7.62 LC brass.. how to resize for 308

[kritos666]

Hello folks,

I have reached a quandary and i'm hoping you can help.

I searched, but found no answers other than I can use the 7.62 brass if I prep it. Unfortunately no one said how to prep it.

I have adjusted my dies 6 ways to sunday. I can't seem to get it right I have tried in 2 different weapons neither will allow me to roll the bolt completely over. Being new to reloading, I had inadvertently used some Winchester brass from 07 (WCC) and that chambers fine. However the LC from 08, which I just bought a bunch of, is a no go. Based on related articles it seems to have been run thru a machine gun and possibly over expanded. I have already swaged out the primer pockets. The LC brass has a steeper and higher shoulder than both the WCC from 07 and Federal commercial brass. I would attach an image to demonstrate, but I don't have a place to upload the image. Unless I can figure out how to get the head space right I just paid a lot for a bunch of useless brass.


Hopefully you guys have an idea or two.

Thanks much

 

[ChrisGarrett]

Re: 7.62 LC brass.. how to resize for 308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kritos666</div><div class="ubbcode-body">Hello folks,

I have reached a quandary and i'm hoping you can help.

I searched, but found no answers other than I can use the 7.62 brass if I prep it. Unfortunately no one said how to prep it.

I have adjusted my dies 6 ways to sunday. I can't seem to get it right I have tried in 2 different weapons neither will allow me to roll the bolt completely over. Being new to reloading, I had inadvertently used some Winchester brass from 07 (WCC) and that chambers fine. However the LC from 08, which I just bought a bunch of, is a no go. Based on related articles it seems to have been run thru a machine gun and possibly over expanded. I have already swaged out the primer pockets. The LC brass has a steeper and higher shoulder than both the WCC from 07 and Federal commercial brass. I would attach an image to demonstrate, but I don't have a place to upload the image. Unless I can figure out how to get the head space right I just paid a lot for a bunch of useless brass.


Hopefully you guys have an idea or two.

Thanks much </div></div>

Either pitch them in the recycling bin, or try to find a small base body, or FL sizing die. Redding makes them.

These give you a bit more compression for brass fired in sloppy chambers.

Chris

 

[Grumulkin]

Re: 7.62 LC brass.. how to resize for 308

How to prep the 7.62 NATO brass:

1. Adjust the full length sizing die so when the ram comes up the shell holder firmly contacts the base of the die.

2. Lube case well and run through the die.

3. Trim the case if needed.

If brass prepared as above won't chamber then your die isn't sizing them enough and you would need a small base die as noted above.

Of course, there is a small part of the case around the head that's covered by the shell holder so can't be sized. If that part of the case is so expanded as to make chambering impossible, you probably should discard the brass.

One other thing; you don't mention crimping. If crimping isn't done right, it will keep the cases from chambering. You don't need to crimp 308 Winchester cartridges so if you have been crimping, try loading some cartridges without crimping.

 

[95LTZ]

Re: 7.62 LC brass.. how to resize for 308

As others have already said a Small Base sizing die is your friend. I have had similar difficulties with various brands of 308 brass. Now I always run the cases through the SB die the first time. Redding makes a set of competition shell holders which bump the shoulder back & allow a little more case to be resized. Adjust the ram on the shellholder with the least bump until it touches the shellholder then tighten 1/8th turn. Now which each change in shellholders you'll get a little more sizing until a case chambers easily. I had to use this method on Lapua cases that someone had fired in a M1A.
Semper Fi

 

[Rookie]

Re: 7.62 LC brass.. how to resize for 308

You can also take your sizer die to a machine shop and have a few thousands milled off the bottom. I've had to do that twice for custom builds. A local rifle builder should be able to do that while you wait.

 

[Gene Poole]

Re: 7.62 LC brass.. how to resize for 308

I had the exact same situation. I bought 250 LC NATO cases from a gun show. They all went through a FL die, but maybe one in 4 wouldn't chamber in my R700 BDL-V. For the ones that failed to chamber, I pulled the bullets, popped the primers, then coated the whole case using a blue magic marker. I shoved the case into my rifle and tried to force the bolt closed. Some would with moderate force; others wouldn't. They all showed rubbed off magic marker on the body of the case, about 1/2 to 5/8 inch up from the base. Shoulders were fine. That's when I got a small-base die and that did the trick.

 

[turbo54]

Re: 7.62 LC brass.. how to resize for 308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rookie</div><div class="ubbcode-body">You can also take your sizer die to a machine shop and have a few thousands milled off the bottom. I've had to do that twice for custom builds. A local rifle builder should be able to do that while you wait. </div></div>

A flat surface and sandpaper is a cheaper/easier approach.

Also, you can simply skim some material off the top of your shellholder, rather than monkeying with your die.

 

[former naval person]

Re: 7.62 LC brass.. how to resize for 308

But, for some excessively expanded cases, the reduction of length of the shoulder/base dimension by trimming the die or shell holder MIGHT not be the answer. You could eventually get the base sized down enough to chamber, but you could also have induced excess headspace, so that when you fire them, the case will stretch and maybe separate. A small base BODY die will fix the situation, and is useful in other conditions wherein you wish to bump the shoulder only and neck size in a separate step.JMHO

 

[Kentucky Jelly]

Re: 7.62 LC brass.. how to resize for 308

Biggest problem I have had with LC 7.62 is the expander ball pulling the shoulders forward. Try sizing them with the expander ball removed to see if that helps.

Before buying new dies, or modifying your current dies. Be sure of the issue. Compare measurements from your once fired brass from that chamber to your sized LC brass.

 

[targaflorio]

Re: 7.62 LC brass.. how to resize for 308

John Feamster will tell you to throw away machine gun brass. I follow his advice.

What are the fired case headspace dimensions?

If you can find a military shooting team, you can ask them to give you their match brass in exchange for the mg brass. To them, brass is brass.
Good luck!

 

[Kinsman]

Re: 7.62 LC brass.. how to resize for 308

I had the same problem with MG fired brass.
Tried trimming the die, and got excess headspace.
Small base die solved the problem completely. After using the small base die, fireform and go to the standard die.

 

[Scaup58]

Re: 7.62 LC brass.. how to resize for 308

I use lots of "machine gun" brass and have no issues. I size with Hornady match grade die & Redding bushings for a .003" shoulder bump for my AR10. This brass is very long after it's first sizing and needs trimming, you didn't mention weather you trimmed or not. My AR10 is NATO chambered and probably more generous than your bolt gun though. Redding makes a small base body die, P/N 74148 that you may need to use the first time through with the LC. I would set your current die to bump your shoulder only about .001 or so for your bolt gun, lube the inside neck well and if the LC still gives you trouble get the redding die. On second thought, that LC stuff is really junk, send it to me and I'll dispose of it properly for you.

Seriously, I've found the LC to be quite uniform in neck wall run-out, less than .0005 90% of the time. The necks are about .002 thicker than most other brass though which may contribute to shoulder pulling if necks are not inside lubed. This is why I use a bushing die.

 

[kritos666]

Re: 7.62 LC brass.. how to resize for 308

Thanks for the replies....

clearly a Small Base sizing die will be the way to go..

I did trim the brass, I will also try removing the expander ball and see if that helps. I figured there would be some mojo to make this work.

Once I figure out a method, perhaps ill create a how-to doc for other noobs like myself and we can post as a sticky. Or something simliar

Thanks again.

 

[kritos666]

Re: 7.62 LC brass.. how to resize for 308

Well I got it working.. Thanks Kentucky Jelly! taking the expander ball pointed me in the right direction. I was working with a used set of dillon dies. and in trying to take the expander ball off, I found out it had been loctite'd .. as such without a lot of work, I left it. Then I went with plan B. I decided to heck with it. and just kept cranking down the die .. it ended up being 3 full rotations past bottoming out on the ram. But, now all of the shoulders are correct. Ill run thru this stuff. and chalk this up as a lesson and a 1/2.

Thanks again guys

 

[Gene Poole]

Re: 7.62 LC brass.. how to resize for 308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kritos666</div><div class="ubbcode-body"> I decided to heck with it. and just kept cranking down the die .. it ended up being 3 full rotations past bottoming out on the ram. But, now all of the shoulders are correct. Ill run thru this stuff. and chalk this up as a lesson and a 1/2.

Thanks again guys </div></div>

Unless I'm missing something here, how does threading the die in more after the base has already made contact have any effect on shoulder? Once the base makes contact, there's no more relative motion between the shell holder and the die no matter how far you thread it in. Am I missing something?

 

[kritos666]

Re: 7.62 LC brass.. how to resize for 308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gene Poole</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kritos666</div><div class="ubbcode-body"> I decided to heck with it. and just kept cranking down the die .. it ended up being 3 full rotations past bottoming out on the ram. But, now all of the shoulders are correct. Ill run thru this stuff. and chalk this up as a lesson and a 1/2.

Thanks again guys </div></div>

Unless I'm missing something here, how does threading the die in more after the base has already made contact have any effect on shoulder? Once the base makes contact, there's no more relative motion between the shell holder and the die no matter how far you thread it in. Am I missing something? </div></div>

You make a good point. Heck now I'm confused. To tell you the truth, I was grasping at straws trying one last time before buying a RCBS Small Base FL sizer. When this adventure started I was showing a buddy how to setup his dies (we have different OAL's). That was where I discovered the issue. Then, after trying for quite a while, I asked him for a second set of eyes. No matter what we did, we could not get the cases to chamber. Not a one would cycle before moving the die down.

Once I re-adjusted the die the other night, I was able to get them to cycle. I subsequently tested, the first 10 that I re-sized, and then every 5th and after about 50 I took it as functioning fine.

Sorry I don't have anything more concrete.