Loose neck fit in mosin

[fireflyfather]

OK, possibly a weird one, and I'm not sure what info is necessary, so I will throw it all out there in the hopes that someone can help.

I've got some trouble with loading CB in 7.62x54R cases. The gun is a 91/30, slugged at .312". The CB is the Lee TL-312-160. I calipered a good sample of the bullets, and they came out to .312, as best I can remember, so I tumbled them w/ LLA, and started to load them up, which is when I noticed the bullets rattling around quite a bit in the necks.

Now, I am using PRVI brass, twice fired (in the same mosin), a Lee Loader, my CBs, and a low charge of red dot w/ WLR primers. I've trimmed the cases, and tried beveling and not beveling. I'm seating the CB with the crimp in the last lube groove, and ended up warping a case neck by using too much force(I worked up slowly), in an effort to get a good crimp with a tight fitting bullet. I did spot some very small lead shavings after seating, in many cases. Most of the rounds I could get to stop rattling with a good crimp, but I am wondering if the CBs have shrunk since casting, or if the shavings from the driving band have resulted in an undersize CB.

As for the CB itself, I am using it without the GC, and the driving band near the base seems to be just a shade wider than the lube grooves/nose just above the grooves. Should I seat it deeper and crimp into the un-grooved portion? Work on eliminating shavings? Get more exacting in my bullet sorting/casting? Thoughts?

[MtGun44]

Sounds like your Lee die isn't reducing the neck ID enough, and you
probably need to slightly flare your brass to avoid the shaving lead.
With a bench type press, I'd suggest the Lee Universal Flaring Die,
which is just excellent for neck flaring to prevent shaving lead. A Lyman
M die does the same job, but only works on one caliber, a big disadvantage
IMHO. The lack of enough neck tension will have to be dealt with by
gettin another sizer die or thicker walled brass. You should try to
measure the ID of the case neck, which is tricky, before and after sizing.
You may find that Lee will replace the sizer portion of your set with one
that is tighter. You want to wind up with the neck ID about 0.002-0.003"
smaller than the boolit diameter, and tighter is often used.

Probably the easiest thing to try is some different brand brass that may
have a thicker neck. When sized in your die, the thicker brass will make
the inside diameter smaller with the same outer diameter. You should have
decent neck tension to keep the rounds together. Common problems with
low neck tension are pushing the boolit into the case when loading from
magazine to chamber, and also leaving the boolit in the throat when
unloading an unfired round, which spills powder everywhere and ties
up the rifle until you can get a rod and knock out the boolit. So you need
at least enough neck tension for good mechanical integrity in handling.

Good luck.

Bill

[Nightfisher]

I don’t know if this will help but I had the same problem with one of the dies for my 308 and I read in the lee manual that if you had a problem with the case neck being too lose to remove the mandrel from the die and take .001 off if the mandrel. I put the mandrel in a drill and miked it before I started and sanded it down until I had removed .001 and it worked perfect. It made the bullet fit tight and if it was a cast bullet I would use the Lee universal flaring die to flare the neck before installing the bullet to keep from shaving the sides of the bullet then used the Lee Factory Crimp die to crimp.

Hope this helps.

Nightfisher

[Baron von Trollwhack]

You say you are using a Lee Loader? The neck size only, mallet powered loader? None of the responses so far are applicable. You may need to buy the cheapest die set and press from Lee to get something workable. I like those Lee Loaders but some are dimensioned so that they really don't work well or at all with CBs. BvT

[Nightfisher]

If this is not applicable read Lee Modern Reloading, Second Edition, Chapter 3, Page 65 and go to the 2nd paragraph on the Lee Collet Die and it applies to any die where the case neck is crushed against the mandrill. If it is too large the bullet will be loose in the neck. My bullets could be put in by hand without the press until I did as instructed in the manual.

Check it out and see if it is applicable. There is nothing wrong with your equipment that a little adjustment will not solve.

Nightfisher

[Ricochet]

But the Lee Loader doesn't have a mandrel. It's a conventional neck sizing die.

I think the boolits are ending up loose because the unflared case mouths are shaving off lead.

[Larry Gibson]

I agree with Ricochet. Also the tighter brass necks are "sizing" the bullet since you are ot using a GC on the bullet. Also "I calipered a good sample of the bullets, and they came out to .312, as best I can remember" can be pretty "iffy' for me which is why I right many things down. Suggest you measure the bullets again and also the inside of the sized necks. The necks inside diameter should be .002" less than the bullets diameter at a minimum. The lee universal flairing tool or .31 M die is a must also (a tapered punch can be used but the dies are much more convenient).

Larry Gibson

[Ricochet]

A closed pair of needlenose pliers works well while you're waiting for the Lee Universal Expander Die.

[9.3X62AL]

+1 to Ricochet's most recent recommendation first--then a change in brass (neck thickness) would be my next experiment.

I started with Lee Loaders c. 1976, in 38 Special--30-06--and 223. The exact problem you are having--loose bullets in the 223--prompted a change in brass (from Rem to WW, IIRC) to address the issue--and it worked. This sort of annoyance and the limited utility of the Lee Loaders prompted purchase of an RCBS Reloader Special combination after 4-5 months of s---l---o---w ammo processing and a couple launched primer drive rods. The transition to single-stage reloading would not only speed up processing--but you could use the press to size your bullets and install gas checks using the Lee tooling.

[mandrake]

See the problem. I use the 8mm, (.324") mold and size the bullet down to .314".

I have to use a slightly turned down 3/8" bolt, (capscrew) to open the necks on the casings.


This bullet works well in all of my Mosins, pushed by 50gr. of H4350.

[pa_guns]

Hi

With Chinese micrometers running around $12 or $15 it's pretty easy to measure everything up very accurately. That's the only way I know to really figure out what's going on.

Bob

[fireflyfather]

Sorry for the inexact figures. I wasn't writing from my workshop, so I didn't have my records handy. I do have a set of calipers, and the bullets were .312". I will be checking the neck ID next. I tend to think that it is a combination of thin necks and shaving lead. Thanks for all of the great info. I fired the rounds the other day, and once I figured out the elevation (650yd setting for 50yd actual range), I was getting 4moa out of this load (7.1gr red dot), i.e. 2 inch groups, with my crappy eyes & even crappier shooting skills. I am very pleased. Very minimal leading. Now that I have some empty brass, it's back to the workshop to get this ironed out.

To confirm, yes, I am using the old school mallet-type Lee Loader, not a set of dies. I am basically broke, and I invested a couple hundred bucks in casting & reloading equipment/supplies/wheel weights for 2 calibers. I am not going to be in the market for dies/presses anytime soon short of winning the lottery. The expert help around these parts has helped me be able to afford to shoot on a budget now so nonexistent, it rivals big foot, the snow yeti, and the loch ness monster. Thanks again gents.

[jhrosier]

fireflyfather,
If you are having trouble with your Lee loader, call Lee. I'm sure that they will try to straighten out the problem.
If that doesn't work out, get a set of regular loading dies and I will send you a Lee Reloader press. I have one NIB that I am not using. Just click on my name at the left and send me an email with your name and shipping address.

Jack

[Mr Peabody]

I had the same problem in my M39.
I sent my dies and some fired cases to RCBS and asked what gives.
They sent my dies and brass back to me with a piece of Norma brass.
It's the brass being too thin in the neck.
The very nice and very expensive Norma brass works properly.
Just our luck.

[fireflyfather]

I'm going to try flaring the cases more (I flared half the cases when I noticed the shaving going on, and I was using a .38 special flaring tool from my .38 kit, VERY gently). I'm also going to try seating the bullets a bit deeper and crimping into lead rather than the last lube groove. I'll let you know what I come up with.

Mr. Peabody, I hear what you are saying, but I want to see if I can get the bullets in without shaving them before I give up on the brass. I've got a lot of it. It may very well be the brass, but if it is, I want to see if something can be done to make it work better. If it isn't the brass, I don't want to spend money I don't really need to. Want to use what I have to make it work if possible.

[Mr Peabody]

I see you say you've beveled the case. Have you flared it?
If your shaving lead when you seat the bullet somethings not right.
In my salad days I used a short punch whose stem didn't contact the base of the case but whose taper would flare the case neck.
I wouldn't worry about a crimp, just barely remove the flare and seat to the base of the neck.
Does that help at all?

[fireflyfather]

Update: Finally got around to working on these cases again (holiday nonsense & a nasty cold). The short version is, I fixed the problem. It was a combination of bullet shaving and insufficient beveling/flaring.

Solution: Scraped the inside of trimmed necks with pocket knife. Inserted needs nose pliers inside necks and twirled around a couple times. Seated bullets a little farther, so that the crimp did not fit into the last lube groove, but into the surface of the bullet. Saw no shaving, bullets seated easier, were firmer even without crimping. A couple had the neck slip into the lube groove during crimping, and I experienced the same looseness. I pulled those, seated a little deeper, and they were perfect. I had been seating them as far out as possible without actually engraving on the rifling, but I guess I'll have to settle for a slightly shorter OAL and see how the accuracy does. Thanks for all the advice.

So, to sum up: Seat deeper, prepare case necks better. The brass was FINE.

[pa_guns]

Hi

Good to hear you are better now. I *do* know what you mean about a nasty cold.

I had to go back to the top to see what we were talking about in this thread. It's been a while ...

Lube groves do not always make for a very good crimp. If you crimp down far enough to really grab, the brass is being worked a whole lot.

I would recommend that once the Christmas bills get paid you go for a cheap tube micrometer. The same goes for a conventional one if you don't have one already. The pair should set you back less than $40 these days.

Bob