Blackpowdersmoke

Well,

I'm not an in-line guy but I went with my gut instinct on this one and voted that the "flame channel was too large" and I see that I ended up in the 40% who chose that. Who knows?... Maybe the moon and stars were not properly aligned on that day for that combo and the blackhorn, foghorn leghorn, whatever, powder didn't like it!!

BPS

Muley Hunter

I'm not a fan of Remington anything.

I like and use the Federal primers.

Gm54-120

1) A 5/32 flash CHANNEL works fine in a variety of plugs even at higher pressure.

2) The anvils are not pushed back out of the cup so head space is fine.

3) Leak appears to be from between the anvil and cup which leads me to believe the cup is expanding just enough to allow some blowby.

4) I would like to see a Win209 primer shot from the same plug with the same load. The Win209 cup may be slightly larger OD and/or slightly tougher than the STS primer's cup.

If i can shoot loads all day that break 30Kpsi with a Win209 or Fed209A in a Savage plug and with my NULA using CCI 209s, i cant imagine its the ID of the flash channel and a sub 22kpsi load.

sabotloader

Scott, I think you have solved the problem... knowing Ron and his experience - I believe there is no way that he had a restricted 'flash channel' and the .032 'flash hole' is perfect. His powder load and bullet weight really should not have caused excessive blow back or pressure. I never voted in the poll but if your suggestion were added to the poll it would get my vote. Your explanation would also account for the metal discoloration under the rim of the battery cup.

I did not mic it - but I just dropped a STS primer in an Omega BP primer hole - it is quite loose... Remington's have a battery cup diameter of 0.240 while W209's are 0.242. Euro primers (Cheddite-Fiocchi-Rio's) run a little fatter at 0.243/0.244.

Nice job Sherlock!

Gm54-120

Yep, and my WAG is......

A Win209 or a Cheddite may not leak in the same area. Its also possible the primer pocket in the plug does not cover as much of the primer as say....My Savage or NULA plug covers. The NULA plug for example covers and supports the entire primer.

The more the primer protrudes from the plug, the less support it has. (obviously)

Its also my opinion that the Win209 primer cup is a bit tougher than some others. It may not swell as much. They seem to handle the higher pressures of Savage loads better than some primers.

I would have to agree, Ron appears to be pretty thorough when it comes to ML maintenance. It would be unusual for him to allow his flash channel to get too dirty. That would have been my pick if he was not the OP.

ronlaughlin

Did some shooting this morning with 3 different primer brand. Once again the shooting began with the same cold clean 45 caliber Omega rifle, and breech plug. The same bullet, sabot, and powder was used as in the original post. The breech plug' flash hole has now grown to 0.033". The flame channel is still 5/32". Before the breech plug was installed into the rifle, it was shortened 0.020", which reduces the head space, and necessitates the use of an o-ring. There was zero blow by around the nose of all three primer brands, because of the seal provided by the o-ring. However the STS leaked. Neither the Federal, or the Winchester leaked.


After the 10 shots, the breech plug was removed in the field, yes a tool was needed, and replaced by a brand new factory breech plug. No o-ring was used in this shiny new breech plug. Using the same load, three shots were taken with each primer brand.









Once again, the STS primers leaked. Neither the Federal 209A, nor the Winchester W209 primers leaked. There was some blow by around the nose of the 209A primer, but none around the W209.

ronlaughlin

This morning, those STS primers were tried in a different rifle, the Optima V2. The load was the same as in the OP; 200g Shockwave, and 115g Blackhorn. The sabot needed changing to Harvester dark blue, because the Optima is a 50 caliber. Note, there is zero leakage through the primer!



Then the notion came to try a heavier bullet, and see what happened. There were some 300g XTP rolling around in the truck, so they went into the rifle. The primer stuck in the breech plug. The load was 115g Blackhorn, 300g XTP, Harvester short black sabot, and the STS primer. All three times, the primer stuck tight in the breech plug, and required a leatherman. The primers show the marks on the rim, which were made by the leatherman tool. Even using the tool, removing the primers took a bit of effort. Note, the primers didn't leak.













The previous 6 shots were all made with an o-ring in the primer socket of the breech plug. The next 3 shots were done after removing the o-ring from the primer socket. There were no more XTP, so 300g Deep Curl from last hunting season were used instead. The load was 115g Blackhorn, 300g Deep Curl, Harvester short black sabot, and STS primer. These primers could be pulled some out of the breech plug, but fingernails were already busted up from the previous primers, and the leatherman was handy, so the primers were easily pulled with the tool. Note these STS primers didn't leak.

Omega218er

I use STS primers in an Omega with 80 grains of Blackhorn and 300 grain XTP's and they have never leaked.

ronlaughlin

Makes sense.

ronlaughlin

• 1. Chances the flame channel was plugged are near zero; the rifle was cleaned before the shoot.
  
  2. Never have seen a plugged flash hole from shooting Blackhorn... probably over 35 pounds have been burned.
  
  3. The flash hole was 0.032", which many feel is perfect, not a problem... not too large.
  
  4. It seemed the head space might be too tight, but the next day the primer still leaked when the o-ring was removed... didn't seem to be the problem.
  
  5. Doesn't seem the head space would be too large, after an o-ring was added, plus the primer anvil didn't come out of the cup.
  
  6. The flame channel wasn't too small; it was larger than new... at 5/32".
  
  7. Enlarging the flame channel would reduce the pressure on the primer; doesn't seem an enlarged flame channel would cause the primer to leak.
  
  8. A flash hole larger than new, wouldn't seem to be too small.
  
  9. Too much powder is probably the best of the available choices.
  
  10. It was a cool morning, so the temperature wasn't too high.

Following is what i believe is the very best answer.