primer issues with french 1873

[burnt_servo]

I recently rechambered my French 1873 to 45 schofield . got the headspace within 3 10thouandands between the cylinders , the tightest cylinder was just over 2 thou clearance , the loosest cylinder was just under 2.5 thou clearance ( between the frame and the back of the rim ) .


loaded 60 rounds today with 5 grains of trailboss , with a cci large magnum pistol primer and 216 grain hollow point bullet from jethunter .

the issue I am having is , the primer is flowing around the firing pin , locking op the cylinder . the primer is not moving backwards , just a portion is stretching and expanding backwards about 7 thou , forcing the operator to turn the cylinder by hand to get it to advance .

just a primer in a case by itself is worse than loaded ammo .
I drilled the flash hole from 5/64's of a inch to 7/64's of a inch and the problem almost went away .... but I am kind of leery about opening up the flash holes in case that creates a new unforeseen problem .

I moved the firing pin down a hair so it strikes perfectly dead center , and widened it a bit in a attempt to hammer down the stretched out area on the primer . this almost worked , the cylinder needs about 1/10 the effort to manually rotate 6 fired rounds , but not enough to move it by cocking the hammer .

where the firing pin comes through the frame could be bushed and a smaller hole possibly made ,but this isn't a road I want to travel down yet .

I tried a Remington 9 1/2 large rifle mag primer ( it did seat flush ) and while it didn't bulge out like the pistol primers , it did almost completely push the firing pin impact mark back out of the primer ( this was just the primer nothing else ) .

there is no place in town that has regular large pistol primers to try . I believe my issue is with the magnum primer creating too much pressure for the unsupported area of the primer face and pushing it into the hole for the firing pin .
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anyone run across something similar ?

 

[Tyockell18]

Yes I have had similar issues, these old guns have very large firing pin holes, those magnum primers are too hot. I think you will have much better results with just a regular one. I certainly have.

 

[dingus]

Try unique 5 grs of unique or TB and winchester large pistol primers i have good results with this in my 45 schofield rounds in original schofields.
I never use magnum pistol primers in antique handguns because the loads are mostly lighter , i see its all you have tho.
The wichester primers are alot better than federal ones from what i have seen in my reloading.
TB is a good powder but i like unique better.
I think wholesale sports sells primers and ships them you need to get some regular large pistol primers.

Oh and Never shoot just a primer in a empty case not only will it jamb up the gun instantly it can damage stuff as the primers want to back right outa there seating.
I always shoot something in the cases.

 

[burnt_servo]

thanks guys

 

[Metman2]

Try unique 5 grs of unique or TB and winchester large pistol primers i have good results with this in my 45 schofield rounds in original schofields.
I never use magnum pistol primers in antique handguns ......
The wiches

Oh and Never shoot just a primer in a empty case not only will it jamb up the gun instantly it can damage stuff as the primers want to back right outa there seating.
I always shoot something in the cases.

I found this out the hard way ;-) I also discovered that if you ream out the flash hole you will reduce the back pressure and then the primers will not back out as much and jam up the gun, if fired in an empty case. It does ruin the case for regular use, I think, but if you absolutely must try it (as I thought at the time), it might work.

 

[Tyockell18]

Try unique 5 grs of unique or TB and winchester large pistol primers i have good results with this in my 45 schofield rounds in original schofields.
I never use magnum pistol primers in antique handguns because the loads are mostly lighter , i see its all you have tho.
The wichester primers are alot better than federal ones from what i have seen in my reloading.
TB is a good powder but i like unique better.
I think wholesale sports sells primers and ships them you need to get some regular large pistol primers.

Oh and Never shoot just a primer in a empty case not only will it jamb up the gun instantly it can damage stuff as the primers want to back right outa there seating.
I always shoot something in the cases.

Agreed, Unique is good stuff. Always use it in the 8mm lebel with excellent results.

 

[burnt_servo]

after doing some searching , it appears that most of the non magnum large pistol primers are in private hands .

Canadian ammo has some dominion in stock , so I ordered a couple boxes from them .

 

[burnt_servo]

in the top pick is where the firing pin was hitting before I moved it .

in the bottom pic , the top 3 cartridges going from left to right are , the rem 9 1/2 mag primer , modified hammer with one strike against the primer , and modified hammer with several strikes against the primer .


I had some pics and I thought I'd post them anyway .... even the though the issue is more than likely I was using mag primers and not regular ones .

 

[dingus]

Just so you know the reason the fireing pin hits them primers off center is the thicher 45 schofield rims sit back alot farther than the original 11 MM ammo would sit as the fireing pin falls in farther it strikes lower on the 11 mm ammos thats why 455 cases work good in theses they have thin rims. they still can strike off center abit tho, just not as much.

Looks to me like you got it right on pretty much for your rim thickness now.
Just get and try the regular primers you should be good to go but might have to give the cases alittle more head space all primers deform abit so if your 45 schofield back face is almost rubbing on the recoil sheild now you might have to get abit more of a gap there.
Thats a nice chamber full of ammo did you have to seat the bullets way back in the case ? id like to see some of the loaded rounds ?
Is there any chamber throat left in the chambers ?
Or did you just shorten them 45 schofield cases.

 

[burnt_servo]

I left a thin lip on the cylinder so I could still use 455 , but I didn't want to make the ledge of the lip too deep , that is why I ran the headspace fairly tight .

playing with it last night , with the firing pin mods and opening up the flash hole 1/64 " I can use mag primers .

I had cut the rim back on one case so the headspace was about that of a webley case on the loose side , and with no other changes the mag primers where still binding things up .

the bullets I'm using are a hollow point and need to be seated a fair amount deeper than a solid round bullet to keep from poking through the other side of the cylinder . ( they are nice and soft about 216 grains from jethunter . )

I ran a 45 acp reamer 1.120" into the cylinder , then used a 45 colt reamer to open up the rest of the chamber and cut the throat . I haven't measured the throat yet , but it is about .200" long ( roughly ) and I opened up the throats to .454 diameter so everything moves easily and no pressure spikes are created .

i'll post some pics when the new primers arrive and I make up some more ammo .


btw I left the case full length , I hate trimming brass . the extra length of brass also serves as a decent sized lip to crimp into the bullet .

 

[dingus]

Sounds good. Just watch the bullets might advance on you if you cant get the bullets to crimp tight.
If you cant use a crimp grove as you take each shot the bullets will walk forward in the other cases and could cause Jambs at the front of the cylinder. not likely with the light loads your useing but ive seen it happen with hotter loads. its not a big deal just thought id mention it tho.
Thats really makeing full use of the chambers once you solve the primer issiues 100% i bet the gun shoots accurate.
Most of theses guns have .452 dia bores so thats what you want the bullets and chamber throats if posible.
454 will work to just be abit higher presure.
Jethunters bullets are great because he understands not to make them to hard for antiques.

 

[jethunter]

We weren't sure what bullet to use for this pistol. Since the French 1873 was regulated for lighter bullets I suggested these. Will be interesting to see how they shoot.

I think the mag primers are causing the problem. It will be nice when this dam reloading components shortage finally runs it's course. I hear rumours of the frenzy dying in the USA and maybe we can get back to "normal" before too much longer.

 

[burnt_servo]

did some more testing today , but this time with fully loaded rounds and with just the firing pin mods there is slight resistance with 6 fired rounds ( you can use it in double action easily , as opposed to having to turn the cylinder by hand as you #### it in single action ) . it appears the firing the round off is thrusting the case back enough to push the primer face back in a bit .

with opening up the flash hole 1/64 of a inch , you would never know there was a problem .


the few hollow points I have recovered have mushroomed nicely and are penetrating about 18 to 24 inches of sand / pea gravel . the gun shoots about 6 inches high at 25 yards .

loading these bullets in the way I am I am doing it seems almost perfect . some of the tips of the bullets are deforming slightly in the seating die due to the heavy crimp and the soft bullet .

case length 1.1 inches , overall length 1.345 inches ( length of cylinder 1.350 inches ) , 5 grains of trail boss , with a 216 grain hollow point soft lead bullet .

this should put it very close to 45acp power levels , but without the pressure ( due to the larger case volume )

 

[anchor3593]

I have no troubles in my 1873 guns - that I chamber to .45 acp - and here are things that I do notice.

You are crimping a lot. If your case is actually sliding up onto the front shoulder of the chamber, the case will expand on firing and hold the case back.

When a bullet fires, the first thing to happen is the primer backing out - this is normal - then the case slides back and reseats the primer and then the case expands to seal the exploding gases into the chamber. If the charge is not heavy enough, the case will not slide back to reseat the primer and the case may not expand enough to seal the gases in - so the side of the cases may be blackened. Messing with primer hole sizes is not necessary if the charge is heavy enough - however - don't make the mistake of overpressuring - and here is a cause of that. The original barrel is 11mm - inside the lands - this is very small to shoot a .452 bullet through - so I use a bullet seated deep into a .45acp case - so that the bullet is moving before it hits the lands ( remembering that in rifle, loading to the lands will cause higher pressure). Also, I use a Hornady taper crimping die that does a long taper crimp to swage the seated bullet much smaller after it is in the case. I use a 200 grain Lee tumble lube bullet with lots of lube.

One more thing that I wonder about is opening up the throat to .454 - I don't do this - and I am wondering what goes on with yours when the bullet hits the lands. Will the gases come forward around the bullet and exit the cylinder gap?

Your primers do not look unusual for this model of gun.

Maybe you have the issue settled already - but I was just wandering around in my thoughts early in the morning.

 

[burnt_servo]

I have no troubles in my 1873 guns - that I chamber to .45 acp - and here are things that I do notice.

You are crimping a lot. If your case is actually sliding up onto the front shoulder of the chamber, the case will expand on firing and hold the case back.

When a bullet fires, the first thing to happen is the primer backing out - this is normal - then the case slides back and reseats the primer and then the case expands to seal the exploding gases into the chamber. If the charge is not heavy enough, the case will not slide back to reseat the primer and the case may not expand enough to seal the gases in - so the side of the cases may be blackened. Messing with primer hole sizes is not necessary if the charge is heavy enough - however - don't make the mistake of overpressuring - and here is a cause of that. The original barrel is 11mm - inside the lands - this is very small to shoot a .452 bullet through - so I use a bullet seated deep into a .45acp case - so that the bullet is moving before it hits the lands ( remembering that in rifle, loading to the lands will cause higher pressure). Also, I use a Hornady taper crimping die that does a long taper crimp to swage the seated bullet much smaller after it is in the case. I use a 200 grain Lee tumble lube bullet with lots of lube.

One more thing that I wonder about is opening up the throat to .454 - I don't do this - and I am wondering what goes on with yours when the bullet hits the lands. Will the gases come forward around the bullet and exit the cylinder gap?

Your primers do not look unusual for this model of gun.

Maybe you have the issue settled already - but I was just wandering around in my thoughts early in the morning.

I'm going to dissect your post and answer each section ......


"You are crimping a lot. If your case is actually sliding up onto the front shoulder of the chamber, the case will expand on firing and hold the case back."

the case is not moving backwards . I used the 45acp reamer and cut 1.120" into the cylinder , that is 20 thou farther into the cylinder than the brass is long ( 1.1")

-------------------------
"When a bullet fires, the first thing to happen is the primer backing out "

the primer is NOT moving at all . this is the first thing I checked . the primer face is stretching and expanding into the unsuported area of the receiver around the firing pin .
you can check this with plastiguage or something similar ( soft lead , wax , some types of gum even ) .

-------------------


" The original barrel is 11mm - inside the lands - this is very small to shoot a .452 bullet through - so I use a bullet seated deep into a .45acp case - so that the bullet is moving before it hits the lands ( remembering that in rifle, loading to the lands will cause higher pressure). Also, I use a Hornady taper crimping die that does a long taper crimp to swage the seated bullet much smaller after it is in the case. I use a 200 grain Lee tumble lube bullet with lots of lube.

it is bigger than 11mm .... after slugging my barrel the slug comes out sort of oblong , the grove diameter on one side measure .458 , on the other side .453 .
the tops of the rifling measure .440 and .441 . ( 4 grooves , 4 lands to measure across from )

the barrel I have is pretty clean and not worn as many of the machining marks are fairly crisp still .

--------------


"One more thing that I wonder about is opening up the throat to .454 - I don't do this - and I am wondering what goes on with yours when the bullet hits the lands. Will the gases come forward around the bullet and exit the cylinder gap? "

the throats where around .445 ish . even after reaming the chambers the throats where still too tight .


the tight throats are what can cause these antiques safety issues . what happens is you end up trying to swag down a .452 bullet down to .445 to go down a bore that measures .453-.458 .

what happens is a huge pressure spike as your trying to compress the bullet down to .445 . this might be fine for a modern gun , but this is an antique .

to make matters worse , with 45 acp , if someone puts a factory round in with a jacketed bullet your starting off with a over pressure round and creating a pressure spike with a tight throat .... how long will it last before it goes boom ?


after the bullet has made it past the .445 throat , the bullet is now .445 and it can now just barely engage the rifling while it rattles down the bore .


what I did was make the bullet a sliding fit through the throat , then added about a thou .

now there is no longer a pressure spike when the bullet hits the throat , and you are now making the forcing cone do its job of compressing the bullet for the barrel , but you are doing it at dramatically less pressure ( read no pressure spike ) . and you also have the cylinder gap acting as a fuse of sorts as it leaks pressure in case there is some sort of pressure spike . ( you no longer have a sealed container for the pressure , but you now have a engineered leak introduced into the system ) .



back to the heavy crimp , now that the throat is loosened up so there is virtually no resistance to the bullet , how does one get the pressure built up to the point of complete burn .
it won't work in the barrel as you have a leak at the cylinder gap , at least not on something that runs at low pressure .
the only way to do that is with a heavy crimp.

also crimping the brass the way I am doing this , as the bullet leaves the cylinder it will be riding on 3 bearing surfaces at the same time , the edge of the case where it is crimped , the edge of the throat and the leading edge of the forcing cone .