CAS 357 Magnum load underperforms - Crimping issue or ??

[AJC1]

I would add this to the list of reasons I own lathes.

The only limit one has with a lathe is their imagination, and volume of stock their willing to turn to scrap to complete the desired part. I'll go ahead and assume I generate far more scrap on my way to the goal than you.

 

[JimGnitecki]

I have not read the whole thread as it makes my eyes bleed, there is so much static and extraneous information. Information overload!
357 mag loads are not this difficult

You have gone from you go to load using Trail Boss. It probably gave you good case fill
Now that you are using Tite Boom, in that big case,how is the case fill?
If already discussed that never mind.

Have you considered powder position in the case?. Could be what ale's you

Yes, the powder case fill is pretty awful, but unavoidable, since both Trail Boss and Tin Star are now no longer being made. And .357 Mag replica 1873 lever rifles seem to run more reliably with .357 Mag cases than with .38 Special cases.

Powder pposiiton in the case is unlikely to be the problem, since I load the revolver JUST before shooting a 5-shot string each time, and hold the revolver horizontal the entire time until I tilt it to extract the fired cases. Not much more I can do about powder posiiton. And in actual CAS matches, the handguns will unavoidably be holstered vertically and then pulled out and fired horizontally, with the speed required for CAS shooting making slow and gentle consistency of revolver handling impossible anyway. As many have already adminished me, "It's not Bullseye shooting".

Jim G

 

[JimGnitecki]

The only limit one has with a lathe is their imagination, and volume of stock their willing to turn to scrap to complete the desired part. I'll go ahead and assume I generate far more scrap on my way to the goal than you.

My metal fabrication skills are basically non-existent! However, I did successfully make an articulating guard for my radial arm saw out of 3/16" aluminum to replace the 1/8" clear plastic OEM guard that had already fractured 4 times. But i broke a bandsaw blade doing it, having to make one too many sharp turns with it!

I AM also learning to TIG weld, and doing so on ALUMINUM. THAT is a challenging and elegant process, and I love learning the "must dos" to get that "perfect stack of dimes".

Jim G

 

[Soonerpesek]

Have you considered powder position in the case?. Could be what ale's you

I don't think beer is gonna help his problem with the loadings, but powder position may be what's ailing the situation.........

 

[.45Coltguy]

Too bad OP cannot locate any 2400. That might help solve the powder end of said quest. Lot of stuff going on here.

 

[Jim Watson]

Too bad NAFTA doesn't cover such dangerous items as hobby reloading parts but ITAR does.

Too bad OP cannot locate any 2400. That might help solve the powder end of said quest. Lot of stuff going on here.

Nope. Magnum Power is not allowed in CAS.
Underloading 2400 for low velocity does not work. I have seen it tried and it is just an erratic mess.

 

[.45Coltguy]

Too bad NAFTA doesn't cover such dangerous items as hobby reloading parts but ITAR does.



Nope. Magnum Power is not allowed in CAS.
Underloading 2400 for low velocity does not work. I have seen it tried and it is just an erratic mess.

Whoops! Forgot that. Not being a CAS, slipped my mind.

 

[lordpaxman]

And that Double Alpha expander is intended for the Mr. BulletFeeder, not the Dillon powder drop.

Not quite - they sell the expander for either the Hornady LNL or the Dillon line, and it specifically fits the respective powder drop. It’s typically used when adding the bullet feeder to the press, to help give a nice ledge to hold the bullet when it drops. I don’t have a bullet feeder, but it’s a nice ledge for coated bullets.

I have been afraid to use anything like Hornady One Shot because in order for it to work, it has to leave a layer of lubricant on the case, and that lubricant might affect powder drop (via its by-definition stickiness) and bullet-to-case fricition (which affects peak pressure developed in the case before bullet release).

The case lube is specifically designed to… lube cases… and not affect the process, nor the finished product. I can tell you after many many thousands of rounds, it’s not an issue. Everyone’s entitled to their predilections.

 

[Jim Watson]

help give a nice ledge to hold the bullet when it drops.

The DA I bought for .38 Special had only a barely perceptible line, not the step of a real Lyman M die, which is not as deep as the expanders I use on BPCR for soft cast bullets.

 

[jmorris]

and hold the revolver horizontal the entire time until I tilt it to extract the fired cases.

Try pointing it to the sky and slowly lower to target before each shot.

 

[Hooda Thunkit]

Try pointing it to the sky and slowly lower to target before each shot.

I don't think there is time for that in CAS. The 'A' in CAS stands for Action.

 

[reddog81]

That IS a possibility, but I hesitate because I've repeatedly been told that trying to do both in one die is not a recommended practice.
Jim G

If your lead bullet has a crimp groove and is for revolvers it was meant to seat and crimp in the same step. People that reload yet can't seat and crimp in the same step scare me.

 

[JimGnitecki]

If your lead bullet has a crimp groove and is for revolvers it was meant to seat and crimp in the same step. People that reload yet can't seat and crimp in the same step scare me.

The Hornady 10408 bullet I am using does NOT have a crimp groove. Its entire shank is cross-hatched and has a dry lubricant coating over the entire shank. You can evidently use either a taper crimp or a shallow mouth crimp like the Lee Factory Crimp die can produce.

I can see getting a decent crimp in a grooved bullet that does not damage the bullet if you aensure that the crimping begins at the TOP of the groove. Then, the rim of the case has room to bend inward into the bulelt without mashing the actual bullet diameter.

Jim G

 

[P Flados]

That IS a possibility, but I hesitate because I've repeatedly been told that trying to do both in one die is not a recommended practice.

Jim G

The recommendation to do seating and crimping separate make more sense for a 9mm, 40 or similar case. For revolvers, I would say that more than 95% of the "old fashion" (non turret) reloading is with both at the last step using a standard 3 die set. Of my many many thousands of cast bullet revolver rounds, I have never had a standard load where I did it in two steps.

 

[Bill M.]

I seat and crimp hand gun loads separately because I really like using my fancy sliding sleeve seating dies,

 

[.45Coltguy]

I've been using a Lee FCD om .38/357, .45 acp, .45 Colt and 30-30 for a spell, no problems. And it doesn't scare me at all.

 

[AJC1]

If your lead bullet has a crimp groove and is for revolvers it was meant to seat and crimp in the same step. People that reload yet can't seat and crimp in the same step scare me.

Well I'm willing to compare my load oal variation to yours for proof in the pudding. A superior product is what floats my boat. I'll leat anyone shoot my loads in my guns if I want because my standard is for my child's saftey. Your way works for you, and that matters, don't be smug.

 

[jmorris]

I don't think there is time for that in CAS. The 'A' in CAS stands for Action.

If the readings all of a sudden get more consistent, you know the powder is position sensitive.

If you don’t test both ways, you would never know.

 

[JimGnitecki]

If the readings all of a sudden get more consistent, you know the powder is position sensitive.

If you don’t test both ways, you would never know.

Good Point, jmorris. I WILL try that just to see, the next time I go to the range.

Jim G

 

[WVRJ]

I used to load those Hornady bullets for my Marlin lever gun and my Blackhawk,and I got along good using a roll crimp on the front corner of the cross hatch area.The OAL is a little short,but they worked good through my rifle.Deep seating will also help any powder position problems,and may raise the pressure enough to help expand the brass properly.

 

[JimGnitecki]

I used to load those Hornady bullets for my Marlin lever gun and my Blackhawk,and I got along good using a roll crimp on the front corner of the cross hatch area.The OAL is a little short,but they worked good through my rifle.Deep seating will also help any powder position problems,and may raise the pressure enough to help expand the brass properly.

I wondered about that. I was concerned about how MUCH it might raise the peak pressure. I say that because with my current handload, I am at 1.580" COAL right now (.010" already under the load table data), and I have at LEAST 1/16" = .0630" more swaged area since protruding from the case. So, I would be at no more than 1.580" - .063" = 1.517" to do what you are suggesting. That's 73 thousandths shorter than SAAMI spec. And if I accidentally get some cartridges shorter, via lead particles accumulating on the inside of the bullet seater, I could get even shorter pretty easily and not notice it. A little risky.

It's not like I NEED a strong crimp either. The load is very light (158g bullet with MV = 770 fps average with current COAL), so recoil setback is not likely. I THINK a modest "clamping" on the crosshatched area is sufifcient, don't you?

Jim G

 

[reddog81]

SAAMI Spec is for max OAL. Your using loads below Hodgdon's .357 starting load data. It's very, very, very common to adjust seating depth a bit based upon the specific bullet being used. A 158 grain bullet going 770 FPS in a .357 isn't going to hurt the gun if seated .01" deeper. A human hair is .003". .01 = about the width of 3 human hairs, i.e. not much

Lead should not being a accumulating inside the bullet seater. Lube from lead lubed bullets sometimes accumulates if the bullets have lubed smeared to the sides of them, but that should not be your case.

 

[WVRJ]

I agree with Reddog,your load is very mild anyway,so I doubt if you'd get into pressure problems from seating a little deep.I'd do a gentle roll crimp on the front edge of the bearing surface of the bullet and see how it works.You're getting lots of input from some fairly competent reloaders,and I'm sure you'll hit the right setup soon.

 

[JimGnitecki]

I think I will wait for the Lee Factory Crimp Die and the Uniquetek expander funnel I have ordered from The U.S. to arrive, and try them first. I say that because I suspect that the current re-swaging of the bullet down to just a .355" bullet diameter is harmful - it's marginal for a lead bullet in a .357 Magnum barrel. If that does not make a favourable difference, then I will try reducing the COAL enough to crimp the case into the bullet above the crosshatched portion. I'll need to be careful and do that in trail steps, as the COMBINATION of much shorter COAL AND a harsher crimp MIGHT be a little much in terms of peak pressure compared to the current peak pressure.

Jim G

 

[P Flados]

Jim, With the low percent fill of your specific combination the pressure will not go up that much.

Cartridge          : .357 Magnum (SAAMI)
Bullet             : .358, 158, Hornady SWC 10408
Barrel Length      : 6.5 inch = 165.1 mm
Powder             : Hodgdon TiteGroup

Cartridge O.A.L. L6: 1.580 inch = 40.13 mm

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms
+00.0   34     4.00    896     281   16651   2157    100.0    0.890
+25.0   43     5.00   1022     367   24635   2622    100.0    0.744


Cartridge O.A.L. L6: 1.517 inch = 38.53 mm

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

+00.0   38     4.00    917     295   18869   2097    100.0    0.850
+25.0   48     5.00   1046     384   28182   2544    100.0    0.711