Question about .40 S&W Velocity

[alipinski397]

Hi All,

This is my first post on CB although I have been a member for a while now. Just have been reading, learning, and trying to take it all in or as much as possible anyway. I apologize in advance for the long winded post.

Just for reference I'm shooting a XDM 4.5 in .40 S&W. Boolits are 175 gr TC from a Lee 6 cavity mold - powder coated.

So i finally got to take my first reloads with cast boolits to the range today and shoot them through a chronograph. I was pleased and everything went pretty well. All the rounds went bang, no kabooms. They all chambered well with no hangups or stove pipes. No leading so my powder coating was good.

My only concern is the velocities for all my loads were near or above the published max velocities for the data I used even at or near the starting grains. There didn't seem to be any signs of high pressure in any of the rounds, not that I'm experienced enough yet to know for sure. I was with 2 other guys who have quite a bit of shooting experience (not reloading though) and they thought the same.

Load 1: Lymans Cast Manual 4th Ed
Power Pistol - 5.8-6.4 grains
175 gr Lead TC Powder Coated
Brass - varying head stamps
Winchester Small Pistol Primer
COL - 1.122

The published start grains was 5.8 with a max of 6.5.

All my range data for each shot is here along with a picture of the published data i used - https://docs.google.com/spreadsheets...#gid=509143370

You can see my FPS at the 5.8 starting grains was a little higher than the FPS of the published max.

I also tested another load with the only difference being the powder. This time HS-6, and i had similar results. I didn't shoot the last 2 groups of the HS-6 because i had already hit 1200 FPS and wasn't comfortable going higher until i did more research.

Load 2: Lymans Cast Manual 4th Ed
HS-6 - 7.2-7.6 grains
175 gr Lead TC Powder Coated
Brass - varying head stamps
Winchester Small Pistol Primer
COL - 1.122

Range Data - https://docs.google.com/spreadsheets...#gid=626015815



Chronograph was about 7-8 ft in front of the muzzle, and shooting off a bench rest. I also shot some factory Winchester Ranger 180gr Jacketed FP through the chronograph for comparison and those were about 1090-1105 FPS.

So should i be worried that my velocities are so much higher compared to the published data i used? My OAL's were longer than published min so i had though that would have reduced the pressure some and lowered velocity?

The only other thing that sticks out to me right now is the published data used a 4" barrel and my XDM is a 4.5. Could the extra .5" of barrel length create more FPS?

Any insight from those more experienced would be much appreciated.

Thanks,

[Tackleberry41]

Books are not gospel, I see it all the time that data is above or below whats published. Thats what they got out of a particular weapon, with certain primers, and brass, under certain conditions, often say test barrels. Temp affects things. I had some nice subsonic loads all worked up for my mosin, done in the winter time. Had a nice warm day, suddenly they weren't subsonic anymore. Had left a little room but it was close to 100fps difference. Just enough they were not subsonic anymore. Was testing some yesterday, had to drop back .6gr to get them back down to around 1030fps.

And yes barrel length changes things, some calibers more so than others. A 45 ACP being sort of low pressure, doesn't seem to change things. High pressure like a 40 S&W, barrel length makes a difference. I have a mech tech upper in 40, I got a good 300 fps over what it said in the book. A 180gr bullet that at max load was subsonic in a standard pistol barrel was past that at min loads in mine. Had to go down the chart to find a powder at min load that would keep that 180gr subsonic.

[CT-shooter777]

Books are not gospel, I see it all the time that data is above or below whats published. Thats what they got out of a particular weapon, with certain primers, and brass, under certain conditions, often say test barrels. Temp affects things. I had some nice subsonic loads all worked up for my mosin, done in the winter time. Had a nice warm day, suddenly they weren't subsonic anymore. Had left a little room but it was close to 100fps difference. Just enough they were not subsonic anymore. Was testing some yesterday, had to drop back .6gr to get them back down to around 1030fps.

And yes barrel length changes things, some calibers more so than others. A 45 ACP being sort of low pressure, doesn't seem to change things. High pressure like a 40 S&W, barrel length makes a difference. I have a mech tech upper in 40, I got a good 300 fps over what it said in the book. A 180gr bullet that at max load was subsonic in a standard pistol barrel was past that at min loads in mine. Had to go down the chart to find a powder at min load that would keep that 180gr subsonic.

Nailed it..................

[alipinski397]

Thanks for the reply's! I knew i probably wouldn't see the same data as the book but I just didn't expect such high velocities at the minimum starting grains. Just glad to know its a "normal" thing and not something i screwed up.

[GREENCOUNTYPETE]

.

Load 1: Lymans Cast Manual 4th Ed
Power Pistol - 5.8-6.4 grains
175 gr Lead TC Powder Coated
Brass - varying head stamps
Winchester Small Pistol Primer
COL - 1.122

,

that is almost exactly my load 6.3 power pistol with that bullet sized .401 , I haven't tried powder coat yet as my first batch of PC are in the oven as I type this

mine are shot in a 4.5 inch barrel smith

they shoot very consistently and never show any pressure sines I have probably a 1500 of these down range maybe more I have no chrono but to make you feel a bit better about your velocity for the charge Lee 2nd edition modern reloading lists 6.5gr power pistol as the starting charge with a 180gr cast lead boolit and 6.9gr max I figure it is computed data as they show the velocity lower with more powder than the 180gr jacketed load they list with a starting of 6.3gr power pistol and that doesn't make any sense cast glides easier as does cast PC it should almost always be faster with an identical charge

I have been shooting the 6.3 now for 2 years , I recently wanted to see if I could make them a little hotter in the hopes that it would race my POI just a bit more and bumped to 6.5gr power pistol still no pressure signs but I have't shot enough of them on paper to see if I have changed POI from needing to cover the target at 30 feet , on the uspsa cardboard it wasn't an issue because of the tall narrow A zone but when they bring out the little plates on the dueling tree I have to cover to much of the plate with the front sight I would like to hold on the bottom edge

[Schrag4]

I've done relatively little reloading for the 40 S&W, but 175gr moving 1200FPS? That seems more than just a little high to me, too. That's well into 10mm territory, is it not?

Personally, I've stopped testing a load before when my lowest 2 charges yielded velocities higher than I expected. I'd rather waste a trip (if that's all I'm there for) and verify my findings rather than take a chance if something doesn't seem right.

[GREENCOUNTYPETE]

your power pistol data seems fine but your HS-6 data does seem a touch hot Hogdon on their web site lists 6.6 to 7.4 with a berber FP and puts max velocity with the 7.4 gr load at 1041fps they also list data for a 180gr XTP at 6.1 to 6.9 but the xtp is a wide hollow point and that will put more bullet in the case reducing room for powder.

your PC lead is going to have less resistance and therefore should have less pressure than the copper jacketed bullet and may go some faster for less resistance with the same charge and also you have a half inch of barrel and inch of barrel can often add nearly a hundred fps.

Larry would say the real question is who got their data with a computer model and who did real pressure testing.

but I don't see any reason to push any further , MY question is where was the accuracy.

[alipinski397]

Thanks for the feedback guys.

Green-accuracy was OK however I only shot them at 10 yards. This trip I was more concerned about everything functioning properly and checking velocities. I have a couple more combinations to test out, then I'll pick a couple to test again at longer ranges for accuracy.

[GREENCOUNTYPETE]

I was able to shoot the 6.5gr power pistol rounds laoded with my PC 401-175TC sized .401 after the powder coat , they brought the POI up to a very usable aprox 1 1/2 inches above the front sight on a 3 inch bull at 10 meters I hope to talk the guys into bringing out the dueling tree tomorrow night at action pistol so that I can see that I have fixed my issue

6.5gr power psitol also seems good out further a 6 oclock hold wrists wrested had them hitting a 10 inch plate at 60 meters , not sure where I hit as I didn't paint the plate before I started shooting it and it was already splattered up

[Ford SD]

Hi All,

This is my first post on CB although I have been a member for a while now. Just have been reading, learning, and trying to take it all in or as much as possible anyway. I apologize in advance for the long winded post.

Just for reference I'm shooting a XDM 4.5 in .40 S&W. Boolits are 175 gr TC from a Lee 6 cavity mold - powder coated.

So i finally got to take my first reloads with cast boolits to the range today and shoot them through a chronograph. I was pleased and everything went pretty well. All the rounds went bang, no kabooms. They all chambered well with no hangups or stove pipes. No leading so my powder coating was good.

My only concern is the velocities for all my loads were near or above the published max velocities for the data I used even at or near the starting grains. There didn't seem to be any signs of high pressure in any of the rounds, not that I'm experienced enough yet to know for sure. I was with 2 other guys who have quite a bit of shooting experience (not reloading though) and they thought the same.

Load 1: Lymans Cast Manual 4th Ed
Power Pistol - 5.8-6.4 grains
175 gr Lead TC Powder Coated
Brass - varying head stamps
Winchester Small Pistol Primer
COL - 1.122

The published start grains was 5.8 with a max of 6.5.

All my range data for each shot is here along with a picture of the published data i used - https://docs.google.com/spreadsheets...#gid=509143370

You can see my FPS at the 5.8 starting grains was a little higher than the FPS of the published max.

I also tested another load with the only difference being the powder. This time HS-6, and i had similar results. I didn't shoot the last 2 groups of the HS-6 because i had already hit 1200 FPS and wasn't comfortable going higher until i did more research.

Load 2: Lymans Cast Manual 4th Ed
HS-6 - 7.2-7.6 grains
175 gr Lead TC Powder Coated
Brass - varying head stamps
Winchester Small Pistol Primer
COL - 1.122

Range Data - https://docs.google.com/spreadsheets...#gid=626015815



Chronograph was about 7-8 ft in front of the muzzle, and shooting off a bench rest. I also shot some factory Winchester Ranger 180gr Jacketed FP through the chronograph for comparison and those were about 1090-1105 FPS.

So should i be worried that my velocities are so much higher compared to the published data i used? My OAL's were longer than published min so i had though that would have reduced the pressure some and lowered velocity?

The only other thing that sticks out to me right now is the published data used a 4" barrel and my XDM is a 4.5. Could the extra .5" of barrel length create more FPS?

Any insight from those more experienced would be much appreciated.

Thanks,

Having shot a few rounds over a chrony I would say you are too close

I have used min 10 heel-toe workboots to set up my chrony for pistol and min 15 for rifle

I have a cz in 40cal /lee 175g and had to go over 0.1g over max load with WSF to make a 178 pf

[THerbert]

I have been shooting the 6.3 now for 2 years , I recently wanted to see if I could make them a little hotter in the hopes that it would race my POI just a bit more and bumped to 6.5gr power pistol still no pressure signs but I have't shot enough of them on paper to see if I have changed POI from needing to cover the target at 30 feet , on the uspsa cardboard it wasn't an issue because of the tall narrow A zone but when they bring out the little plates on the dueling tree I have to cover to much of the plate with the front sight I would like to hold on the bottom edge

Believe or not, if you want to raise you point of impact with a pistol, you should lower your velocity, not increase it. The physics of recoil with a pistol are different than with a rifle. Rifles tend to recoil straight back, rather than up. But because a pistol is held farther below the line of the bore than a rifle, recoil tend to make the muzzle rise. So, a higher velocity will exit the muzzle sooner, before the muzzle has a chance to rise much due to recoil. If you slow the bullet down, the muzzle will rise further before the bullet exits, raising your point of impact.