Not exactly...
The RCBS X-Die does limit case growth, but you must still trim your brass and RCBS suggests that it should be trimmed short, after which you can reload several times before trimming is required again. However, the M14 is very hard on brass. No matter what you do, you are only going to get 3 to 4 loadings with brass fired in an M14. Brass seperation at the base is common and comes early.
I'm curious, Welding Rod. How much fore and aft slop is there in the bolt body to receiver when the extractor and ejector is removed? If the hammer is able to drive the bolt and cartridge forward an unusual amount upon ignition, perhaps it would account for some of the overworking of your brass, resulting in unusually "blown forward" shoulders. (It would actually be a case of "blown rearward" case heads.)
The cartridge tears about 1/2-3/4" from the bolt, leaving the front part in the chamber. Best tool to remove the remnant is the chamber cleaning brush. on a section of cleaning rod. Just jam it in and pull it straight back. The wires will act like barbs and grab it good.
I wish I didn't know this. But there is a reason I've been posting to this thread.
Other idea, from working on a M94 Win 30-30. The make a 307, basically a 308 with an added rim. Shells are heavy walled, heavier even than LCM. Making them into custom 308 wouldn't be too difficult. Chuck in a lathe, turn off the rim, deepen the groove, touch it with a file to round off the 'rim' of the rimless case. More brass = longer case life?
RCBS X mandrel won't retrofit into the usual die, I asked them. Of which I already have two sets. So I may turn out my own mandrel that will retrofit, just for the sake of a test drive. I'll simplify it, probably need one pass to do the X die thing, then a trip through the usual die de- and re- cap plus expand the neck. But it takes 3 operations to trim: trim, chamfer ID, chamfer OD, so I would be two steps ahead, and get much longer case life.
They do sell the X sizing die separately. but it cost only about $2 less the the set. Plus the mandrel is a much heavier de-capping pin shaft, better for use in crimped primer cases. Too bad it wasn't an option 25 years ago when I bought the gun and dies.
I don't know the limit, but you can burn a ring into your chamber. Not beneficial.
Usually, a case it good for umm 2-3 trimmings, then discard next time it grows to max, listed in every reloading manual.
I did make up my own mandrel to retrofit my old sizing die. Sure does work to shorten cases. I could feel somehtin happen in the last bit of stroke, must be the excess 020. getting pushed back to where it started. A quick trip to the range, with the twice-trimmed, once X'd, cases did give me a separation. So maybe two trimmings, plus fire one more time, is the limit?
No, but can lead to a really difficult to clear malfunction as the next case tries to feed. I suppose you could etch a ring in the chamber, but I've never heard of such.
There have been broken shell extracting tools made to clear brass remnants (including just case necks) that have been made over the years in all sorts of military calibers, from 45-70 on up.
I loaded 43.5 gr IMR 4895 in Civvie Win brass, Nosler 168. To two different seating depths. Ten each. COAL of 2.760 and 2.740. Brass was fired two or three times previous to resizing with my home made X-die.
Had three case separations in the long ones, and stretching to 2.015 - 2.020 in those that didn't break. Flattened primers too.
Shorter loads, No separations, stretched to only 2.008-2.010 in the shorter loads. Primers still slightly rounded. I'm thinking that gives me a bullet jump of about .040".
I guess now I need to work up the load for accuracy again.
He uses the exact same load I do. I bounce between 43.5 and 44 grains but we are using commercial WIN brass which is lighter than NATO brass and we are also using standard primers instead of magnum primers.
That load chronographs around 2600FPS so it's pretty safe in service rifles. I have noticed Sierra is more conservative with their load data. Speer lists data closer to what I use.
I've always liked the Lyman book. It gives an asterisked load, which is the load that gave the most constant internal ballistics. Accuracy starts in the chamber, if you are not consistent internally, you can't be consistent down range.
In the case of 168gr HPBT, 13 powders, two show the asterisk. IMR 4064 and 4895.
But OOOPs, the max. * they show for 4895 is 42.5. Maybe I ought to keep my glasses closer to my library. Still, other manuals say up to 47. So I guess my 43.5 load may have gone too hot for accuracy?
Now, back to my regularly scheduled bedding experiment.
I think you guys are on the right track myself. I have never used the short COAL that casebro is using but I ran it through my QuickLOAD software and I was surprised at what I saw. Personally I would test the load range that tonyben recommended, I might extend it a bit (43.0 - 44.1 grains) but I think that you guys are going to get some really nice groups in there somewhere.
As for pressure, QuickLOAD is no substitute for an actual pressure measurement but I've been pretty successful at estimating chamber pressures so far and the range of powder charge weights I mentioned should produce a chamber pressure range of about 50400 - 54400 psi, and that is equivalent to what military ammo produces regardless of what most people will tell you (check out this link for actual pressure test run by Larry Gibson http://m14forum.com/ammunition/100445-7-62-x-51-cartridge-vs-308-winchester-differences.html#post706954)
Setting the bullets in deeper seemed to lower the pressure. .060 shorter COAL. In civvie Win and GI WCC '67 brass. 41-42.5 grains Looks like my gun ought to like about 40gr of H4895 in either civvie or commercial brass. 41 was tighter than 42 in either case today.So something is making sense, finally...
30 rounds, slight rounded edge on all primers still, no case seps. Though flattest was GI with my high load of H-4895.
I haven't sized them yet, but some of the GI cases are actually mic shorter than before firing. I guess they must have stretched in the diameter, pulling the length back? The civvie Win stuff mostly stayed at 2.000, with a couple stretching to 2.010.
24 years with this gun, looks like my problem is solved. Hallelujah !
eta: Makes me wonder of the lore about how "GI guns CAN'T have long case life" is malarky. Many may have short bullet jump, where the bolt guns in the civvie world all have long jump to preclude high pressures?
You beat me to it and found out for yourself casebro. Cartridges made where the bullet touches the lands of the rifleing can drastictly increase chamber pressures and shorten case life. I like to have about 20 thou. clearence, but watch for differences in bullet ogive that can be different even in batches of the same lot no. Happy new year to all.
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