FTF issue

[bikerbeans]

Hi All,

FTF issue with my BC 45-120.  Problem appears to be with only my Norma 45-120 brass.  Average rim thickness on this stuff is about .060" and I get FTFs with both Rem and CCI mag LR primers.  If I use Larry's method and fire a primed and unloaded case the primer on the Norma brass backouts out of the primer pocket by 0.011".  I also have some RCBS 45 Basic brass (thanks gcrank1!) that has a rim thickness of 0.068" and have no FTFs with this brass.  Also I chambered a bunch of 45-70 brass with these primers and they all go bang.  Rim thickness on the 45-70 brass around 0.066".   

I removed enough material from the face of the ejector so that the ejector spring keeps the Norma brass againist the receiver.  FTFs do not go away.  I have .06" of F pin protrusion and verified the hammer is not making an early strike on the frame.  I have wolff extra power hammer springs on the way to see if this will elimate the FTFs with the Norma brass.  If it doesn't then what?  If I modify the extractor or rim cut to properly headspace the Norma brass then the RCBS brass will not chamber correctly.  Any ideas on modifying the rim of the Norma brass?

thanks in advance

BB

[gcrank1]

Will your chamber throat allow you to seat the bullet out a bit into the rifling to help keep the back end closer to the standing breech? Maybe that in concert with your ejector mod. will get you enough strike force.

[torpedoman]

try the simple solution don't use norma brass.

[revbc]

BB,
I have been through the same issue with a 357max that I may have cut the rim to deep rechambering it.  Had about .012 headspace from the brass to barrel face, this did not include space when closed which would be more.  Filed the hammer face, wolf spring, shimmed the extractor (and filed) out to hold the brass against the breech.  This last solution worked until the extractor broke from being pounded on.
My primers were swelling outward and started to get some pierced.  So this last week, I decided to bite the bullet and put the barrel on another frame I had.  It would not lock up on this frame and had clearance at the top of the barrel so I knew it was to long.  Carefully filed the barrel face (which was removing the headspace) until I got a super tight fit.  It will lock up on .0005, I am still slowly stoning the barrel catch shelf.  It is still occasionally popping open. 
But now, I have shot it probably 30 rds. and primers look good and NO FTF'S.  Before I would have had 3 out of 10 FTF's.
However, your mileage with the other solutions may vary.  I would try the wolf spring and any other good idea before going my route.  This has been a long process.

[bikerbeans]

try the simple solution don't use norma brass.

torpedo

I would buy more of the RCBS 45 Basic but I don't think it is available.   Anybody have some of the Jamison 45-120 brass and can measure the rim thickness?

revbc,

I thought about changing the barrel to another frame but it is currently on a case hardened BC frame and as perfect lockup.  I have been shooting 45-120 NE loads (fairly high pressure) with no issues and don't want to create another problem.   I have removed as much metal as I can from the extractor and probably better order a backup one.

gcrank,

I loaded a cast bullet into a primed only case that was into the rifling about 0.01".  Primer went off and I knocked the bullet out with a dowel rod.  Problem is I only want to shoot jacketed bullets at fairly high velocity and I think having a jacketed bullet into the lands with the loads I am shooting will lead a more serious problem.


thanks

BB

[gcrank1]

Im all for keeping pressures down too!
How about mothballing those Norma cases, or selling them on the classifieds to someone who is thinking of doing a '120 and could ream their rimseat specifically for them. In the meantime finding thicker rim cases for yours IS the best approach, since it is working that way.
Or, think of the FTF as 'anti-trigger jerk practice'...........

[quickdtoo]

I think this has been discussed before, but how bout soldering a shim in the rim cut,  cut it to the proper OD with an undersize ID, then silver solder it, then carefully open the ID up to chamber diameter, maybe with a ¼" drive conical shaped stone, then cut the ejector/extractor slot with a needle file?

Tim

[gendoc]

jamison .067~.070........  bout 10 were checked

[bikerbeans]

jamison .067~.070........  bout 10 were checked

Doc,

Thanks, looks like the Jamison brass would work fine, pretty much same thickness as the RCBS.  Now to unload about 3 dozen hit or miss Norma rounds.   Shootin' these cartridges is like playin' Russian Roulette w/o pointin' the gun at your noggin'.

BB

[gendoc]

bb, i would contact them first and request specs on there product.
jus cus mine mic'd that doan't mean nut'n.
i've had'um fer a few years

[gcrank1]

BB, pop off as many as will go bang, that many less to have to 'erase'. I know youve been shooting quite a bit already, but all trigger time is good practice  .