Arsenal 313-115-RF in the 30/30

[Glaciers]

The only time I have experienced head space in a lever was with Winchester’s from the early part of the last century. These were takedown levers that had loosened up from abuse, and a lot of use. Picked up 4 or 5 1894’s that were in various stages of being loose. Finally got advice from P. O. Ackley himself on the repair. The conversation went through his daughter as Ackley couldn’t hear worth beans. I think his daughter was in her 60’s, but the advice allowed me to relay the instructions to Bill Peacock my gunsmith friend who effectively repaired my rifles.
But, other then that I’ve not seen head space problems with leverguns. I’m sure there out there, people do stupid things all the time, but an over load I would think would cause a bulged chamber first before head space issues.
Just some thoughts, but there’s guys on this Forum much more knowledgeable then me so I’ll watch with interest.

 

[Rick]

Probably not the brass, the primer protruding is the result of enough pressure to push the primer back but not enough pressure to thrust the case rearward reseating the primer. Speer wrote about this way back in Speer manual #9 or 10.

 

[Rick]

I don't ever remember seeing a headspace problem with a rimmed case. The round headspaces on the rim, not the case mouth. Could be a rifle problem but then you would have the same issue with everything you fired through it, not just this one low velocity load.

 

[Ben]

I think the low pressure is the key to this issue.

Ben

 

[462]

For what it's worth:
It was many years ago so my memory is a bit foggy as to the exact details, but my .30-30 Winchester 1894 would exhibit backed-out primers. I know the bullet was the Ideal 308291/Lyman 311291, and I think the load was
10.0-grains of Unique.

Low pressure is the culprit. In this case a light-for-caliber bullet exiting the barrel at about half the speed of the heavier bullet the cartridge was designed around.

Oh, just remembered: I experimented with neck sizing and primers were still backing out.

 

[RBHarter]

I've seen this in a X39 . Just low pressure . In that case a false shoulder fixed the brass and back out .

 

[Spindrift]

I was thinking of loading some rounds with COL set to zero jump, and a hotter load to reset the head space. Making a false shoulder is probably better. I’ll have to see if I have a suitable expander.

 

[Rockydoc]

You might try enlarging the flash hole on a case and see if that would stop the protruding primers. You should not use those cases with enlarged flash holes for normal high pressure loads.

 

[popper]

Assuming the rifle doesn't have a real HS problem, the bolt is a recessed head and chamber. A thin rim or out-of-spec recess will allow the case to be pushed forward (extractor/ejector). When fired, primer (like a bullet) moves out. Hotter loads will push the case back against the bolt, re-seating the primer. Equal and opposite actions until it hits the bolt face. It is not a problem. If you set your sizer to let the shoulder almost HS, 'problem' goes away. I set my sizer this way to reduce case stretch on full power loads. Enlarging the flash hole just allows some powders to ignite better (bigger match). IMHO it also increases the force on the primer (pressure x area). I process my brass in batches. When I find a cracked neck, toss it and anneal the batch. Most of my brass is as old as the Marlin (15 yrs?), I do pick up range brass. Scraped one batch I bought of once fired as necks cracked right away.

 

[Jeff H]

The light primer strikes, is it possible that your brass primer pockets are starting to enlarge? There’s something about light loads, shoulder set back and primers setting back. Not sure that would happen with a rimed case.
Not familiar with the Vectan Ba10, what velocity do you think your getting? I’m wondering about the pressure curve moving the primer back a before the bullet exits the barrel.
Do you have some new brass you could duplicate these loads and see if the results are the same.

With RIMMED cases with a shoulder, specifically the 30/30, I've not had the problem of shoulder set-back with light loads, but I'm watchful for it in rimless cases.

I've not had primers left standing proud on similar loads in my 30/30 and I don't think they pushed out and got shoved back in, because they are always still nicely rounded - almost like new. This could be specific to the Contender or may be specific to MY Contender. I'm not shooting this bullet, but a LEE, C309113RF, with t he GC removed - 118 grains at about 1200 fps, using seven grains of Unique.

With the 30/30, I resize using a LEE Collet Neck Sizer, FLR'd OLD cases initially, some years ago.

You can maybe get a half-decent measurement of the depth of the rim cut by doing something like a reverse pound-cast by driving a lead ball into the breech and popping it back out with a rod. I think a .490" ball would be marginal, but a .520" ball should fit into the action and "print" enough of the rim cut to get something of an idea.

I don't know if this is of any help, but it's what I've seen on my one gun and these are the loads I shoot most from it.

 

[Ian]

I have five .30-30s and all of them save the one I rebarreled and chambered myself will push the primers back with light loads. My findings are that it is a combination of excessive rifle headspace and light loads acting as Rick described.

Having measured dozens of case rims and owning a set of headspace gauges I found that rifles err on excess and cartridge manufacturers err beyond minimum. The shoulder tends to function as a datum point in actual practice rather than the case rim, and when this is compromised by the light loads the excess rim headspace shows up.

By the way, it isn't the firing pin driving the case forward in the chamber and setting the shoulder back, it's the force of the PRIMER explosion. Enlarging flash holes mitigates shoulder set back because there is less primer pocket surface area for the primer blast to act against that drives the case forward.

When I rebarreled Jackie's 1899 Savage I had to fix all kinds of lockup issues and square the bolt face before reaming the chamber to final depth. Then I ended up turning the barrel shoulder back a few more thousandths to closing up the headspace a touch so the bolt bit hard on the "go" gauge, as in absolute minimum. Full length sized brass with the thickest rims I have on hand still rattle in the chamber, if that tells you anything.

I assume by "false shoulder" you guys mean partial sizing so as to leave an unsized bit at the base of the neck to act as a datum point on the shoulder/neck junction of the chamber? Remember that when neck sizing with the Lee collet neck die we control the diameter but not the LENGTH and the neck base is set back all the way to minimum. To leave a false shoulder on brass with the collet die, place a common steel 1/2" flat washer over the cartridge case so it goes between the shell holder and the collet sleeve base to space the case down a little in the collet fingers.

 

[RicinYakima]

Same issues I have trying to help people with the 32/20. Doesn't matter what the "spec's" say, what is the reality?

 

[Spindrift]

My understanding of the «false shoulder»- solution to excessive shoulder set-back, is this:
1) You expand the neck of the brass to a larger caliber, say .30 -> .338
2) Then, you run the brass into the correct, and well adjusted FL- die. This will reduce most of the neck to the original caliber, save a small portion at the base which will act as a small shoulder on which the cartridge can headspace.

Due to the very relaxed shoulder angle of the 30/30- brass, I’m unsure how well this concept will work. I think I’ll just load some forming rounds with zero jump, allowing the cartridge to headspace on the ogive. Or just throw the brass away, we’re only talking 20 pieces of well- worn brass here

 

[fiver]

put some celo tape on the back of the case.

 

[Bret4207]

I think someplace between the invention of the rimmed cartridge and today, the "it headspaces on the rim" idea kind of got modified. In a single shot falling block or something, yes. In a repeater, be it lever, auto, pump or bolt... I'd say it "depends on". I've seen this myself a number of times, where the "headspacing" is less the rim being trapped between the bolt and rim recess of the chamber and more the rim sort of floating against the extractor and whatever else is nearby, or so it appears to me. I know I've seen several rimmed cartridge rifles that were notorious for light primer strikes. I put this down to wear and tear, manufacturing tolerances in gun and cartridge and things like that. Take down rifles are known for this. In a tight rifle it's a non issue. In a well worn rifle it's just part of the game. Answers to the issue include things like the SMLEs interchangeable bolt heads or building up the bolt face with anything from braze to silver soldered steel disc to electro plating with chrome. Is any of that worth it when you can just use the shoulder in cartridge with a real shoulder? To some it must be because I've seen several rifles with those fixes.

Interesting discussion!

 

[Jeff H]

.......

By the way, it isn't the firing pin driving the case forward in the chamber and setting the shoulder back, it's the force of the PRIMER explosion. Enlarging flash holes mitigates shoulder set back because there is less primer pocket surface area for the primer blast to act against that drives the case forward......

That makes a lot more sense that what I've heard so many times before about the firing pin doing the dirty deed. I know what it feels like with the mechanical advantage of a press to set a shoulder back and have always questioned how a firing pin, hitting something meant to give way like it does (the primer) would have enough oomph to set the shoulder back.

I have some cases for which I enlarged primer flash holes for VERY light loads for rimmed and rimless and it seems to prevent, or at least mitigate said setback, because I don't end up with that particular issue after several firings. I've shot a lot of these in the 357, but not as many in the 30/30, so my observations are based on pretty limited data.

I have to assume that on my ONE 30/30, the Contender, I have a fortunate combination of headspace/rim thickness* AND, I never thought my 118 grain RF at 1200 fps was really THAT light of a load to cause such a problem.

*If one were to believe that the firing pin set the shoulder back. I've never outright disputed that hypothesis, but never quite bought it either, since I typically don't rely on the rim for headspace. I set the shoulder to where the base of the case is flush or a few thousandths proud of flush, depending on the barrel/breech-face gap, which is easy to achieve with a break-action.

 

[popper]

The 'spring' Marlin extractor pushed the case forward. Full power load pushes head back against the bolt. Light load won't. Yup, tolerance stack-up. I FL size all my brass and it still lasts a long time. Don't worry about it.

 

[Rockydoc]

put some celo tape on the back of the case.

Fiver, what do you mean: “back of the case”?

 

[fiver]

on the head, over the primer.
that will force the rim further forward.
if you can put 2 layers on and chamber the round you need to get the rifle looked at.
celo tape is about 2 and a half thousandths thick.

it's sorta kinda like using 0-rings on 303 cases to get them fire formed a little too big, but in the opposite direction.

 

[Bret4207]

on the head, over the primer.
that will force the rim further forward.
if you can put 2 layers on and chamber the round you need to get the rifle looked at.
celo tape is about 2 and a half thousandths thick.

it's sorta kinda like using 0-rings on 303 cases to get them fire formed a little too big, but in the opposite direction.

Huh! I never thought of that! Dead simple. I like it!