PDA

View Full Version : 44 magnum boolits jumping crimp



40-82
05-08-2014, 03:26 PM
I am looking for a 44 magnum load I can use in my 629-1 with a four inch barrel that won't jump the crimp. The bullet I am using is an RCBS 250 that weighs out with my alloy at 265 grains. The load I tried a few minutes ago was 15.4 grains of 2400. I tried two cylinders of this load using Winchester brass that had been fired several times, and after I fired the first five rounds, and I checked the remaining cartridge in the cylinder the crimp held. But when I loaded the cylinder with Starline brass the last round jumped the crimp. When I loaded the cylinder with IMI brass the last two cartridges jumped the cylinder so far that it tied up the gun. Both the Starline and the IMI brass has been loaded several times. All of the loads were seated to the same depth, and as far as I could tell by eye and feel the crimps were the same. I know 24 rounds is far from enough to create a valid sampling, but I wonder if this emerging pattern I am seeing that the Winchester brass performs properly and the other two don't is valid, and if it is does anybody know why.

161
05-08-2014, 03:44 PM
I just finished up working this problem out with the help of several here. Check out this thread, should help you a bunch.
http://castboolits.gunloads.com/showthread.php?239921-44-mag-sizing-die

Petrol & Powder
05-08-2014, 03:54 PM
I shoot the same RCBS 250 gr. bullet out of a 4' 629 Mountain gun and have no problems. I seat to the crimping groove and apply a moderate crimp with a Redding Profile crimp die. A few things come to mind:
1. Not enough crimp
2. Expander plug is too large
3. spilt case mouth that you didn't catch
4. your load is hotter than you think (bad scale)

It's hard to diagnose via the intranet. Some pictures would help.
Also, I prefer to seat and crimp in separate operations. It's an extra step but I've always had good results.

mdi
05-08-2014, 04:09 PM
I shoot a 629 w/6" barrel, with 265 gr. lead bullets and I too, use a Redding profile crimp, and have no problems. Having problems with one or two mfg. of brass would tell me that they probably have thinner case walls and thus a lighter crimp. I'd sort by headstamp and give those problem cases a bit heavier crimp...

W.R.Buchanan
05-08-2014, 05:15 PM
We kind of need some pics of your loaded cartridges.

I have been shooting hotter loads than what you state for nearly 40 years with cast boolits and have never had a boolit jump crimp which leads me to think you are doing something wrong.

This can be a problem, especially with lighter guns that have dramatic recoil, however a good solid roll crimp in the crimping groove of the boolit generally keeps the boolit in place.

If you are experiencing this on your first loads thru this gun then something mechanical is wrong with the ammunition.

We need some decent pics of your loaded cartridges so we can see what they look like. Without pics we can't definitively say anything that matters.

Randy

40-82
05-08-2014, 05:23 PM
I tried another six rounds. This time with brand new Starline brass. I used an RCBS tungsten carbide sizer, an expander out of a Redding 44-40 die set, a bullet seater out of an RCBS 4 die set, and then to do the crimp I changed from the RCBS crimping die to a Lee Profile Crimp. I don't have the Redding Profile Crimp die. I used the same 15.4 grains of 2400 and the RCBS cast 265 grain sized to .430. After firing the first five, I checked the crimp on the sixth cartridge. It had barely moved forward past the original crimp, not enough to tie up the cylinder, but this shouldn't happen.

I think I have my charge weight correct because I often check the scales against items of known weight, and I dropped the powder charges with an RCBS Little Dandy, which ought to be reasonably close anyway. According to my measurements it was dead on.

161,

I did read the thread you recommended, and it was interesting, but I haven't yet figured out my problem. Part of my problem might be a heavy bullet in a light gun, but I hope the only solution is not to make the choice between accepting some crimp jump or dropping to a 44 Special level load.

I'm not set up right now to do pictures, but to my eye the cases that jump the crimp look about the same as the ones that don't. I've switched back and forth between Hornady, RCBS, and Redding dies, and I haven't yet come up with the right combination.

40-82
05-08-2014, 05:44 PM
104332
I hope I successfully attached a picture of my 44 magnum reloads

Tatume
05-08-2014, 05:54 PM
There's nothing wrong with your charge of 2400, as it is well below max at the Alliant site, where they do list the 250 grain RCBS Keith bullet.

http://www.alliantpowder.com/

I'm curious about
an expander out of a Redding 44-40 die set Although the 44-40 uses a nominally smaller bullet, the outside diameter of the case is also substantially smaller, due to much thinner case walls. It would not be my choice to use this die, but I can't say it would cause problems either.

My first recommendation would be to use an expander/belling die made for the 44 Rem Mag.
My second recommendation is to use a good roll crimp die, and I would start with the RCBS bullet seater. After your bullets are seated, back off the bullet seater stem, then screw the die body down until you can apply a firm crimp. It should not be so much that the case is deformed, but just enough that the case mouth is rolled into the bottom of the crimp groove on the bullet. If the RCBS crimp solves your problem, and you don't want to readjust your dies frequently, just buy another.

I've been loading 44 Rem Mag for 4" through 7-1/2" revolvers for many years, with maximum loads and much heavier bullets than yours, and I don't have this problem. I also use mixed brass, and I use them until the mouths split, and still, no bullet creep. I think your problem lies with your dies.

Take care, Tom

Petrol & Powder
05-08-2014, 06:08 PM
OK the picture helps. The cartridge on the left looks like the bullet could stand to be seated just a hair deeper. The top of the casing should be right at the bottom of the front driving band before the crimp is started. It also looks like you could put a little more crimp on those rounds so that the casing "rolls" into that crimp groove and follows the angled contour of the lower portion of the crimping groove in the bullet.

40-82
05-08-2014, 06:11 PM
Tatume,

I used the Redding 44-40 expander, hoping the smaller expander might help when the expanders that came with the 44 magnum die sets did not help. I don't know that my problem is with the expander, but I have tried the expanders that came with an RCBS 44 magnum die set, another from a Redding 44 magnum die set, and another from a Hornady die set. Other than that I am doing something fundamentally wrong I don't know what it is. I'd like to guess that the problem is with the dies, but since I have three sets of dies from good makers with a Lee profile crimp thrown in, my best intuition suggests that the problem is an error in technique.

mdi
05-08-2014, 06:25 PM
Never heard of a Lee Profile Crimp die. Are you talking about a Lee Factory Crimp Die? That may be the problem; swaging the case/bullet after seating. FWIW, try pushing the seated bullet against the bench to see how tight the expander leaves the case. Also measure the id of the case after the expander. I've never had a problem with .44 Magnum expanders in either of the two die sets I have (RCBS and Lee) nor my Lee Loader. I kinda think the problem is from your crimp, as I've not experienced your bullet jump problem in 25+ years of reloading the .44 Magnum...

gray wolf
05-08-2014, 07:06 PM
Are you using a soft alloy ?, also I think you are using an expander meant for jacketed bullets, that can squeeze down a bullet
and the LFCD can compound the problem. When your all done with the round can you see the outline of he bullet in the case ? Measure the expander,
and what size are your bullets ? Load a dummy and pull it and check the size. Note how much force it takes to pull the bullet, it shouldn't come out with one whack.

I shoot a 260 gran GC bullet with 19 grains of 2400 in my SRH with a moderate crimp and it doesn't move.

C. Latch
05-08-2014, 07:12 PM
If I'm seeing and understanding your pictures correctly, I'd say your crimp is insufficient.

AlaskanGuy
05-08-2014, 07:20 PM
I crimp mine with the standard rcbs crimp that came with the die set... Crimping either the Keith or the much bigger 310 lee or 340 gr lyman. I tighten the crimp die down pretty good to really put a good, curved crimp on the boolits....

104335

Also, i try to crimp so that the crimp seats right on the top of the crimp grove, to give maximum amount of distance for the crimp to form, so to speak.... Sorry about the cruddy pic. But you should be able to see the curve of the crimp, and how it fits right at the very top of the crimp groove...

Hope this helps,

AG

1bluehorse
05-08-2014, 07:47 PM
I crimp mine with the standard rcbs crimp that came with the die set... Crimping either the Keith or the much bigger 310 lee or 340 gr lyman. I tighten the crimp die down pretty good to really put a good, curved crimp on the boolits....

104335

Also, i try to crimp so that the crimp seats right on the top of the crimp grove, to give maximum amount of distance for the crimp to form, so to speak.... Sorry about the cruddy pic. But you should be able to see the curve of the crimp, and how it fits right at the very top of the crimp groove...

Hope this helps,

AG

It may be just the picture, but it appears to me you are applying TO MUCH crimp, hence getting a bit of bulge at the top of the case (just below the crimp) and losing case neck tension...I'm like the others in the fact that I haven't had any issues with bullet jump in my 44's and I load a bit more 2400 than you are.....also I seat and crimp at the same time with my RCBS or Hornady dies with about 3/4 turn of the seater die after case mouth contact, just enough I can run my fingernail down the side and not catch the case mouth.....case neck tension is the key, not crimp.....to much crimp not good...

AlaskanGuy
05-08-2014, 07:56 PM
It is the pic... There is no bulge, except in the lens of this silly Ipad...lol

NYBushBro
05-08-2014, 08:01 PM
I crimp mine with the standard rcbs crimp that came with the die set... Crimping either the Keith or the much bigger 310 lee or 340 gr lyman. I tighten the crimp die down pretty good to really put a good, curved crimp on the boolits....

104335

Also, i try to crimp so that the crimp seats right on the top of the crimp grove, to give maximum amount of distance for the crimp to form, so to speak.... Sorry about the cruddy pic. But you should be able to see the curve of the crimp, and how it fits right at the very top of the crimp groove...

Hope this helps,

AG

What bullet is in this photo??? Looks nice.

Tar Heel
05-08-2014, 09:24 PM
Or this..

104349

Tar Heel
05-08-2014, 09:39 PM
Seat and crimp in separate steps if possible. Your crimp is too light. It should look more like this.

104350

rondog
05-08-2014, 10:52 PM
Or this..

104349

Now you're talkin'!

runfiverun
05-08-2014, 11:14 PM
one thing I have run into before is that I need to spin the case around and crimp again.
I have seen dies want to do one side of the case well, and the other side barely at all.

I was also thinking your win cases are a click longer than the other ones are [I know starline cases have a slightly smaller capacity than win cases do] but the shorter case length would affect the crimp and allow the movement.

Tatume
05-09-2014, 07:36 AM
Now you're talkin'!

+1 Excellent crimp, and excellent photo of a crimp.

sammorgan3
05-09-2014, 08:42 AM
From what I know, the vast majority of retention should be neck tension. Don't be afraid to crimp gutentite in the crimp groove. :razz:

40-82
05-09-2014, 09:33 AM
I really appreciate the response. You've given me a lot of ideas to work with. The first one I'll try this morning is to load a seated round without crimping and use the bullet puller to determine the amount of neck tension with several different expanders. I had read about the importance of case tension on the bullet, but it never occurred to test it that way.

Shuz
05-09-2014, 09:46 AM
In my experience of over 50 years with the.44 mag, I've determined that case neck tension is far more important in preventing boolit jump/creep, than any amount of crimp. An added benefit is that cases that aren't belled too much to accept the cast boolit without shaving; and then crimped too hard to prevent jumping, last much longer before the necks start to split.

Wayne Smith
05-09-2014, 10:04 AM
If nothing else works anneal your brass. Hard brass (Starline) will bounce back.

Petrol & Powder
05-09-2014, 10:43 AM
I'll second Shuz concerning the benefit of belling the case mouth just enough to start the bullet without shaving lead.
Over-working the that last 1/16" of brass at the case mouth will result in shortened case life.

mdi
05-09-2014, 11:23 AM
Heed Tar Heel's post! BTW Tar, good photo...

Tar Heel
05-09-2014, 12:43 PM
Heed Tar Heel's post! BTW Tar, good photo...

I started playing with the "super macro" function of the camera. The feedback it provided was revealing. Your eye can't detect those .001 or .002 gaps but there is no fooling the lens. Thanks for the compliment.

Regarding neck tension in a straight walled revolver case.....I have NEVER tested it. Bullets have to be pushed into the case so it must be enough. EVERY time I had bullets jump crimps in my .357, 41 Mag, 44 Mag, and 454 Casull, I have stopped it by applying a proper, heavier and/or better roll crimp. While I don't doubt that case neck tension plays a minor role here, the crimp is the deciding factor. IMHO

40-82
05-09-2014, 01:11 PM
I tried Gray Wolf's suggestion and seated some of my RCBS boolits in an empty expanded case and tapped them out with the inertia puller. They came back out way too easy. When I tried pulling boolits after using several different expanders I didn't feel much difference. Then I remembered that in my last potful I made some 429421's with the old single cavity Lyman mold I used as a teenager. I don't remember in those days having any trouble with boolits jumping the crimp even when I used the old Keith load of 22 grains of 2400 in my old Ruger Super Blackhawk. I weighed a few of these 429421's and they came out at 253 grains. I distinctly remember my typical weight when I used wheel weights that the weights tended to go between 245 and 247 grains. My guess now is that the alloy I am using may be too soft for good neck tension in a magnum load. In recent years I have used mainly lighter loads and things like wheel weights and monotype are harder to come by, and I have tended to hoard them rather than use them. So, I think it is going to be back to the casting pot to make a few boolits with a harder alloy.