44 Mag Crimp Jump Issue

[SteelHorse44]

Hi All,

I have had crimp jump issues since I started loading 44 mag and trying to diagnose cause and next steps. I am thinking I may need to try a different bullet but thought I would see if any here had some thoughts:

Press - Lee Turret Press

Dies - Lee dies and a Lyman Neck Expanding die. I load in the following order - resize all brass in 1st step. 4 turret steps - neck expander, powder through expander, hornady powder cop, seat and crimp.

Bullets - Xtreme Bullets, plated, 200 grain RNFP

Powder - 8.9 grains 700x (only powder I had access to when I started reloading, I have many other options now of course)

Primers - CCI Large Pistol Primers

Gun - S&W 629 4"

Current cartridge measurements:

- After reloading - 1.547 OAL, this gets the crimp to the center of the cannaleur
- 6th cartridge after firing 5 in cylinder - 1.560-1.563 (taken from 3 samples). Jump of .013-.016

Questions:

- Is this an acceptable amount of jump or should I keep working for no jump?

What I've tried:

- Heavier crimp - I am about as heavy as I can go I think before shearing the plating becomes a concern

- Adjusting settings on original Lee dies - feel like I have tried a ton of different things including going as small a bell as possible on the powder through expander.

- Lyman Neck expanding die - this was my last try after doing a bunch of reading. I read neck tension is 90% of the issue and crimp about 10% so I thought maybe using this would solve the issue.

Possible Solutions:

1) Xtreme plated bullets with their shallow canneleur and plating just aren't a good match for 44 mag (work fine in my other loads). Try something else like Missouri Bullet Company coated bullets or step up to a more expensive jacketed option. I bought 1000 of these on sale before I knew better

2) Possible the Lee powder through expander in station 2 is undoing somehow what the Lyman neck expander is doing in station 1 (though I thought I rolled off the expansion on this station, something to double check).

3) Try a different powder with the Xtreme bullets to see if maybe a lower pressure solution may help. The manuals don't give much info on the starting load pressure of 8.9 grains of 700X (200 grain jacketed bullet data) so I don't have data to compare. High end pressure is roughly in line with other loads. Speed is definitely on the low end.

Anyway, any thoughts would be appreciated.

 

[243winxb]

Only time bullet jump was a problem for me , was caused by thin walled Super Vel brass. Does all brandS of brass do it? Bullet diameter is listed as .429" Your expander(s) should not be larger than .427"

 

[SteelHorse44]

I have only used new Starline Brass.

 

[murf]

welcome to thr, steelhorse44.

xtreme bullets are swaged lead copper plated bullets. the bullet may be getting sized down when seated in the case. i'd measure a bullet diameter, seat the bullet, then pull the bullet and remeasure the diameter to see if it is getting reduced. that could be the bullet pull problem. the cure would be a roll crimp over the ogive of the bullet along with a reduction in powder charge (to allow for the reduction in internal case volume).

the speer manual shows a max charge of 9.0 grains in the "short barrel" section. even the max load is not close to max pressure, so you should be ok with your current load. if you are going to crimp over the ogive, you will want to reduce that charge, lets say 10 percent, and work up.

another thing you can do is measure the case tension on the bullet by measuring the outside diameter of the loaded round. measure just down from the mouth and again just below the base of the bullet. the latter reading should be a few thousandths less than the former. if they are the same, you don't have enough tension.

luck,

murf

 

[Malamute]

Is the Lyman expander the M type?

If so, in this case, a regular expander may help retain neck tension. The M type is stepped, and expands more for the part closest to the mouth of the case than other expanders. Its intended to be gentler to cast bullets, but most cast bullets have more crimp groove than it sounds like yours have. If its a question of being able to use the bullets, I'd be giving them a heavy roll crimp regardless of if it damaged the plating.

No amount of jumping crimp is OK to me.

 

[oldpapps]

This may sound a little backwards but....
Easy up on your crimp.
I have found that a 'hard' crimp actually bows/buckles the case a little and removed case tension.

Did you ever think of trying a Factory Crimp Die.

Just thoughts from a wandering mind.

 

[joneb]

I have mitigated this issue for 357 mag with plated bullets by reducing the expander plug diameter. I got a extra from RCBS and turned it down .002"

 

[IMtheNRA]

Does the bullet jump stop when the "end" of the cannelure reaches the crimped case mouth or does it continue to jump out past the cannelure? If the end of the cannelure stops the the forward jump of the bullet, then I think the cannelures and crimps are doing their job.

 

[Iron Sight]

The Xtreme plated Bullets I am familiar with don't really have much of a cannalure, if you can even call it that?

 

[Shaq]

I also wasn't aware that Xtreme bullets have a cannelure. I've loaded "Berry's" plated 44 Mag bullets that don't have a cannelure & I got a taper crimp die from RCBS - yes, they do make them for revolver bullets with no cannelure. I've never had a problem with bullet movement.

 

[Grumulkin]

Just get a Lee Factory Crimp Die. It will solve the problem.

 

[ArchAngelCD]

IMO it's the plated bullet causing the crimp problem. You can't apply enough crimp to a plated bullet to prevent movement without deforming the bullet. Go all lead, coated bullets or jacketed bullet and the problem will go away.

Why are you using a powder cop die on a turret press. A powder cop is usually necessary on progressive presses where you can't easily see into the case to check for powder. On the turret press you are only doing 1 process at a time and the Auto-index feature makes it extremely difficult to double charge a case. Just my thoughts but I think it's unnecessary to use a powder cop on a turret press and I never skimp on safety.

 

[Walkalong]

You need a taper crimp (True taper crimp) die to put heavy crimp on plated bullets. Then hope it doesn't ruin accuracy. Only one way to test that. SOme bullet/applications can take it, some can't.

 

[grandpawj]

Walkalong, love your Trooper, got one just like it!

 

[SteelHorse44]

First, thanks for the welcome and all the great ideas so far! I'll try to answer what's been put forth:

another thing you can do is measure the case tension on the bullet by measuring the outside diameter of the loaded round. measure just down from the mouth and again just below the base of the bullet. the latter reading should be a few thousandths less than the former. if they are the same, you don't have enough tension.

I'm seeing .454 just below the case mouth and .451 just below the bullet on a completed cartridge.

Is the Lyman expander the M type?

Yes, it is the M type

Did you ever think of trying a Factory Crimp Die.

I have one but have not used it yet. I will put that on the list to try.

Does the bullet jump stop when the "end" of the cannelure reaches the crimped case mouth or does it continue to jump out past the cannelure?

Unfortunately slightly below the cannelure. The cannelure on these bullets are merely some verticle grooves and very shallow as others have mentioned. Nothing like the Missouri Bullet Company coated bullets I have also.

Why are you using a powder cop die on a turret press.

It makes me feel warm and fuzzy inside Plus it has caught a couple errors so far. I really like having it and don't mind the extra steps if necessary. It is really a nice tool and I load seated (I have back issues) so tough to look into the case with my setup.

So things to try:

1) Lee Factory Crimp Die
2) Coated bullets with much deeper cannaleur.

 

[SteelHorse44]

Also, looking at Walkalong's pic, I am definitely not getting that long of a crimp. Just looks like maybe .055 according to the calipers. Time for some adjustment.

 

[243winxb]

Your expander(s) should not be larger than .427"

 

[SteelHorse44]

Inside of the case just past the case mouth is measuring .427-.430 after the Lyman M expander stage. Getting the same measurements after the powder-through-expander stage so that doesn't seem to be adding any extra flare.

Are those numbers OK or should I back off the M expander slightly to hit the .427 mark?

 

[243winxb]

The case mouth needs a slight flare to start the bullets. It takes pin gauges to measure the inside of the case, accurately. Measure the expander diameters. On the Lyman, measure below the step.

 

[SteelHorse44]

Lyman expander - .430 on the expander right after that second step ledge.

Lee expander plug is bigger at .436. - i had that one backed out far enough that the expander plug was high enough as to not adding any more expansion (from what I can tell).

 

[243winxb]

.427" is needed . On the Lyman, the first part to enter the case is .430" ?? The Lee expander is way to big, if it goes inside the case like my Dillon powder thru expander.

 

[SteelHorse44]

The very last portion that tapers (not the hard step) is .425-.427. Once it flattens out higher up, it is .430.

So judging from your posts, I should back that out and only let that first part in enough to flare just large enough for the bullet to seat but try to keep the rest of the area the bullet will sit into around the .427 width which will give me the neck tension I need?

 

[243winxb]

Internet photo. Your Lyman should be about the same.

 

[243winxb]

Post 22. Correct. Good luck.

 

[SteelHorse44]

Thanks 243winxb for all the help, really appreciate it.

Now I suspect that the Lee powder through expander is further expanding as I look at it without the powder hopper on. Why in the world would they make that a .436 diameter when the target is .427? This is what I remember reading about that led me to buy the Lyman expander - Lee's system was over-expanding and not allowing sufficient neck tension.