How many separate their 209 Primers by Length?

[tpcollins]

With 20-30 shots, one O-ring ought to last me 10 years.

No doubt some think they need to have primers at a certain length and diameter, but this reply I found in an online forum seems to make more sense than worrying about the primer’s length.

If it fits snug under the rim I would think it would be hard to get any blow by - but maybe it does.

I just measured my Winchester W209 primers - .243” did, .3005” length. My last shot was Dec 2019 (we could use any legal rifle during the last 2 Michigan Covid seasons) - and did not shoot prior to that ML season. One shot dropped a nice 10 point at 80 yards.


Posted December 7, 2014
The length of a primer has no significant affect on the fit of a shot shell Primer. The diameter just below the rim, where the primer seats in the case head is the critical dimension. These dimensions are as follows:

.240 = Rem.

.241 = CCI, Fed,

.242 = Nobel Sport, Win, Wolf,

.243 = Cheddite, Fiocchi,

.244 = Rio.

These dimensions are from an article by Tom Ceretto in Trapshooting USA, issue 4, page 50, Nov/Dec 2009

 

[ElDiablo]

The length of a primer has no significant affect on the fit of a shot shell Primer.

I think this an apples and oranges situation. Shotshells vs breech plugs.

 

[HC]

Exactly!

 

[ronlaughlin]

I just measured my Winchester W209 primers - .243” did, .3005” length

Seems like a primer 0.3005" long should 'crush' in your rifle, and thus provide clean ignition.

 

[deermanok]

9262K611 from Master-Carr
You can get 20-30 shots per o-ring before replacing them. $5.05 per 100

I'll should get some of those. I finally got some 209 primers from another member here and switched from my northwest plug back to the 209 plug for my pistol and I do get some definite blow back.

 

[tpcollins]

I have 3 different QT breech plugs that I interchange and never noticed any difference in accuracy. So the next time I go to the range I’ll check for blow back.

When I break open the action after shooting, I assume i can just wipe over the primer head while still in the breech plug with a cleaning patch to see if there’s blow back? Thanks.

 

[billyboy*]

Primer Recommendations « Blackhorn 209

I have 3 different QT breech plugs that I interchange and never noticed any difference in accuracy. So the next time I go to the range I’ll check for blow back.

When I break open the action after shooting, I assume i can just wipe over the primer head while still in the breech plug with a cleaning patch to see if there’s blow back? Thanks.

Might be stating the obvious:

Have you Drilled Out your Flash / Flame Channel with a 1/8" Drill Bit? (for OEM TCs)

Have you Measured to see if your Flash Hole has Grown Larger than .035"?

 

[ronlaughlin]

Seems like a primer 0.3005" long should 'crush' in your rifle, and thus provide clean ignition.

This is incorrect. The length was misread (misunderstood) as 0.305" which could provide a blow by free ignition. 0.3005" is too short to give zero blow by. 0.305" is nice and long, and may provide a blow by free ignition.

 

[GM54-120]

Put a primer in the plug and only close the action on it. DONT FIRE IT........Then remove the primer and remeasure. If you got between .003-.005 reduction in length (crush) it should seal pretty good to excellent. More than that could be hazardous in a break action.and less could leak.

 

[Travis299]

I wasn’t aware that this was an issue.

Is there a standard size O-ring we should use? I would assume we‘d need to get them in bulk?

I would think these would be non reusable.

CVA BP Rifle primer blowback problem.



IMO, when the primer is fired there is a lot of resistance or back pressure on the primer ignited hot gas caused by the small size of the fire/flame hole, .028” to .033”. This resistance/pressure means that it is imperative that the primer is sealed into the primer pocket to prevent the hot gas from escaping back around the primer and exciting to the rear, blowback. This blowback can foul the firing pin assembly in addition to the fact that it is wasted hot gas that is intended to ignite the powder charge. The sealing of the primer is also made more difficult because all primers are NOT the same length. If the fired primer has black carbon/soot on the sides of the primer than this is an indication of the blowback problem. I have found, from recommendations on BP forums, that using the rubber O-Ring in the primer pocket that the blowback problem is solved for whichever primer I am using. The O-Ring will last for 10/20 shots and you get 100 O-Rings for about $5. This is the site for the O-Ring.

McMaster-Carr

This O-Ring can be seated into the base of the primer pocket using a primer to push the O-Ring in. When loading the primer into the BP rifle, point the open action down while inserting the primer and then close the action with a firm snap. Also check that the firing pin bushing is flush with the face of the receiver with no indention or protrusion. This will insure that the action will open/close without any problems.

 

[tpcollins]

This is incorrect. The length was misread (misunderstood) as 0.305" which could provide a blow by free ignition. 0.3005" is too short to give zero blow by. 0.305" is nice and long, and may provide a blow by free ignition.

My measurement was correct per my calipers.

It was .3000” PLUS another half of one thousandth (.0005”). That’s .3005” the way I was taught. If I had used a micrometer it would have been the the same reading.

If I get ambitious later I’ll take a pic and post it.

 

[tpcollins]

How would you guys interpret this measurement?

 

[HC]

TP you are correct.

 

[michiganmuzzy]

.3005"

 

[ronlaughlin]

My measurement was correct per my calipers.

It isn't your measurement that was incorrect.

What was incorrect was me saying the primer was long enough to seal. Your measurement was misread by me so my understanding was it was 0.305". What i read was 0.305"; what you wrote is 0.3005". Evidently i was lost.

Apologies for the confusion. My intention in my post was to correct myself; my own misunderstanding.