357 158 gr bullet velocity swings with 2400?

[twodog max]

Alliant data lights 2400 with standard primers so I have always used those.

 

[Bob T]

I found I had pretty wide swings with standard primers while I was working up my 2400 158gr loads. I reworked them with Magnum primers and they settled down nicely for me. YMMV

Same here for the Outdoorsman. Mag primers settled thing down.

 

[rwsmith]

I use regular primers.....

But if I got that kind of variation the first thing I'd try would be magnum priers. Getting a consistent burn is harder with slower powders. That's why most good target loads are with faster powders.

 

[gwpercle]

If your loads are accurate , don't worry about the deviations.
If the deviations bother you or the groups are lousy , try a magnum primer to see if it helps.
2400 is an excellent powder for magnum loads, if the standard primers aren't doing the job try magnum primers, if that doesn't work out , try another powder....that's what handloading is all about , tailoring ammo to fit and preform in your gun.
Good luck ,
Gary

 

[USSR]

I was shooting over the chronograph at about 3-4 yards. Too close? I was not using the sky screens.

With the Chronys, ALWAYS, ALWAYS, ALWAYS attach the sky screens and then tape some paper or cardboard to them so as to eliminate any early afternoon sunlight hitting the sensors from the side.

Don

 

[alwslate]

I have chronographed a lot of different 357 loads with 2400 powder
and I get much better consistancy with magnum or small rifle primers
than with std primers. I use mostly Win primers.

 

[kennethdlarson]

I've been using a Lee carbide factory crimp to crimp the case mouth into the cannelure on the bullet. I'll definitely try the sky screens with the chrony next time as well as moving back a bit. I'll leave the mag primers as a possible solution of last resort if the above doesn't work.

 

[tops]

I load 15 grs. 2400, 158 gr. SWC, Win. standard primers. A 6 in. Python will average over 1400fps. A 2 1/2 M19 is over 1200 fps. I don't have the individual speeds wrote down. I just wrote down the averages. Larry

 

[BLUEDOT37]

getting velocity swings...a load of 15.0 grains of Alliant 2400 on top of a CCI 500. Bullet is an Xtreme 158 gr. hollowpoint.

For years now, Speer & Alliant have been say not to use Magnum primers with their 2400 loads as excessive pressures will result. No exception for the 357 Mag as it's started there too.

They also say, as we know, that a good roll crimp is needed to insure proper (& thorough) ignition, which is where I think your issue may lie since you can't get that with these plated bullets & the regular CCI primer.

I've shot a lot of Xtreme, & others', plated bullets & whenever I try slow powders with them poor/inconsistent ignition usually occurs. These Xtreme .357 bullets have a cannelure but I only use it as a seating reference, not to roll crimp into, & use a firm taper crimp (as Xtreme recommends) instead. Usually I just drop back to a slightly faster powder, which is more efficient in this situation, with these.

15.0gr/2400 works fine with JHP, or cast SWC, & a firm roll crimp.

.

.

 

[Doc Hollywood]

If you are flaring the cases before you seat the billets make sure you are flaring them as little as possible and as consistent as possible. Sometimes if you flare a case too much the brass will spring back loosening your crimp.

 

[scooter123]

Chronograph is a Shooting Crony F-1. I was out load testing my left hand Winchester M70 26" 7mm Rem Mag with the same chrony and found "my load" - 63.0 gr of IMR 4831 behind a Hornady 162 gr. ELD-X on a CCI 250. .75" at 2900 fps - good in my book...

My experience with my Shooting Chrony is that you'll get wide swings in velocity if you allow elevation over the sensors deviate by more than about 1/2 inch TOTAL. This means I have to be very careful when testing handgun ammunition and make sure that the bullet is dead center in the joints for the wires that hold the sky screens. Anytime I get sloppy and don't pay attention the reward is a big swing in velocity of as much as 200 fps.

 

[fredj338]

When I learned to reload I was taught to use magnum primers for loads over 8 gr. Don't think I've ever seen 2400 loads with a standard primer.

False thinking. 8gr of what, what caliber? it all matters. You use a mag primer with Unique at say 9gr??I don't look at a magnum primer in any handgun load unless it is H110/W296, maybe lilgun. In rifle, not until charges are over 60gr.
2400 doesn't need a mag primer for good ignition. Load density is more important to good ignition. I suspect your powder measure or the plated bullets variation in hardness & ability to get a good crimp. Look at Alliant data, no mag primers used. Try a mag primer, it may or may not help.

 

[fredj338]

My experience with my Shooting Chrony is that you'll get wide swings in velocity if you allow elevation over the sensors deviate by more than about 1/2 inch TOTAL. This means I have to be very careful when testing handgun ammunition and make sure that the bullet is dead center in the joints for the wires that hold the sky screens. Anytime I get sloppy and don't pay attention the reward is a big swing in velocity of as much as 200 fps.

Why I can never recommend the Chrony line, just **** screens. Though it's more error or a reading, not variation in the readings.

 

[rwsmith]

Does anybody think....

Does anybody think that heavier crimps may be required? 2400 isn't as slow as 110/296, but it's still a slow powder and gets close to the performance of the slower powders.

 

[fredj338]

Does anybody think that heavier crimps may be required? 2400 isn't as slow as 110/296, but it's still a slow powder and gets close to the performance of the slower powders.

The slower the powder the more it will benefit from a firm crimp & mag primer.

 

[rockquarry]

It's necessary to experiment with the degree of crimp. Your "heavy" and someone else's "heavy" are seldom the same and one or both of them may be too heavy or even too light.

Try several degrees of crimps and shoot some groups at twenty-five yards from a rest, taking special note of things like accuracy, unburnt powder, and bullets jumping crimp. Standard or magnum primers are a secondary factor, often very secondary. Same with velocity deviations. Unless huge, they are of little or no significance. If they are huge and you have an accurate load, no unburnt powder, and bullets don't jump crimp, try another chronograph.

 

[kennethdlarson]

Thanks all for the replies and info. I'm going to stick with 15.0 grains of 2400 and the CCI 500. If I still get crazy velocity swing I'll back off a 1/2 grain and see how that goes. I am putting on a pretty good crimp but I'll reset the die from scratch just to see if that makes a difference. If 2400 doesn't work, then I'll shoot the rest that I have and then go back to 16.0 grains IMR 4227 with the CCI 500s or Winchester SPM because I know that is good load in my sixgun. Thanks again!

 

[ArchAngelCD]

Thanks all for the replies and info. I'm going to stick with 15.0 grains of 2400 and the CCI 500. If I still get crazy velocity swing I'll back off a 1/2 grain and see how that goes. I am putting on a pretty good crimp but I'll reset the die from scratch just to see if that makes a difference. If 2400 doesn't work, then I'll shoot the rest that I have and then go back to 16.0 grains IMR 4227 with the CCI 500s or Winchester SPM because I know that is good load in my sixgun. Thanks again!

I am not a fan if 4227 in the .357 Magnum, the .44 Magnum yes but not the .357.

Are you not a fan if W296/H110 with 158gr bullets in the .357 Mag? I feel its the best choice although I have not yet tried 300-MP.