.357 magnum trouble

shil

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I made up some .357 magnum ammunition using Accurate #9 powder and Hornady's 140 grain XTP, using data from Hornady's 9th edition manual. Charges were as published, from the suggested start to the maximum. Using the start charge, through a 686, my first three shots seemed very mild. Muzzle blast and recoil were unusually light. The fourth round was a total squib, lodging a bullet in the barrel. ALL STOP! Now, I deviated from the published data in that I used standard primers instead of the magnum primers called for in the data, having read from several sources that Accurate #9 did not require magnum primers. Were the standard primers responsible for the squibs in this instance?
 
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AA9 does best with heavy bullets per caliber, for me its 158 minimum for 357 and a heavy crimp. I try to use Winchester primers as they are also listed for loads needing either magnum or stand primers.

It does very well at what it does but light bullets with light crimps and standard primers is asking it to perform outside those boundaries. I really like AA9 with 160 + in 357, 180-200 gr in 10 mm, and 250 + in 44 magnum. I won't shoot it with lighter bullets as I had one stick in the bore before. The bullet lodged in the forcing cone and the powder was sort of greenish black. A standard primer and a light crimp was used on a 44 Magnum, 240 gr load.
 
Did you put on a good crimp? When I first started with 357 I forgot to crip and have what you described. I have heard different things about mag vs non in the primer dept. You will probably get many different opinions here about that. Crimp is not only important for bullet creep with a revolver but, also how the powder burns.
 
Thank you, all, for your responses. I pulled apart the last offending round and found the load to be as published: 11.2 grains. Firm roll crimp. Velocity estimate (Hornady's) of 1100 fps. The remainder are stepped up in groups of five rounds to Hornady's maximum of 12.9 grains. Significant, I think, is that Sierra wants 14+ grains for their 140 grainer. Their loads are of higher estimated velocity. My records show I used in the past a charge of 14.5 grains with that bullet with no issues; however, Sierra called for a magnum primer, which I used. Question: Shall I pull down all my remaining test rounds or try the maximum Hornady load of 12.9 grains? I hate waste, but I'm inclined to do a pull-down.
 
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You need to either put in a magnum primer or switch powders. (By the way, W296 & H110 require a magnum primer, too.) Increasing the powder charge isn't the answer. Your 'standard' primer just isn't hot enough to be reliable.
 
I'd probably shoot them up rather than pull them, but I'm not sure how many rounds we're talking about. In the past in a similar situation I decided it was easier to shoot them and knock out the occasional squib vs whack-a-mole. But I was using lead bullets and they knocked out easy. I got some funny looks at the range.

Way back when, in the Golden Age of Magnum Revolvers, I sometimes would roll crimp and taper crimp to ensure a solid crimp. These days you can accomplish much the same in one step with the Redding Profile Crimp Die. If you're shooting magnum revolver cartridges the Profile Crimp Die is a wonder.
 
I NEVER shot heavy weigh bullets out of my "Long" barrels with a
Starting load, to prevent a Squib from happening.

All my copper bullets start with at least a factory loading, from all data.

I will only shoot low FPS loads out of my snub nose with a lead bullet,
in case a load is too slow, to clear the barrel.

I almost had a squib in my 9mm, with IMR4227 powder, it only turned out to be two stove pipes.
 
Hodgdons lists a START of 12.8gr of #9 for a Sierra 140gr JHP @ 1.575", an estimated velocity is 1,252 fps. There is no listing for the 140gr XTP, which I find a bit unusual...?

It is also interesting that their START load for the 158gr XTP is 12.4gr and 10.8gr for a 180gr XTP. That's only 0.4gr less for a bullet that weighs 28.5% more!

That Hornady START of 11.2gr seems very low (at least to me?) for a considerably lighter bullet: I would opine either a possibly shorter OAL or 1.6gr less powder for what is virtually the same kind of JHP ( Sierra vs. Hornady) could have much more to do with a potential squib load than the difference between a standard vs. magnum primer, although #9 is not an Accurate powder I am familiar with...

It would appear that the Hornady MAX of 12.9gr is not necessarily the actual "MAX" for a 140gr JHP: the Hodgdons MAX for the 158gr XTP is 13.8gr...

Cheers!

P.S. Depending on how many of each you loaded "from the suggested start to the maximum" you might just consider shooting a few (one at a time) to see how they (hopefully) improve before breaking them all down...?
 
Upon checking, I see Sierra handgun bullets are again available after seeming to have disappeared. I'm tempted to buy a box of their .357 140 grainers for a side-by-side bullet-to-bullet comparison. In any case, in deference to published data for .357 magnum with Accurate #9, I guess I'll have to locate some magnum primers. Drat! I bought two bottles of #9 instead of W296 some months back because Accurate #9 supposedly didn't require magnum primers :mad:. Thank you, all, for your responses. At age 73 and 40 years of reloading, I apparently still have things to learn!
 
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Upon checking, I see Sierra handgun bullets are again available after seeming to have disappeared. I'm tempted to buy a box of their .357 140 grainers for a side-by-side bullet-to-bullet comparison. In any case, in deference to published data for .357 magnum with Accurate #9, I guess I'll have to locate some magnum primers. Drat! I bought two bottles of #9 instead of W296 some months back because Accurate #9 supposedly didn't require magnum primers :mad:. Thank you, all, for your responses. At age 73 and 40 years of reloading, I apparently still have things to learn!

Don't feel like Clayton Moore: @ 72 I consider it a bland day when I don't learn something new!

Well, there's always 357 SIG & 10mm (which, unfortunately, also often comes with LPPs) to reload...?

Cheers!

P.S. Were we not so far apart I'd gladly trade you a lb. of Longshot for one of #9...
 
One thing to wonder about is the length of the case that the Hornaday manual used. Hornaday .357 brass is shorter than normal length. What length of case did Hornaday use in developing their data?
 
Looking through my 9th edition Hornady manual, it looks like they developed their loads for the 140 XTP with normal length cases. The 140 FTX is the only one shown with a notation about using the shorter cases.

As for Hornady's powder loads shown, they seem to be much lower than what my Sierra manual shows for their 140 JHP bullet, which has a very similar profile to the 140 XTP. Sierra's starting load for their 140 JHP is .3 higher than Hornady's max load shown for the 140 XTP. And Hodgdon's online data shows a 140 grain Sierra JHP with a powder load of 12.8-14.2 grains of Accurate #9. All 3 show the use of Win Small Pistol Magnum primers.
 
This topic got my attention because I'm very interested in loading .357 Magnum for my Marlin 1894 Cowboy. I just got my hands on the April 2021 issue of Handloader Magazine, which contains a detailed article on the subject, with a significant number of loads listed with many different bullets and powders. The author is Brian Pearce. He states that "many of the loads listed were pressure tested, but others have not." He also doesn't think that the loads not tested exceed SAAMI pressure max of 35,000 PSI, but you have to take that for what it's worth.

I mention this because he has many loads using Accurate #9 and 140gr Hornady FTX. These loads run from a minimum of 14.0 grains to a maximum of 15.3 grains. None of them use a magnum primer. In fact, he states that his testing showed that using magnum primers with A#9 boosted pressures by 8,000 to 10,000 PSI with no change in the powder weight. His results look pretty impressive, and with standard CCI 500 primers.

He does note what others have, that H-110/296, and L'il Gun require magnum primers.

I'm not here to debate anyone on whether or not this information is correct. I'm just adding some additional information to the discussion in the hopes that it helps the OP succeed in what he's trying to accomplish.
 
I've never used magnum primers with #9 powder and never seen it written that they are needed. I know it is a magnum handgun powder and I've always loaded it halfway between min and max on up to max without any hint of a problem and it's always performed wonderfully.
 
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