Fiocchi Brass vs. PMC Brass

[0321jarhead]

So, yesterday I finished doing full length case sizing trimming and all the prepping that needs be before adding powder and bullets. These shells are 7.62X39 and were fired for first time using the same rifle, a Yugo 59/66A1. 50 rounds were fired. Fiocchi was factory new and the PMC were NEW 1st time fired by me loading them with 1680 powder @ 24.0g, bullets 123g V-max. After prepping I check the brass with an L.E. Wilson case gage. The PMC passed with flying colors but, Fiocchi brass (nearly 50%) failed. In the meantime I am going to adjust the FL Die to see if there is any difference to maybe make the Fiocchi to go. Has anyone run into this type of issue?

http://www.lewilson.com/casegage.html

[8mmFMJ]

is it a Lee die set?

[0321jarhead]

is it a Lee die set?

"Yes it is".

[8mmFMJ]

When you say the brass failed, did you check it with a caliper gauge? are you checking before or after a deprime/resize? If after, try a Fiocchi case lubed up well and pressed through the FL die 3 times. Then give it a trim and see if it passes. Some might be trimmed too long due to harder brass, and some might have not resized all the way, also due to the annealed necks.

*I have never used a case gauge, I use a caliper and see exactly where the case has been cut to.

[0321jarhead]

The case gage is used for semi-auto rifles.

After trimming the shells they were then the proper length.

What I did discover is apparently the base (headstamp/rim diameter)of the shell somehow had expanded slightly after being fired. I had discovered that with comparing with an unfired Fiocchi round using my caliper. My theory is, that when the bolt of the SKS chambered the round the brass expanded a hair. With one empty shell I very lightly ground the brass. Inserted it into the case gage and it fit like it should. After that, I chambered the empty shell. The one I trimmed and one I did not. Both cycled correctly with the SKS. Possibly being a softer brass than the PMC. After all that I loaded them up with 26.0g of AA1680 and 123g Sierra FMJ. I believe that PMC is better and less hassle than the Fiocchi.

[FLIGHT762]

You discovered one of the issues of using a drop in gauge like the Wilson. Autoloaders are hard on the cases. Case rims sometimes get bent a bit and it can be difficult to see.

If there is a burr or the case rim is slightly bent, the case will not fall freely into the gauge, even though it has been resized properly. As you found, these cases will chamber in the rifle fine.

[0321jarhead]

Interesting. I had not given it any thought concerning a bent rim.

As I had inserted those cases into the shell holder, I had to pivot them a bit to slide in. Funny, though the PMC was perfect. Quality brass perhaps as compared to Fiocchi.

Thanks.

[6mmintl]

Wilson case gages are for that perfect SAMI case/size gaging, Com Bloc military chambers are way oversize and a case gage is just a reference point that make you feel good and overworks the brass by continuous sizing.

I set my dies up off shellholder .030"- .060" to just kiss the side walls of a fired case during sizing, you will get a mini shouldered neck (self aligning cartridge to bore and much more accurate) , seat your bullets out, add .5 grains more powder and try single loading and you will see much improved accuracy.

If you reloading to mag length for magazine loading/feeding your wasting money and need to buy more crappy surplus.

If you want significant accuracy improvement try the above.

[0321jarhead]

I have had good accuracy regarding the way you have mentioned. My C.O.A.L. at 2.195.

Btw-The PMC cases I am using, is the case I bought from you at the Sac Silhouette Match last year. Thanks!

[6mmintl]

I just went thru all my 7.62x39 brass and the fiocchi seems to be very soft and expands more then usual, also a lot of bent rims.

Going to stay with Win and PMC.

[0321jarhead]

The subject of soft brass is what I thought as a "could be". As for the "bent rims", I never thought or heard of such a thing until you mentioned that to possibly be an issue. Good to know, thanks.

[Jimi Jah]

PMC brass seems to be a slightly different color than other brass, briter. Is it a different alloy?

[pacrat]

OP this quote is from the link you provided.

Note: Does not measure body diameters. This gage is intended to be used with fired cases to determine a basis for full length sizing and trimming.

6mmintl said,

Wilson case gages are for that perfect SAMI case/size gaging, Com Bloc military chambers are way oversize and a case gage is just a reference point that make you feel good and overworks the brass by continuous sizing.

I agree with 6mm. Rifle chambers and case metallurgy are all variables. If it chambers in your rifle, and cycles in your rifle, and fits the mag of your rifle, and is accurate in your rifle. Leave the gage in the drawer where it belongs, unless it is needed to help diagnose any of the previous that doesn't work in your rifle.

JM2c