7.62x51 FLS Die Question

[LRDGCO]

I load suplus military brass for a PTR-91. Have worked through a 500 round order and tried to move onto a new batch this evening. All LC. Thoroughly cleaned and polished in walnut medium before sizing. Using Lee 308 dies have had no problems, until now.

The brass has presumably been used in machine guns and requires some force to full length resize. In this new batch, I cannot run the brass full length in the die. It stops about an 1/8” to 1/6” short and no amount of pressure will move it that last bit. Based on what I am seeing in the brass removed from the die, shine and pressure signs in the top quarter of the neck, it appears that the collet is too tight for the neck brass.

I cleaned the die out really well, applied a bit more case lube. No change. The neck brass appears too thick for the die tolerances.

Has anyone experienced this?

Is it brass thickness, or am I overlooking something?

Is ther such an animal as a 7.62x51 FLS die that accounts for the thicker brass?

I am not going to neck turn the brass. Is there another solution?

Just as I finished writing this, I thought “what if the brass is really stretched?”, so will check that and revert.

Thanks very much for your assistance.

 

[ArchAngelCD]

This is why most handloaders avoid brass used in a SAW.

If you want to use this brass you will need to purchase a Small Base Die to completely size the case outfit back to SAAMI specs.

The die is on sale right now.
https://www.midwayusa.com/product/597261/rcbs-small-base-sizer-die

Welcome to the forum.

Edit to add second link and it's on sale too. For only $6 more you get the two die set.
https://www.midwayusa.com/product/681255/rcbs-small-base-2-die-set

 

[FROGO207]

Welcome to the forum.
Hopefully you are using a full length sizing die to size this brass. A Lee collet die will not return the brass back to correct SAAMI specs so you need to full length size them. The dies above will do it for you. I full length size all my brass I use in semi auto firearms. The center decapping pin/rod may be down too far in the die and stopping the brass from fully entering the die if you are using a full length sizing die. This would be something to check as well.

 

[Slamfire]

As stated by the guys previously, if you are neck sizing, you are going to experience jams in your semi auto rifle. You absolutely must full length resize cases for semi auto mechanisms.

I regularly full length resize surplus LC 308, or at least used to, and I use a small base sizing die and I use RCBS water soluble case lube, or Imperial sizing wax. You try to small base size with some of those spray on lubes, or those other wax lubes, and you will stick a case in the die. Getting a case out usually involves ruining the spindle in the process. You have to drill a hole in the primer pocket, tap the case, and use a special screw puller to get the case out of the die.

I recommend using one of these for setting up your sizing die. It is critical to size the case between "Go" and "No Go" or you will experience function issues.





Sizing dies come with instructions to size to the shell holder plus a quarter turn, this is typical, once you get these cartridge case headspace gages, you will find that nothing sized to that advice is within tolerances. And, you will find that the die has to be re adjusted for difference batches of cases. They spring back differently.

 

[z7]

LC 7.62 brass fired in machine guns is tough and ballooned out. I found that a small base sizing die is needed and that annealing the neck/shoulder helps.

 

[Blue68f100]

Annealing will be the most beneficial when it comes to sizing MG brass. I've done this several times for my neighbor. He also discovered what case head separation is with the brass on the first firing. He though it was strange for the brass to need 0.040-0.050" trimmed off. Doing so allows for std base dies to work. I have never had the need for SB dies in any caliber. And most all of my guns have tight minimum spec chambers. When sizing this kind of brass, soon as the loads gets over the normally required force, back out. Apply more lube and go again. This has always worked for me with Imperial Sizing Wax. Failing to stop is going to leave you with a stuck case. Also if your forcing things inspect your dies and brass for scratches. So you can in bed brass onto the surface of the sizing die. Best to catch this early while it's easy to clean out.

 

[LRDGCO]

Thanks for the responses.

As stated in the OP, I full length resize using Lee standard .308 Win dies. I use RCBS case lube and a Rock Chucker press. I was unable to get back to the bench last night but I bet I have excessive length on the most recent brass. My reference to “collet” was to describe what appears to be excessive pressure/force being exerted on the top 1/8” or so around the case mouth, between mandrel and die neck.

I have to admit that “get a die that requires even more forceful resizing” seems a counterintuitive response. I am not having issues chambering or firing previously resized LC brass. The problem is actually full length resizing the current batch of brass.

I need to check the length of the most recent LC brass and also check that the decapping pin hasn’t slipped long some how.

Thanks for the advice and counsel.

 

[Walkalong]

check that the decapping pin hasn’t slipped long some how.

Have had that happen before (I adjusted it wrong), and it will cause issues no doubt.

 

[Slamfire]

I need to check the length of the most recent LC brass and also check that the decapping pin hasn’t slipped long some how.

That has happened to me. The spindle could also be too high in the die. That will cause problems.

A Rock chucker is a great press but the leverage on mine was insufficient to small base size 30-06 brass. So I used a 12 Ga Topper shotgun barrel on the end of the handle. I would recommend something else, for if I had damaged the barrel, I would have been out a shotgun.

Sometimes cases are so expanded that you cannot reduce them sufficiently with over the counter reloading equipment. That is when an equipment upgrade is necessary.

Case Pro 1000 roll sizer. http://www.casepro100.com/ The basic roll sizer is $893 and the 308 Win dies are an additional $243. I assume you will want to use if first for pistol brass, so getting the 308 Win dies will be an after thought.



The first time I size once fired rifle brass, be they some one else's, or new brass fired once in one of my rifles, the cases are always over length and need a lot of trimming. If you have not gotten case headspace gages, I will again urge you, to get a set. If you can't measure the shoulder to base distance of a sized cartridge, you don't know what you are doing to the case. The Sheridan case gauge is dimension ally correct for a SAAMI chamber. The Wilson gage, it will only measure base to shoulder distance. but that is still a very important measurement. The Wilson will tell you if the case is too long, the Sheridan will also tell you if the case is too fat. This is important for gas guns, if you want the case to extract.

 

[rsrocket1]

All the above advice is good. A case gauge while not absolutely necessary will ensure your brass will fit in any gun. I would strongly recommend you try chambering a few resized cases in the gun you want to shoot them in. It would be a shame to process and load a bunch of brass that won't fit in your gun.

 

[LRDGCO]

Ordered some Imperial Sizing Wax to help. The new batch of brass is looooong. A sample 25 cases showed an average of 0.015” - 0.026” over trim length. I adjust the decapping pin up a little.

So will do some trimming, apply ample lube, and go for it. Then I’ll go down to my reloading bench and do something about this brass.... ;-)

 

[troy fairweather]

take out the decaping pin and run them in then again with it replaced

 

[Ireload2]

Get a tube of Mystik JT6 grease in the bright metallic green tube. It is messy but it will cut your sizing force in half.
A 14 oz tube is about $4.50.

I have formed hundreds of machine gun fired 30-06 brass with my Rock Chucker. At least use Imperial but the Mystik JT6 is even better.

 

[Walkalong]

At least use Imperial but the Mystik JT6 is even better.

Must be very good stuff.

 

[Walkalong]

These are for .223, but another vote for setting up a FL sizer with case gauges when the rounds need to fit any autoloader in that caliber.

 

[Ireload2]

It is much more slippery than Imperial but it is very messy.
It works really well the first time you FL resize machine gun fired cases. Once your cases have been resized and fired just go back to using the Imperial.
I only used the Mystik because it is a water proof grease that I had for my 4wd Suburban. It is almost clear and transparent. There may be other chassis lubes that work just as well but they may be even more messy.

Must be very good stuff.

 

[LRDGCO]

So, pulled the pin, cleaned again, and readjusted. Trimmed 5 cases 2.010 max and liberally apied case lube. They are a bugger but all five full length resized.

The chamber on whatever MG these were fired in was bigger than the last bunch. Have Imperial wax coming. I will take the advice above and get a case gauge as well.

Thanks very much.

 

[ArchAngelCD]

Ordered some Imperial Sizing Wax to help. The new batch of brass is looooong. A sample 25 cases showed an average of 0.015” - 0.026” over trim length. I adjust the decapping pin up a little.

So will do some trimming, apply ample lube, and go for it. Then I’ll go down to my reloading bench and do something about this brass.... ;-)

Do you really consider 0.015" "looooong"? Considering a sheet of paper runs between 0.05" and 0.10" thick I don't see 0 .015" all that long, IMO of course . Even the 0.026" length is half the thickness of a sheet of paper.

 

[Slamfire]

Do you really consider 0.015" "looooong"? Considering a sheet of paper runs between 0.05" and 0.10" thick I don't see 0 .015" all that long, IMO of course . Even the 0.026" length is half the thickness of a sheet of paper.

It's all relative.

Basically you trim brass so the case neck won't pinch the bullet in the throat. I had that happen, and it blew primers. Trimming too short, unless the bullet falls off, I don't know where too short is. I recommend just trimming 308 Win to 2.00" because it is an easy number to remember.

I have a PTR91,



had to install a port buffer because without the port buffer, cases were severely dented and ejected maybe 20 yards away.



I don't remember case measurements after firing, whether they were extra long or not, but that fluted chamber sure messes up the cases. They can be reloaded, but they are not pretty.

 

[ArchAngelCD]

Slamfire, I wasn't suggesting the brass shouldn't be trimmed, only that it wasn't excessively long.