bltmonty
Member
I have a bunch of .40s and two 10mms, and I have found that Longshot produces the best velocities and most consistent accuracy among all the powders mentioned.
Blue Dot vs Longsot or Power Pistol 10mm?
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MachIVshooter
Member
I don't have a pressure barrel, so couldn't tell ya. But there are no signs of overpressure, brass life is OK, and most published data is substantially under 37.5 ksi anyway. Max book load was 10.1 or 10.3, IIRC, so we're <10% over max.
The original spec for 10mm was also 40 ksi, if memory serves.
ArchAngelCD
Member.
Barrel length means little. The powder that generates the highest velocities in an 11" barrel will also do it in a 5" barrel. Somehow the reloading public got this idea in their head when talking about a "slower" handgun powder it's actually slow. It's not so.
OilyPablo
Member
ArchAngelCD said:
Longer barrel length does make for higher velocity.
Please provide an explanation............see my post below.
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Arch explained it fine.
Yes, higher velocities can be obtained with longer barrels all other things equal. That is what a lot of manuals post unrealistic FPS as they were tested in a say a 10" test barrel and we are shooting out of a 4" barrel.
So the same load of Longshot in 6" barrel will "probably go faster than in a 3" barrel, Using a powder like Longshot will produce faster velocities than say Bullseye,
That said.
A powder that produces the highest velocity in a long barrel will also do the same in a short barrel. Those powders are almost always slower burning powder not fast burning powders.
OilyPablo
Member
Well of course I know that slower powder doesn't mean slower bullet.
I use Longshot for higher velocities in my 10mm 11" DI AR because it's a SLOWER powder. Fast powders, with light charges hardly drive the gas system.
But take a 2" barrel vs 11" barrel.
In the 2" barrel, I'm not sure Longshot would give you the top velocity vs. some of the other faster powders mentioned. Yes sure as you step it out to 6", 9"+, sure. So where is that line drawn? I see plenty of people post that they increase, say a Longshot charge in a 4" barrel and get no more velocity, but in an 11" barrel, going to book and beyond, increased velocities are seen.
I use Longshot for higher velocities in my 10mm 11" DI AR because it's a SLOWER powder. Fast powders, with light charges hardly drive the gas system.
But take a 2" barrel vs 11" barrel.
In the 2" barrel, I'm not sure Longshot would give you the top velocity vs. some of the other faster powders mentioned. Yes sure as you step it out to 6", 9"+, sure. So where is that line drawn? I see plenty of people post that they increase, say a Longshot charge in a 4" barrel and get no more velocity, but in an 11" barrel, going to book and beyond, increased velocities are seen.
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Wreck-n-Crew
Member
But you left that out and to me its not a fair comparison to judge a load that leaves the comforts of published data and claim it as full power load going at said velocity.
Also warm is an understatement. those are hot. Warm is when you use a powder at max data that performs real well in a given published load and have more velocity than most other powders or it can even be a +p load that is still listed. Anything outside published load data is hot.
In fact those loads are more than %20 more powder charge than max according to my Lyman 49th and that is more than dangerous IMO.
ColoradoShooter77
Member
Hodgdon list's a max 10mm 180 grain velocity with Longshot at 1287 fps. The max with a 180 grain 40 S&W load is 1159 fps.
I was getting a solid 1100 fps at 7.3 grains in the 40 and the max listed charge is at 8 grains. I think that would deliver 1150 fps.
I can basically load my 40 S&W to 90% of what a 10mm will produce.....I'm down with that!
I was getting a solid 1100 fps at 7.3 grains in the 40 and the max listed charge is at 8 grains. I think that would deliver 1150 fps.
I can basically load my 40 S&W to 90% of what a 10mm will produce.....I'm down with that!
Physics is Physics Look at any of the short barrel load data in say Speer under 38 Special. Slower burn powders produce faster velocities.
Doesn't matter what caliber, look at the data under 10mm, Who shoots10mm out of a 2" barrel??. It;s like shooting a 357 mag out of 2" snubby, is it worth it over just a +P 38 special?? Again I don't think so,
Sure there is diminishing returns. Is it worth all the blast and flash to eek out an extra 50 fps or so? I do not think so, but it is what it is.
OilyPablo
Member
Understood.
Doesn't a relatively slower powder continue to build pressure for a relatively longer time period? IE the pressure curve is wider (longer time). I guess this is very short amount of time relative to bullet travel.
Doesn't a relatively slower powder continue to build pressure for a relatively longer time period? IE the pressure curve is wider (longer time). I guess this is very short amount of time relative to bullet travel.
ColoradoShooter77
Member
100% of the powder is burned in the first inch of barrel.
If a certain powder produces the highest velocity in a 26" barrel .308, it will also produce the highest velocity in a 20" barrel .308.
https://www.shootersforum.com/handloading-procedures-practices/21467-short-barrels.html
Post #4 and the last post.
If a certain powder produces the highest velocity in a 26" barrel .308, it will also produce the highest velocity in a 20" barrel .308.
https://www.shootersforum.com/handloading-procedures-practices/21467-short-barrels.html
Post #4 and the last post.
Wreck-n-Crew
Member
I thought i would share my findings using three different powders from slow to fast and chronograph tested them in both a pistol and a carbine since to topic of barrel length and different powders have different affects on velocity.
However is was done with 9mm and for the most part the results do have the same effects on 10mm as well as other pistol calibers.
My understanding is that slower powders produce higher velocities because the powder continued its burning and expanding as the bullet travels down the barrel.
Also was my understanding that a longer barrel would also produce a larger increase in velocity percentages with a slower powder than with a fast one based on those same principals.
Here are my test results...
http://www.thehighroad.org/showthread.php?t=799017
However is was done with 9mm and for the most part the results do have the same effects on 10mm as well as other pistol calibers.
My understanding is that slower powders produce higher velocities because the powder continued its burning and expanding as the bullet travels down the barrel.
Also was my understanding that a longer barrel would also produce a larger increase in velocity percentages with a slower powder than with a fast one based on those same principals.
Here are my test results...
http://www.thehighroad.org/showthread.php?t=799017
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OilyPablo
Member
Thanks Colorado and Wreck-n! I will read those in entirety later.
I studied various cartridges last night using a couple estimated powder burn rate lists. While it's generally a (strong) tendency for slower powders to produce higher velocities, either the lists are wrong (powders change, etc) and/or there are other factors at play as well. Just make an example, take 10 powders listed for any given cartridge, one, two or three, "faster" powders show a higher velocity than "slower" listed powders.
I studied various cartridges last night using a couple estimated powder burn rate lists. While it's generally a (strong) tendency for slower powders to produce higher velocities, either the lists are wrong (powders change, etc) and/or there are other factors at play as well. Just make an example, take 10 powders listed for any given cartridge, one, two or three, "faster" powders show a higher velocity than "slower" listed powders.
OP,
Check the powder burn rate. Now it is all relative to the powders listed, they had to assign them somehow, so a difference between say 63 and 64 is meaningless (since they are the same
)
Also there are 150 powders listed and some are pistol some rifle. So there is a very BIG spread of "relativity".
How much difference is say H110 and AA #9?? in a short barrel?? I don't know but I doubt it is very much.
https://www.hodgdon.com/PDF/Burn Rates - 2015-2016.pdf
Check the powder burn rate. Now it is all relative to the powders listed, they had to assign them somehow, so a difference between say 63 and 64 is meaningless (since they are the same
)Also there are 150 powders listed and some are pistol some rifle. So there is a very BIG spread of "relativity".
How much difference is say H110 and AA #9?? in a short barrel?? I don't know but I doubt it is very much.
https://www.hodgdon.com/PDF/Burn Rates - 2015-2016.pdf
MachIVshooter
Member
Mine aren't the only loads developing those velocities.
https://www.buffalobore.com/index.php?l=product_detail&p=114
http://www.doubletapammo.net/index.php?route=product/category&path=303_301&page=1
Swamp fox also had loads in that velocity range before they went under.
OilyPablo
Member
Not at all defending anyone or going over any book, but Lyman 49 is very conservative with 10mm. Look at the pressures and velocities. Those velocities are hardly respectable 40S&W. And they don't even list some of the best 10mm powders like Longshot. Always work your way up, but I know for a fact all my 10mm guns can easily and most importantly safely exceed those given loads.
ColoradoShooter77
Member
Hodgdon list's 9.5 grains as the max 10mm load with a 180 grain bullet.
OilyPablo
Member
That's a good maximum recommendation in my humble opinion. Some barrels see no more gains at 9.3 and 9.4 grains. That said 6.2" barrels and beyond see gains up to 10 grains or so with no signs of excess pressure.
Wreck-n-Crew
Member
We are not talking just about velocities we are talking about velocities due to overloads. More important we are talking about pressure and overloads!
Buffalo bore uses a powder that produces the highest velocities possible while remaining within SAAMI pressures ( unless otherwise marked +p or +p+). Your loads don't. And they are still slower that yours...not that it matters at this point.
I still don't understand your reason for disputing your first argument. The statement was misleading. Because you admit it wasn't a typo and that the load was %20 over load listings. In fact you could go back and changed that if you haven't already to make it a fair statement.
Instead and in defense of the statements we are on the subject of hot loads. Its ridiculous at this pont to detract any further from this discussion with ridiculous statements that are misleading as to how safe they are too. Its off topic and so far the only thing we have gained is that you loaded a hot round to get high numbers.
So if there is nothing to add to validate your post of the 800x being better for full power loads the reciprocation is moot and its time to move on to a more productive discussion.
Wreck-n-Crew
Member
ColoradoShooter77
Member
I just looked at it again....it is indeed a max of 9.5 grains Longshot with a 180 grain JHP.
http://www.hodgdonreloading.com/data/pistol
http://www.hodgdonreloading.com/data/pistol
OilyPablo
Member
I know this to be true.
Is it being suggested that longer barrels don't show pressure signs where a shorter barrel would? Or that gains can be realized from a longer bore?
Certainly the latter is true in most cases.
Arguing 'over book' isn't an argument at all, either it is, or isn't. That said, published data is often based on one bullet per weight, and different styles and construction can yield significant differences. Nearly identical (dimension & weight) bullets (155 XTP & 155 MG JHP) produce different velocities and case expansion for identical charges.
To say 9.5gr of powder X with bullet Y is max (unless supported by published data) is nonsense.
For the 10mm I've loaded 29 powders, 55 bullets, for 361 loads (with another 217 ready to test) - below book, above book, and off book. I believe all have been done within the confines of safe.
Certainly the latter is true in most cases.
Arguing 'over book' isn't an argument at all, either it is, or isn't. That said, published data is often based on one bullet per weight, and different styles and construction can yield significant differences. Nearly identical (dimension & weight) bullets (155 XTP & 155 MG JHP) produce different velocities and case expansion for identical charges.
To say 9.5gr of powder X with bullet Y is max (unless supported by published data) is nonsense.
For the 10mm I've loaded 29 powders, 55 bullets, for 361 loads (with another 217 ready to test) - below book, above book, and off book. I believe all have been done within the confines of safe.
MachIVshooter
Member
You don't know that. Pure speculation. Just because a load is higher than published data does not mean it's overpressure. The margins exist for tight chambers and thick brass.
You express doubt at my results and insinuate that I can't remember bullet weights, whilst you misquote published maximums yourself
Maybe 20% over according to your books. You do realize that these numbers vary, yes? Mike Mcnett of Double Tap has posted data with 10.8 grs. under a 180 and advice to work up. Many 10mm shooters load 800x heavier than published data with no pressure signs or ill effects. Clark, perhaps our best resource in this forum, has played with 800x in 10mm, and found that 800x loads can easily exceed published maximums safely with supported chambers. He has gone WAY beyond 10% 0r 20%.
If you're not comfortable loading beyond listed maximums, then don't. I published the disclaimer in my post, and detailed my personal experience, which mirrors that of others who use this powder. Lots and lots of recipes with 800x in the 10-11 gr range under 180s out there. Other than metering like crap, it's a fantastic choice for top 10mm loads for those who know what they're doing and take the time to work up.
Just let it be, man.
Wreck-n-Crew
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