Mike, my older CVA Breechplugs had the spring in them to hold the primer in, but the newer BP's for My ACCURA dont, they fit too loose. Im thinking they are causing the blowback as the carbon escapes around the inside diameter of where the primer fits into the breechplug. I dont have a problem with fit as when the action meets the breechplug and primer, that is good. It's the primer fit in the breechplug hole where the primer sits.
I have to be careful in the dark in the morning when I put the primer in and close the action as sometimes the primer falls out befor I get the action closed and I dont notice it, or I do see it fall out and have to put a fresh one in. I'd be really bummed if it fell out and I did'nt see it and then have a good buck in my sights and pull the hammer back and then nothing! So now I have to be careful when puttng the primer in to make sure it's there and did'nt fall out. Also Im still gonna send you the pic of my big doe to put on the forum for me, but I was waiting for a pic of a big buck to go with it,,,lol Thank's Mike
(BP)

Breechplug

Something has to hold the primer in... You do not think it is a magnetic thing do you? I know some breech plugs have that now...

I just mic'ed a T7 primer and they have a diameter .244 - I measured a Cheddite and it measures .2465. So they might be a little small but something besides diameter has to hold them in place.

Gotta go to the CVA site be right back... Well that was no luck... could not find anything...

Check with UC - he can tell you for sure -

But, anyway the shooting of the primer and the pressure should make them obturate out a bit to help make that seal. I am at a loss...

Ok two more thoughts just came to mind... I think Mountain Devil -Fronter Gander or what ever is experiancing the same thing you are talking about. He started a thread about wrapping his CCI ML primers with teflon tape to help seal the BP blowback - did not mention that they fall out of his Accura... so maybe this is common thing thing....

Second - I just tried a T7 primer on one my shot gun hulls. It dropped right in the primer pocket - no pressing neccessary - just turned the shell over and tap and it fell back out.... It is definetly thinner than a regular shotgun 209 primer, but only by a few thousands...

No my mind is running away - I thought you were a trap shooter also.. what primers do you use for reloading if you reload???

I keep checking my email looking for it... the picture

I haven't shot the accura yet but i backed out the firing pin bushes a few thousandths to push the primer tightly into the BP. Im not worried about the primer fouling, its nothing since i remove my scope for cleaning. Wincheste W209s are longer than the ccis im using and those w209s are super clean.

I've shot nothing but Win209A in mine with blowback only an issue when I fired Swiss behind a 496 grain conical. With sabot loads, I get almost nothing.

If you hold the rifle barrel pointed up when opening the action, the W209A are loose enough to fall out but not for normal action opening. Very easy to remove though.

After 12 rounds of T7 FFg plus 9 rounds with BH209 (sabot loads)

Breechplug

From those two replys - I think your original assement may be correct the T7 primer might not be the best fit.

While they are the longest 209 primer that i have they are also the skinniest. The Win W209 that UC talked about is almost the same length. I just tried dropping that one in a Remington hull also. I could seat it by just pushing it in with my finger so it is not much thicker than the T7 (which makes sense since they both are made by Win)

The Remington STS is thicker than both of the Win's, as are Cheddites and Feds.

The next thing is to look into to what FG said...

I have no idea what he may be talking about but if that can be done it would certainly help if you could pin the primer against the shelf in the BP.

that there lil screwy thingy. Inside it holds the firing pin/spring. Back it out a little and adjust for proper fit. The CCI Inline MZL primers now fit tight when its locked up. May take a couple shots later on and see if it does anything or not. Will be sure to report back.

Not often i can agree with FG but on this particular thing I think he has a got an good idea if it can be done without damaging the mechanism. It that part strong enough or the threads on both the part and block to handle the blow back pressure? Over many-many shots. I always worry about a loose part, as a loose part creates movent, even a a small movement, can cause a failure...

i fired 2 bare primers today. The first was perfect but the second primer had a real funny, dull/sizzling sound and primer smoke poured out of the stock. Keep in mind, this was just a bare primer!! I opened the rifle and i dont know what the deal was but the primer did something to where it got to messy it splattered my BP grease all over. I think some primers are just a lot weaker than others or something. What ever it was, that second primer was plain bad.

Guy's I dont have a problem with the T7 Primer as fit with the firing pin, everything works well, no need to adjust the fit by backing off the firing pin. I guess the problem with the loose fitting T7's wont be a problem as long as I make sure it does'nt fall out as Im closing the action. I think CVA should have the stainless wire on the breechplugs like on my older CVA's, they fit snug no matter what size primer you use, but some you do need the capper extractor to remove it after firing. I guess the stainless steel wire on the older BP's of CVA's has it's advantages and disadvantages, the only disadvantage would be if you needed a quick seconf shot and did'nt have the extractor toll handy you'd never be able to get the spent primer out fast or with just your finger. But I am getting blowback with the bigger than average hole in the BP for the primers now used in the ACCURA.
(BP)

I would just switch to the Win209A and be done with it. Those T7 and similar primers seem to just cost more so far as I can tell. Sub 1" groups suit me.