45-70 Primers backed out

[David Battersby]

 Thanks to the "Black Powder in the 44-40" thread under the 1873 Forum ( and help from John Kort ) my Uberti 1873 is a black powder only rifle. Accurate, fun and powerful.
 After a year of frustration trying to get good 200 meter accuracy from my 1886 Japchester in 45-70 I have been trying, you guessed it, the Holy Black.
 The most accurate load so far has been my hand cast 405 grain bullets in 25-1 alloy, DGL in the lube and crimp grooves, 67 grains of Swiss 1.5F compressed about .2in , then the bullet seated on top of the powder with a light taper crimp Winchester large rifle primers all in Starline brass.
 With a tang sight I got just under 4" goups at 200 yards. ( oh how I dream about those @%$#!! 200 meter rams ).
 Then I see primers backed out of some of the cases.
  Is this a problem or a common occurrence ?

[Dick Dastardly]

All primers 'back out'.  Then the pressure pushes the cartridge case back over the primer.  For reasons I can't see, you are not developing enough pressure to push the brass back over the spent primer.  Let me know if this helps.

DD-MDA

[Sir Charles deMouton-Black]

You haven't stated your over-all-length. For single shot rifles I like to have the bullet touch the throat of the barrel. Doing that, I can get about 75 grains of GOEX FFFg into a W-W case under a Lyman bullet.  But then the mv is too high for the finest accuracy, and I think you should try a 500 grain plus bullet for target use. Sticking with the 405 gr bullet you might need some sort of filler to keep the mv down to about 1200-1250

Whoops; I was thinking about the 1885.

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[Drydock]

He's got an 1886, which won't feed 500 grainers, and he's getting under 4" at 200 yards.  Don't change a thing.  The backed out primers simply mean you're not getting enough back thrust to reseat the primer once pressure falls enough to allow the case walls to release from the chamber.  This is simply not a problem considering the results you're getting.  Its certainly not hurting either the rifle or you. 

I might experiment with a heavier crimp to get a  higher start pressure, but again, with your results, I doubt I'd change a thing,  sounds like you've got a load your rifle likes.

Is this new brass?  I also suspect the more  you shoot it, the less this will occur.

[David Battersby]

  No it is not new brass. They are Starline and have been fired at least five times before. I have not loaded any smokeless powder ammo hotter than just below starting loads in the lever gun section of the manuals. The brass is "neck sized" just enough to get good bullet grip without sizing down the body. I have a theory, I just don't know if it makes sense . With everything else being equal, previous loads tried with less powder/compression did not leave any primers backed out. I tried 55 and 60 grains with poor accuracy, then this load with very good accuracy. I am very careful and make sure that my brass and chamber are clean and dry. I think this heavier load has the brass gripping the chamber very well and the primers are left set back. The load is fairly stout, the fouling thin, a grease ring on the muzzle and the brass comes out as clean as it went in. After posting and reading your responses I looked at the primers under magnification. The faces and radius's are round not flattened and the firing pin indents are no where near pierced with no gas blow by.
........I think I am okay.

[wildman1]

  . I have not loaded any smokeless powder ammo hotter than just below starting loads in the lever gun section of the manuals. 

That right there may be the problem.  wM1

[rifle]

I try a heavier crimp to the case for a few of them and see what happens. It's known(believed) by some that a heavier crimp lets the pressure build a little more fer a better burn.

I'd check the headspace of the rifle or have a gunsmith with a gauge do it just to see if that is too large.

If possible I'd try setting the bullet forward as was mentioned.If it will cycle thru. The Japchester has "no throat" to the chamber and that plays a significent role in how the gun ammo is loaded.

The brass....Starline......can come hard from the factory. Every time it's fired it can get harder from "work hardening". It may be a good idea to anneal the brass ifin you can do it properly without ruining it. If the brass is coming out clean like there's no blow back then the brass must be right enough...just a thought bout the hard Starline brass.

Anywhooooo....I'd try a firmer crimp and set the bullet out to kiss the rifling. Setting the bullet out to kiss the riflng ,if possible, may even improve the groups a little.

The Swiss 1.5 FFg powder is a good one fer blackpowder cartridge but........FFg can be good as well as FFFg and the rifle can take the extra pressure fer sure. Might try a finer powder. Might set the brass back over the primer.

I'd go right to checking the head space though,first. Any primers back out with smokeless powder?  I'm of the school of thought that says primers just should not back out if a gun is right.

Anywhooo...you get good groups fer a rifle with "no throat" to the chamber.

I'd wonder ifin different primers may work better too.

Anywhooooo........all primers don't set back like light loads in revolvers let the primers set back to rub the frame and make the cylinder hard to turn.
The brass stays where it is from the pressure and the primers swell from the pressure and stay where they are...in the pocket if the pressure isn't too low. The pressure from the loads of blackpowder as shown above aren't too light to swell the primer to stay where it should in the pocket. The primer very well could be swelling from that pressure but still set back from the overly wide headspace.
If the primer can set back then the thin part of the brass can stay in place and let the solid case head set back and cause a case head separation and have a catastrophic event happen.
My logic says better to be safe than sorry and have the headspace of the rifle checked. I don't believe a normal within tolerance headspace would let the primer backout that far as the picture shows.

I have a ASM 1860 Army 38special conversion type revolver with a headspace a lil too wide. I shoot smokeless and black and the primers don't set back at all even with a wide headspace since the pressure swells the primers and won't let them set back and .....the head space isn't wide enough to let the case head set back. I know the wide headspace could let the pprimers set back and make the cylinder hard to turn but....there is enough pressure to not let that happen....because the primers swell and stay in the pocket because the loads aren't way too light. If the loads were too light the primers would set back and make the cylinder hard to rotate.

When I see a safety concern I have to speak up(type up) even if I have sore hands and shoulders right now and typing hurts.

I wouldn't shoot any/many hot type smokeless loads in that mentioned above rifle till it's checked out.

Anywhoooooo.......A go,no-go gauge from Brownells would work to check it. It's if it closes with the gauge in there it's no-go(too much headspace) and if it won't close with it in there it's a "go" (not overly wide headspace). I thunk that's how they work.

The clue is the revolver cartridge primers setting back from overly light loads but not normal loads that let's ya know primers stay where they are from the proper pressure just like the brass does from the pressure.
Overly light loads can detonate a revolver cylinder too. Did I say that already?

Sorry I type too much and hope I don't bore you Hombre.

That's one reason to follow the loading manual "book" with the tested loads and don't go below min. or above max.

I know overly light loads can detonate a revolver cylinder but I'm not sure if an overly light load can detonate a rifle. I thunk maybe it could. Best to follow the book and stay at or above min. and at or below max.

I'm not trying to be like a "know it all". I'd fail at that. I just know what I know and know what I don't know. At first glance that doesn't make a bit of sense does it?

[litl rooster]

I agree with Drydock and Wildman

[Dick Dastardly]

All primers "back out", but they are pushed back in when pressure builds and forces the brass back over the spent primer.  If your primers are still "backed out" when you eject the brass, the brass wasn't forced back over the spent primer.  More pressure should cure that.


DD-MDA

[rifle]

My thunkin on that "backed out primers" is.....

The action and following reaction.....the primer ignites....the brass begins to swell and the bullet begins to move.....before the pressure seals the brass to the chamber any gas escaping around the bullet(before the pressure is built enough to seal the brass)...the action and following reaction moves the brass and the primer with it against the bolt/block so the primer doesn't back out first. It goes back with the brass before the brass seals.

When that tiny speck in time is where the brass opens a little to let a little gas out around the bullet when the brass hasn't sealed against the chamber walls is when the brass with the primer in it moves back against the bolt/block so that is where the brass seals from the rise in pressure with the primer against the bolt /breech block.

Know what I mean? Before the brass seals to the chamber walls the action and following reaction of the little bit of gas escaping round the bullet moves the brass with the primer against the bolt/breech.

When the head space is too wide is when the brass seals before it's back against the bolck/bolt and lets the primer backout and can cause a case head separation where the thin part of the case swells and seals and the case head being solid is set back against the breech block and disconnects it from the thin part of the brass that locks in place from swelling and sealing.

If primers do set back some it would happen more when they are loose in the brass if the brass is old or the primers a loose fit. That may be true that primers set back some but if they do and the brass stays forward of the bolt/breech block sealed there then the pressure is high enough and the head space could be too wide.

Primers set back in revolver loads when the load is too light and the brass doesn't move back since the bullet isn't movin and the brass isn't beginning to swell so it can seal(no gas escapes around the bullet before the brass swells).


Anywhoooo...no matter which way it is...primers always backout or not....to be safe and not sorry the owner should have the head space of the rifle checked. Checked also to see if it closes properly evey time too.

Since all the primers don't set back the brass may be too loose fer the set back ones or the rifle isn't closing right everytime or the head spacedoesn'tset closed the same every time.

The amount of black powder used in the above loads is enough pressure to set brass back against the bolt whether the primer sets back first or not so.....why not check the functioning of the rifle to be sure and safe? The pressure could be sealing the brass to the chamber before the brass can move back and that could be a head space problem. Hopefully it isn't. Raising the pressure could be just enough to get a case head separation. The worst of the lot even worse then a ruptured case. Case head separation could blow the gun since the case can get back around the case head since it's solid.

Anywhoooo...that's the way I see it and I could be wrong but maybe right enough to show the head space should probably be checked along with the way the bolt locks up to see if it locks properly everytime. You know...not just assume the primers always set back first and then the brass and leave it at that. Better to be safe than sorry I say.

It doesn't matter who is right about primers always settin back or not since it's not us shootin the rifle and the shooter should check the rifle so to stay safe.
I wouldn'tknow where to research the primer settin back all the time thing. It would be nice to see some reliable data/info backin that scenario up. If I could find the data somewhere to back up either opinion I'd post it.

[Bunk Stagnerg]

Last weekend I ran through 75 rounds of .45-70 with no primer back up problems. The first load was 40 rounds loaded in REM plated cases 50 grains (volume) of FFFg Du Pont, a .454 gas check skirt down, a fiber wad  topped with a laser cast 405 grain bullet re-lubed with a beef tallow, bees wax, Crisco mix.  Winchester LR primers were used throughout. The bullet compressed the load slightly and gave acceptably accuracy at 100 yards in Cody Dixon competition.  30 rounds were fired in the completion, the rest in sighting in and practice.

These were used in my Winchester (Miroku) 1886 lever action rifle.

The second load was 50 grains (volume)  GOEX Olde Eynsford  FFg dropped through a 36” tube into REM plated cases, an .030 fiber wad, a 1/8” felt wad lubed with SPG, The load was compressed about 1/16” with a Chey-Cast 350 grain re-lubed bullet.  Winchester primers were used. The reason for the lube wad in this load was a small amount of hard fouling at the muzzle end of the barrel when I cleaned after shooting the first load. It seems, the small lube grooves on the bullet could not carry the distance so I added a little more lube.

This second load was shot in practice and gave me a good grease ring at the muzzle. It is my plan to get this fall one of DD’s proper BP bullets, but frankly it is 3PM and here in central Texas my thermometer shows an even 100 outside so casting must wait.
Respectfully submitted,
Bunk

[Dick Dastardly]

At Squinty Eye we shot some long range metal.  For reasons beyond my knowledge I've developed a blank in my vision field.  It'a below and left of the center line and I should be able to deal with it.  I held forth with my Rem. roller chambered 45-70.  Scored 100% at 100 yards, 100% at 200 yards, and then just lost track of what I was supposed to be shooting at.  I think I shot a hole in the roof of the biffy.  Beyond that, I was at the mercy of the white buffalo.  I shot him close and far but never the right one for score.  What a hoot.  Lots of dings, lousy score.

I'll be back with lots more ammo.

DD-MDA

[rifle]

I don't remember having any primers back out when shot with my Winchester 1886 made in Japan. Of course I used only smokeless powder in it so far.

The problem I have with my Winchester 86 from Japan is it will ignite Federal primers all the time but misfire when using other primers. At least it functions with Federal primers.

Anywhoooo.....the way the bolt lugs lock it up I can see they are tight but the face of the bolt is where it would have headspace problems if they occur.

I started out using TrapDoor type less pressure loads and then went to the "lever action " section of the loadin manual.

Once the barrel is broke in a lil more I'll be smokin up the countryside with Fg or FFg Goex. I hope my lube will hold up all the way to the muzzle. I use beeswax.paraffin wax, mutton tallow equal unless I thunk softer lube is needed I add mutton and is it's too hot and want harder lube I add paraffin till I get what I want.

I thunk my 1886 has a firing pin a lil too short and a lil too light. Federal primers are the soft ones so they work. I might heft up on the mainspring some to see what happens. I've thunked at times that if I cut the bottom leg of the mainspring strut some and replace the length with a spring the right stiffness the hammer strike can be improved. Improved so the hammer doesn't rebound with the same force it bounds forward. Have the same length to it even with the spring on the end of the bottom leg of the strut so it goes to half cock and will be safe unlike when people cut some from the bottom leg and leave it that way with a short bottom leg to the strut

It just seems to me that the hammer needs reconfigured to function right when the same force springs the hammer forward and the same force springs it back to half cock. The geometry is off somehow. Like  the bottom of ther hammer should be longer and the bopttom leg of the strut down further or ....the hammers hole lowered some.

Too often the Japanese Winchesters misfire from light primer strikes.

[Bunk Stagnerg]

I had some serious modification done by competent gun smiths who removed that silly rebound spring, and removed that odious safety. The safety on that gun is ME and i don't need another. They also cut a bunch of coils off of the mainspring that  reduced the trigger pull from somewhere north of 6 1/2 pounds t a very comfortable 3 1/2 pounds. The trigger spring was lightened and a lot of extra metal was removed from the sear shelf. Over all that made the gun much easier to operate and shoot accurately. The trigger spring work  also reduced the force needed to move open the lever.
there are 30 rounds loaded with HOLY BLACK on the bench  that will go down range in the morning before it gets hot.
I did have some problems with failure to fire but it would seem to be a combination of very dirty primer pockets. that and some Winchester primers that are in the white box I found on the back shelf of my shop. i am not sure how old but the price sticker says $2.50 a hundred. usually they fire on a second hammer strike, with only 2 complete duds in about 150 rounds. These are used in practice ammo with fresh CCI for competition.
respectfully submitted
Bunk

[rifle]

Bunk, they don't remove the rebound spring all to grther since it'sthe same as the mainspring. They would have had to remove or shorten the bottom leg of the mainspring strut.What I've heard is when that is done the half cock safety is not reliable and the trigger can be pulled when on half cock and the gun can fire.Not every time but maybe half the time.

I'd ask the gunsmiths if they modified the half cock notch any to compensate so it is actually safe.

The rebound spring is the mainspring so if the lower leg of the mainspring strut is shortened to get rid of the rebound then the hammer may not return to the proper half cock safe position and stay there properly under accidental trigger pull.

Removing coils from the mainspring is logical after removing the tension of the rebound to the hammer by shortening ther lower leg of the mainspring strut since the force isn't there anymore to dampen the forward thrust of the hammer from the mainspring as it came from the factory.

[john boy]

Is this a problem or a common occurrence ?

Only when the cases are not consistently crimped hard enough.
If it happens all the time - head space issue!