Different bullet weight -same FPS?
- Thread starter gifbohane
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Was the 115 extra slow or was the 124 extra fast? I'm guessing by your charge weight that the 115 was slow, both around 1030? I run a similar scenario with my .327, 6.7 gr of Longshot with 85 gr htps gets around 1400ish, my 100 gr htps use the same charge weight and... yup 1400ish.... starting charge weight for the lighter bullet matches the max charge weight of the heavy bullet. Not that strange really, your 4.5 is just under the 4.7 starting weight from hodgdon for the 115 and just barely above the 4.4 max charge weight for the 124.
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LiveLife
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Not strange and it should make sense because you were using start charge for 115 gr bullet and max charge for 124 gr bullet to produce similar velocities:
- 9mm 115 gr Speer TMJ RN W231 COL 1.135" Start 4.4 gr (1026 fps) - Max 4.9 gr (1133 fps) - https://reloadingdata.speer.com/downloads/speer/reloading-pdfs/handgun/9mm_Luger__115_rev1.pdf
- 9mm 124 gr Speer TMJ RN W231 COL 1.135" Start 4.0 gr (887 fps) - Max 4.5 gr (998 fps) - https://reloadingdata.speer.com/downloads/speer/reloading-pdfs/handgun/9mm_Luger__124_rev1.pdf -
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gifbohane
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I always thought that the heavier bullet should get less powder.
Hornady lists the 115-
4.1=1000
4.4=1050
4.7=1100 and max
I have found these number to be useless in my experience. Probably because the measurements were done on a "machine."
Hornady does not list the 124 grain bullet for HP-38.
BTW I did another experiment and seated the 124 from 1.125 to 1.115. Which should have caused more pressure and still the same numbers. Used a Labradar. Season might have been different.
Horsey- What do you mean by "Was the 115 extra slow or was the 124 extra fast? "
Hornady lists the 115-
4.1=1000
4.4=1050
4.7=1100 and max
I have found these number to be useless in my experience. Probably because the measurements were done on a "machine."
Hornady does not list the 124 grain bullet for HP-38.
BTW I did another experiment and seated the 124 from 1.125 to 1.115. Which should have caused more pressure and still the same numbers. Used a Labradar. Season might have been different.
Horsey- What do you mean by "Was the 115 extra slow or was the 124 extra fast? "
LiveLife
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Here are some chrono numbers from "actual" firearms instead of "machine" with different bullet weights producing similar velocities with same charges of powder - https://www.thehighroad.org/index.p...n-9mm-40s-w-45acp.799231/page-4#post-10338994
- 115 gr RMR HM RN 3.9-4.0 gr Promo @ 1.135": 1204-1276-1259-1273-1247 fps (59 F - PSA carbine)
- 124 gr RMR HM RN 3.9-4.0 gr Promo @ 1.160": 1231-1201-1210-1227-1193 fps (59 F - PSA carbine)
The only way a 115 matches a 124 velocity with same charge weight is it's slower than normal or the 124 is faster than normal. Yes the heavier bullet should get less powder, YOU ARE AT THE MAX for the 124, and just at the bottom for the 115 from hodgdon data....also if you did not have any data for the 124 (inferring from "hornady doesn't have data for the 124) why did you think loading it with the same charge weight as your 115 was a good idea? Eta if the rmr bullet is as hard as the xtp, you are ABOVE max for the 124. https://www.hodgdonreloading.com/reloading-data-center?rdc=true&type=54
Asking for load data sources BEFORE loading would have been more prudent than asking how close you are to the danger zone after finding something that disturbs you.
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gifbohane
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Horsey-- The numbers do NOT disturb me. I climb "the ladder" on every round. At the outset of my ladder, if I remember right, I started at 3.9 grains and the cases just about ejected. I could look at my note but think that
1200 FPS, in a pistol, is a zone that I do not ever enter. Some factory ammo comes close.
My original post was to ask for comments on something that surprised me.
I am curious to see if any of you think that 1050 FPS is a real max load?
1200 FPS, in a pistol, is a zone that I do not ever enter. Some factory ammo comes close.
My original post was to ask for comments on something that surprised me.
I am curious to see if any of you think that 1050 FPS is a real max load?
Yes see above load data......
Other powders will get more speed, for HP-38, yes with a 124 gr bullet 1050 is max. With a 115? No.
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Skeptic13
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The reason you are getting the same velocity with the same powder charge is that the heavier bullet seats deeper in the case creating a smaller reservoir. More pressure is created in that smaller space propelling the bullet at an equal speed. I am guessing that you are measuring velocity at the muzzle and that the velocity of the heavier bullet would decrease faster that the lighter bullet as you got farther away from the muzzle. You will always get more pressure in a smaller space with equal powder charges.
sparkyv
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I don't...not even close.
AJC1
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Ok your going to have to explain that train of thought how two bullets leaving at the same speed the heavier slows faster.... being of the same shape the heavier will always have a higher bc.
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gifbohane
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I don't either. But that is my opinion
Horsey- I think that you are referring to the data on your chart presentation when you say " Yes see above load data......
Other powders will get more speed, for HP-38, yes with a 124 gr bullet 1050 is max." I believe that book charts (like Hornady) are notorious for recommending lighter loads as max due to the lawyers. IMHO
I don't completely disagree with the lawyer statement... that being said hp38 also shows a max load yielding 845 with a 147, while many other powders push that same bullet to 940-100 fps, such is the case with the 124 too. Some powders yield higher velocities for a reason, this is kinda like trying to push velocity with bullseye when other powders do the job better. I don't always agree with lawyers, but I don't recommend going above max because gun in question may just be the one that gets a lawyer a payday. Hp38 in 9mm to me is like Longshot in my magnum revolvers, slow to middle of the road loads, if I want more speed I don't push it further, I grab a better suited powder to get the job done, and there's plenty enough out there to choose from that it's not like the risk is mandatory. Even with the 115s hp38 is NOT the powder for highest velocities, so seeing a 124 cruising at 1050 just isn't shocking, it definitely does better with the 115 than the 124, but as with other cartridges, (rifle or handgun) faster powders work with lighter bullets, slower powders with heavier bullets, another example would be in .380 with hp38 and 90 gr pills I'm ok with 940 fps, if I want more oomph, there's a jug of autocomp ready to go. In the 100 gr pills, hp38 for target loads, autocomp for the "wow" (as wow as a .380 gets around here anyway) I'm not just talking about lawyer data, I'm talking about trying to use an s10 to pull a 16' loaded stock trailer when the Silverado is just sitting there for the same amount of price and time it takes to get hitched up.
Load Change-result questionable-HP 38 9mm
OK.. I need help. I consider myself an amateur at this handloading game. In December I shot (S& W 9mm) Win Carts, Berry 124 grain, with HP 38 at 4.4 grains at COL of 1.15. The Chrono showed an average FPS of 1130 for about 10 rounds. Yesterday I shot 20 rounds of the same EXCEPT for using...
www.thehighroad.org
fxvr5
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Does it take a law degree to know you should not exceed maximum SAAMI pressure limits? Could a person without a law degree understand that? How many people here understand that you should not exceed maximum SAAMI pressure limits that don't have a law degree?
light loads win Win231 can leave a bit of powder unburned in my experience. in theory that ligher bullet should have a higher velocity, but if you are at the lighter end of the load data on the Win231 with the lighter bullet weight, my guess is you aren't getting a really good combustion at the lighter end of the load data with Win231/HP38
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gifbohane
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Does SAAMI publish max pressure limits? I have only seen max numbers in shooting manuals. If so, can you publish the site? I think that a fps max of1050 for a 9mm is somewhat low.
BYW the 115's and the 124's that have the same FPS with the same load are all given an OAL of 1.115 with the same amount of HP 38. Hence my question.
Would love to hear what others think max FPS for them is? Going to google SAAMI now.
mrawesome22-250
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Most of Hornadys data hovers in the "rediculously light" range. Their 9x19 data is in the "absurdly light" area.
I love Hornady bullets and they have some fine products but their reloading data is pure garbage.
I love Hornady bullets and they have some fine products but their reloading data is pure garbage.
35,000 psi, hodgdon max with hp38 and an xtp (4.2) lists pressure at 33,600. Unless you can pressure test, you're just a w.a.g. I KNOW what the old max for hp38 was with a 124, but not gonna post it cuz it was c.u.p.= less exact than psi, wanna play with the territory above max under the pretense of lawyer nonsense, do it privately. I can dig up manuals from the 80s that show MUCH different loads than we have now.... and respectively KABOOMS happened more frequently, since this is the 2nd time you've read the numbers for a 124 with hp38 (that I know of), find out without suggesting in a place where an unsuspecting newbie might stumble upon the information and become a tale of warning. 1050 is right in line with federal syntech and only 100 short of many factory loads, hp38 isn't a max fps powder, period, you want 1120? Other powders do the job well, otherwise post the disclaimer and have your own fun, again, this was addressed 5 years ago, shocker if the answers don't change.
fxvr5
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Max pressure limits and max velocities are completely different.
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gifbohane
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Yep, and I cannot compute either with my Labradar.
Maybe instead of being snarky. You should go learn about how pressure is measured, powder burn rates and pressure curves.
There's usually some good information in the front of older reloading manuals.
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gifbohane
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MAVRACR- I had no intention of being "snarky." I tried to agree with you that I did not have the extensive equipment required to establish pressure, powder burn rates and pressure curves. Sorry.
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