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Posted: 3/19/2016 11:09:49 AM EDT
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First, I've been using H110 at full power loads for 30 Carbine and 357mag for years and I have 0 issues so no problems there. However, recently I decided to back off on the full power loads a bit so my wife could enjoy shooting them a bit more. (ETA: I loaded up some 357mag loads with new Starline Brass, CCI 550 primers, 158grn Gold Dot bullets and) decided to load up a few at Hodgdon's recommended starting load for my bullet and H110. I fired a few and wow! I had primer issues! Thinking I'd maybe loaded them long and understanding H110's disdain of low case densities, I re-seated the bullets lower in the case to approximate the volume of the powder reduction and while it helped, I still was showing some pressure signs. Then I loaded up some more at the mid point between min and max loads and had the same pressure issues both at the original OAL and with the bullet seated deeper. I'm wondering why that is. I followed Hodgdon's loading manual and am positive my loads are within their specified range for the bullet. I have a good crimp and even loaded up 10rds at max charge and standard OAL and they fired as normal. Anyway, I talked to Hodgdon and explained it and he didn't have an answer for me. He asked if I might consider changing to magnum primers as they give better ignition and I explained that I used magnum primers exclusively with H110. He had no answer for me. Thoughts? |
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Hodgdon shows the pressure of the starting charge to be very low. So, low pressure is your problem. To raise pressure, use a smaller expander for more neck tension. Other wise, use a powder that is starting load friendly. Old Win 296 data said not to reduce or change any components. |
 From Hodgdon manual in 2002 Old data here > http://castpics.net/dpl/ |
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Interesting.
Did you try the reduced loads in the gun you usually shoot? Maybe the jump to rifling or forcing cone is longer, allowing the volume to increase too much. I would test for position sensitivity, too. Maybe try a different primer, but that seems like a stretch. |
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Quoted:
158 GR. HDY XTP in 357 magnum Hodgdon Powder H110 Bullet Diameter .357" C.O.L. 1.580" Starting Load Grains 15.0 Velocity (ft/s) 1,418 Pressure 28,600 CUP Maximum Load Grains 16.7 Velocity (ft/s) 1,591 Pressure 40,700 Source? Look at that pressure spread for a tiny charge increase. Hornady data starts at 12.7 grains, max is 15.6 grains. |
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Quoted:
When you say primer issues, exactly what are they doing? Got pics? Also what are you judging "pressure issues" by? Flat CCI-550s really don't mean a thing. If you are getting excessive recoil and difficult extraction then I'd say you may have pressure issues. If you are not getting either of those or tight cylinder rotation or hang firing, I'd say you are ok. Motor |
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Whether 296 or H110 (Both SXT) following the advice of done reduce more that three (3) percent is good advice.
This powder performs best when following this load practice. Maybe the OP should just find a plinking load with coated bullet that is more pleasant for his better half to shoot! Wasting premium jacketed bullets is fruitless! |
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Quoted:
I'm pretty sure that Steve (the OP) stated in the OP that he was NOT below the recommended starting load. So he is not attempting to shoot reduced loads. All the comments pertaining to this are valid but do not pertain to this thread. Motor I'm finding the recommended start load as 15.0 grains with a max of 16.7 (per their website as of right now). A 3% reduction in 16.7 is only 16.2, so the 15 grain charge would be well below a 3% reduction that was warned against in their older manual. |
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Quoted:
I'm finding the recommended start load as 15.0 grains with a max of 16.7 (per their website as of right now). A 3% reduction in 16.7 is only 16.2, so the 15 grain charge would be well below a 3% reduction that was warned against in their older manual. Quoted:
Quoted:
I'm pretty sure that Steve (the OP) stated in the OP that he was NOT below the recommended starting load. So he is not attempting to shoot reduced loads. All the comments pertaining to this are valid but do not pertain to this thread. Motor I'm finding the recommended start load as 15.0 grains with a max of 16.7 (per their website as of right now). A 3% reduction in 16.7 is only 16.2, so the 15 grain charge would be well below a 3% reduction that was warned against in their older manual. The key word here is "older". That is why it's older. It's not current. I just talked to Hodgdon about "older data". Same answer. The new 45-70 data for Marlin 1895 rifles is a whopping 20% increase over there old data. But it's also correct. So unless "they" say otherwise I'm going with the new over the old. Motor |
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Small spherical powder is a bitch to get it ignited correctly for a clean linear flow burn, and even worse when the power is not held tightly together as well.
Hence when the powder is not held tightly together (less than a 80% volume fill in the case), the primer gets the powder semi started, but as the bullet is being pushed forward, the gap between the powder cause a slight stall in power linear burn, and once the loose powder does get a flash again to start it burning again, you end up with a flash over of all the remaining powder trying to burn all at once isntead. The easy way to describe this is you every pulled a bullet off a 22LR, set it on a brick and ignited the powder in the shell to watch it burn. The powder takes about half a second to burn down until it reaches the primer section at the bottom of the case to ignite it was well. Now with loose H110/296 and the flash over problem, the loose powder will burn like Black powder instead, with all the energy of the powder giving off at once isntead (pressure spike, isntead of the linear pressure burn of the powder instead). So the short version, if you are going to use a reduced load of 296/H110 (same powder), then you need to use a primer hot enough to get it ignited correctly, and at the same time, use a filler (TP works fine) to keep the powder all tightly together and tight against the primer flash as well. Hence this keep the powder tight together as it burning, to keep the powder burning linear continuously, isntead of it loose with a stall and flash over to ignite the remaining of the power at once isntead. Or, just reserve the H-110/296 for full loads, and use a flake type powder that will do better will less volume fills isntead. P.S, if you reload 410 with 299/H-100, you see the same problem as well. Hence although the power is held tightly in the hull via the wad, the pressure burn, verses the shot being pushed down the bore rapidly, end up with some of the powder not getting ignited, and leaving some of the un-burnt powder still in the bore. The difference via the 410 and 357, less volume of bore, so with the 357, still enough flash in the bore to ignite the loose powder before the bullet exits the barrel instead (were you are getting the pressure spike from). |
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If you look at current data for various calibers from various sources you will find that the 3% rule has been completely abandoned or may actually only pretain to a specific cartridge or two.
One example: Hornady 8th edition. Start with H-110 is around 35gr. Maximum is around 43gr. I think that is around 20% difference. Then look at Lyman's newest cast bullet manual and you will find a start load of around 30gr and a maximum of 34gr. So for the same size casing with similar size bullets we are seeing 30 to 43 grain spread using H-110. I don't think Hornady and Lyman is going to publish data that is going to cause SEE. It seems that the rules have been re-written. You still need to look for specific data and cautions for what you are loading for. Motor |
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Quoted:
Look up the OLD Winchester load data for 296 in 357 and the warning. . Yes , things have changed. I done. I totally agree. The older manuals and data are just as you and others have stated. It's very apparent however that the people who make and test the powder and loads have changed their position on this. This is nothing new. I see no reason to debate it on a forum. Just call or email Hodgdon and ask them about the "old" H-110 3% rule and post their reply on here. Motor |
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Sorry for not responding sooner. As stated by 243winxb, the load data from Hodgdon is what I used so my full power, COL 1.580" loads are 16.7grns - great, no issues at all; starting load data at 15.0grns - shows flattened primers and a bit of a crease in the primer face because of the ejector portion of the Rossi's bolt face; and mid level load 15.8grns - also shows flattened primers and a bit of a crease in the primer face because of the ejector portion of the Rossi's bolt face, both indicating excessive pressure. To answer AeroE, all the load testing was shot through the same Rossi 357mag 24" rifle that I've shot over 4,000rds of the full power loads through without any issues. Further, I tried them also through my Ross 357mag 20" carbine that I've also shot over 4,000rds of the full power loads through without any issues and the results were the same. To answer We-rBorg, no pictures, however, as I state above, the 2 reduced loads show flattened primers and a bit of a crease in the primer face because of the ejector portion of the Rossi's bolt face. Compared to the full power loads with a normal looking primer, these clearly show excessive pressure. Then I fired the 15.0grn and 15.8grn loads with the bullets seated farther down at 1.560" to attempt to duplicate the case density % of the original loads but saw no difference in the primer appearance. As to the questions of reducing the charges, I have called Hodgdon this morning about my results and they stand by their load data claiming that their starting loads as listing in their on-line and printed manuals are correct and safe, however, their 'expert' with H110 powder has been notified and has been asked to call me and discuss this issue. I'll see how that goes. |
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Steve. Could you be seeing the effect of primers that have backed out ever so slightly then got flattened when pressure got high enough to push the case head back against the bolt face?
I have seen evidence of this on many casings that were fired from both lever and break open rifles like H&R's. Just the very slightest delay in pressure build can allow a primer to back out while the casing is being held forward by the firing pin and by pressure. On a rimmed casing there is no way to control head space. Motor |
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Take another look at the huge jump in pressure for this load from above -
158 GR. HDY XTP in 357 magnum Hodgdon Powder H110 Bullet Diameter .357" C.O.L. 1.580" Starting Load : Grains: 15.0 - Velocity (ft/s) : 1,418 - Pressure : 28,600 CUP Maximum Load : Grains: 16.7 - Velocity (ft/s) : 1,591 - Pressure : 40,700 The external difference in a Gold Dot and XTP is minimal; I wish I had one of each to compare, but I know I don't have any Gold Dot bullets now. Sectioned bullets might yield the answer. If I had to bet, it will be that the Gold Dot has a thicker jacket in the ogive. |
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243winxb, you'll note I mentioned both were Rossi rifles. I should mention that I tried the reduced load at 15.8grns first and had primers backing out far enough that I had burnt marks on the pockets but I found out that someone had messed with both my bullet seating and crimping dies such that the bullet were loaded long and with a loose crimp. The primers were not only backing out, they were separating completely!! When a buddy fessed up to fooling with my press, I seated and crimped them correctly and then is when I noticed the issues I reported here. Bottom line is that the thoughts of the light loads causing primer backing out may be on to something. Maybe the signs are just indications of that. I have a Uberti 358mag Cattleman SA Cav model that I'll take out next time (however, snow tonight) and test to see if there are any differences. If they seem fine, then it's just the primers backing out in my Rossis and not true over pressure signs. ETA: Thanks guys for steering me to the primers backing out idea. I wasn't going to shoot them in my Uberti as it's action isn't as strong as the Rossis and if I was getting really high pressures I didn't want to risk damaging it. With this information, I think I'll give the loads a try in it and that may confirm this thought. This is where the real power of this forum shows - information, experience, ideas coming together to create knowledge. |
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Quoted:
Steve. Could you be seeing the effect of primers that have backed out ever so slightly then got flattened when pressure got high enough to push the case head back against the bolt face? I have seen evidence of this on many casings that were fired from both lever and break open rifles like H&R's. Just the very slightest delay in pressure build can allow a primer to back out while the casing is being held forward by the firing pin and by pressure. On a rimmed casing there is no way to control head space. Motor I have heard this as well, several times. Maybe all from Motor1. Ha! Seems logical, but science is filled with examples of when logic is wrong. Try reloading some max charges to see if they still work. Maybe something non powder has changed. |
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Quoted: I have a Uberti 358mag Cattleman SA Cav model that I'll take out next time (however, snow tonight) and test to see if there are any differences. If they seem fine, then it's just the primers backing out in my Rossis and not true over pressure signs. |
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Quoted:
If you look at current data for various calibers from various sources you will find that the 3% rule has been completely abandoned or may actually only pretain to a specific cartridge or two. One example: Hornady 8th edition. Start with H-110 is around 35gr. Maximum is around 43gr. I think that is around 20% difference. Then look at Lyman's newest cast bullet manual and you will find a start load of around 30gr and a maximum of 34gr. So for the same size casing with similar size bullets we are seeing 30 to 43 grain spread using H-110. I don't think Hornady and Lyman is going to publish data that is going to cause SEE. It seems that the rules have been re-written. You still need to look for specific data and cautions for what you are loading for. Motor I was looking up data to load some 44 mag XTP bullets tonight and was suprised to see the data given for H110 and 240 grain bullets. 19.4 to 24.8 grains max for rifle ammo according to the 9th edition hornady manual. That's almost 22 percent 
It's amazing how much published data changes. |
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