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Anyone got 155 & 180 xtp at or above underwood velocity this is what I've been using loading the max and it could be better I feel. What is underwood secret sauce for 10mm xtp
10mm load data
- Thread starter Cmorency13
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Everything I can find is at least 100fps less than what Underwood advertises. I also noted that Underwood does not say what the barrel length used to get their numbers. That makes their speed claims suspect. I call them WLS numbers. When Lightning Strikes. I suspect if you ran them over a crony, you would see numbers closer to numbers in the reloading manual for your barrel length.
What good is 1500fps when it gives you 10" groups and beats the shit out of your pistol? I'll sacrifice 100-200fps for accuracy and being easier on the equipment.
If it is just because you want to see what you can do, rock on. That is what reloaders do. I've done it. Regretted it. Moved on. There is no data I can find that comes close to what Underwood claims. Be careful of old manuals that list loads far in excess of what is published in current manuals. Powders change, test methods get better and more accurate. The original 10mm specs were eye watering. Norma must have gotten better pressure measuring equipment because those loads disappeared pretty quick. Just because they liked the velocity numbers doesn't mean they were valid. Further, better testing scared them into backing off. Nobody but the Norma engineers know why.
What good is 1500fps when it gives you 10" groups and beats the shit out of your pistol? I'll sacrifice 100-200fps for accuracy and being easier on the equipment.
If it is just because you want to see what you can do, rock on. That is what reloaders do. I've done it. Regretted it. Moved on. There is no data I can find that comes close to what Underwood claims. Be careful of old manuals that list loads far in excess of what is published in current manuals. Powders change, test methods get better and more accurate. The original 10mm specs were eye watering. Norma must have gotten better pressure measuring equipment because those loads disappeared pretty quick. Just because they liked the velocity numbers doesn't mean they were valid. Further, better testing scared them into backing off. Nobody but the Norma engineers know why.
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Alright so I was testing 155gn xtp projectiles starline nickel plated brass 11gn of 800-X and WLP primers seated @ 1.26". Got an average velocity of about 1600 out of 10 shots thru a 5.2" barrel with NO signs of Over pressurization.
WARNING This was developed by me for use on hogs. Use at your own risk! I will not accept responsibility for your actions.
WARNING This was developed by me for use on hogs. Use at your own risk! I will not accept responsibility for your actions.- Joined
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Not trying to be a Karen but...
That load is 1.2 grains over any published load.
Hodgdon only lists one charge weight for their XTP load. As a long time reloader, that tells me that it is a tricky powder to work with. No start charge means load it this way or else! Some powders do weird things at certain densities, charge weights and pressures. I wasn't in the lab when they developed this so I don't know why they didn't experiment more. Reloaders love to experiment and play, they saw something they didn't like.
If 800-X were the only powder I had, I would load it exactly to the book. The one charge weight is a red flag telling you not to screw around with it. It is not the powder to experiment with.
That load is 1.2 grains over any published load.
Hodgdon only lists one charge weight for their XTP load. As a long time reloader, that tells me that it is a tricky powder to work with. No start charge means load it this way or else! Some powders do weird things at certain densities, charge weights and pressures. I wasn't in the lab when they developed this so I don't know why they didn't experiment more. Reloaders love to experiment and play, they saw something they didn't like.
If 800-X were the only powder I had, I would load it exactly to the book. The one charge weight is a red flag telling you not to screw around with it. It is not the powder to experiment with.
I concur.
Max pressure for the 10mm is 37,500psi. (More than 357 or 44 Magnum)
If a load of a particular powder is making maximum velocity, it is also making maximum pressure. Ergo, if you are getting 250fps more than the published max load, it is logical to assume you are generating pressure in excess of the SAAMI max of 37,500psi.
The max load for 800X with the 155 XTP in the Hodgdon database is 9.8gr which produces 1350 fps at 30,000 psi. It is the only load listed that does not exceed 30,000psi. This is curious as all the other loads are in the neighborhood of 35,000psi. As bkbrno points out, this is a red flag. Loaded hotter than this tells me this powder does quirky things pressure wise if the charge weight is increased beyond 9.8.
There is no way to accurately determine the pressure of ones handloads unless you have a lab test them in a pressure barrel with a piezo transducer to plot the pressure curve. I think that if these loads were so tested, it would scare you.
The fastest load listed for the 155 XTP is with AA#9 at 1414fps and well below max pressure. This is right up there with lower rung 41 Magnum loads. I would feel much more comfortable using that. And I doubt the hogs will complain.
Fun fact:
Years ago, I shot with a guy in High Power who loaded his ammo "hot". Always pushing the envelope kind of guy. He wasn't getting pressure signs either. No pierced primers, no overly flattened primers and no sooty primers. On more than one occasion, he had a lug break off of his AR15 bolt. It was always one of the lugs next to the extractor. Those two lugs bear an asymmetrical load because the extractor occupies the space of a lug. So two lugs are bearing the load normally borne by three.
Now AR bolts are normally good for 10K+rounds. In High Power, we always use a new bolt with a new barrel, so his bolts never had more than 5K rounds on them because barrel life was usually 4-5K rounds. That's when you start dropping points at 600, the barrel is still good for short ranges, but most shooters replace the barrel and sell or give it to a new shooter than can get some more mileage out of it.
There was an article some time back where one of the gun magazines had some handloads pressure tested by H.P. White labs. Max pressure for the caliber was 50,000psi. The test results came back showing the pressure was 60,000psi. This is approaching "Blue Pill" territory, and he was happily shooting this load on a regular basis.
The morale of the story is, that pressures beyond published maximums may not cause the gun to fail right away, but after a continual diet of ammo loaded too hot, something eventually has to give.
Max pressure for the 10mm is 37,500psi. (More than 357 or 44 Magnum)
If a load of a particular powder is making maximum velocity, it is also making maximum pressure. Ergo, if you are getting 250fps more than the published max load, it is logical to assume you are generating pressure in excess of the SAAMI max of 37,500psi.
The max load for 800X with the 155 XTP in the Hodgdon database is 9.8gr which produces 1350 fps at 30,000 psi. It is the only load listed that does not exceed 30,000psi. This is curious as all the other loads are in the neighborhood of 35,000psi. As bkbrno points out, this is a red flag. Loaded hotter than this tells me this powder does quirky things pressure wise if the charge weight is increased beyond 9.8.
There is no way to accurately determine the pressure of ones handloads unless you have a lab test them in a pressure barrel with a piezo transducer to plot the pressure curve. I think that if these loads were so tested, it would scare you.
The fastest load listed for the 155 XTP is with AA#9 at 1414fps and well below max pressure. This is right up there with lower rung 41 Magnum loads. I would feel much more comfortable using that. And I doubt the hogs will complain.
Fun fact:
Years ago, I shot with a guy in High Power who loaded his ammo "hot". Always pushing the envelope kind of guy. He wasn't getting pressure signs either. No pierced primers, no overly flattened primers and no sooty primers. On more than one occasion, he had a lug break off of his AR15 bolt. It was always one of the lugs next to the extractor. Those two lugs bear an asymmetrical load because the extractor occupies the space of a lug. So two lugs are bearing the load normally borne by three.
Now AR bolts are normally good for 10K+rounds. In High Power, we always use a new bolt with a new barrel, so his bolts never had more than 5K rounds on them because barrel life was usually 4-5K rounds. That's when you start dropping points at 600, the barrel is still good for short ranges, but most shooters replace the barrel and sell or give it to a new shooter than can get some more mileage out of it.
There was an article some time back where one of the gun magazines had some handloads pressure tested by H.P. White labs. Max pressure for the caliber was 50,000psi. The test results came back showing the pressure was 60,000psi. This is approaching "Blue Pill" territory, and he was happily shooting this load on a regular basis.
The morale of the story is, that pressures beyond published maximums may not cause the gun to fail right away, but after a continual diet of ammo loaded too hot, something eventually has to give.
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I did some deep digging. Old posts, 2005-2010 time frame mention 800-X as the magic pixie dust we all dream about. The Hodgdon manual used to list 11.0gn as the max. A couple of blown cases later, I guess they got around to pressure testing it and got real scared. 9.8gn says 30,000psi. I'll bet a beer it did some spectacular things on the pressure gauge as the charge went up. I'm guessing a huge spike that was not linear as expected. Maybe changing temperatures did strange things. 11gn might be SAAMI max but 11.01gn may be 60,000psi for all we know.
Handloaders reported that velocity increased to a certain point then it stayed the same or went down as the charge increased. I'm guessing that point is around 9.8gn. This tells me that 800-X is one of those strange ranger powders that does real well in certain applications but past performance does not guarantee future returns in other applications. The key point was that nobody had consistent results.
Too many people have to learn the hard way that that last 100fps was not worth it. Always cross reference with a couple of sources and for heaven's sake, don't believe everything you read on the internet.
Handloaders reported that velocity increased to a certain point then it stayed the same or went down as the charge increased. I'm guessing that point is around 9.8gn. This tells me that 800-X is one of those strange ranger powders that does real well in certain applications but past performance does not guarantee future returns in other applications. The key point was that nobody had consistent results.
Too many people have to learn the hard way that that last 100fps was not worth it. Always cross reference with a couple of sources and for heaven's sake, don't believe everything you read on the internet.
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I will get into this at a later date. I have an extensive data base on the 10mmAuto cartridge with over 15 years of reloading it. I can't post charts and tables. Not sure that I will post my loads because they are for my guns.
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800X is temperature sensitive !!! And does spike at pressure with hotter loads. Also hot loads can and will stretch brass. Most of my 10mm hollow point ammo is 180gr XTP in the 9.2gr to 9.4gr range. Do your own research, start below the bookmark and work your way up. Remember , my guns , my loads !!! You may find 8.9gr of 800x with a 180gr projectile is too much for you or your gun. Be smart , take your time and get several load manuals.