209s...Powerful little suckers!

[AndyHass]

Could there really be something to the fact that several people are making after-market conversions to go from 209 primers to small rifle primers?
   I recall reading on the Precision Rifle website that a 209 would move a bullet several inches up the barrel all by itself.  I tried this in my old Traditions, and it moved it about 3 inches.  Enough to convince me it could be the reason for some of my unexplained flyers.  I switched the gun back to #11 ignition and no more flyers.  That made me "nearly" a believer.
   Last weekend my buddy was out shooting his Omega, which has a much more sealed breech than my Traditions, which sends half the gas back through the bolt.  He forgot to add his powder before ramming the bullet (gave him a hard time about that) so he popped in a primer and fired it just to see what happened....he found the sabot TWENTY FEET from the muzzle!!
   If my new Omega has any accuracy problems, I might look into a conversion.  It's way too pricey to put in a gun if it's already a tack-driver, expecially with the need to prime cases (though they might be easier to load with frozen fingers!).

[DEPUTY]

good thought andy, i have an encore that already is good shooter out of the box with a 100 of t7 and a 250sst, but iam getting a 25 acp conversion just for giggles, to play with and maybe having the qla removed and recrowned, the 209 are hot thats for sure, as far as casings go much easier to deal with than  cappers and disc. IMHO

[whitfang]

I'm sorry, but I don't understand what you are saying here.  You think a 209 primer is responsible for random bad shots?  How would that  happen?

[AndyHass]

According to the theory (I first heard if from Precision Rifle, but it makes sense), occasionally the power of the 209 ignition will unseat the bullet/sabot combo before the powder charge actually ignites.  The inconsistency in pressure and position of bullet at time of ignition causes a significant shift in impact, ie a "flyer" from an otherwise tight group.  Think of it this way...if you measured your barrel and stopped ramming the bullet when it was 1-2" off the powder charge, do you think it would fly the same as a properly seated bullet?  (OF COURSE, DON'T TRY THIS!!!).  Bullet seating pressure can affect accuracy, so imagine what would happen if the bullet is actually UNseated.
   That's the theory.  I have personal experience to back it up.  But it's still a theory all the same.  Like I said, if the gun shoots fine I won't bother with it.  But on my old gun it caused me to switch back to the #11 cap to get rid of flyers.

[Underclocked]

The Cecil Epp "Reverse Ignition Stalk" is explained here: http://www.prbullet.com/hornet.htm


By the way, http://www.prbullet.com/encore2.htm looks like CRAP, Cecil.  Why not a tiny set screw or such?

Signed, the set-screw king.   :grin:

[RandyWakeman]

The theory is that the primer energetic moves the sabot down the bore before the powder ignites properly. It may well do that, as a 209 Federal alone will shoot a 405 gr. Powerbelt out of my Encore (without gas check) some 20 yards.

It remains just that, as 209 primers are not match grade primers, and vary quite a bit from breechplug to breechplug-- which they were never designed for in the first place.

[whitfang]

OK, thanks.  So this is what is meant by 'internal ballistics' - what happens to the bullet before it leaves the barrel.  

At least this gives me a new excuse when I flinch like I'm being electrocuted and throw a shot into a nearby tree.  It's those darn 209 primers!