Handloading Mystery

[Bert the Turtle]

I’ve got a real head-scratcher going on and I presently can’t even figure out how to figure out what it going on.

I’m developing and putting together loads for my upcoming buffalo hunt.

Started the process with previously-fired brass, using my Lee collet dies to maximize case life. Roughed in a load, then went to full-length sized and crimped and finally over to new brass (same brand), full-length sized and crimped. Finally, I made up a batch of ammo as follows:

New brass, full-length size, clean off sizing lube, trim, debur, inspect, prime, powder, seat (length adjusted to 0.375 datum as determined in load development), Lee factory crimp, feed check.

I loaded up the solids a few days ago and all went smooth as silk. Cartridges all fed well.

Tonight I started seating softs and something was just not right. A lot of them were very hard to start and I even managed to buckle a few necks. I’ve already developed the load with these cases and these bullets and haven’t had any problems but tonight it was as if the necks were just too tight to seat the bullets properly. I got about 20 seated and ruined about 5 cases and decided I needed to sort things out before ruining anything else.

To make matters worse, when I went to feed check them, a few fed fine and then the fourth one I checked wasnt even close to feeding. I thought maybe I somehow didn’t seat the bullet deep enough but it checks out perfect. I’m 2/100ths off the lands on the ones that feed and the ones that don’t. No obvious differences visually and everything I could measure with a caliper seems to be the same. I’m completely baffled. I can’t figure out why it’s suddenly very hard to seat the bullets, like way too much neck tension nor can I figure out why not all the rounds feed.

The solids seem fine. The only differences I know of on the softs is the bullet, and I’ve used the softs (same box) in developing the load so I know those worked. Also, I haven’t put the factory crimp on the softs yet because I may be tearing them down. I checked the loads with and without the crimp during development and they worked fine either way.

I did do the solids as one batch and the softs as a separate batch so perhaps I set up the sizing die incorrectly somehow? If I did, I’d expect all the rounds not to feed rather than some to be just fine and others to not even be close.

 

[fourfive8]

Smoke or mark a bullet with felt tip, and by trial and error, establish the jam length OAL of a particular bullet in a dummy round- the OAL where the bullet just touches the lands when chambered. Different bullets will have slightly different ogives thus yield different jam lengths. Seat the bullets deeper than the jam length by about .030-.050" or to the next crimp groove if the bullet has a groove or drive bands.

To prevent bullet seating issues, remove the neck expander button with de-capping pin from the sizing die. Size the cases with the sizing die sans the provided expander. Use a Lyman M Die to expand necks. (375 Lyman M Dies are about $35 on Amazon). Use a universal de-priming die in lieu of the decapping pin usually found on the neck expander spindle. Adjust the M Die so the expander's larger step enters the case mouth about .1". Seat bullets. Crimp into front edge of pre-determined, best groove with FCD.

As to the feeding/chambering issue? That might be a couple of things. Could be the necks are being compressed and deformed when seating the bullet? Could be the neck wall thickness is slightly greater than on other brass and the bullet is distorting the necks when seating? Every bullet design has slightly different jam length and that .020" may not be enough clearance. You might also carefully measure the neck diameter of a fired case to get estimate of neck diameter of chamber and compare that to loaded round neck diameter.

Also, might smoke or mark shoulder of sized round with felt tip and see if there is contact that would interfere with chambering. Re-set die if needed to slightly reset shoulder.

Usually these issue are fairly easy to correct if the gremlin can be identified. Using a Lyman M Die might not correct this problem but I've found that method to be almost foolproof for expanding necks and bullet seating consistency.

 

[shootist~]

Just more food for thought:
Disassemble and clean dies. Verify expander ball is set correctly, if applicable. Also check to see lock ring did not slip
Pull and weigh sample bullets that did not seat easily - also verify OD ( looking for wrong weight or out of spec caliber).

Edit to add: Verify max COL again to be sure ogives are consistent.

 

[fourfive8]

Here's a pic of the expander in a Lyman M Die. Note the "step"

 

[Bullthrower338]

Your expander wasn’t deep enough, adjust it further into the case mouth

 

[PHOENIX PHIL]

I hate to ask an obvious question but unless I missed it, I didn’t see where you said you chamfered the case mouth. Did you make sure to do that? Once in awhile I forget that simple step and it’s quite obvious quickly in that the bullets are harder to seat.

 

[Bert the Turtle]

Thanks for the ideas. Everything seems to be pointing to neck expansion. It may well be that the expander wasn’t deep enough, although it did work fine for load development with the softs and throughout for the solids. I don’t think I changed it, but neck expansion does seem to have been the issue.

I hate to ask an obvious question but unless I missed it, I didn’t see where you said you chamfered the case mouth. Did you make sure to do that? Once in awhile I forget that simple step and it’s quite obvious quickly in that the bullets are harder to seat.

I did put a chamfer on when I deburred the case mouth but it may not have been enough. Well, clearly it wasn’t enough in the circumstances. Everything points to the neck being a bit too tight and I think I’ve figured out what happened- thanks to everyone for pointing to the necks.

What really had me stumped is why the trouble now, but not previously in the load development with the softs and not at all with the solids? I think I’ve figured it out. It was quite a combination of things that lead to problems with the softs only now and no problem with the solids at all.

I used a sharpie to mark the cartridge that wouldn’t seat, hoping to at least figure out where the problem is. That didn’t help, but I noticed that there was a new small nick on the case mouth, so I ran it though the factory crimp die and then it seated just fine. That narrowed the problem down to the case mouths. Measured them and found the ones that didn’t chamber were 4/1000th over. Factory crimp solved it all but I was a bit concerned- if the necks are too thick, that could cause an overpressure situation. But once crimped, they measured fine just behind the crimp, so it appears to have been just the very end was a bit belled from the seating process (I seated without a crimp, intending to do the factory crimp).

That still didn’t explain why I had no problems like this during load development with the softs (once I checked the jam length and worked out the seating depth) but I think I’ve got it figured.

404 brass is currently hard to come by; I have enough but I wanted to be frugal with it. So early load development was with a few cases using my Lee collet die. Then I full-length sized the brass and checked velocity again to make sure all was well. I think because the test brass had been fired at least 5 times by the time I full-length sized it for the last stage of load development, the neck was loose enough that loading the softs didn’t cause issue. With the new cases, it was very hard to get the softs started and that caused some of the case mouths to get imperceptibly distorted. If the bullet wasn’t absolutely perfectly aligned on entry it caused a few 1/1000ths of distortion before it got started and that was enough to cause the problems.

That still left the mystery of why I didn’t have any peoblems seating the solids. inspection shows the solids have the slightest chamfer while the softs are a true flat base. That chamfer must have been just enough to get the solids started. They were certainly secure going into the new brass, but I didn’t buckle any cases. The softs are fully square and they just don’t start easily in the tight necks of the new brass. The Lyman die with the step would solve that if they make one in 404. In the meantime, I’ll double check my expander ball and more aggressively internal chamfer the mouth.

Thanks to everyone for the help!

 

[PHOENIX PHIL]

Thanks for the ideas. Everything seems to be pointing to neck expansion. It may well be that the expander wasn’t deep enough, although it did work fine for load development with the softs and throughout for the solids. I don’t think I changed it, but neck expansion does seem to have been the issue.


I did put a chamfer on when I deburred the case mouth but it may not have been enough. Well, clearly it wasn’t enough in the circumstances. Everything points to the neck being a bit too tight and I think I’ve figured out what happened- thanks to everyone for pointing to the necks.

What really had me stumped is why the trouble now, but not previously in the load development with the softs and not at all with the solids? I think I’ve figured it out. It was quite a combination of things that lead to problems with the softs only now and no problem with the solids at all.

I used a sharpie to mark the cartridge that wouldn’t seat, hoping to at least figure out where the problem is. That didn’t help, but I noticed that there was a new small nick on the case mouth, so I ran it though the factory crimp die and then it seated just fine. That narrowed the problem down to the case mouths. Measured them and found the ones that didn’t chamber were 4/1000th over. Factory crimp solved it all but I was a bit concerned- if the necks are too thick, that could cause an overpressure situation. But once crimped, they measured fine just behind the crimp, so it appears to have been just the very end was a bit belled from the seating process (I seated without a crimp, intending to do the factory crimp).

That still didn’t explain why I had no problems like this during load development with the softs (once I checked the jam length and worked out the seating depth) but I think I’ve got it figured.

404 brass is currently hard to come by; I have enough but I wanted to be frugal with it. So early load development was with a few cases using my Lee collet die. Then I full-length sized the brass and checked velocity again to make sure all was well. I think because the test brass had been fired at least 5 times by the time I full-length sized it for the last stage of load development, the neck was loose enough that loading the softs didn’t cause issue. With the new cases, it was very hard to get the softs started and that caused some of the case mouths to get imperceptibly distorted. If the bullet wasn’t absolutely perfectly aligned on entry it caused a few 1/1000ths of distortion before it got started and that was enough to cause the problems.

That still left the mystery of why I didn’t have any peoblems seating the solids. inspection shows the solids have the slightest chamfer while the softs are a true flat base. That chamfer must have been just enough to get the solids started. They were certainly secure going into the new brass, but I didn’t buckle any cases. The softs are fully square and they just don’t start easily in the tight necks of the new brass. The Lyman die with the step would solve that if they make one in 404. In the meantime, I’ll double check my expander ball and more aggressively internal chamfer the mouth.

Thanks to everyone for the help!

Glad you seem to have it sorted. I bought one of those Hornady case prepping tools awhile back. A very nice add to the bench. One of the motorized features is for chamfering the case mouth. The head has several cutting blades and it only takes a moment of touching the case to the blades to get a full chamfer. A little nicer than doing it by hand and it’s quick.

With the bigger bores, but true enough for smaller too, I go slow when seating the bullets. In that I try to have the bullet as perfectly vertical as I can see and slowly lower the ram arm and keep my fingers on the bullet until I have to remove them. In theory this lessens how much the die has to center up the bullet when seating. It seems to help.

That may also help out if you don’t already do the same. Let us know how things work out.

 

[Bert the Turtle]

I hate to ask an obvious question but unless I missed it, I didn’t see where you said you chamfered the case mouth. Did you make sure to do that? Once in awhile I forget that simple step and it’s quite obvious quickly in that the bullets are harder to seat.

I just tried it with a much more aggressive chamfer and problem solved!

I’d been giving it what I thought was a chamfer but after giving it a good chamfer and comparing, I’d say what I had been doing was really more like breaking the square edge after trimming. That was fine with boat-tail bullets and OK with the slightly chamfered solids but didn’t cut the mustard with a truly flat-based bullet. Once I gave it a real good chamfer, it’s like
Night and day!

 

[fourfive8]

Too much chamfer will render the case mouth almost useless for an effective crimp. The Lyman M Die solves all that. Once trimmed, the case mouths should only be chamfered enough to remove the inside and outside burr created by the trimmer. The Lyman M Die also prevents case neck "pull" and the possibility of changing the position of the headspace datum ring during the expanding process that the neck expander can cause in a conventional sizing die.

 

[Bert the Turtle]

Looks like M die is not made in 423 caliber. Perhaps they will do a custom die.

 

[Inkgardener]

Looks like M die is not made in 423 caliber. Perhaps they will do a custom die.

I switched from a regular chamfer tool to the VLD style, RCBS I believe. It’s just more of an angle, but helps with a smoother seating.

I have several of the NOE expanders that work just like the M die, I’m sure they would have a .423.

 

[Nevada Mike]

On my 404 and 375 I generally follow your procedure but use a dry lube on the case neck. I finish with the Lee FCD. I do not try to seat close to the lands, as DG shooting does not require any special accuracy steps, but DOES require the best feeding performance possible.

 

[Ridge Runner]

I had this similar problem.

1) Checked: COAL, Die settings, Case lengths, Powder charge weights, etc.. Still had the problem.

2) Check and cleaned all of my dies and equipment, and complete reset up my dies and scale. Still had the problem.

3) Check and segregated 5 boxes of 100 count/ box of bullets by weighed individual weight.

4) Multiply Measured each bullet diameter for roundness and length with calipers. Now I have a gauge and gig.

Numbers 3 and 4 were the problems.

Bullets varied in weight by -5 grains to +10 grains. Burrs and deformed around the bullet bases. Lengths varied by -.03 to +.15 inches.

It was a PITA and time consuming but I separated the bullets into individual bins by weight grain weight ie 163+ grains, 164+ grains, etc. and those with only a few would be placed into the next higher bin, those bins with more than 3-4 mixed weights were set aside for target practice only. The bins having significant quantity of bullets or with only 2 mixed bullet grain weights are used for hunting. Bullet bins of excessive long bullets and excessive short bullets are loaded separately for range practice.

The bullets with burrs and deformities around the base were filed and/or sanded to remove the burrs or excess copper to proper diameter and roundness then into one seperate bin for reloading for range practice.

Since range practice is not always about shooting accuracy. I use these "bad" bullets to practice shooting form, recoil, quick reloading/ working the bolt, moving from shooting off sticks to shooting standing off hand, and shooting from a seated position. Thus saving my "good" bullets for accuracy shooting, checking my scope, and hunting.

 

[Luvthunt]

I found the 416 Rigby to be most critical of neck prep and went to inside dry lube, mica, usually and have not collapsed a shoulder over hundreds of reloads since.
Not a cure all as I follow most of the steps as outlined by the other folks in this thread.
Chamfering is good and I very lightly bell the mouth to help. May be overkill but as stated above my issue disappeared years ago.

 

[AZDAVE]

Make sure you check the case length. Just a few thou to long and they won't chamber in some rifles. and possibly causes other problems.