do I have a die problem or chamber problem?

[Dand]

I picked up a set of Lyman 7 mm mag dies from a garage sale to load some ammo for a friend.
Started sizing cases he gave me - I assume he fired them in his older Ruger m77.

Brass is Remington factory loaded once fired.

Even though I prelubed the inside of the die (learned that trick with new dies) it was surprisingly hard to size the brass even with the compound leverage of my Lyman T mag press. I had brushed the inside case necks and dry lubed  them inside and out.

Then I noticed a couple of the shells had brass shavings when I wiped the lube off ( Hornaday Unique). Closer look, toward the base the die was shaving a bit as it approached the belt.  A slight burr remained on the cases just above the belt. I destroyed those cases and used some more that didn't seem to shave when sized.

I started paying real close attention to placement of the case in the shell holder etc but still got a couple shaved cases.

Does this sound like a die problem or could he have a really big chamber?

My 300 win is a match grade chamber and brass sizes real easy even with max loads. I haven't loaded any other belted brass so experience is limited.

[Doug B.]

I would TOTALLY disassemble the dies and clean them thoroughly making sure the "vent" hole, if your die has one, is clean as well, even though your problem may not concern a "vent" hole. Problems as you are describing most often are dirt related, although you may have a die that is gouged. Total disassembly of the die should give you further insight.

Good luck.

[Land_Owner]

Might not be a bad idea to mic the cases before and after too.  See if there is bulge in your case, give yourself some clue in regard to chamber dimension at the case base too.  Certainly agree a good die cleaning and inspection is also in order.

[huntducks]

Try seizing a brand new case and see what it does.

I'm betting there is something wrong with your garage sale dies but I don't like lyman dies to start with.

[skb2706]

Could be a shellholder problem and that would be my first guess.

[Dand]

The die seemed pretty clean but a more thoro cleaning and inspection is a good suggestion.

I'll see if I can find some other 7mm brass that's new or from a different gun.

I too wondered about the shell holder but its the same one I use with my 300 win mag with no troubles.

I tried a few more tonight first chamfering the case mouths in and out, brushing inside neck more and used some Imperial Sizing wax  - the wax worked a bit better - have to concede that in the really tough size jobs the Imperial does better than the Hornady Unique.

Still getting some shaving on a couple cases - not all tho. There are no streaks or marks like there might be if there is a burr in the die or sand on the cases. I thoroughly tumbled the cases before sizing them - bright and shiny as factory new.

I need to try the mic too - a close look at the cases just ahead of the belt, it appears these cases have expanded quite a bit. I wonder if my buddie's gun has a max chamber.

Thanks for the suggestions - any more ideas?

I do wonder if this is why these dies were cheap.
I've had ok luck with all the other Lyman dies I have.

[Land_Owner]

I need to try the mic too - a close look at the cases just ahead of the belt, it appears these cases have expanded quite a bit. I wonder if my buddie's gun has a max chamber.

I would wonder if these cases were fired with far too much powder in them, at excessive pressure, and in a gun with a chamber too large, possibly the wrong gun.  Maybe others can expound on that.

[Dand]

LO, these were Remington Factory loads. And the gun is stamped 7mm Rem Mag. But some of the case heads show extractor marks. I wonder if they had been sitting in the sun before he fired them or some such. But here in Alaska even in the sun they often won't get particularly hot.

I'm thinking I should really clean his gun for him, might be the bore is a bit fouled and pressures might be high. He's not a real sophisticated shooter and only uses a few dabs of Outers Bore cleaner in it. I'll run some shooters choice thru it, or CR10, maybe Wipe Out and see what I get.

Sure appreciate the interest and suggestions.
Oh and I ordered some RCBS dies to compare.

[Autorim]

Make sure the shell holder is clean.  Debris can build up in the groove and prevent the case from fully seating in the shell holder which can cause misalignment. It can be as simple as a spilled grain of extruded powder in the groove.

[Dand]

Well I dug into this issue tonight as it was pouring rain and cold outside.
Disassembled the die and cleaned it - pried some brass out of the relief cut for the case belt. The edge of the relief cut is quite sharp with no radius to it - especially compared to my RCBS die for 300 win mag. The rest of the die seems fine, vent hole open and working.
Shell holder clean and fine.

I got the bright idea to run the 7mm Mag shells into my 300 win mag die first to see how that went - lubed of course. It went well. The cases require firm pressure on the press handle and the 300 die just sizes the lower .5 to .75 in of the shells where the problem has occurred. But the RCBS die sized it down real smooth. The RCBS sizer doesn't size all the way to the belt tho, it stops about 1 or 2 mm up from the belt.

Then I ran the fully lubed (necks inside and out with Imperial graphite, body with Hornady Unique) thru the Lyman 7 mag die. Still a little gritty feeling but WAY better and no real case shaveing. But that Lyman die comes right down to the belt. My shell holder is an RCBS, and the die is screwed down to touch the shell holder. I'm wondering if a lyman shell holder is a little thicker and would stop the die a little higher off the belt.  I can't detect any set back of the shoulder.

So, I finally got 40 cases sized with no more brass removal.

I lay out 6-7 load manuals to pick a powder and load. I want to use up some old H 870. Lots of variations from the few manuals still listing it.

But while I'm doing this I start seeing weird loads in my Hodgdon 2010 manual I just got in January. Finally figured out the pages must be messed up. Sure enough - go to Hodgdon website and pp 108 and 109 are reversed. BE CAREFUL IF YOU LOAD SOME OF THE 7MM MAG CARTRIDGES PAGES 108 AND 109 IN THE 2010 HODGDON MANUAL ARE INCORRECT. GO TO HODGDON'S WEBSITE AND EMAIL THEM FOR A CORRECTION

I knew I couldn't fit 95 grains of powder into the 7mm rem mag case.

So I pick a middle of the road load for H870 for a 175 Rem Corlok bullet. But decide to figure out if the cannelure on the bullets will give the right OAL before I put powder in the cases.

Screw in the seater die and start to seat a bullet in an unprimed, empty case.
HMMMM something else is weird; case won't go into the die far enough, or jams on the bullet.
Weird, it turns out I don't think the die is bored properly for the 7mm mag. Its like the neck and crimp portion is bored for a 264 or something. The bullet will go into the proper place but the case neck stops against the shoulder portion of the die. If I try to force the case in further it will crush the case neck.

Maybe this die set was made on Christmas Eve or some Foot ball Friday or the Monday after Super Bowl. They are a mess.  I still need to put a mic on the cases and dies but I  think the problems are very obvious.

I have emailed Lyman to see if they are interested in inspecting a garage sale set of their dies. They refurbished a carbide die I'd bought from them years ago. Maybe they'll help me here.

In the mean time I'm glad I have a set of RCBS dies coming from the GB classifieds. I expect they'll work better.

Oh, and I do still suspect that this gun has a MAX chamber to boot.
So I loaded nothing but learned a lot tonight.

Thanks for the comments and advice everybody.

[Autorim]

I also expect your RCBS dies will perform better. All of my dies purchased since 1962 have been RCBS or Redding with the only exceptions the Lee crimp dies and Dillon dies for the 550. I have had no problems with any of these.
All shell holders are RCBS or Redding.

[Dand]

Auto and others, you are right. I received the RCBS dies from Oldgoat today and they work! Smoothly and easily. I think those old Lymans were a defective set from the get go. That will teach me to grab a "deal" at a garage sale.  Really wish I had dug up some 7mm brass to test them right away instead of waiting 9 months. Oh well live and learn.

At least I am back to the business of making some ammo.

[Lloyd Smale]

Ive had nothing but trouble with lyman dies and wouldnt have another set if they were given to me.

[Doug B.]

I have one set of Lyman dies in .270 and they have given me some minor problems that I have learned to deal with. BUT....I don't think I would buy any more.

[Dand]

I'm not going to bash all Lyman dies.  I have 3 sets of their custom deluxe handgun die sets that have worked very well for me. I also really like their M dies for loading cast bullets in my 30 cal rifles.

But this 7mm Rem Mag set has problems.

All companies make mistakes now and then. I had a custom cast bullet sizer / lube die made by RCBS and they forgot to bore the holes in the die to allow the lube to go into the grooves in the bullets. They made good on it tho in the end.

[Siskiyou]

Dand:

Glad the RCBS are in hand and working.  I believe I have three sets of Lyman All-American dies.  I have been using them for 40+ years.  I have broken a few de-capping pins but that is the only problem.  I think the de-capping pins are a weak point.  I have also replaced a few, but fewer RCBS de-capping pins.  The cure for both was a Lee de-capping die setting in the turret.

A 357 carbide die has taken over 99.9% of the duties from the original die.

Every once and a while I come across used dies for sales.  I normally pass, for different reasons.  Recently I passed on a number of die sets because the buyer wanted more than I could buy a new set for.

Let us know how your friends do with the loads; hopefully you guys will be eating moose next fall along with your buffalo. 

[mechanic]

It is also possible that some fella' customized the dies.  I found several of my Dad's old ones that he had changed this or that on for forming brass etc. for custom calibers.  Some are marked M1-30 and he has scratched numbers in them and changed parts to make custom dies for a several process routine......just  thinkin'.....

[Siskiyou]

mechanic:  You make a good point, my wildcater brother has modified dies, or hand them modified to fit his vision.

[Dand]

I received an email from Lyman today asking me to send in the dies with an explanation of the problems. So they seem concerned. I'm pleased to get the response.

I may size a couple pieces of brass and send them along to show the issue.

I'm eager to find out what they'll do.

[Siskiyou]

The brass is a good idea!

[Sweetwater]

+1 on sending sized brass. That will help them a lot.