I have been getting higher velocities with my alpha from my 6" GP100. I have been using 4.4grs. of Universal
Velocity Confusion
I have an Alpha Chrony that I use for working up loads. Currently, I'm working up some hotter .38 Special loads using X-Treme plated 125 gr flat points with H-38 and I'm not getting near what I expected in velocity based on Hodgdon's site. I'm using a new Taurus Model 66 with a 4" barrel, and I do expect to be lower than the published data with the shorter barrel but not as much as I'm seeing.
To test the Chrony, I shot some Remington Green Box +P 125 gr SJHP at 10'. Remington data says 945 fps MV and I'm getting 890 fps at 10' so I think the Chrony is pretty accurate.
Now for some reloads. Hodgdon doesn't publish data for plated bullets but I expect it to be faster than jacketed, slower than lead for the same load based on what I've read, so I'm comparing to Hodgdon's data for the 125 gr Hornady XTP. For 5.3 gr HP-38 (+P load) Hodgdon calls for 1018 fps and I'm getting 840 fps, which is a big miss to me. For 4.9 gr (max .38 Special load) they list 934 fps and I got 775 fps, again a big miss. My measurements are at 10' since I want to protect my chrony.
Anyone else have a similar experience or do you get the velocities Hodgdon publishes? Thanks.
To test the Chrony, I shot some Remington Green Box +P 125 gr SJHP at 10'. Remington data says 945 fps MV and I'm getting 890 fps at 10' so I think the Chrony is pretty accurate.
Now for some reloads. Hodgdon doesn't publish data for plated bullets but I expect it to be faster than jacketed, slower than lead for the same load based on what I've read, so I'm comparing to Hodgdon's data for the 125 gr Hornady XTP. For 5.3 gr HP-38 (+P load) Hodgdon calls for 1018 fps and I'm getting 840 fps, which is a big miss to me. For 4.9 gr (max .38 Special load) they list 934 fps and I got 775 fps, again a big miss. My measurements are at 10' since I want to protect my chrony.
Anyone else have a similar experience or do you get the velocities Hodgdon publishes? Thanks.
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Sometimes it just don't work out as predicted. 
There's no way you're going to burn that much HP38 in a 4" barrel. What length barrel did Hodgdon use?
Actually, I was about 150 fps slower with the revolver and about 150 fps faster than Hodgdon with a 20" Rossi Model 92. No idea what Hodgdon used.hodThere's no way you're going to burn that much HP38 in a 4" barrel. What length barrel did Hodgdon use?
Possibly a dreaded 24 inch test barrel, shot on a 68 degree day, at an altitude of 12,000 feet , and the target was down in a valley at sea level??Actually, I was about 150 fps slower with the revolver and about 150 fps faster than Hodgdon with a 20" Rossi Model 92. No idea what Hodgdon used.hod
thats the way everybody was testing their published loads back in the 70's when the velocity wars was going on!-Griiin.
the testing apparatus makes alot of difference.
A lot of uniiversal recievers seem to be used now days.
I would be loking at variations in the velocity, if close then be content that its likely correct with you setup.
MadKaw, why do you say that much HP-38 can't be burnt in a 4" barrel. I think of HP-38 as a fairly fast powder, and expected pretty full burn even up to low .357 Magnum levels. Hodgdon lists 8.5 gr of HP-38 as max for .357 Magnum, and I was planning to try some rounds in the 6.0-6.5 gr levels. They don't say what length barrel, and I don't think I would try that much in a 2" snubbie, but 4" is pretty respectable.There's no way you're going to burn that much HP38 in a 4" barrel. What length barrel did Hodgdon use?
What powder would you recommend for a bit hotter .38 Special (+P or +P+) in the 4" Model 66? My hands don't really like full house .357 Magnum loads but every once in a while something a little louder is fun at the range.
OK Not Mad Kaw and not answering for him but!MadKaw, why do you say that much HP-38 can't be burnt in a 4" barrel. I think of HP-38 as a fairly fast powder, and expected pretty full burn even up to low .357 Magnum levels. Hodgdon lists 8.5 gr of HP-38 as max for .357 Magnum, and I was planning to try some rounds in the 6.0-6.5 gr levels. They don't say what length barrel, and I don't think I would try that much in a 2" snubbie, but 4" is pretty respectable.
.
No powder is going to burn in that length of barrel or with that charge!
Simply the only time that any powder is going to completely burn is when you get a squib from such a seriously under loaded projectile!
IF you have muzzle flash then you have unburned powder , simple as that.
what the object is to get a powder, charge rate that will burn as completely as possible in a certain barrel length and produce as much FPS as posisble with the lowest chamber pressure.
all projectiles should still be accelerating as they leave the muzzle, therefore you still have powder burning.
Sorry to interupt the discusion but had to throw that in.
You are shooting a different bullet in a different barrel - I wouldn't expect to match their data. It sounds like your chrony is pretty trustworthy, I would tend to believe it.
ol' hit many of my points. Thanks for jumping in.MadKaw, why do you say that much HP-38 can't be burnt in a 4" barrel. I think of HP-38 as a fairly fast powder, and expected pretty full burn even up to low .357 Magnum levels. Hodgdon lists 8.5 gr of HP-38 as max for .357 Magnum, and I was planning to try some rounds in the 6.0-6.5 gr levels. They don't say what length barrel, and I don't think I would try that much in a 2" snubbie, but 4" is pretty respectable.
What powder would you recommend for a bit hotter .38 Special (+P or +P+) in the 4" Model 66? My hands don't really like full house .357 Magnum loads but every once in a while something a little louder is fun at the range.
The mfg's max load is solely based on safety. It is the largest load that stays within SAAMI pressure limits in a SAAMI specification pressure barrel under SAAMI specified testing conditions. That has nothing to do with best performance or efficiency. It is quite possible for that load to be unsafe in any individual gun because of manufacturing variability.
HP-38 is a moderately fast powder. It is between AA-2 and WW-231, but it is 28 on Hodgdon's list of powders by speed. It's not even Hodgdon's fastest powder.
Burn Rate
I have no personal recommendations for you as all of my load development has been for accuracy, not pop. I would just have to peruse the loading manuals.
That said, I've been partial to AA-2 in the. 38 case for more than 20 years.
Are you adding a crimp to your reloads? That can have some effect on muzzle velocity and will also raise pressure as well.
If you are interested in learning about pressure testing:
http://www.saami.org/specifications_and_information/publications/download/205.pdf
http://www.saami.org/specifications_and_information/publications/download/205.pdf
Yes, the X-Treme plated bullet has a cannelure and I'm using a moderate roll crimp (1/2 turn on the Lee FCD). The Berry's plated bullet does not have a cannelure and I'm using a moderate taper crimp (1/2-3/4 turn with a modified 9mm taper crimp insert in the Lee FCD).Are you adding a crimp to your reloads? That can have some effect on muzzle velocity and will also raise pressure as well.
i would recommend Titegroup, higher velocity potential (1069fps vs. 1018) and faster burning (#14 vs. #28) than HP-38, sounds like a good match for your barrel length. I use it with 158gr cast bullets in .357 from my 4.5" Blackhawk but have not bothered to shoot them over a crony.
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