7.62 brass question

[snaggdit]

OK, I have been working on accuracy with cast in my SKS. I noticed something yesterday. I had pounded out a few mistakes and went to add them to the half box of fired rounds for tumbling. They sank deeper in the foam. I took out one of each and discovered my SKS fireforms the neck of the brass almost an additional 1/8".

Here's the question. I don't have a neck sizer die, only a full case sizer. Since they are only for my gun, can I load them again as is? Or, if I size them, can I raise the sizer die to only size the neck to boolit size without squeezing the shoulder back? I would think if I kept squeezing the shoulder back my EXPENSIVE NEW 7.62 brass will not last as long:(. Thanks!

[geargnasher]

I have a reg'lar old Lee sizer die for my .30-30 and have been loading it for 15 years running the cases about 3/16" shy of the shellholder touching the die for the same reasons you are asking about. Doing that provides just enough tension (with factory crimp die crimp) to hold boolits and doesn't size the body or shoulder any, and since brass is only shot in my 1 gun it doesn't matter and brass lasts A LOT longer and doesn't have to be trimmed as often.

Try it and see what happens by just pushing your cases in the die until the neck-sizing part just touches the shoulder of the fireformed brass. You may have to move the decapping pin/neck pilot to the lowest position it will still hold in or use a universal decapping die first.

Gear

edit: it might be a good idea to cast the chamber and see about the neck size in the chamber, the throat, and the leade to see about neck diameter, boolit diam, case trim length for your particular chamber (may be longer than spec), and seating depth if you are interested in accuracy.

[snaggdit]

OK, that's what I figured. Now, new question. With once fired fireformed brass will the pressure change since the case is a bit bigger? Velocity difference, etal?

[oneokie]

Pressure and velocity both will probably be lower due to the increased volume of the case.

[Leftoverdj]

I'd stop right there until I had that problem sorted out. You had grossly excessive headspace on that firing, and those cases probably have starting case head separations. It could be those cartridges at fault or you could have major rifle problems. I'd want to find out.

The .30-30 is irrelevant. It headspaces on the rim. You can blow the shoulder all the way out and turn it into a .35-55 case without hurting anything.

The 7.62x39 headspaces on the shoulder, and that much headspace is to be taken very seriously.

[Ole]

Get your rifle checked by a gunsmith.

I have a Norinco and I have some brass cases that have over 10 firings on them. They still are holding up great. SKS rifles are like a box of chocolates.

You can smoke the shoulder with a candle and adjust your resizing die so it doesn't set the shoulder back. I would be concerned if my shoulder fire formed a full 1/8" though.

[Slow Elk 45/70]

Snaggdit, To answer the first question, yes you can size down as far as you need to hold the boolit with out sizing the shoulder, when using in the same chamber, You might have feed issues with the semi-auto, without full length sizing. Try a few and see.

As Leftoverdj says, you may have some issues with the head space. Best to check this and the Brass out and find the problem , before you have an "Event"

[jdgabbard]

I'd stop right there until I had that problem sorted out. You had grossly excessive headspace on that firing, and those cases probably have starting case head separations. It could be those cartridges at fault or you could have major rifle problems. I'd want to find out.

The .30-30 is irrelevant. It headspaces on the rim. You can blow the shoulder all the way out and turn it into a .35-55 case without hurting anything.

The 7.62x39 headspaces on the shoulder, and that much headspace is to be taken very seriously.


Get your rifle checked by a gunsmith.

I have a Norinco and I have some brass cases that have over 10 firings on them. They still are holding up great. SKS rifles are like a box of chocolates.

You can smoke the shoulder with a candle and adjust your resizing die so it doesn't set the shoulder back. I would be concerned if my shoulder fire formed a full 1/8" though.

This is good advice. However, there is one issue with it. Most SKS's and AK rifles HAVE excessive headspace. It is pretty common, and to the extent that many that reload for these two families of rifles have case head separations after as few as one loading.

This one of several reasons why so many com bloc countries used steel cased ammo. Aside from being a little bit cheaper then brass (which was not in as great a supply as in other countries) steel will hold a higher pressure.

I have, in my building of AKs from part kits, noticed in the past while checking headspacing on matching numbers kits that sometimes when you align the hole up for the barrel pin and check headspace that it is so excessive that the barrel has to have some "shaved" off the face (sometimes this requires you to re-chamber), and set farther back. Where the hole will be redrilled in that location, resulting in the issue being solved.

However this is not something that is as easily done on the SKS. And even if you take it to a competent gunsmith, I fear that most are going to be un-educated about how to properly remove the barrel to fix the problem.

My advice would be to check your bolt and carrier to ensure they match the serial on the reciever. Next look for excessive wear on these two parts as well as the receiver to ensure that it is locking into battery correctly. I would also take a chamber cast to compare with established measurements of the 7.62x39 cartridge.

If you still coming up empty you can take it to a smith. But to be honest with you each SKS I own has excessive headspace (all three norincos), and not one of them has ever had any issues. At least while in my possession.

[runfiverun]

once you fireform the brass you don't have excessive nothin.
it now fits.
just do the pfl resize like you planned.
i set most of my dies to just barely size the neck they might squeeze the body some and if they do i neck size in my 308 short neck sizer then re expand with the correct sizer button for the boolit diameter i am using.
annealing helps a ton here if it is a lot.
i have a couple of die sets that resize the necks on my 31's down as much as the 308 sizer does anyways.

[snaggdit]

My advice would be to check your bolt and carrier to ensure they match the serial on the reciever. Next look for excessive wear on these two parts as well as the receiver to ensure that it is locking into battery correctly. I would also take a chamber cast to compare with established measurements of the 7.62x39 cartridge.

If you still coming up empty you can take it to a smith. But to be honest with you each SKS I own has excessive headspace (all three norincos), and not one of them has ever had any issues. At least while in my possession.

Well, I hade an issue with the firing pin actually puncturing the primers (and then driving the firing pin back out of the bolt) and replaced the bolt assembly last fall. I just had a few do it again, but at least this time the released pressure did not drive the firing pin out of the bolt like before. Could the headspace issue be causing the punctured primer issue? Case driving forward, then base being stretched back into the firing pin causing a puncture? I can just picture the responses now...:???:

[jdgabbard]

Shouldn't be causing a punctured primer. Those are caused by excessive firing pin protrusion. You can make you a guage out of some card stock. On the bolt that doesn't rupture primers, cut a little square out of the cardstock that is the height (as near to exact as possible...this is redneck gunsmithing but it works) of the firing pin's protrusion. Next just lightly sand the tip of the pin untill it matches, or is just slightly under.

Those of you who have Mosin rifles that came complete with the cleaning kit have a tool already that is similar to this for checking the firing pin's allowable protrusion.

Another thing I wonder about... Is the bolt you put in the rifle of the same origin as the rifle itself?

[jdgabbard]

Shouldn't be causing a punctured primer. Those are caused by excessive firing pin protrusion. You can make you a guage out of some card stock. On the bolt that doesn't rupture primers, cut a little square out of the cardstock that is the height (as near to exact as possible...this is redneck gunsmithing but it works) of the firing pin's protrusion. Next just lightly sand the tip of the pin untill it matches, or is just slightly under.

Those of you who have Mosin rifles that came complete with the cleaning kit have a tool already that is similar to this for checking the firing pin's allowable protrusion.

Another thing I wonder about... Is the bolt you put in the rifle of the same origin as the rifle itself?

[snaggdit]

The new bolt/firing pin assembly was for a Yugoslavian SKS, which is what I have.

[sheepdog]

OK, I have been working on accuracy with cast in my SKS. I noticed something yesterday. I had pounded out a few mistakes and went to add them to the half box of fired rounds for tumbling. They sank deeper in the foam. I took out one of each and discovered my SKS fireforms the neck of the brass almost an additional 1/8".

Here's the question. I don't have a neck sizer die, only a full case sizer. Since they are only for my gun, can I load them again as is? Or, if I size them, can I raise the sizer die to only size the neck to boolit size without squeezing the shoulder back? I would think if I kept squeezing the shoulder back my EXPENSIVE NEW 7.62 brass will not last as long:(. Thanks!

I feel for ya brother, I got a mess of 7.62 brass and realizing it will wear out way too fast. I would think that the way the SKS and AKs grab so hard on extraction you're going to lose your extraction rim or wear down your webbing before wearing out your brass at the neck. While neck sizing might save you around the shoulder you're probably going to get extraction issues from not fullsizing and therefore either get stuck cases or cause even greater rim wear on higher friction extraction.

[mpmarty]

Not to hijack this thread, but my AK 7.62 is a 7.62 Nato sixteen inch Saiga. I have reloaded the same fifty cases for it eleven times now and not had a problem as described here. These particular cases are mil surp from Portugal as I recall and have been loaded with 150gr spitzer boat tails with 44 grains of H-4895. I only partially resize these cases by tightening the die against a fully raised shell holder with a nickel placed on the shell holder as a spacer. They feed and function perfectly. Wish I could make the same comment about my recent attempts to get a cast boolit load to shoot in under three inches at a hundred yards with this turkey.

[snaggdit]

I feel for ya brother, I got a mess of 7.62 brass and realizing it will wear out way too fast. I would think that the way the SKS and AKs grab so hard on extraction you're going to lose your extraction rim or wear down your webbing before wearing out your brass at the neck. While neck sizing might save you around the shoulder you're probably going to get extraction issues from not fullsizing and therefore either get stuck cases or cause even greater rim wear on higher friction extraction.

I have been considering the gas port mod that a member (can't remember who OTTOMH) posted by drilling a second hole in the cylinder to reduce ejection force. That might reduce strain on the rims. I c&p'd it to a word file for future reference.

[FAsmus]

Gentlemen;

My answer to the case battering during extracton/ejection is to stick with a Yugo SKS with gas port on/off capibility so that you may run the rifle by hand and not hammer the brass to death OR spend the rest of your life hunting for your brass where ever it landed after firing and being ejected.

Then, just go buy an inexpensive Lee collet-type meck sizing die and use it to neck size your brass just enough to securly hold the bullets.

The combination of neck-sizing only and operating the rifle by hand will enable you to pretty much depend on the rifle/brass to give you similar life as does a good tight lever rifle.


Good shooting,
Forrest

[snaggdit]

I got to looking into the problem and think it was my fault. I don't remember why I had those couple set aside to pound the boolits out of, but they were loaded several months ago. I just compared a fired case with a new (never fired IMI brass) unsized case and a loaded case and there is very little difference. The new case is 1.515 long. The fired case is 1.505 long. The loaded case is 1.507 long (not counting the boolit). To the top of the shoulder, the new case is 1.307, fired 1.322 and loaded 1.302. Looks like I must have had the sizing die too far down when I did those few:roll:. My math tells me firing expands the shoulder .020, or a little over 1/64". Guess I should have done more checking before posting. I still think I want to just neck size, though. At least until I run into extraction problems. I will also look into doing that mod. Flinging expensive brass 20-30' is a little excessive, not to mention the wear and tear on the action/brass.

[geargnasher]

Snaggdit-

Make a cheap brass catcher out of window screen cloth or a $5 tarp and a couple of 2x4s, size your stuff just enough to cycle in the gun, and go blaze. As everyone her knows these guns are terribly crude but also very effective and reliable. If it hasn't blown up (or blown up a case head) yet you are probably ok. The fact that you hadn't reported any other case problems on your first post led me to assume you had no major gun issues, even with as much case growth as you reported. If it locks up well and isn't blowing the case heads off or blowing the primer out of the pocket your headspace is probably ok. Even if the case heads are weakened by excessive headspace that should show up pretty soon with most of a case being left in the gun. Again, before any of us assume too much cast the chamber and check the headspace just to be sure.

Do the firing pin trick the gentlemen above recommended, too.

Good luck

Gear

[FAsmus]

Snaggdit;

My biggest problem with running the rifle as designed semi-automatic has been the battering of brass by the ejector. My SKS smacks the case head so hard as part of the ejection cycle that it dents the brass badly enough that it will no longer fit into the shell-holder for subsiquent reloading.

Good morning,
Forrest