Very nice post. Thanks.

 

Wow! Thanks for putting all the effort into those tests!

One thing to be mindful of though: gas leakage due to expanded primer pockets can vary greatly depending on the particular brand/geometry of primer used. IOW the Nitros might have had better life had you used another brand.

 

Interesting post and info.... What were the loads, and was the same load used exclusively in all of the tests? Same primers for all of the tests? same shotgun for all of the tests?
{hs# :? :?

 

I must be doing something wrong, I only get 3-4 reloads from any hulls I load. It would be great if you could post the loading data you used for this test. I would be interested to see pictues of the uncrimped end and then the finished crimp and the primer/head of each hull at each number loading. I know that is a lot to ask, but for me it would tell the story of what you are loading and the condition of the hull before you load it and after you load it. Velocity testing at each reload number would also provide info on how extended hull reloads affect velocity of the payload.

 

Another thing you must consider is the fact that the case heads on the Gun Clubs are steel, whereas the Nitro 27's are Brass.

The steel case heads would seem to not stretch the primer pockets as easily as the brass Nitro's. I doubt primer brand would change that.

Even so, the cases with the brass case heads are IMHO better reloads for ease of reloading and easier ejection from guns after firing. Not a big factor with all guns but important in some.

DLM

 

This is considered to be an undesirable condition(unsafe) and makes a sooty mess in the receiver.

Good test, but outside of soot in the receiver, what is the "safety" concern ?

 

This is considered to be an undesirable condition(unsafe) and makes a sooty mess in the receiver.

Good test, but outside of soot in the receiver, what is the "safety" concern ?

Good question. I have never seen or heard of a safety problem with minor leakage around a shotshell primer.

Loose seating primers can be a problem for autoloaders by falling out when ejecting, and winding up in the trigger group and rendering the gun inoperative.... But safety?? No way.

DLM

 

Good question. I have never seen or heard of a safety problem with minor leakage around a shotshell primer.

Loose seating primers can be a problem for autoloaders by falling out when ejecting, and winding up in the trigger group and rendering the gun inoperative.... But safety?? No way.

DLM

+1. No safety issue at all.

 

I would think it would cause a pressure reduction

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I would think it would cause a pressure reduction

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If the VOLUME of pressure leaked were large, then yes, it could effect overall pressures. However, the amount of leakage there is so minute, that any reduction of pressure probably couldn't be discerned, even with the most sophisticated pressure equipment on the face of the earth.

It simply could not/would not, cause a reduction in performance.

DLM

 

I assume you used a USA manufactured primer in your tests. Have you considered using a Euro sized primer, which are slightly larger in diameter, than the US made primers to continue testing? They might just seal better in the expanded primer pocket enough to get the nitro's to 15 reloads.

 

To answer a few of the question and comments:

The same load was used for both tests with the same components, here is the load:

CCI 209
17.2g ClayDot
CB1100
.9 oz of #8 or 8.5 lead shot(depended on which bag I opened at the time)

It is .9 oz because that is as close as I could get to 1oz and have it drop consistently. The side benefit was that the crimps were a little better. Sorry, no photos of the finished shell, just picture in your mind a sooty factory crimp.

I don't feel that the blow by was all that unsafe, but it would depend on how your gun locks up. I shoot an Winchester O/U with nicely machined flat receiver faces. It locks up tight but not gas tight, there is potential for hot gasses to blow in you face. Interestingly, my CZ O/U has groves cut into the receiver face to create a path out the side of the receiver for any blow by. However if you have an auto loader where the bolt face is covered by the receiver when in battery, I don't think that there is any major safety issue at all. Not like popping primers in high power rifle.

I feel that the brass base vs steel base is the difference. I think the the brass stretches a bit more each firing, whereas the steel doesn't stretch as much. Pure conjecture on my part, as I have no proof of this.

Changing to larger primers would probably work but that would have changed the experiment.

As for all the other tests that have been suggested, sounds like a good project, go for it.

 

Does primer blowby cause breechface erosion or does the flange effectively deflect the hot gases from harming the breechface?

I know that it is a problem with rifle and pistol primers but maybe it's not a problem with shotshell primers?

 

Not sure what the hot gasses do in a shotgun. The pressure is much lower so I would think that a shotgun shell would do less damage. The only blown primers I have ever experanced was with my AR-15, a hole where the firing pin hits. This blows hot gasses into the tip of the firing pin. Sometimes a chipped tip will do this too. I always carried extra firing pins when I shot a match.

 

What do you think that the STSs would do compare to the GC or Nitros? thanks

 

From what I understand the STS(green ones) and the Nitro's (the gold ones) are exactly the same except for the color. Some of my fellow shooters refer to the gold ones as STS Nitro's. So, I would think that ether hull would have about the same results. But, for any of them(GC's, STS, Nitro's), load them about 8 times and toss them and you'll be good to go.