I recently used the last of my 168gr Federal Gold Medal Match and began the case prep process in order to start developing loads. After measuring the fired cases with the Hornady Headspace gauge to determine my desired .003 set back I lubed and sized a few pieces of brass in order to ensure everything would work in the Giraud. I removed the lube and tried to trim the cases. I ended up having cases which were very difficult to remove from the collet and were emerging with large variances in OAL. I eventually bumped the shoulders back over .003" in order to ensure the brass was fully sized and have my sizing die set-up to contact the shellplate plus a quarter turn for a full cam over.

This large variation in OAL after trimming combined with the difficult case removal is leading me to believe the cases are indexing off of another portion of the brass besides the datum line.

The extreme spread of the measurements with the Hornady Headspace gauge after resizing and removing the case lube had all 10 pieces of FGMM brass within .003" from 1.218-1.221" leading me to believe the OAL after being trimmed should fall roughly within that same variance, just like the .223, 300BO and 7.62x54R that I've trimmed with the Giraud. The piece of Winchester brass that came with the .308 collet measures 1.220" with the Hornady gauge. The outside diameters of the FGMM case necks are .002 larger than the Winchester piece that came with the collet and the shoulder and case head diameters on the FGMM are both .005 larger than the piece of Winchester.

In order to see if it was the collet or the FGMM brass, I ran some R-P brass through the same process and had zero issues with case removal as well as an OAL within .005 across 50 pieces of the R-P brass after trimming them. Additionally, the headspace lengths, case neck, case head and shoulder diameters on the R-P brass were exactly the same as the FGMM, which makes sense as they were resized on the same press and die.

While I wasn't expecting to get a dozen reloads out of the FGMM brass based on a number of posts discussing their quickly loosening primer pockets, I was not expecting to have an issue with trimming them on the Giraud.

Anybody else encounter this issue with FGMM .308 brass and a Giraud trimmer?

Any ideas as to what I could try to do in order to fix this issue would be appreciated. I used plenty of case lube, ensured the lube was totally removed via dry tumbling and even went so far as to resize a few cases with the die turned nearly 3/4 past contact with the shellplate to ensure the case body was being completely resized.

Any help is appreciated.

Thanks

Eric

Doug's standard case holder is based upon FL sized cases. He does for a fee customize case holders if you supply him with a few of the fired cases....

I figured that was the problem when I initially only bumped the shoulders back .003, but for them to still stick after being full length resized is what's perplexing me.

The R-P brass slides in and out just fine, but the FGMM is all over the place.

IIRC, Federal .308 brass necks are thick

I had this problem once when trimming sized 223 TAA cases.  I found that a small chunk of

tumbling media had lodged/stuck in the neck area of the Girard trimmer insert

preventing proper trim length.  Hope this helps.

I'll check it out to make sure.

Thanks

Are you neck sizing, full length sizing, or neck sizing + shoulder bumping?

Full length resizing with a standard Lee die.

Finally got a chance to take the collet out of the trimmer and see exactly what the issue could be as well as compare the R-P and FGMM brass a,little more thoroughly.

It looks like the FGMM bras does in fact have slightly thicker necks, which is likely causing the binding and inconsistent trim lengths. I removed the collet and inserted the brass from the bottom towards the top with the R-P and FGMM brass to rule out neck thickness and sure enough, the FGMM brass stuck inside the collet while the R-P went in and fell right back out.

I guess the only option for these cases, if I'm going to trim them in my Giraud, would be to turn down the outside of the necks. Since I don't feel like doing that, and since Federal brass is apparently not the longest lived when it comes to primer pockets, I'll just hang on to them in case I evener end up with a different trimmer.

Looks like an investment in some once fired or new production commercial cases is in order. Any advice regarding which brand of commercial brass for a bolt gun? I'm not a good enough shooter to warrant the investment in Lapua or Nosler at this point, but if there's a big enough difference between R-P, Win, PPU or the rest I'd be interested in hearing what anyone has to say on the subject. I'd prefer commercial over LC as I could use the extra case capacity with only having a 20" barrel on my Rem 700 AAC-SD and have read in numerous places that capacity is diminished on the LC due to thicker brass.

Thanks for all the ideas on what this issue could have been and in advance for any pros/cons towards a brass purchase.

Eric

You could polish your resizing die's expander ball .001" smaller at a time until your brass just fits. Spare expander balls are cheap and easily modified by spinning them in a drill with 600 grit or finer wet/dry paper.

If you modify your expander ball it will increase neck tension. Using a dedicated expander ball will insure that only the Federal cases get tighter neck tension. You can use K&M Expandiron or Sinclair International's expander mandrels if you feel the need to open the neck back up.

You could send the shell holder back to Doug with some of your resized Federal brass so he can fix the issue.

Improved trim length accuracy can be improved with every power trimmer by simply allowing the trimmed case to spin in the case holder with light pressure being applied after the blades have stopped cutting. This technique has given me trim lengths within +/- .001".  

Don't load the Federal brass at maximum levels and it will last longer.

I like Winchester brass if I can find it. Especially in .308 because it has the highest internal capacity and is of very good quality. Stocks are hard to near impossible to find. If you uniform primer pockets, debur the flash hole and separate them by weight they are every bit as accurate as Lapua.

If you don't want to do any work just buy Lapua. It's commonly available and considered the best .308 brass out there, but at over .70 cents a piece it's not cheap. It lasts a long time which helps to moderate the cost.

I thought about buying and modifying an expander ball for this batch of brass. Might give it a go if other projects are finished up.

With regards to sending it back to Doug: if this issue is only present with Federal cases I'd rather leave it alone as the R-P brass was getting trimmed to within +/- .001" when comparing the headspace measurements to the OAL post trimming. His trimmer is awesome, just doesn't like the thicker Federal brass, apparently.

Sir, while I always consider advise from Mr. Borderpatrol to be excellent the notion that FC brass has thicker case necks piqued my curiosity.  I measured the neck thickness of 10 randomly selected LC cases and compared them to 10 randomly selected FC cases.  I used a ball mic to ensure any dings or dents in the brass would not interfere with the measurement.  Generally speaking the two groups neck thickness were both about .013"-.0115".  Most were very close to .014" plus or minus 1/10000 or two.  My conclusion is that generally speaking there is no appreciable difference in case neck thickness between the two groups, at least as far as the groups of cases that I have.  I suspect there is something else going on with your dies and or die adjustment.

My hunch is that the FC brass "springs" back a bit more after resizing and has a larger finished OD that other cases.  In my humble opinion that possibility reinforces Mr. Borderpatrol's suggestion to turn down the OD of the expander ball a bit which would reduce the finished ID of the case neck and therefore the OD also.  Since case neck thickness is about the same there would be no appreciable effect on neck tension.  FWIW, I also measured a few RP and WW case neck thicknesses with results being most were .0126".  All case measured were once fired in one of my match M1As and have not yet been resized.  While I would agree that the FC and LC case neck are indeed thicker than the commercial cases I measured the difference is only .0014".  Not a big deal in my experience.  The point being to reduce the finished case neck OD to fit the Giraud trimmer shell holder.  

The ID of the case neck portion of my Giraud trimmer .308 shell holder is .343".  I tried to insert a few of my unresized cases into the shell holder and most fit quite easily with the exception of a few that had a dent or other defect.  I suggest you measure the ID of your Giraud shell holder for sake of comparison.  It is my opinion that reducing the OD of the expander ball of your resizing die is probably the easiest COA without more precise info.  Readjusting the die downward to set back the case shoulder another .001" would also probably be helpful.  HTH 7zero1.

Thanks for the measurements on the brass with the more precise ball mic. You're likely correct in that it's a 'spring back' issue more so than a 'thick brass' issue, but either way it appears the Giraud collet is cut to accept the less springy brass from other manufacturers. I'll measure my collet and see what I come up with to ensure it isn't smaller than yours. If it is, I'll give Doug a call.

With regards to bumping the shoulder back far enough, all of the brass mentioned was full length resized with the die turned 1/5 of a turn past contact with the shell plate which moved the shoulders back nearly .007" from their unsized headspace measurements. I don't believe it's a headspace/resizing issue in that regard.