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Thread: It won't fit

  1. #1
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    Default It won't fit

    A longtime reloader just sent me a box of 7mm Rem mag cartridges as a gift topped with 175g Speer magna-tips.
    I found today that they would not chamber properly. the bolt would only close with extreme difficulty, so I did not care to experiment with my trigger.
    The bolt removed, the 7mm cartridges fit the face well, but I had to remove the bolt to tap back the cartridge, which was (lightly) lodged in the chamber. Other rounds chambered fine. What should I investigate? OAL was fine, but I didn't measure any other parts at the range.

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    Member 8x57 Mauser's Avatar
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    Default If it's not the bullet...

    I share your first suspicion - that the bullet was seated so far out it jammed into the lands when you chambered it.

    Ignorant question: How did you get the bolt out with the cartridge still lodged in the chamber?

    Assuming there's a simple answer to that, I guess I'd suspect the guy neck-sized the brass after firing it in a rifle with an out-of-round chamber. Do they roll uniformly on a very flat surface, or do they wobble?

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    The bolt came back leaving the cartridge in the barrel because it never actually grabbed the bullet, but just acted like a plunger. I've rolled the cartridges and they seem as round as the fired brass on the kitchen table. There are also no marks on the bullet or cartridge to indicate extra metal contact at any one point.
    I'd smoke the round with a candle for easier chamber marking, but it's loaded, so that's a no-no. The reloading equipment I access is at another home, so other than disassembling one bullet and measuring various tolerances, how could I determine why the loads won't chamber?

  4. #4

    Default smoking

    Try using a black marker to color the round.

  5. #5

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    If the bullet was seated out too far, in all likelihood it would stay jammed in the rifling when you extracted the case. You'd know immediately because of all the powder that spilled when you ejected the round. It's also rare for lots of effort to be required on bolt closure when this condition exists. The bullet would also be shoved back down into the case a ways, allowing a little "give."

    On the other hand, if your friend only neck-sized the case, all cobb could break out when you try to seat them in a different rifle than the one it was originally fired in. Then there's the whole question of head space with belted cartridges and varying chamber specs among rifle manufacturers. I don't recall the latest standard, but at least originally some mag rifles head spaced on the belt, rather than on the shoulder as in beltless cases. You could end up with excess gap at the shoulder, even if things were "properly" head spaced on the belt.

    I haven't bought any new mags in a while, but for all my older ones I have adjust the sizing dies to head space on the shoulder instead of the belt so the shoulder isn't being set back each time I size a case. That has extended case life dramatically in a couple of them that were giving poor case life while vastly improving accuracy in all of them. But at the same time, it has resulted in cases that may be too long at the shoulder for another rifle. In fact, I've got a couple in 7 mag (different brands) for which I have to use different sizing die settings, as well as keep the fired cases seperate. Ammo for the one with the longer chamber will not fit in the one with the shorter chamber, while ammo for the short one will fit in the long one, even if case life is poor. Yet factory ammo fits fine in both.

    My rule of thumb anyway, is to always try chambering once-fired brass from another rifle in the one I intend to use it right after resizing and before I go on with the loading process. Odds are about 50-50 in my experience that I'm going to have to readjust the sizing die before going on with the loading process. At the very least I'll ajdust a sizing die all the way down to strike the ram before loading. If that doesn't solve the problem, there's not a lot you can do since you can't squeeze the case back any further.

    Did I miss anything, anyone?

    BTW- If marking the ammo you have in hand with a black marker indicates the problem is shoulder length, you'll either have to pull the bullets and try resizing to set the shoulder back to factory specs or dump the ammo.

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    Problem determined. After marking a cartridge top to bottom with a marker, I found the sticking point was the barrel rifling itself. It seemed odd that a handloaded cartridge visibly shorter than other factory ammo I had would jam at least .03 in the barrel, until I checked lyman. The 175g mag tips require a 3.26" OAL versus the more common 3.29" OAL for most lighter 7mm bullets.

    So that's it. They were seated too high. Next step-can I seat them lower, or will I destroy brass and bullet by chucking it in a seating die and going for that extra little bit. The cartridges did look shorter, but perhaps not by enough, because the bullet has either a shorter ogive or a longer bearing surface.

    There does not appear to be a crimp.

  7. #7

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    I'm really surprised that .03 seating into the rifling caused as much difficulty as you described in your original post.

    Lead or unrifled barrel space in front of the chamber varies with the brand of rifle, just as orgive varies with bullet make and variety. I'm not surprised that your friends loads touch, because it's pretty tough to load high spec ammo for unseen rifles.

    Seating the bullets deeper won't damage either the bullets or the cases.

    But it will increase pressures. The question is how much. Before seating the bullets deeper consult with your friend and see if it is a "max" load, as well as get the details on what's hidden inside the case. Once you have the load data he used, check that against a reputable manual. A .03 increase in seating depth will cut space inside the case and inevitably increase pressures, but the question is whether they go up too much.

    If it's a safe load that performs well in your rifle, send him the final OAL that works in your rifle so he can log it, just in case he feels generous again.

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    Full load figs are

    175g Speer MagTip, 66g IMR 7828, CCI mag primer.

    The figures this reloader used (long-time at it, served in Kenai and began reloading in the 50s) are from lyman, p197. The 175g bullet lyman specs is a 175g Speer GSSP, not the Mag-Tip. With 7828, that bullet maxes at 68.5g, and these loads are 2.5g less. Pressure may not be an issue unless the bullets are drastically different.
    The new question-do the mag tips and GSSP, both speer bullets, share the same reloading parameters? If anyone has an older speer book which lists a load for the 7mm with 175g mag-tips, please let me know.

  9. #9

    Default Using reloads from friends

    Better yet, just don't use reloads from non-professional loaders. It has been known to cause pain and the loss of a friend as well as law suits. Better safe then sorry. Of course, this doesn't mean that professional loaders don't make mistakes, just less often.

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    Default

    Do you have a caliper, or are you "measuring" OAL by eyeballing? From the begining, your problem sounded like the bullet was seated too far out and lodging in the lands, although Brown Bear's points are well taken...but there's just not enough information to determine what's up. You were definately wise to not have fired these rounds. First step is to measure all of the rounds with a caliper, and check the OAL for ALL of them. I think you're going to be surprised. Next step is to get more information before doing anything else. The person who loaded these rounds for you should have placed a sticker on the ammo box giving you important information, e.g., powder type/grains, bullet type/grains, primer type, case length, OAL, and some information about the brass (new, if not new then how many times fired, full length sized, neck sized, etc.). If that information isn't recorded on the box it would be a big red flag to me (no offense to the person who loaded the ammo for you, but most of us are pretty precise and record such information on the box otherwise we don't remember what we did). If you don't have the information, call him and get it. If he says he didn't write down what he loaded for you, or if it sounds like he isn't sure, make a mental note and post it. Don't do anything until you get the data, then you can start problem solving. Right now you're kind of guessing, as are we. Get the aforementioned information, post what you find out, and keep being wise.

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    Default

    Yikes...while I was typing my previous response and drinking morning coffee there were several new posts with information that I didn't see. Sorry about that.

    My Speer Manual #13 lists the following for 7mm Rem Mag with 175 grn Mag-tip and Grand Slam bullets using IMR 7828...starting load 61 grns...max load 65 grns.

    This tells me several things. One, it's great that you didn't fire the rounds. Two, if he loaded to 66 grains then he loaded one grain above recommended max loading from Speer, and it appears that the over max grain loading was due to referencing a different load source for a different bullet shape or something like that. Three, if all of that is true, it's called careless handloading (no offense to the man), and I'd either get rid of the ammunition or pull bullets, soak primers and salvage pieces and parts to start over.

  12. #12
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    Your problem is common to belted cases use in other peoples chambers. I have a special die that is made to size right down to the base of the belt (not cheap). The best way to avoid the problem. Remove the fireing pin from your bolt and function feed all rounds through the action.

    Any that don't pass, gets tossed. That is unless you are willing to pay about a hundred buck for one of these special dies?

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    Doc points out a difference of opinion between lyman and Speer. Lyman#48 sets a max load at 68.5g for 7828 w/175g, but Speer only at 65g (according to Doc's post, speer uses this load for both the magtip and GSSP, so I'd be covered with another source referencing only one bullet). What I have was loaded to lyman spec, not Speer. Difference in trustworthyness of source? Lyman seems a household name for reloading advice.

    My next step is to get back to the bench and measure the various clearances which would jam a bullet too far in the barrel. If I can simply seat the bullets deeper, then great.
    Loaded a grain heavy according to speer, but still 2.5g less than lyman seems like a little flex room, because surely a hundred other people have loaded and fired successfully 75mm 175g magtips with 7828 to lyman spec (over speer).

  14. #14

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    No difference of opinion between lyman and speer. Just different guns. Every gun is different, even identical models and chambering sitting next to each other on the assembly line. That's why the reloading manuals, every single one of them, says start below max and approach with caution. I've got an "identical" pair of 257 Roberts, bought on the same day and with consecutive serial numbers. Max for one is almost three grains lower than max for the other with identical cases, primers, powder and bullets, yet velocities of each with its own max load are pretty close to each other.

    Thank your friend for his efforts and generosity, but dump his reloads. He's an experienced reloader and I'll bet hes an all around sterling fellow, so he'll understand much better than a beginner if they simply aren't right for your gun.

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    I am with Mauser on this one. Don't use other peoples reloads. Your friend could of easily just neck sized this brass to fit one of his own rifles.
    If you want to use these reloads pull the bullets and resize and prime the brass then reload them yourself.
    Tennessee

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    New member George's Avatar
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    Default problem fit

    Without knowing exactly what is going on... all is a guess. At that point, my inclination would be to pull the bullets and start over. I too can't see how a bullet seated .003" long would cause such difficulty in bolt close or extraction. Especially to the point of pulling the extractor over the rim and leaving the cartridge in the chamber! One other possibility is that the case necks are too long- swaging the end of the neck and bullet into the leade/throat. That could account for such difficulty in fully chambering the cartridge and sticking the cartridge in the chamber. If that is the case... don't shoot the cartridges! All the other possibilities have been well covered in previous posts. Regroup and proceed with caution.

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    Default

    Remove the decapping pin assembly and run the shell up into the resizing die. It will size the case back to where it will fit into your chamber.
    Do ask your friend what his load is. Then just seat the bullets to where they feed fine in your rifle.
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    They could fail to fit for a number of reasons.

    Like they’ve been sayin, if they don’t fit, don’t shoot’em.

    Your friend shouldn’t handload for a rifle he doesn’t have in hand.

    If he had the rifle, he could make sure the bullet was not touching the lands, and that the sized cases, would chamber, and the loaded rounds, fed properly through the magazine, and other things.

    Even if he used data for the specific bullet, and seated to the OAL shown in the Manual, the bullet could still be seated too long for your rifle, due to a difference in throat length.

    Don't give the loads back to him, if he's gonna give them to someone else.

    I would tell him that they didn't fit your rifle, though. I think he needs to know.

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    All advice is much appreciated. After measurement and reference to both lyman and speer manuals, the final culprit is OAL, but not .03". The bullets were seated nearly a tenth too long.

    Most 7mm cartridges seat for an OAL of 2.29. The Speer GSSP seats at 2.26, or .03 less. The loads I was given were 2.28. Still too long, but the real catch was the OAL mentioned in the speer manual for their two 175g bullets. Same weight, same diameter, different OAL by .06". The 175Magtip requires an OAL of 2.20, resulting in an extra long bullet. The cause for this-looking at the two bullet types side by side, is a thicker shoulder, or shorter ogive, on the mag tips. Perhaps the magtips have q thicker jacket, which is lighter than a lead core, so the bullet shape is a bit bulkier to reach 175. The GSSPs are a bit sleeker, perhaps with a thinner jacket and more lead.

    A good lesson in reloading is here, which Lyman also notes in one of the earlier chapters. The lesson is to not substitute bullets of even identical grain weights and identical manufacturers unless the reloader knows how to look for problems.

    Resolution: I disassembled all cartridges last night and will lube, expand, and reload the cartridges soon. I salvaged all brass, powder, and all but one of the bullets (mucked up by jamming against the lands). When reloading, I'll see about finding the appropriate OAL for my gun-Lyman spells out a process to do so, but any advice on the proper clearance is welcome.

  20. #20
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    Do yourself a favor, go to this link and look at the Davidson depth checker. This keeps the ojive under control for seating depth. I have one each for each caliber I load for. SDC-OX, Don't buy the base as it is not necessary.


    http://www.sinclairintl.com/cgi-bin/...TCO&type=store

    Makes life and re-loading much simpler.

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