Military 300 WM brass problems

MK20

MK20

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    • Apr 17, 2018
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    #1
    I recently ordered a bunch of military once fired 300 win mag brass from online. I ran it through my FL sizing die (Lee) and trimmed it to length. Polished it and tested some of it to see how it fit in my rifle. I recently put a criterion remage barrel on and wanted to see how it cycled. I drop the case in the chamber and it goes in. I attempt to close the bolt and the bolt will close to within 1/16th of the limit of forward travel before the bolt knob begins to be lowered. At this point it stops and I have to apply pressure to get it to go forward. The bold kinda clunks forward a little and then stops still short of being able to lower the bolt knob. Once I do this I have to put a cleaning rod down the barrel and bang on it to get the bolt and case back out. They are stuck forward. I tried some factory Hornady to see if it cycles properly and it does. No issues there so I confirmed that I set the headspace properly.
    Any ideas would be greatly appreciated.
    My only thought as of right now is that I got a bunch of MK248 Mod 1 brass that was fired in a loose chamber and is blown out and not resizing properly. That is just a guess with no science to back it up.
    If I end up having to switch to different brass does anyone have a recommendation?
    Rifle is a Remington 700 with a 300 WM match chamber.
    Thanks
     
    #2
    MK20 said:
    I recently ordered a bunch of military once fired 300 win mag brass from online. I ran it through my FL sizing die (Lee) and trimmed it to length. Polished it and tested some of it to see how it fit in my rifle. I recently put a criterion remage barrel on and wanted to see how it cycled. I drop the case in the chamber and it goes in. I attempt to close the bolt and the bolt will close to within 1/16th of the limit of forward travel before the bolt knob begins to be lowered. At this point it stops and I have to apply pressure to get it to go forward. The bold kinda clunks forward a little and then stops still short of being able to lower the bolt knob. Once I do this I have to put a cleaning rod down the barrel and bang on it to get the bolt and case back out. They are stuck forward. I tried some factory Hornady to see if it cycles properly and it does. No issues there so I confirmed that I set the headspace properly.
    Any ideas would be greatly appreciated.
    My only thought as of right now is that I got a bunch of MK248 Mod 1 brass that was fired in a loose chamber and is blown out and not resizing properly. That is just a guess with no science to back it up.
    If I end up having to switch to different brass does anyone have a recommendation?
    Rifle is a Remington 700 with a 300 WM match chamber.
    Thanks
    Click to expand...
    You need a good set of dies regardless, those Lee dies will not be satisfactory. Try Redding or Forster match dies and I'll bet you will be fine.
     
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    #3
    In addition to the above suggestion, add a Redding body die. If the cases were fired in an oversize chamber, a F.L. die might not be able to fully size the lower portion of the case. A body die will accomplish this. Like a F.L. die, it can be set in small increments to size the brass down to allow chambering without oversizing.
     
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    #6
    I'm with Culpeper on this. Also, check the HS at the datum line on the mil brass against the Hornaday. You may need to bump it back more.

    I have two mk13s that were cut with the same reamer. Brass from my first one won't chamber in the second. HS is the same but the first rifles chamber must be a little fatter, allowing too much spring back. A willis die might fix this, but I just keep the brass seperate.

    As to m248 mod1, is there any ejector flow on the brass you bought? My A191 chambers shoot it great but it ruins every piece of brass due to flow.
     
    #8
    Culpeper said:
    BS on the Lee dies. WTF, when in doubt just get even more FL dies. Check the web area of the brass just above the belt for bulging. Paint the whole case with black marker and do the same thing all over again. Find out where it is oversized.
    Click to expand...
    FatBoy said:
    I'm with Culpeper on this. Also, check the HS at the datum line on the mil brass against the Hornaday. You may need to bump it back more.

    I have two mk13s that were cut with the same reamer. Brass from my first one won't chamber in the second. HS is the same but the first rifles chamber must be a little fatter, allowing too much spring back. A willis die might fix this, but I just keep the brass seperate.

    As to m248 mod1, is there any ejector flow on the brass you bought? My A191 chambers shoot it great but it ruins every piece of brass due to flow.
    Click to expand...
    As an owner of about 8 or 9 different sets of Lee rifle dies and 7 sets of Forster rifle dies and former owner of 3 sets of Redding rifle dies, not to mention about 10 sets of RCBS dies, I wasn't talking out of my ass. I have had about 20 years to compare and contemplate the merits and failings of all.

    The OP will want a set of match grade dies anyway, if only for the competition style seater. The probability that the match dies will have a slightly tighter dimension in the base area next to the belt is a good one. So, you asked WTF? That is the WTF.
     
    #9
    That shit made me smile. I like how you ended your last post.

    It's not like that. I run Redding and Whidden on almosteverything. . Just saying it's free and easy to figure out where its hanging up in the chamber before he decides on a course of action. Brass could just be junk.
     
    #10
    You can always try an Innovative Technologies belted magnum collet sizing die. This is a rough equivalent to a small-base sizing die for the body above the belt.

    diesmall.jpg
     
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    #11
    FatBoy said:
    That shit made me smile. I like how yiu ended your last post.

    It's not like that. I run Redding and Whidden on almosteverything. . Just saying it's free and easy to figure out where its hanging up in the chamber before he decides on a course of action. Brass could just be junk.
    Click to expand...
    I can appreciate that.

    I will add that I have a 5 gallon bucket full of military 300 win brass (both FC and W-W) and my Forster sizer does size the bases enough for my match chamber. It's no guarantee to the OP of course, but it's an option.
     
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    #12
    Sinister posted what I call a willis die. That would probably allow me to put brass from the 700/300 into the mod7, but f it. Life's too short to fight primary extraction.

    FWIW, I had to have about. 025" cut off my Redding body die so I could get the damn thing to size all the way down to the belt. I have it set now so it FL sizes to the belt and sets the datum .005" off. works great.
     
    #13
    He said it was military! You know, "Mil Spec", to those of us in the know. :rolleyes:

    "No. My rifle is NOT Mil Spec. It's a fukton better than that!" - Fig
    Skookum said:
    I can appreciate that.

    I will add that I have a 5 gallon bucket full of military 300 win brass (both FC and W-W) and my Forster sizer does size the bases enough for my match chamber. It's no guarantee to the OP of course, but it's an option.
    Click to expand...

    Mine does too. I think it's because of how thin the jaws are and how they grab just on the head. We're talking about hundredths here, so it's hard to determine, but it seems to negate the need for ever using a body die, or at least I've never had the need to run one.
     
    #14
    Fig said:
    Mine does too. I think it's because of how thin the jaws are and how they grab just on the head. We're talking about hundredths here, so it's hard to determine, but it seems to negate the need for ever using a body die, or at least I've never had the need to run one.
    Click to expand...
    That is a point I hadn't considered. I was talking just about the dies previously, but the fact that I also use the Co-ax press may allow my dies to size further down than they otherwise would with a typical shell holder.
     
    #15
    Brass fired from a factory military Remington M2010 means they used a mass-production Remington reamer. You don't know how many weapons were chambered with that particular tool, so it could have been tight or loosie-goosie.

    Your Criterion has what appears to be a much tighter chamber, and factory Hornady cycles correctly. Your clues seem to be leading to the fact that the .mil brass came from a fat chamber and the Lee dies aren't completing the job to standard -- especially with a freshly-sized unloaded case.
     
    #16
    Thanks for all the advice guys. I am currently remodeling and moving at the same time so free time is limited but I will get out the sharpie and micrometer tonight and find out what is going on with the brass. I will report back with findings in a little while.
    Thanks again.
     
    #17
    So the belt and case head are all in spec as is the neck and body except for just above the belt. There is a ring there that is blown out a bit even on the resized cases. Do the Forster does have a good chance of fixing this?
    Thanks
     
    #18
    You can try, but I doubt it. You need a specific die to do that. Several have been mentioned, the Innovative Technologies looks like the real deal. A body die is a lot cheaper, might be a good place to start.
     
    #19
    MK20 said:
    So the belt and case head are all in spec as is the neck and body except for just above the belt. There is a ring there that is blown out a bit even on the resized cases. Do the Forster does have a good chance of fixing this?
    Thanks
    Click to expand...

    No.

    What u c is normal expansion. No die will size that out. Well, a roll sizer would but you’re not going to spend that kind of money.

    Get a rcbs small base die.
     
    #22
    I really appreciate the help guys. I did the sharpie thing and there was a ring right where Uncle Ed said. I noticed that when I ran some of the cases through my sizing die it would shave off brass in this area too, so it looks like the Willis die is what I need. I will also check out the small base die but with how out of spec some of these cases are I think the collet die might be the right way to go.
    I am very thankful for the help as I have to get this gun up and running with a good load for elk season that starts in 13 days, so my timeline is kinda short.
     
    #26
    Fairly new to reloading, but have re-sized and fired about 200 rounds of 300 win mag. My RCBS die is FL, and was set to almost touch the empty shell holder. Lube, insert, whammo, full length sized case. They were a little tight, not quite as easy as .223, or .308, but they sized, chambered, fired, sized, chambered again. Just my .02, again, I'm no pro, so maybe mine just worked
     
    #27
    And there you have it. Skook, you need to add the Willis to your collection. Saw that right off.

    OP, once fired WM brass shouldn't bulge like that badly. You will need to keep an eye on that brass for signs of case head separation as you use this brass for the rest of their usefulness if the bulging continues. There is the possibility you won't need the Willis die after you fix this brass. In Skooks behalf he doesn't have the Willis die in his wheelhouse because he never needed it and rightly so. The Willis die is really only useful for H&H reloading because the belt is actually there for a reason by obsolete design. Needing it for subsequent belted cartridges means something else is not right. Anything from loading too hot to just plain ol' weak ass brass or sloppy chamber. If you listen carefully to Mr. Willis DVD he will quickly refer to this as well. But you have to pay attention because he glosses over this fact. There is not many of us H&H reloaders out there to help unload all those dies he had built and shelved.
     
    Last edited by a moderator:
    #28
    Culpeper said:
    And there you have it. Skook, you need to add the Willis to your collection. Saw that right off.

    OP, once fired WM brass shouldn't bulge like that badly. You will need to keep an eye on that brass for signs of case head separation as you use this brass for the rest of their usefulness if the bulging continues. There is the possibility you won't need the Willis die after you fix this brass. In Skooks behalf he doesn't have the Willis die in his wheelhouse because he never needed it and rightly so. The Willis die is really only useful for H&H reloading because the belt is actually there for a reason by obsolete design. Needing it for subsequent belted cartridges means something else is not right. Anything from loading too hot to just plain ol' weak ass brass or sloppy chamber. If you listen carefully to Mr. Willis DVD he will quickly refer to this as well. But you have to pay attention because he glosses over this fact. There is not many of us H&H reloaders out there to help unload all those dies he had built and shelved.
    Click to expand...

    Once fired mk248 will. The Willis die works well on all belted magnums.

    O.P. Did you make sure the brass would hold a primer? That is one of the more common complaints on once fired mk248. That stuff is very hot, and the once fired brass from it is usually junk.
     
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    #29
    And now for something completely enlightening.

    Following the Wimbledon Cup victory the .300 H&H Magnum cartridge obtained widespread attention in the U.S.A, influencing future cartridge designs. The belt of the H&H case and the term ‘Magnum’ were viewed as features that went hand in hand. To be of magnum power, it was considered that a cartridge must have a ‘reinforcing’ belt. Therefore, although later cartridge designs featured appropriate shoulder angles for reliable head spacing without the need of a belt, the belted case was an easy marketing ploy to symbolize magnum power.

    https://www.ballisticstudies.com/Knowledgebase/.300+Holland++Holland+Magnum.html
     
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    #30
    MK20 said:
    Could you explain why? Concerning the RCBS small base die, have you used one personally and it worked fine? That would be the better way to go cost wise if it works.
    Thanks
    Click to expand...

    I have and it does. The Willis die works best if used on brass fired in a match chamber. On my rifle the brass comes out .515” and my Redding die gets it down to .513” and the Willis Collet gets stuck in the die because of the amount of force needed to size the brass from .513” down. And you have to lube the Collet and the case for every case you’re sizing. A better way to go is to first size it in a standard die, followed by a small base die than to fuck with the Willis die.
     
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    #31
    I have one and don't lube the collet and the case for every try. I spray the collet, the die and the brass all with lube and start sizing. My rifle was a factory 700p. Not likely a match chamber. But I can't say for sure, I didn't measure, I knew it was a common problem, so I ordered the die and sized the area above belt when shoulder bump no longer resolved hard chambering.

    Belted cases are retarded.
     
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    #32
    Yeah, I can go a long time with just a little Hornady lube as recommended by the manufacturer. Doesn't take much. All it does is pinch the case above the belt. Inserting the collar in the right direction is done by hand and requires no force. But this die is not a solution for everybody.
     
    #35
    When you want a case fired in a large chamber to fit in a small chamber, you have to overcome springback. You have to use a small base die that one time. Afterward, you can resize with the standard die only and the case will conform to the new chamber without further issues. You don’t have to use the small base die everytime you size.
     
    #36
    steve123 said:
    I sold my belted magnums to folks who'll eventually buy a Larry Willis die and waist time on a extra step.
    Click to expand...

    I sure was looking hard at dumping all my 300wm stuff. I didn't see the 300 PRC on anyones remage barrel list yet though. I will burn this last one out. Hopefully I wont have to size right above the retarded belt too many times. :poop::D
     
    Last edited:
    #38
    .300 WM is a cartridge I just started reloading about a year ago. I got a lot of FC brass and have been looking for a good bunch (at least 500) LC brass.

    For my military brass, a primer pocket swager is a very good investment. You can also mount up a primer pocket crimp removing tool in a drill and remove the crimps. But beware cutting too deep or at an angle, which is easy to do if you are 'feeding' them by hand. I use my little unimat lathe for trimming out the crimp. The primer tool is put in the chuck and I can use the taper on the tailstock to keep the case true. PITA for 500 cases at a time. But is only done once.

    For swaging, I have an RCBS tool, bought here on the 'hide, that works great.

    And for my BMG loading, I have a dial indicator on a press to get primers to an exact depth. I've never bothered using this on .308, but am thinking seriously about setting it up for .300 WM as well as BMG. It's a great unit and not outrageously spendy! When I get home, I'll post some pictures. You can sort of see these items in the 'building the perfect reloading room' thread, but not close up.

    Great Zulu footage above.... I love that scene. And that movie! Though it's massively made-up... it's still a fantastic flick! In some ways, the real history is even better.... but was not what Britain needed at the time, during the WW2 recovery period, to remember the greatness of empire. But as they said in 'The Man Who Shot Liberty Valance'.... "When the legend becomes bigger than the fact, print the legend."

    Cheers,

    Sirhr
     
    #39
    MK20 said:
    I appreciate all the advice. I will definitely check the primer pockets on this brass before I start fully prepping it. I really wish that it wasn't belted now.
    Click to expand...

    They are not really that bad. Its just something we like to bitch about, like a bunch of old ladies arguing over biscuit recipes. LOL Moving forward, when all my brass is trash, I have been looking real hard at the 30 Nosler and 300 PRC. They both have very similar capacity to the 300wm. If you don't push the ragged edges, you wont have to use the LW die often. Some of the last brass I sized with it, had 15 loadings before I used the LW die, some had 8. It all started giving me problems shortly after trying to push the 220 CC.
     
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    #42
    I agree with SCD in this. I use out of bag WW bulk pushing a 230 Berger OTM at 2800fps ("slow" compared to most here) and the brass gets 6-7 firing FL sized before it gets sticky. That's way more than any bulk brass owes me.

    When I go to ADG, or Peterson if they ever get around to making it again, I may change my tune.

    I have also looked at switching after the 300WM barrel is burned down. 300WSM or 30 Nosler both look great for their own reasons, but each will have to have more than one source of brass available regular before I seriously consider a change.
     
    #43
    It is important to differentiate between eurobrass and American brass when talking about sizing belted mags. They are constructed differently. Eurobrass expands further down the case and into the first 33% of the belt whereas American brass stops expanding slightly in front of the belt. The two react differently to sizing. Eurobrass is more prone to being shaved by an aggressive FL die.
     
    #44
    With all this talk of "changing", I'm curious as to what everyone will be changing to. I'm kind of a dumb bitch on this one, but there has got to be a reason the 300wm works so well, and has for so long. Sure, the case leaves much to be desired to some; but what, if any, .30cal round will do what the good 'ol win mag can accomplish? Obviously not trying to hijack here, but changing caliber due to case makes no sense to me; and I'm totally unaware of a .30 cal round, non belted, that does what the win mag can. Reads to me as one of those "buy once, cry once" things that get talked about here so much. Theres got to be a million dollars worth of optics on this forum alone, but no stock of dough for some extra brass? Maybe I haven't had my .300 long enough to see its faults, but I sure have no problem finding a reason to have more reloading stuff for the win mag as opposed to anything else.
     
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    #45
    AMGtuned said:
    With all this talk of "changing", I'm curious as to what everyone will be changing to. I'm kind of a dumb bitch on this one, but there has got to be a reason the 300wm works so well, and has for so long. Sure, the case leaves much to be desired to some; but what, if any, .30cal round will do what the good 'ol win mag can accomplish? Obviously not trying to hijack here, but changing caliber due to case makes no sense to me; and I'm totally unaware of a .30 cal round, non belted, that does what the win mag can. Reads to me as one of those "buy once, cry once" things that get talked about here so much. Theres got to be a million dollars worth of optics on this forum alone, but no stock of dough for some extra brass? Maybe I haven't had my .300 long enough to see its faults, but I sure have no problem finding a reason to have more reloading stuff for the win mag as opposed to anything else.
    Click to expand...

    There are at least three different fast 30s mentioned in this thread that are with in about 10% capacity of the 300wm that don't have belts. Maybe read the thread, then answer it.

    I spend more on components and ammo each year than anything else shooting related.. Not interested in upping that cost for no good reason.
     
    #46
    supercorndogs said:
    There are at least three different fast 30s mentioned in this thread that are with in about 10% capacity of the 300wm that don't have belts. Maybe read the thread, then answer it.

    I spend more on components and ammo each year than anything else shooting related.. Not interested in upping that cost for no good reason.
    Click to expand...

    If you had read, I said I was curious, and dumb to the fact. As i also stated, I'm unaware of a .30 that will deliver 3000+lbs of energy on a target, at the far beyond reasonable speed of the win mag. Maybe read the post, then be a dick. And if you're cost is too high, maybe you're shooting too many calibers? I'm in it for the fun, so I've come to grips with the cost. You've got to pay to play, right?
     
    #48
    AMGtuned said:
    With all this talk of "changing", I'm curious as to what everyone will be changing to. I'm kind of a dumb bitch on this one, but there has got to be a reason the 300wm works so well, and has for so long. Sure, the case leaves much to be desired to some; but what, if any, .30cal round will do what the good 'ol win mag can accomplish? Obviously not trying to hijack here, but changing caliber due to case makes no sense to me; and I'm totally unaware of a .30 cal round, non belted, that does what the win mag can. Reads to me as one of those "buy once, cry once" things that get talked about here so much. Theres got to be a million dollars worth of optics on this forum alone, but no stock of dough for some extra brass? Maybe I haven't had my .300 long enough to see its faults, but I sure have no problem finding a reason to have more reloading stuff for the win mag as opposed to anything else.
    Click to expand...

    It's not a "need to change thing
    " but I'll try to answer your question. FWIW I like 300WM and don't have any issues loading it BUT for someone starting from scratch...

    300WSM. Can push a 210gr bullet to 2900 pretty easy. Quite a feat since its capacity is 19 gr less than the WM. Case is significantly shorter so you can load out longer of you like which may help in the mag. Trim length on 300WSM is 2.1", 300WM is 2.6" The 300WSM held (may still hold) the 1k BR record group.

    30Nosler. Can push anything the 300wm will and case is about .1" shorter. Brass is said to be excellent. You loose about 3gr capacity but I don't know anyone shooting heavily compressed 300WM. I don't know anyone shooting 30Nosler so I don't know how MV compares, though I would bet similar.
     
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    #49
    AMGtuned said:
    If you had read, I said I was curious, and dumb to the fact. As i also stated, I'm unaware of a .30 that will deliver 3000+lbs of energy on a target, at the far beyond reasonable speed of the win mag. Maybe read the post, then be a dick. And if you're cost is too high, maybe you're shooting too many calibers? I'm in it for the fun, so I've come to grips with the cost. You've got to pay to play, right?
    Click to expand...

    I read exactly what you wrote, and told the answerers were already written in this thread.

    Costs of consumables and costs of optics aren't comparable.

    I wont answer your question because the simple act of actually reading the thread, should have done that for you.

    If you don't understand that being very close in capacity, makes them very close in velocity, you should not even be commenting here. Let alone doubling down on this dumbassery.
     
    #50
    @FatBoy, thank you for replying with facts, point taken.

    @supercorndogs, cost is cost. The rifle will fire the bullet with a $20 scope, the same as a $2000 scope. The $20 scope gives you more dough for extras. That's all I was saying. If no one responds, or asks questions, how does one learn?
     
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