Why is my brass showing high pressure signs?

[sbeatty1983]

I have a 125gr 357mag load worked up for my dad's 28-2. 19gr Win 296 with cci 550 primers. This is no where near a max load. The load shoots fine in my dad's 28-2 but when I shoot it in my 686-0 I get flattened and pierced primers. I only ran one cylinder full and stopped when I saw the primers. Nothing unusual about the recoil or report. My 686 has not been back for the recall, now I think I am going to send it back and let S&W take a look at the gun.

 

[S&WIowegan]

I had a 686 that did the same thing. My theory is the chambers are oversize and the cartridge slams back hard when you fire. Just my guess.

 

[What the]

The recall may well fix your problem. Is that the only load you have those symptoms with?

 

[125JHP]

Thanks for the good pics. Do you have any to compare from the 28?
Give us the complete load data to analyze... What bullet are you using? What OAL, how much crimp, etc.

What load source are you using ? From what I can see in some of the data I quickly looked at, 19 is close to max except in some of the older books that are known to be a bit warmer.

Speer 13 shows 20gr as Max @ 1.575" for a jacketed bullet.
Hornady # 6 shows 19.4
Winchester (booklet) shows 18.5gr
Speer #9 shows 21gr
Sierra #3 = 19.8 Max
Lyman #46 = 21.5gr

Lead and plated lead would be lower.

 

[jepp2]

There are roughly 25 different indicators of high pressure. Only a portion of them really apply to revolvers. Of all the signs, I find flattened primers to be one of the least reliable.

How was extraction? If fired cases just fall out of the chambers, even with flat primers I don't view the load to be near maximum. The real key is the combination of several indicators when I start to feel I need to back off some.

 

[K&Nframe]

As jepp2 mentioned, hard extraction is one of the best indicators of high pressure. Max loads are different for all guns. This is why there is a starting load. If you are having difficult extraction along with flattened primers then the load you are using probably produces too much pressure for your particular gun. No matter what the manual says is max.

If you are not having any signs other than flattened primers, then it may not be overpressure. Pierced primers are another story, as they can damage the gun over time.

Fifw, many factory 357 loads produce flattened primers in many guns.

Kevin

 

[sbeatty1983]

thanks for the replies. Seems to be alot of conflicting load data about 125gr jacketed bullets and 296. Winchester calls for a min of 21 gr and a max of 22 gr for 125 xtps. The load I used is a 125 mystery HP. They were in my dad's reloading stuff in a ziplock bag. I have them loaded to an oal of 1.574 right at the crimp groove. Extraction was sticky. had to use the heal of my hand to tap on the ejector rod. My usual load is a 158gr SWC in 38 special. The gun is our night stand gun so its loaded light in case my wife has to use it while im gone. here is a pic of a loaded bullet and an empty that came out of the 28.

 

[Aticus]

Were the cartridges difficult to load? Often when shooting 38 Spl in a 357 there is a ring of fouling build up at the end of the 38 case. This will cause loading problems and possibly sticky extraction. If the chambers are clean then the combination of extraction and primers bespeaks pressure. Normally flattened primers show pressure or head space trouble. Other than that I have no idea what is causing your trouble if this is the only load that does it. Hope this gives you some thoughts to start with.

By the by, in the past 296 was only recommended for heavier bullets and a heavy crimp.

 

[Alk8944]

sbeatty,

296/H-110 are not powders to load light. In this case "Light" means anything more than 3% reduction from maximum. This is Winchester's recommendation, not mine! Current Winchester data calls for 22 gr. maximum for the 125 gr JHP. The starting load on Hodgdon's site, 21 gr, is actually lower that the Winchester recommendation when they were still the distributor of 296.

The reason for this recommendation is that 296/H-110 can exhibit erratic burning, both squibs and extremely high pressure excursions can result. With your 19 gr. load it appears you are experiencing high pressure excursions at times. My recommendation is to dismantle these and, if you want lighter than full power loads, reload the bullets with Universal, Unique, 4756, HS-5, or any of several others in he medium burning range. 2400 can be reduced with no problems too.

 

[sbeatty1983]

sbeatty,

296/H-110 are not powders to load light. In this case "Light" means anything more than 3% reduction from maximum. This is Winchester's recommendation, not mine! Current Winchester data calls for 22 gr. maximum for the 125 gr JHP. The starting load on Hodgdon's site, 21 gr, is actually lower that the Winchester recommendation when they were still the distributor of 296.

The reason for this recommendation is that 296/H-110 can exhibit erratic burning, both squibs and extremely high pressure excursions can result. With your 19 gr. load it appears you are experiencing high pressure excursions at times. My recommendation is to dismantle these and, if you want lighter than full power loads, reload the bullets with Universal, Unique, 4756, HS-5, or any of several others in he medium burning range. 2400 can be reduced with no problems too.

Thats where contradicting load data comes into play. I loaded these using the 13th Speer manual and as best I remember their min and max loads were lower than the hodgedon's manual using the same weight bullets.

 

[trulyapostolic]

I'm not being rude but a couple of the replies gave excellent advice. Load manuals should only be used as a compass and not a roadmap. Load books were not written using YOUR gun with your chamber/barrel dimensions or cylinder gap. That's why loads must be developed specific to the firearm they're being used in. I judge pressure by extraction and, your case seems obvious, primers. I keep a notebook for every gun that I load for. In that I'll write notes next to each tested load indicating potential issues. Some guns have exceeded max load book recommendations, without any pressure signs, while others maxed out prior to the load book maximum. Hope this helps...

 

[Titegroups]

Sure looks like too much pressure, isn't the primer blown in the first one? I think the key is they shoot fine in another gun. Could be a oversize firing pin bushing is allowing the primer to extrude into the hole. That's where I'd start.

 

[fredj338]

All guns are diff. Tighter bore, tighter cyl throats, tighter chambers, smaller cyl gap, all can make a "normal" load over pressure for that particular gun. It's why we do load workups. You do know too that bullets are NOT plug & play. Diff bullets of the same wt will have longer or shorter bearing surfaces, harder or softer cores, all affect pressures. BTW, that bullet is the Remington 125gr, one of the better cup/core, old school designs.

 

[jibjab]

I do my load development with fresh brass. Brass that has been work hardened by numerous loadings can give a miss read of over pressure signs.

 

[alwslate]

I doubt your problem is caused by excessive pressure from your load.
I have found CCI primers nearly impossible to fully seat sometimes
in my handloads. This can vary somewhat depending on the make,
caliber and age of brass. Check your loaded rounds to see if the top
of the primers are slightly below the case head surface. If they are
flush or slightly above the case head, dimensional differences in the
two revolvers could mean the 28 tolerates them and the 686 won't.

 

[shovelwrench]

Hop over to "gunsmithing" and start a thread on how to check your headspace and what it should be.... Excessive headspace will do the same thing to primers in a revolver.

While H110/296 are sensitive to light loads I honestly don't think your in that real yet...

 

[growr]

What signs are shown in the use of factory ammo? If you have the same thing with factory ammo it tells me that there is a problem with the mechanical functioning of the gun and needs to have a trip to S&W.

If not, then start changing one thing at a time and use a chronograph to see what is happening for real. You may find the REAL source of your problem that way.

Randy

 

[11e40]

i had a model 57 do that to me once. turned out to be a bullet jacket lodged in the forcing cone. could'nt see until i really cleaned it. hth.

 

[bogman]

Your gun is on the recall list, because of that very problem. S&W will send you a shipping label & fix it for free.

 

[Steve C]

I think your load could be a little hot. The 2002 Winchester free on line manual showed these .357 mag loads. Note that their maximum load was only 18.5 grains. I have always trusted the Wincheseter data over what Hodgdons. Personally I don't use either W296 or H110 with any bullet weight below 140 grain. IMO these powders work best with heavier bullets.