I've been reloading 30-06 Springfield for several years, but I occasionally encounter some difficulty with the sizing process. I typically trim my cases to 2.470" OAL and I've set my resize die to push the shoulder back to fit my chamber properly. What I run into from time to time is that I'll have a case that fits very tight into my rifle... so much so that it is very difficult to unlock my bolt. After inspecting the cases that seem to get stuck, I've found evidence of scuffing near the base of the case. When I look at other cases (such as my 308Win cases) I see the same thing, so I'm thinking this is normal due to the chambering process, and I'm not convinced that this is my problem, but I'm not sure.

In the photo below you can see five cases. All have been trimmed and resized, along with ~100 others. Of the entire batch, the bottom 4 in the photo caused my bolt to lock up, the top one (along with the remainder of the batch) did not - note the lack of scuff marks on the top case. Can anyone tell from looking at this photo what type of problem I may be having? I wonder if I'm not running the cases into the die far enough? If I run them in farther, then I think I'll be pushing the shoulder back more that I want to, but I suppose this may be necessary in order to produce a more consistent fit.

Recommendations?

K5yac,

I have a couple of questions here, first is if all these cases are from the same batch or have some cases possibly been fired either more times or with hotter loads than other ones? Have you possibly changed shellholders at some point?

Also, do you have a micrometer? Not a caliper but a 1" mic? If you do you can try measuring the shiny band and then the same area on other cases that do not stick?

If I had to guess here, I'd suggest tightening down the sizing die 1/8 turn or something close and seeing if that changes things on the tight cases but only after inspecting the brass really well.

Mark:

Right, these cases are inded from different sources. Most is LC Arsenal, but I have picked some up from the range, that is why I chose to start with trimming all of them to a known acceptable length. I do have access to a micromoter, so I will be checking the dimension that you mentioned. Another good point you make... yes, I did change shellholders at one point, but not mid-run... these were all run together with the same setup. One thing I don't remember is which shellholder I set my dies up with. After I take a few measurements I think I will just readjust my die as you recommended. I was thinking that might be the best approach anyway, but I like the way that most of the cases fit my chamber. I don't suppose there is much choice in the matter if some of the cases aren't fitting properly.

Thanks for the suggestions... I'm sure it's something simple that I'll get worked out by checking a few of the items you mentioned.

quote:

Originally posted by K5YAC:
...these cases are inded from different sources. Most is LC Arsenal, but I have picked some up from the range...

What case dimensions a sizing operation will give you, depends at least on the following factors: size of fired brass (closely related to size of chamber they were fired in), size and setting of die, type of brass, number of times a case has been resized. I'm sure there are other factors, but these should be enough to start with.

I think it is a great idea to set your dies to size cases to match the chamber to be fired in. I use this method myself, and attempt to achieve a shoulder push-back of .001-.002" in my sizing operation.

Doing so and achieving consistent results, though, depends on consistency in your case material. I.e. there is no guarantee that cases fired in a different chamber, or even cases of a different brand, will size properly with a die setting adjusted for brass fired in your chamber. E.g. the pickup brass could have been fired in a chamber, which had a much wider body diameter compared to yours. That, in turn, would mean they would likely come out of the sizing operation with a larger case body diameter, and just maybe, that diameter is on the large side for your chamber...

My advice: use only brass fired in your chamber, use only brass of a particular brand. If you feel the need to use pickup brass, then size that with a different die setting to ensure proper chambering. With any luck (but without guarantee), once fired in your chamber you *may* find the pickup brass to be sizeable with the same die setting as your regular brass.

I personally choose to use only brass fired in my chamber, and I attempt to use different brass (identifiable via headstamps, say) for different rifles. That way, I can easily establish which brass belongs to which rifle, and be assured of proper sizing with the die set up for that rifle and that brass. Works for me.

- mike

hello just some advice that was given to me when i started loading (only in the last year) any pickup or once fired brass from anything other than your gun. full length size the first time around. i would say that probably 90% of my brass i either picked up myself or bought as once fired from a friend who has a deal with a few ranges. he gets it and sorts and resales it at great prices. so far ive had no prblems with this advice.

FWIW, it's always best to segregate brass by head stamp.

If you're saying that the empties are hard to extract but you're not running hot loads, then the culprit could be a dirty or rough chamber.

Thanks for all the thoughts...

I think I will order another FL resizing die and try running my scavenged brass through it first. Most of my stubborn brass is LC Arsenal, but only 4%-5% of what I resize gives me trouble... literally, four of the last 100 stuck. I now recall how/where I got some of this stuff... I purchased a few hundred rounds of M2 milsurp ammo from CMP several years ago, but found that it performed horribly in my Savage 110FP (horrible groups), so I gave it to a friend to shoot through his rifle with the agreement that he would return the brass to me so I could reload it. Most of it doesn't give me any trouble, but it seems that some of it might need a little more squeezing to fit properly.

I'll give a full length sizing a try, but I still want to take some measurements first. I'll try to report back with my findings and solution.

Thanks again!

Using a two cases... one that fit properly (sample 1) and one that causes the bolt to lock up (sample 2) I took several measurements using a 1” caliper. I know that two cases isn’t a very large sample... kind of wish I would have brought more, but I’m doing this at work so here is what I’ve found...

These measurements were taken at several points around the base of the case, just at and behind the point where there was obvious scuffing (see photo in first post).

Sample 1 measured .4683” - .4687”. A difference of .0004”... pretty darn round.

Sample 2 measured .4694” - .4700”. A difference of .0006”... also pretty darn round.


So, the cases don’t seem to be egged or anything, but the difference between the two is as much as .0017”... almost two-thousands of an inch. Even if I took the larger measurements from each sample, which would be the correct dimensions to compare, there is more than one-thousandth (.0013”). Plenty of difference to make one function better than the other, especially when I’ve got my die set to minimize rework for cartridges fired from my rifle.

I think I’ll save myself the trouble of setting up multiple dies... I’ll just try setting my die down a slight more until I can get these cases to fit snugly and leave it at that. It shouldn’t make that much of a difference overall, and should hopefully eliminate this problem in the future.

I full length resize any thing that was not fired in my chamber. Once fired in my rifle I partialy size & all is well.

Okay, here's your problem: some of the brass was fired in a chamber that is significantly larger near the base than yours.

If you had measured AT the pressure ring, I suspect you would have found more difference in diameter (behind the pressure ring they should be pretty much the same, just as you found).

"Regular" full length sizing does DO NOT typically engage the case near its base. "Small base" sizing dies are intended to address the issue of cases which are excessively expanded at the pressure ring. For the small number of hard-chambering cases you could buy a small base die, but I would recommend that that investment and trouble costs more than it is worth. Instead, chamber each resized but unfired case before loading it to see if it chambers and extracts easily. Simply toss the four percent which do not and go merrily on your way with the other 96.

Your methodology of not setting the shoulder back any more than necessary (perhaps none at all) is the proper one and you DO NOT want to vary from it by turning your die lower in the press.

quote:

Originally posted by K5YAC:
...These measurements were taken at several points around the base of the case, just at and behind the point where there was obvious scuffing ...

I'd recommend you measure the Widest Diameter forward of the Extraction Groove(the PRE location). Don't concern yourself if it is "burnished" in that location, because it happens from the Case either rubbing inside the Die or inside the Chamber.

The best way I've found to take the measurement you are looking for(PRE) is to Rotate the Case between the anvils of the 0.0001" capable Micrometer. If it will "hang" between the anvils, loosen it another 0.0001" and try it again until it will not "hang" at all. Then tighten the Micrometer 0.0001", rotate again and if it now "hangs" between the anvils, use that as your measurement. Be sure to rotate the Case slowly so as not to force the Case to continue turning when it should be "hanging" between the anvils.
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I agree with tsturm to Full Length Resize anything not fired in your rifle and then P-FLR. Throwing "good" Cases away is not in your best interest. When FLRed though, I do like to Fire Form the Cases to prevent Insipient Case Head Separation as much as possible.
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If you are doing the P-FLR properly, a regular FL Die will Resize the Pressure Ring, no need to spend money on a Small Base Die. You may think you have the Die set to P-FLR and actually still be a bit too high. As the FL Die moves down the Case and Resizes the Pressure Ring, the Case will lengthen. Go a bit farther and then the Shoulder starts being pushed back.

The way to find out though, is to take one of the Cases which is tight for the Bolt to close on and try P-FLRing it. If it is still too tight, screw the FL DIe into the Press just a tiny bit more(1/16th-1/32nd turn), relube, resize, wipe clean, and try it in the rifle again.

At some point, you may not be able to close the Bolt at all. If you get there, that means the Case Head to Case Shoulder dimension is now longer than the Bolt Face to Chamber Shoulder dimension. Continue screwing the FL Die into the press slowly and you will get to the point that it begins to chamber easily again.

Back the FL Die up a bit, use a different "snug fitting case" and P-FLR it. When the Bolt closes with just a bit of resistance, set the Lock Ring. Then verify it is OK with a third difficult to chamber Case.

Best of luck to you.

a wonderful little product is a Redding Body Die.
nowadays, I use a Lee Collet die to neck size the brass.. and then when they start to chamber tight, then I use the Redding Body Die to bump the shoulder back...

that is giving me some very accurate ammo with minimal problems and with annealing every 4th shot, brass life has increase dramatically also..

Great input so far.

I would add to a post that pointed to the number of times the brass has been fired and sized as the probable issue.

Brass gets work-hardened with sizing/firing. If the brass was fired in a larger chamber than yours and you FL size it to fit, it still has "spring back". It will spring back to a larger size than your brass that started out smaller even though you sized them identically.

I would separate the brass by headstamp and anneal. Size all of the brass lots separately til they fit your chamber.

Range brass- trash/scrap the bad ones that don't chamber correctly.

K5YAC

Observing the photo it is obvious from the sizing on the neck that you are not setting the shoulder back at all. Note where the sizing stops on the neck just ahead of the shoulder/neck junction. The shoulder is being pushed slightly forward on those cases and this is causing the hard chambering.

I suggest you start sizing those cases again adjusting the die in 1/4 turn at a time until they chamber easily. At first they all will be hard to chamber or won't chamber becuase the shoulder is pushed forward. Then they will chamber when the shoulder is set back the correct amount by the FL die. When they do chamber corectly then lock your die ring. You might have to trim them again.

A new FL die is not necessary but if you do decide to get one I suggest the regular RCBS X-die. The SB die is not necessary. The use of the X-die will alleviate most case stretch from FL sizing and you will not have to trim.

Larry Gibson

Welcome to Accurate Reloading!

I was thinking the same thing Larry said. You might try setting the FL sizing die up as per the instructions for FL sizing (run the die down till it touches the shell holder with the ram at the full top position and then screw the die down another 1/8th turn so it cams over). Size the cases that are giving you problems with this setup. If they now chamber, you know your not setting the shoulders back enough.

Also, it sounds like your trimming the cases before you resize them. You should be trimming the cases after sizing them, as the sizing process will change the length of the cases--usually increasing their length.

Good luck.

I had similar issues with a 358 BLR. I thought that I needed special dies but then I found that if I agressivly size the cases with the die seated well into the shell holder, problem solved. It is just a really tight chamber.

When adjusted properly with FL sizing dies you should be able to do this without risk of over-crushing the shoulder at all. Remember to lube the cases, but not too much..