72 Open Tops, problems with primers backing out

[Gus Grizzly]

Hi all as I said, 45 colt, 200 GRN bullet, 5 GRN Trailboss powder, taper crimp, 72 Open Tops, they will shoot the first couple rounds then the fired rounds reach the loading gate and the spent primer has backed out enough to jam.  This does not happen with factory rounds. Primers are Winchester, CCI, etc. What am I doing wrong......

Thanks in advance
Gus

[Sir Charles deMouton-Black]

Just my guess, I,m more bubba than gun-plumber, but How is the wedge & arbour set? Perhaps too much headspace??

[Abilene]

Gus, primers backing out in any gun is often a matter of too light of a load.  Hodgdon shows 5.5 to 6.5 grains of Trailboss for a 200gr bullet in 45 Colt, and you are under that.  I would try upping your powder charge.  Also, 45 Colt ammo would typically use a roll crimp, which might allow the pressure to build up a bit more than a taper crimp.

[Gus Grizzly]

Thanks guys, I forgot to mention these reloads work fine in our other guns, Vaquero's, Piettas, Uberti 1875s etc.... but I will try the bigger load n then ifen that don't work I will try a roll crimp.  I had sent them off to be checked out by Cody he returned them as fine....  so it must be the lighter pressure.

Thanks again

[Coffinmaker]

First question .... Has the Barrel to Arbor fit been corrected??  You may have varying head space and end shake.

Why a taper crimp??  Taper belongs on the 45 ACP.  Roll crimp works better especially with light loads.

Factory ammunition produces enough chamber pressure to recoil the case back to the recoil shield and re-seat the primer.