Are Federal 308 Cases Too Soft For Reloading

Fire4EffectCA

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Nov 28, 2019
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Below are 20 cartridges I recently fired from my early Knights SR-25. It has a tight chamber and is very accurate. The rifle is 100% reliable, but I have noticed that Federal ammo, either 168 gr or 175 gr Matchkings, have pronounced ejector and extractor marks on the fired brass. Any other 308 ammo I shoot from this rifle does not exhibit these marks. See comparison photo below. I would imagine that the displaced metal on the back of the rims would create inconsistent reloading results and the cases should be condemned.
 

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Below are 20 cartridges I recently fired from my early Knights SR-25. It has a tight chamber and is very accurate. The rifle is 100% reliable, but I have noticed that Federal ammo, either 168 gr or 175 gr Matchkings, have pronounced ejector and extractor marks on the fired brass. Any other 308 ammo I shoot from this rifle does not exhibit these marks. See comparison photo below. I would imagine that the displaced metal on the back of the rims would create inconsistent reloading results and the cases should be condemned.

I'd check the chamber with a bore scope for a carbon ring build up. Federal factory ammo can have significant variations in head space as well and case length that could be the reason you're seeing varying pressure signs.
 
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I have used 308 fgmm cases for reloading. Almost all end up with ejector marks. I stopped trying to use them because of this.

I've been reloading .308 FGMM cases and recently retired a batch as they were getting to the point where case head separation was about to happen (no real loose primer pockets). I had 11 firings on them and never had ejector marks on any of them, except when I had some very stout loads during load development.

I always annealed after every firing and always trimmed the cases to the same length (2.005"). I believe keeping them at the same length reduces, if not eliminates, the problem of the carbon ring build up as the ring always forms in front of the case mouth. But, I don't let the carbon ring build up much anyway and inspect that part of the chamber somewhat often with a bore scope to keep track of that.
 
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I'd check the chamber with a bore scope for a carbon ring build up. Federal factory ammo can have significant variations in head space as well and case length that could be the reason you're seeing varying pressure signs.

I will check the chamber, but this issue is unique to the Federal GM308M ammo. I have noticed this issue with this Federal ammo since I purchased the SR-25 twenty-seven years ago.

I just checked the Federal GM308M ammo with a RCBS case gage and they run 3 to 4 thousandths undersize. The custom loaded ammo from DS Mfg runs dead on at zero.
 
I've been reloading .308 FGMM cases and recently retired a batch as they were getting to the point where case head separation was about to happen (no real loose primer pockets). I had 11 firings on them and never had ejector marks on any of them, except when I had some very stout loads during load development.

I always annealed after every firing and always trimmed the cases to the same length (2.005"). I believe keeping them at the same length reduces, if not eliminates, the problem of the carbon ring build up as the ring always forms in front of the case mouth. But, I don't let the carbon ring build up much anyway and inspect that part of the chamber somewhat often with a bore scope to keep track of that.

I have a bore scope and will check the chamber.
 
Are you using the same load in the FC and Win cases?

These are Federal factory loads and custom loads from DS Mfg. I have not fired any reloads from this rifle, but I intend too as soon as the fires settle down and they reopen our range. I am inclined to start with some once fired Remington cases I loaded new a log time ago and shot from other rifles. I will use IMR 4064 powder and I have a boat load of Sierra 168 gr HPBT I bought decades ago. The nickel plated brass is all ready to go.
 

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Gas guns are hard on brass. I have a SR-25 I bought in 1993. Ejector marks show up on FGGM and Hornady TAP. Les Baer also does it as does the GAP 10. I shoot with a few guys that have these rifles and I get the fired brass. We use FGMM and Hornady TAP.

When reloading for the gas guns, typically, the powder charges have to be reduced 1-2 grains from the bolt gun loads I load. You can still get a number of loads out of the brass if you don't hot rod it and stretch the primer pockets out. I can get over 6 loadings out of the brass. Hot loads will smear the ejector on the case head.

When my SR-25 was new, I was getting blown primers with 168 FGMM ammo. I put in a call to Knights and was told to keep shooting it, it would settle down. It did. They said they chambered these rifles with tight chambers. My fired cases from this rifle measure 1.631" @ the datum line. My GAP 10 brass measures out @ 1.634-5".
 
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Gas guns are hard on brass. I have a SR-25 I bought in 1993. Ejector marks show up on FGGM and Hornady TAP. Les Baer also does it as does the GAP 10. I shoot with a few guys that have these rifles and I get the fired brass. We use FGMM and Hornady TAP.

When reloading for the gas guns, typically, the powder charges have to be reduced 1-2 grains from the bolt gun loads I load. You can still get a number of loads out of the brass if you don't hot rod it and stretch the primer pockets out. I can get over 6 loadings out of the brass. Hot loads will smear the ejector on the case head.

When my SR-25 was new, I was getting blown primers with 168 FGMM ammo. I put in a call to Knights and was told to keep shooting it, it would settle down. It did. They said they chambered these rifles with tight chambers. My fired cases from this rifle measure 1.631" @ the datum line. My GAP 10 brass measures out @ 1.634".


So you have an early gun too. My fired cases measure 1.631" too, but no problems.

My rifle had one unusual feature which was an ejection port cover made from piano hinge. It actually looked very nice. I was told that Knight's had not received the stamped covers for the first 100 rifles so they ran down to the hardware store and bought some piano hinge to fabricate covers.

A year later I returned my rifle to Knight's for a gas system modification and the installation of a Krieger Trigger. When they returned my rifle they had replaced the piano hinge cover with a new stamped cover. I called them and asked for the piano hinge cover back since I thought it was unique, but they refused to return the old parts. I guess it was an embarrassment to them that they had to ship the first 100 rifles that way.
 
Gas guns are hard on brass. I have a SR-25 I bought in 1993. Ejector marks show up on FGGM and Hornady TAP. Les Baer also does it as does the GAP 10. I shoot with a few guys that have these rifles and I get the fired brass. We use FGMM and Hornady TAP.

When reloading for the gas guns, typically, the powder charges have to be reduced 1-2 grains from the bolt gun loads I load. You can still get a number of loads out of the brass if you don't hot rod it and stretch the primer pockets out. I can get over 6 loadings out of the brass. Hot loads will smear the ejector on the case head.

When my SR-25 was new, I was getting blown primers with 168 FGMM ammo. I put in a call to Knights and was told to keep shooting it, it would settle down. It did. They said they chambered these rifles with tight chambers. My fired cases from this rifle measure 1.631" @ the datum line. My GAP 10 brass measures out @ 1.634".

I realized, just before this post, that I missed the fact that your gun is a gas gun and I spoke of my experience that is solely from a bolt gun. So, I suspect there may be other issues, though I'd still take a good look to see the extent of the carbon ring.

Hmmm??? Am wondering if a tight chamber may be restricting the case's expansion to some extent when fired thereby increasing pressure, but not enough restriction to prevent spring back for extraction??? I'm not experience with reloading for gas guns, so I'm just trying to think of what might cause such pressure.

Have you check to see if the bullets are being pressed into the case after the bolt locks down, where the load might be compressed?

You're case head measurement sounds good to me. But, what do I know. ;)
 
So you have an early gun too. My fired cases measure 1.631" too, but no problems.

My rifle had one unusual feature which was an ejection port cover made from piano hinge. It actually looked very nice. I was told that Knight's had not received the stamped covers for the first 100 rifles so they ran down to the hardware store and bought some piano hinge to fabricate covers.

A year later I returned my rifle to Knight's for a gas system modification and the installation of a Krieger Trigger. When they returned my rifle they had replaced the piano hinge cover with a new stamped cover. I called them and asked for the piano hinge cover back since I thought it was unique, but they refused to return the old parts. I guess it was an embarrassment to them that they had to ship the first 100 rifles that way.

I was told my rifle was an early one also. Still has the original barrel with the big suppressor nut. My serial # is in the 202XX range. Just a FYI on Federal GMM brass. The older brass with the brass colored primer is softer than the newer brass that has a nickel primer with the blue primer sealant. This newer brass is harder and lasts longer. Federal changed it in the past 8 years or so. The older brass does have a reputation for being softer.

I've been reloading Federal brass since the 1970's and some of the early brass weighed in the 164 gr. The brass started getting thicker and heavier over the years and moved into the 180 - 184 gr. weight.
 
Does it seem to have more recoil with FGMM or bounce ejected cases off of the deflector?
Aero build, not a KAC, but I had a similar issue with Federal factory ammo in 308 and 243. I dunno what powder they use, but it ended up overgassing my rifle and screwing up the BCG timing. Handloads with IMR4350 & H4350 in Fed brass had no issues, and I'm getting ~50 fps over factory.
I run adjustable GBs now, and close them off one click when firing factory. A heavier buffer / spring might also be the solution if that's the case.
 
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Around 2005 or so, we were using Hornady TAP 168 AMax load. Shot fine in the SR-25. Bought some newer lots and all of a sudden blown primers. Got ahold of Hornady L/E and was told to send some of the ammo back to them. They did some testing and then sent me some newer lots. The issue was gone. Newer ammo was fine. They changed something in the load and the SR-25 didn't like it.

In the 1990's, David Tubbs and others were using SR-25's for H/P matches. They found the gas systems were over gassing. They made modifications to the rifles, moving the gas port about 4" forward with longer gas tubes, which helped the over gassing. Eventually they all dropped the AR-10 platform.
 
Around 2005 or so, we were using Hornady TAP 168 AMax load. Shot fine in the SR-25. Bought some newer lots and all of a sudden blown primers. Got ahold of Hornady L/E and was told to send some of the ammo back to them. They did some testing and then sent me some newer lots. The issue was gone. Newer ammo was fine. They changed something in the load and the SR-25 didn't like it.

In the 1990's, David Tubbs and others were using SR-25's for H/P matches. They found the gas systems were over gassing. They made modifications to the rifles, moving the gas port about 4" forward with longer gas tubes, which helped the over gassing. Eventually they all dropped the AR-10 platform.


My SR-25 is not over gassed. I am using an adjustable gas tube.

 
I was told my rifle was an early one also. Still has the original barrel with the big suppressor nut. My serial # is in the 202XX range. Just a FYI on Federal GMM brass. The older brass with the brass colored primer is softer than the newer brass that has a nickel primer with the blue primer sealant. This newer brass is harder and lasts longer. Federal changed it in the past 8 years or so. The older brass does have a reputation for being softer.

I've been reloading Federal brass since the 1970's and some of the early brass weighed in the 164 gr. The brass started getting thicker and heavier over the years and moved into the 180 - 184 gr. weight.


You are correct. My 168 gr Federal GGM is from old lots. The new 175 gr Federal GMM I shot recently does not have the ejector and extractor scars.
 
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Maybe it was just a bad lot but in early 2000's i bought several boxes of Federal 6mm Remington ammo and when I went to reload it after 1st firing about half the primer pockets were so loose the primers would fall out on their own. Have tended to avoid Federal brass since.
 
My only complaint with Fed 308 is that primer pockets can tend to open up.

But IMHO, that's just an indication that I'm using too hot a load.

Try working down to the next lower accuracy node, and see if your pockets stay usable longer.

The 308 is a great chambering, but it has limitations, and some folks just ignore that.

I wouldn't.

I set my limitations as 600yd for 223, 800yd for 308, and use the 260 for 1000yd and longer. Yes, it's a pretty conservative approach; but it gets the job done OK.

Greg
 
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My only complaint with Fed 308 is that primer pockets can tend to open up.

But IMHO, that's just an indication that I'm using too hot a load.

Try working down to the next lower accuracy node, and see if your pockets stay usable longer.

The 308 is a great chambering, but it has limitations, and some folks just ignore that.

I wouldn't.

I set my limitations as 600yd for 223, 800yd for 308, and use the 260 for 1000yd and longer. Yes, it's a pretty conservative approach; but it gets the job done OK.

Greg

As I said here last Wednesday, I had 11 reloads on my .308 brass and was loading them with moderate loads (early on, I once loaded them with a hot load) and the pockets did loosen up a little, but not to where there as any issue of them staying in and doing their job. I do think that because they're softer than most other brass, they won't last long if hot loads are used regularly. As you say, they do have their limitations. But they can do just fine as long as they're not . . . abused. ;)
 
Military 5.56mm brass is produced using a process called "pre-pocketing" which uses an extra strike to harden the head in the K, L, M region. The bean counters at Federal quit doing that and carried over to commercial brass in all offerings

This is why Federal brass is soft. Info is from a guy I know that was Rugers ballistician for many years.
 
Military 5.56mm brass is produced using a process called "pre-pocketing" which uses an extra strike to harden the head in the K, L, M region. The bean counters at Federal quit doing that and carried over to commercial brass in all offerings

This is why Federal brass is soft. Info is from a guy I know that was Rugers ballistician for many years.

That's probably the main reason for the softer case head, but another factor is that the brass alloy Federal uses is simply a little softer than others.