Primers backing out

[milkman]

Gentlemen,
I need some help understanding what is going on. The rifle is a Savage chambered in 35 Whelen. It is several years old and I have never had this problem before.
I loaded 4 sets of 3 cartridges using different powders and all using the same 285g boolit. I am depending on Quickload for data because of the boolit weight, but Quickload shows a minimum of 23K and a max of 34K PSI for the loads.
At least 1 of the primers out of each group of 3 is standing proud by at least 5 thou. and some as much as 15 thou. by my guestimate. I didn't make a trip to the shop for calipers. The higher the pressure the greater number of primers have backed out in each group, with the 34K group all backed out.
The barrel nut and barrel are tight, so I don't think headspace has changed, and I would guess it's not a low pressure scenario.
Any ideas?

[wch]

Have you checked to be sure that you used LR primers?

[dale2242]

It`s possible you are pushing the shoulders back as you resize them. This would create headspace problems.
The firing pin would push the case forward. The cases may be gripping the chamber walls allowing the primers to back out.
Try neck sizing only.....dale

[Sensai]

The case fit/headspace has definitely changed. There wouldn't be room in the chamber for an additional 15 thousanths otherwise. It sounds like a combination of shoulder set back and low pressure load to me, but that's just a long distance guess. Are you full length sizing the cases? If I'm right then a higher pressure load will set the case head back and possibly cause head seperation, so I'd find out exactly what's going on before I shot any more of those rounds. Just my 2 centavos. Best wishes, Gary

[milkman]

Yes, I am sure they are the correct primers and sizing stops about 1/16th above the shoulder so the brass should be fire formed to the chamber, and boolits are jammed pretty firmly into the rifling.

[milkman]

I am not full length sizing and I just checked and there are no stretch grooves inside the cases, but maybe been fired enough to form yet.

Sensi, that is a very good point about not being room for primers to back out with cases that should be formed to the chamber.

[RickinTN]

There is a headspace differential in your chamber and your cases. At the pressures you are running it will take several firings for cases to expand to "fit" your chamber and actually be fireformed.
Rick

[milkman]

These cases have been fired multiple times over the past couple of years, with no problems observed

[milkman]

I just put 7 layers of cellophane tape on the end of a hunting cartridge loaded for last season. At the 7th layer I could just feel the bolt getting a little more snug, 8 will go but the bolt requires some force to turn. If tape is about .002" then that would be about the same amount that the primers are backing out.
I also tried to turn the barrel and barrel nut, but they are too tight to turn by hand, but something has changed!

[Sensai]

Milkman, if you can get your hands on some modeling clay, or even Playdough, make a small ball of it and stick it on the head of a case. Chamber the case and close the bolt, then extract the case. It won't give a measurable and definitive headspace measurement, but it can give you an idea of what's going on headspace wise. Plastigage from an auto supply store will do the same thing with measurable results (with caveats). Best wishes, Gary.

[Ben]

.014 " ...........You've definitely got a h/space problem.
Might be a good idea to get the rifle to a gunsmith and have him put h/space gauges ( Go - No - Go ) in the chamber and see what is going on .

Ben

[milkman]

Yeah, I don't think I will be comfortable shooting this one again till I know for sure what is going on.

Thanks for all the replies

[runfiverun]

you don't have any calipers??
just changing the shell holder will change the cases length when you size.
i'm more thinking the combination of older cases and the low pressure are just allowing the primers to back out and the low pressure isn't re-seating them.

[milkman]

Yes, I have calipers and a micrometer, but was too lazy to walk 100 yd to get them since i didn't think the amount of protrusion really mattered. It could be low pressure, but I have never had 34k Psi loads allow primers to stay backed out before and the .014 to .016" of tape on a case and it still chamber bothers me.

[cbrick]

Just to be an arm chair quarterback since I don't have the rifle or loaded rounds & brass to look at or measure. Something changed and the only thing that could be is headspace, assuming nothing changed with the rifle that leaves only the brass.

Did your die setting change allowing the shoulder to be pushed back? Is the inside of the die clean?

You said the boolit is engaging the rifling, that should hold the case head against the bolt face but boolits are much softer than jacketed and the firing pin could cause them to engrave your additional .015".

When you put the tape on the case head to get your .016" measurement was this with empty brass or with a boolit loaded to proper cartridge overall length? If with a boolit was the ogive further engraved by closing the bolt with the tape?

Try carbide smoke on the case shoulder and boolit ogive both with and without the tape on the case head. You will be able to see exactly where contact is made. See if the ogive or the case shoulder is what is causing the bolt to get stiff with tape. If it's the ogive and not the shoulder there is a headspace problem.

Rick

[Moonie]

It's a Savage, get a set of go/no-go gauges, loosen the barrel nut, set the headspace, tighten the barrel nut done. I believe you can use 30-06 go/no-go guages.

[uscra112]

Well, a primer backing out says excess headspace, without any doubt. The whelen has a very small shoulder, so it's very susceptible to shoulder setback when shooting light loads. The explosion of the primer (NOT the firing pin) drives the case forward, and if the load pressure isn't enough to drive it back, the primer pops out. My .35 Remington has the same problems sometimes. First, use mild primers. I use pistol primers for anything under 30K psi. Second go get a set of Ackley Improved dies, and a reamer, and ream yourself a decent shoulder in that chamber.

You can set those shoulders forward again by (gasp!) greasing your cases (gasp again) and firing them with a light fast load and a light boolit. 7-8 grains of Red Dot should do it. Degrease chamber thoroughly afterward. I use Ed's Red, followed by swabs with straight acetone.

Do not start shifting your barrel! This is not a gun problem, it's a load problem.

[MtGun44]

First off - ALL PRIMERS ALWAY BACK OUT. . . . 100% OF THE TIME. BUT --

ALL primers back out to the extent that there is a clearance between the cartridge and the bolt
face, EVERY TIME you shoot. But with a full pressure round, the case then immediately stretches
out and gets pushed against the bolt face and RESEATS the primer. You have low pressure loads
that are not stretching the cases, and therefore not reseating the primers. This is nearly meaningless,
in my experience. Up the pressure a bit and the "problem" (non-problem) 'goes away' as the
primers are reseated.

99.9% of guns have some clearance between the cartridge and bolt face, a few have exactly
perfect headspace and exactly perfect ammo, I suppose. "Excessive headspace" just means that
FACTORY ammo is a bit small for your chamber. So, as a reloader you can fit YOUR ammo
exactly to YOUR chamber. So - don't push the shoulder back so much once you shoot some
full pressure ammo and then when you shoot low pressure loads, you won't see this. Your
"excessive headspace" gun will stretch factory cases a bit much the first firing, but this
isn't a problem if you will stop over-sizing your brass. What may be 'normal' sizing with
one gun can be 'over resizing' for another gun. Adjust the sizing die so that you just
touch the shoulder on cases that have been fired with FULL PRESSURE loads, then leave
it there for that gun.

If you just ignore it and go on, you brass life with full pressure loads will be a bit lower unless
you stop over sizing your brass and pushing the shoulder back too much. Tight headspace
is highly overrated. Non-handloaders don't care about brass life, so if the case doen't rupture,
so what? For handloaders, just don't resize too much and you have fixed it. No big deal
either way.

Bill

[lwknight]

I'll take a stab.
As stated above, you definitely have excessive head space whether it be from the sizing or just a loose chamber. My guess on the varying primer protrusions is that some cases actually grab on to the chamber walls and don't press back to reset the primer with the lower pressure loads.
Albeit that 35k is not exactly low pressure. I had a 30 Remington that did that on every round even with regular factory loads. I didn't worry about it though.

[303Guy]

I'm inclined towards MtGun44 point of view. 35k psi is a really low pressure load (think 26,000 CUP ball park). The case grip will hold the case forward and not allow the primer to reseat. I've noticed that low pressure loads tend to loosen headspace somewhat. And lubing those cases will not cause the world to come to an end. I would go loading to max with lubed cases though. The case holds up to 10% of the rearward thrust of a medium load but at lower pressures the primer gives 100% of the rearward thrust and the case zero.

I'm not sure the primer drives the case forward. The firing pin acts first but the primer would surely add to it. After all, it can drive a bullet out the case neck. That might explain why headspace seems to increase with light loads.

What may have changed over time is light loads increasing headspace.

[milkman]

cbrick - dies were not intentionally changed. I am still only sizing the neck and stopping about 1/16" above the shoulder. If the shoulder is being pushed back it is by the firing pin strike. The case I put the tape on was a loaded hunting round from last year. I do have some new, unfired cases, but have been busy and have not dug them out to compare.
I am aware that primers back out on firing on all loads. HOWEVER--- My hunting loads have been loaded to about 1750 fps with the 285g boolit and the primers have not backed out. Mid 20s on pressure. I had upped the velocity on these to about 2000 fps and the higher the pressure went the more the primers backed out.

I don't believe a load pushing a 285g boolit to 2000 fps can be called low pressure. Folks that ain't no squib, mouse fart load.

My next step is to get the gun to Goodsteel next week to get head space checked with gauges. If that checks out then I will relax and try to figure out what has happened with the brass. MAYBE, JUST MAYBE my hunting loads, 1750 fps with the 285g boolit really are low pressure and several firings have set the shoulder back so the problem is just showing up now, but the recoil from them has knocked my cap off several times, so there would seem to be enough pressure to seal a case and stretch brass and it does leave them with clean necks with no smoking.

Thanks again for all the replies and I will check back in with what I find out.

[detox]

SIMPLE...I would anneal all brass then load a few rounds with heavy jacketed boolit loaded long to engage rifling and to help keep case pressed against bolt face.. The heavier grain jacketed round nose corelock boolits have extended ogive (reason for long throats). Depending on the design a cast boolit may also work. This should help keep shoulder back from chamber and then form well when fired. These longer rounds will probably not fit magazine and will need to be feed single shot.

Be very careful not to set the shoulder too far back next time you resize. Size case until bolt just closes.

BTW Remington brass is softer than most and fireforms easier.

[runfiverun]

there is an article/thread/discussion somewhere here that talks about the excess headspace thing caused by light loads and the firing pin jamming the case forward bumping the shoulder back.

if there is an issue Tim will find it, but I really think it's just a case of the above showing up.

[uscra112]

C'mon guys, think it through. [smilie=s: The firing pin hits the only soft spot on the back of the vase, the primer. It dents a very thin metal cup and crushes a weak, brittle pellet of primer compound against a flimsy little stamped sheet anvil. How is it going to drive the CASE forward when it doesn't even contact the case? It's the primer explosion that drives the case forward. And that's why the ancient practices of using mild primers and oversizing the flash hole prevents shoulder setback. The first guys to shoot gallery loads in the .30-06 found that out, a hunnert years ago.

Yes, of course the primer backs out. But it can only back out the extent of the headspace. If the O.P. has primers backing out .015", he's got shoulder setback, and hence excessive headspace.

[milkman]

uscrea112
I don't understand your reasoning on the primer.
If the primer going off and the resulting burning gas escaping from a hole in front of the primer drives the entire case forward, wouldn't the powder going off try to drive the entire case further forward into the barrel?
Are you saying that the explosion of the primer is contained within the primer and still drives the case forward before the gasses escape ?
You have lost me.

[Sensai]

I've heard both arguments about which one, firing pin strike or primer explosion, pushes the case forward. What I haven't heard is why BOTH can't be happening. I think it likely that the firing pin strike pushes the case forward until all the excess headspace is taken up, then the pressure between the primer cup and case drive the primer cup back until it reaches the breech face then peens the case into the chamber shoulder. But I'm not in there watching, so I'm just guessing like everybody else.

[milkman]

Sensai
That sequence does make logical sense to me. I'm not entirely convinced, but I can't argue the logic. I have arrived at the enlightened position over the last half century or so that my understanding doesn't really alter the way things work anyway.

[Uncle R.]

First off - ALL PRIMERS ALWAY BACK OUT. . . . 100% OF THE TIME. BUT --

ALL primers back out to the extent that there is a clearance between the cartridge and the bolt
face, EVERY TIME you shoot. But with a full pressure round, the case then immediately stretches
out and gets pushed against the bolt face and RESEATS the primer. You have low pressure loads
that are not stretching the cases, and therefore not reseating the primers. This is nearly meaningless,
in my experience. Up the pressure a bit and the "problem" (non-problem) 'goes away' as the
primers are reseated.

99.9% of guns have some clearance between the cartridge and bolt face, a few have exactly
perfect headspace and exactly perfect ammo, I suppose. "Excessive headspace" just means that
FACTORY ammo is a bit small for your chamber. So, as a reloader you can fit YOUR ammo
exactly to YOUR chamber. So - don't push the shoulder back so much once you shoot some
full pressure ammo and then when you shoot low pressure loads, you won't see this. Your
"excessive headspace" gun will stretch factory cases a bit much the first firing, but this
isn't a problem if you will stop over-sizing your brass. What may be 'normal' sizing with
one gun can be 'over resizing' for another gun. Adjust the sizing die so that you just
touch the shoulder on cases that have been fired with FULL PRESSURE loads, then leave
it there for that gun.

If you just ignore it and go on, you brass life with full pressure loads will be a bit lower unless
you stop over sizing your brass and pushing the shoulder back too much. Tight headspace
is highly overrated. Non-handloaders don't care about brass life, so if the case doen't rupture,
so what? For handloaders, just don't resize too much and you have fixed it. No big deal
either way.

Bill
Here is what you need to do...
Read the above very carefully.
Read it again.
<
Bill knows.
<
Even if your cases are sized to a perfect fit in a chamber with perfect head space, the primer explosion causes some shoulder setback and some clearance at the bolt face before the powder starts to burn. The amount of shoulder setback is influenced by multiple factors - primer strength, flash hole size, case diameter, case hardness and taper, and (Very much!) shoulder size and profile. Cases with small and sloping shoulders can see some pretty severe setback from primer explosions. In normal full power loads the case walls stretch to reseat the primer and fired cases come out looking normal. If there's not enough pressure to stretch the case you get protruding primers, shoulders pushed even further back after multiple firings, and symptoms of "excessive headspace" even when there's nothing wrong with your gun.
<
Uncle R.

[uscra112]

uscrea112
I don't understand your reasoning on the primer.
If the primer going off and the resulting burning gas escaping from a hole in front of the primer drives the entire case forward, wouldn't the powder going off try to drive the entire case further forward into the barrel?
Are you saying that the explosion of the primer is contained within the primer and still drives the case forward before the gasses escape ?
You have lost me.

Area for the powder gas to operate on is the entire area of the base inside the case. Much greater than the area of the primer.

[steve4102]

Your Load is UNDER Pressure. Backed out Primers has nothing to do with headspace.

All primers back out to some extent, then the "High" chamber pressure of the round slams the case head back into the bolt face reseating the primer. If there is excessive "headspace the primer will become flattened and give the false sign of High pressure.

If there is low/weak pressure the case head will not slam back into the bolt face hard enough to reseat the primer.

Nine times out of nine a backed out primer is the result of LOW pressure.

Test it for yourself, but a case primer only, no powder no bullet in one of your revolvers. Fire it and see if the cylinder will spin.

[uscra112]

But the distance that the primer backs out has everything to do with headspace. It cannot back out any more than the headspace, so if it's backed out .015", that's the least that your headspace can be. I use this as a quick-n-dirty headspace check quite frequently.

[geargnasher]

Ya'll need to listen to Uscra112. Yes, the .35 Whelen doesn't have much headspace surface, so it's easier than many to hammer the shoulder back during firing. I challenge any of you who think it's the firing pin energy knocking back the shoulder to actually go take a fireformed case with the dud primer still in it and drop the pin on it a dozen times, then do the tape test to see if it did anything. Even Mausers don't have enough poop in the firing pin and spring to set a shoulder back. Next, refresh the primer and fire it, repeat. The second primer will be backed out. I'll bet that's what's happening here. The pressure isn't enough to stretch the case head (fortunately) so the headspace never gets corrected by firing. Lubing the cases will take care of it as was mentioned.

Gear

[steve4102]

But the distance that the primer backs out has everything to do with headspace. It cannot back out any more than the headspace, so if it's backed out .015", that's the least that your headspace can be. I use this as a quick-n-dirty headspace check quite frequently.

Right, but if the round was producing "Proper" pressure (in the case of the 35 Whelen 58K Max NOT the OP's 34K) then the chamber pressure would re-seat the primer and cause it to flatten, NOT let it sit proud.

If the primer sits proud after firing it is a Low pressure problem. If the OP's rifle has headspace issues, they would show up as "Flat" primers at proper pressure levels not backed out primers.

[MtGun44]

Add more powder or lube you brass and the "problem" will disappear.

Bill

[geargnasher]

I'd go with lube the brass. More likely to stretch from the front instead of just in front of the case head that way. The old Red Dot, Dacron, and Ivory soap boolit works pretty well too.

Gear

[milkman]

Now I can understand why SWTSMBO hates it so bad when I prove her wrong.... totally new experience for me. dang it, dang it, dang it i WAS WRONG !!

I finally found a brass that I was sure was from a new batch of once fired brass. Purchased as "once fired", not fired in my rifle. I cut a piece of .0010 aluminum check material and stuck it to the end of the new brass. It would not chamber. My brass with the primers backed out will chamber with the same material on them. The shoulder HAS moved.

I still do not understand how the brass is able to move forward in the chamber with the boolit engaging the rifling, but apparently that is what is happening. I also would not have believed that 34k Psi is not enough pressure to stretch the brass back against the bolt face. Well, enough crying, at least I know what is happening now.

Thanks again for all the help, and I hope I didn't hurt any feelings with my stubborn disbelief of people who have proved that they know a lot more than I.

Milkman

[FAsmus]

uscra112, milkman et-all;

I have had this problem myself in 30'06.

My fix - after thinking about it, was simply to bring along a tube of white grease in a tube and add a very small touch of it to each cartridge right at the shoulder before I chamber it. Presto! the problem disappeared!

I'm totally with uscra112 in this technique and agree with his explanation of the cause for pushed-out primers.

I wouldn't ever use this technique with full-house jacketed loads but for our stuff - it works first rate.

Good evening,
Forrest

[uscra112]

Now follow up by using pistol primers, and/or enlarging the flash hole. Drilled cases must not ever be used with full-house loads, but you only need to do a couple dozen to be able to test your loads and go hunting.

BTW I used RCBS sizing lube. It washes off with water. Salvaged quite a few .35 Rem cases that I'd spoiled by not knowing the right stuff to do. Now I just use pistol primers for my light K-31 and .30-06 loads.

The total absence of this shoulder-setback problem is one of the factors that makes the good old .30 US (Krag) such a great cast boolit cartridge !

[geargnasher]

And .30-30, .45/70, .444 Marlin, and all the rimmed pistol calibers too! Even the belted cases do well with light loads provided the gun's headspace jives with the rim/belt thickness, which all too often it does not. For .30-30 and .303 British, the o-ring trick works great for fireforming in the typically sloppy guns so chambered.

Gear

[geargnasher]

While we're on the topic, humor me on a side-track. I picked up three boxes of .30-'06 at a public range once from the ground where they had fallen after being ejected from some sort of semi-auto, I presumed an M1. They were absolutely dripping with what I immediately recognized as RCBS case lube II by feel and smell. I thought "What a dummy, didn't they know to wipe that stuff off after loading?", then I realized the cases were Greek military and still had the original, sealed, crimped primers in them which reduced the probability that they were reloaded. Even if the shooter had pulled the original bullets and reloaded them with something else, sizing and sizing lube wouldn't have been necessary. So why the lube? Sticky/unreliable extraction? Primers backing out and locking up the works somehow? I dang sure wouldn't want that much bolt thrust on an M1, but maybe I'm missing something. Any ideas?

Gear

[FAsmus]

Gear;

Was there any supporting evidence of the M-1? Like a forgotten clip maybe?

Anyway, who knows - its open to speculation of course but I'd guess that someone thought the rifle might feed more smoothly is things had a little help ~

Forrest

[MBTcustom]

I'd be willing to bet it was a Remington 742. They don't call em the jamamatic for nothing. One F-up is the FTF, but the other big problem is the FTE and the rifle will many times rip the darn rims right off the case, leaving you with a case stuck in the chamber. One simple fix, is to lube the cases so they can't make grip on the chamber.
I bought a 742 specifically so I could see if I could fix these problems. I jacked with it, got POed and sold it. That rifle was a lousy design on so many levels. Worked superb as a pump gun, but sucks rock salt as a semi-auto. Definitely one of Remington's biggest flops.

[Moonie]

I'd be willing to bet it was a Remington 742. They don't call em the jamamatic for nothing. One F-up is the FTF, but the other big problem is the FTE and the rifle will many times rip the darn rims right off the case, leaving you with a case stuck in the chamber. One simple fix, is to lube the cases so they can't make grip on the chamber.
I bought a 742 specifically so I could see if I could fix these problems. I jacked with it, got POed and sold it. That rifle was a lousy design on so many levels. Worked superb as a pump gun, but sucks rock salt as a semi-auto. Definitely one of Remington's biggest flops.

My oldest son has one, we haven't had much problem with it, but it was always kept clean. One of the biggest issues that caused this was not cleaning the chamber, a rusty chamber really isn't good in any firearm but especially in a semi. The only FTF's we have had have been magazine related.

Great target load for it is 35gr of H4895 with the lee 170gr boolit. Nice reduced load that functions perfectly.