unavailability of Winchester primers and the lack of data for other primers, we are forced to substitute to other brand of primers. I think changing primers would be OK if the Precision Reloading test data comes back within safe limits. My next step would be to further reduce the powder charge and retest if pressures are still too high. Billy

[Gary Laudermilch]

Hmm, hard to believe those huge pressure increases. I have always used Win 209 but now have a supply of Cheddites. I guess there is only one way to know for sure.

[Jim Thoma]

I reloaded with W209 and cheddite primers with same recipes and did not notice any difference in recoil loaded 20 gauge Winchester AA with unique powder, shot one box with the W209 and a box of cheddites and seen no difference.

[Milton C Starr]

I was just reading a thread on another forum where someone managed to get 14k psi with their normal load because they had over compressed the load, perhaps that could have happened in this case?

You want to see something sketchy look at primer swapping using a Fed 209A I think it was .

[Pete Lester]

Here are the testing data sheets on the 20 gauge loads in question that had pressures roughly 3500 psi higher with Cheddite primers than the same loading using Win 209 primers. They also increased velocity by about 100 fps.

For reference Alliant data for Win209 primer is:

The first load with a Win 209 and 15.7 gr of 20/28 is listed on the Alliant Reloading Guide as being 1200 fps and 9370 psi.

The second load with a Win 209 and 16.7 gr of 20/28 is listed on the Alliant Reloading Guide as being 1250 fps and 10,490 psi.

[Jim Thoma]

Will dropping the powder help with pressure ?

[Mike Koneski]

Will dropping the powder help with pressure ?

It absolutely should. One could use a different powder too. No need to shoot 1300 FPS loads. They won't make any bird more dead or make an XX on the scoresheet better than an 1160 FPS load will.

[Billy Gross]

Unless you test the undocumented load, you have no idea of what the pressures are. Pending the results from Precision Reloading, I will reduce my powder charge until I get acceptable pressures. I will take whatever velocity I get. Billy

[Keith Doty]

Identical loads, one in once fired Cheddite hulls primed with Fioche 616, one in new, primed Cheddite hulls. Unfortunately I cannot say which Cheddite primers were in the hulls as I bought them that way. Spit for difference.

[Keith Doty]

Got curious and dug out examples of a number of different gauge, new, primed, factory Cheddite hulls. 20 ga. paper and plastic, 16 ga. plastic, 12 ga. plastic, 12 ga. paper (no pic), 10 ga. plastic. I find a variety of sealer colors on the primers (no clue if that means something) and the 20 paper appears to have no sealer. All except the 20 paper have copper color primer bodies, the 20 paper is brass colored. Referring to Kevin's info, this would indicate all have the same primer but the paper 20.
In loading various "tries" that I had tested the 20 paper ran considerably higher pressure than identical loads in plastic with what I know to be Cheddite 2000 primers. Now, is this primer difference or case volume? As I haven't accurately measures case volume plastic vs. paper, can't say. That's on my "to do" list.

[Mark Garrett]

Hearsay has this increase as nominal, though that likely varies with powder type and other variables. Is that generally what you have seen Mark or is it more in line with the increase in the thousands?

Different powder , different hulls , and different payloads , they all vary nothing really nominal or lineal . Faster powders tend to spike more so than slower powders .

As stated crimp depth can make a big difference also.

[Gary Laudermilch]

After reading this thread and others on different forums relating to pressure increases with Cheddite primers it has raised some concerns. There are plenty of anecdotal comments that suggest Cheddites and Win primers are interchangeable. Data presented seems to indicate otherwise. So I decided it was time to do some testing.

My to to powder for 20 ga has been WSF for decades. I have shot in excess of 50,000 of the load published on the Hodgedon site in all kinds of weather and patterned them extensively. The only substitution I made was using a Claybuster 1078-20 wad for the Win wad.

So, I sent my standard load of 16,8 gr. of WSF off to Precision Reloading and just for the heck of it included a load at 16.3 gr of WSF. Both loads substituted a Cheddite primer for the Win.

The Hodgedon site lists 17,0 gr for 1200 fps at 10,500 psi.

The results are attached.

Addtionally, my son had 600 shells loaded with 20/28 and Cheddite primers so we sent them as well. Alliant lists his load of 15.5 gr at 1200 fps and 1010 psi with the CB wad.

All loads were scale weighed to be exact. In retrospect I wish I had included shells with the Win primer as a baseline and to confirm the published data.

Draw your own conclusions.

[Daniel Carter]

Gary, that is very concerning. I do not load to max. on anything but use that 20/28 load with a grain less and never thought it would be near that. Yes ,wish the Win. primer had been included.
We will have to be careful in that Cheddite seems to be the only primer available.
Thank you for doing this.

[MattHaney]

This thread got me thinking about the various Cheddite primers and published loads. I asked Hodgdon what primer their loading data assumes:

For loads that use Cheddite primers (Ched 209), is any particular Cheddite primer assumed? Cheddite currently offers 3 primers, CX2000, 1000 and 50. Does it matter which one is used for the published loads? Thank you!---Matt

Matt Haney

Help Account <hpchelp@hodgdon.com>
Mon, May 2, 10:20 AM (4 days ago)
to me

Cx 2000 is the one used for the data and the most commonly available for reloaders.

[Mike Koneski]

If you look at reloading specs such as in the BP Advantages manual, the listed loads for Cheddite primers only say Cheddite 209. There is no reference to CX2000, 1000 or 50 due to the reason Hodgdon states regarding accessibility. With those pesky lawyers involved with everything, you'd think if Cheddite 1000 or 50 were used for the data that it would be included in the recipes.

[Mike Koneski]

Gary, those are some snotty loads! Personally, whether hunting or shooting clays I'd keep my velocities at 1220 max with 7/8 oz payload.

[Randy G Roberts]

In retrospect I wish I had included shells with the Win primer as a baseline and to confirm the published data.


Gary that's a little concerning for sure. In an attempt to prod you into doing so I am in total agreement with your statement on sending your Win primer load in for testing. That would be the tell all in my mind for comparison purposes. If that load has never been tested this info you have just disclosed would make me a little timid about shooting them. Could there really be that much of a spike in this primer switch ? Test the Win load and find out, please ..... Thanks !!

[Gary Laudermilch]

I have no desire to load and shoot a load in excess of 1200 fps preferring something under. Because I trusted published data I never saw a need to test. That assumption may or may not be correct. In fact we do not know this test data reflects what goes on in a typical barrel. To that, note the bore diameter of the test barrel of .614, That is a bit tighter than a typical 20, at least the one's I own which are closer to .618. Not much difference but how much does it take to uptick pressures?

I do plan on submitting additional losds for testing and included will be my base load with a Win primer.

[Dan Steingraber]

Would lengthening the forcing cones be an effective way to reduce pressure and act as a bit of a saftey net?

[Dean Romig]

No, not appreciably...





.

[Harold Lee Pickens]

That load with 20/28 really got my attention. I use 20/28 exlusively now for my20 ga's. I would have thought that would be around 10,000 from the charts
I substitute cheddite for Win 209 in my 20 ga loads. I load 3/4 oz with 14 gr 20/28 and 7/8 oz with 14.5 gr 20/28, soft shooting loads that are listed at 1200 fps or under and 7200--7800 psi respectively per the data.

[Craig Larter]

I had my 20ga 3/4oz load tested with Cheddite cx 2000 primers and Unique 14.5gr. They came in a little hotter than I like so I dropped down to 13.7gr and I am having them retested.

[Daryl Corona]

That's a pretty consistent load Craig. It's interesting that the Alliant website calls for 15.4gr Unique at 1200fps and 8200psi. Somewhat alarming that Ched 2000 primer makes that much of a difference. I'm currently loading Universal Clays in my 3/4oz load just because I was able to buy 6lb of it and to save my 20/28 for my 28ga. I found a low pressure 7/8oz load and reduced the shot charge to 3/4oz which keeps it in a safe pressure zone. We have to think out of the box nowadays.

[Aaron Beck]

It seems like someone who knows the rst folks well would be able to discover whether they are using the cx 1000. Many of their other components appear to be what is conventionally available.

[Mike Koneski]

RST buys primed hulls so whatever Cheddite uses in them for primers is what they have.

[Craig Larter]

I have only had five of my loads tested with the Cheddite CX2000 primers in 20ga 3/4oz Unique,12ga 3/4 oz Clay Dot, 12ga 1/8oz Red Dot,10ga 1 1/8oz Red Dot and 8ga 1 1/2oz Clays. I'm finding as a general rule I can reduce the powder by 1.5 gr to 2gr from published data (with WW 209 or Remy 209) and get very acceptable pressures and 1150fps. The smaller the gauge the more sensitive from my experience.

[Gary Laudermilch]

I previously presented some 20 ga test data using Cheddite primers and the results were concerning, at least to me. So, I did some follow-up testing. My initial test set did not include a load that matched published data. This test set does. As previously stated I have shot in excess of 50k shells loaded with published data and never thought anything of it as I trusted the published data. The Hodgedon site lists the following load

Remington STS hull
17.0 grains of WSF
WAA-20 wad
7/8 oz shot
Win 209 primer
1200 fps
10500 psi

I submitted this load for testing. The only exception is I substituted a CB-1078 wad for the Win AA wad. So, not quite apples to apples but close. The first data set listed are the results. Not quite a match. Well, not even close. The second data set is one I did earlier with Cheddite primer. I repeated it here so you can make a side by side comparison..

The following two data sheets are with Cheddite primers with much reduced powder charges. The 15.0 load is a full 2 grains below the published data above or nearly 11% and while the velocity is approaching the published load the pressure is still well above.

This data was intended to serve my needs and curiosity. It may provide some insight for those of you that are forced to use Cheddite primers.

[Art Kirkwood]

Gary, as a new member of this forum, I would like to thank you for your work in testing the above 20 gauge loads. As a sub-gauge tube shooter, pressure excursions are important to me. I follow the reloading forums on SGW and Trapshooters.com. Your work is the first that I've seen in which a powder suppliers published load was tested. In the instance above, the results are way off from published data. This is a real eye opener, indeed. From the above 16.8gr data the w209 ave pressure of 12,138 psi and the C209 ave psi at 12,577 would in this case imply about a 450 psi difference in the primer switch and not 2500 psi that has been mentioned (at least in this case).

[Art Kirkwood]

I have no desire to load and shoot a load in excess of 1200 fps preferring something under. Because I trusted published data I never saw a need to test. That assumption may or may not be correct. In fact we do not know this test data reflects what goes on in a typical barrel. To that, note the bore diameter of the test barrel of .614, That is a bit tighter than a typical 20, at least the one's I own which are closer to .618. Not much difference but how much does it take to uptick pressures?

I do plan on submitting additional losds for testing and included will be my base load with a Win primer.

Gary, My Briley 20 ga tubes are 0.618 also and I agree that the test barrel 0.614 seems tight. The volumetric difference between the two bores is only about 1.3% which doesn't seem significant. What I wonder is how did Hodgdon measure the pressures of therir published reloads? How does their pressure test equpiment differ from what Precision is using to measure pressures? Your tests of identical WSF 20g loads except one used CX2000 and the other used W209 primers showed that there was about 440 psi difference in average pressure with the CX2000 being the hotter primer. The big question for me is how are the powder suppliers measuring pressures of their published recipes and how does it differ from how Precision does it?