Too high of velocity, 10% higher than published data

[NATJAC]

Hi, sorry, not sure where to post this.
Got a question, i've cast up and powder coated 1000+ 9mm hollow point boolits (mp mold) that weigh right around 130 grains.. I'm using WSF powder, which only has data for 124 cast boolits.. I used that data and started at the minimum of 4.0 grains (4.7 grains is the max with a published velocity of ~1055 pfs) I couldn't get any accuracy (and clean brass from sooting) until I got to 4.7 grains.. the 4.7 grains is great for accuracy and clean brass, BUT, my chrono is showing almost 1200 fps! which is over 10% faster than max published data!! I don't have any signs of overpressure such as flattened primer or anything else odd. I want to load up over 500 rounds of this load but I figured I'd check with the seasoned veterans to see if they'd warn me not to do it. Also, as you may know there is a powder shortage so it's not like I can go out and find another powder.. and I would like to simplify and use WSF for many other calibers including shotgun. The WSF shoots great in 9mm, really like this powder, just not sure why they don't have any good published data for anything OVER 125 grains, why is that?
Let me know your thoughts.

[Mk42gunner]

I haven't loaded any 9mm for about twenty five years, so these are going to be general comments. I've also never burned any WSF powder.

Heavier projectile with the same powder charge may generate higher pressures, and thus higher velocity. It may not either.

Your powder coating may affect velocity/ pressure also.

Barrel length. You didn't say what you are shooting these out of, so if the data you are looking at used a four inch barrel and yours is closer to five...

Good Luck,

Robert

[44Blam]

One thing to consider is that you are casting a hollow point. So, that boolit WEIGHS 130 grain but if it was a round or flat nose it might be like a 135 or 140 grain boolit. That's the load data you want with a HP. We kind of get fixated on weight of the boolit but the load data is really based on case capacity with a boolit seated. So if you have the same boolit at max col vs one a couple hundreths deeper the one a little deeper will generally have higher pressure. The grain weight kind of gives us a general idea of where the boolit is going to sit in the case, so we use that as a starting point...

[wv109323]

The type of firearm or testing fixture could make a difference. Bore diameter,barrel length,temperature chrono accuracy and bullet coating can all enter into the final velocity.
I would do more research and maybe call the powder manufacturer.

[JoeJames]

Something else to throw into the mix. I have found in shooting hard cast (water quenched) vs. air cooled of the same alloy that my Lee .430” 240 grain swc’s run about 80 to 90 fps faster if water quenched.

[JimB..]

Are you loading them as long as possible for your pistol? If not, give it a try and see if you can come off the charge a bit and retain accuracy.

I wouldn’t worry about soot on pistol cases, especially for shooting paper.

[44MAG#1]

My questions are:
1. Are you using the same "lot" of powder as the lab?
2. Are you using the same brand and "lot" of primers that the
lab used?
3. Are you using the exact same bullet that the lab used?
4. Does your bullet seat the exact same depth in the case?
5. Are you using the exact same brand of cases and if you are
are you using the same "lot" of cases?
6. Are you testing conditions the same as the lab had?
I predict you will get a plethora of answers by everyone from those that have little experience to those that have thousands of dollars of equipment and more firearms than the US Military.
Just chose who you want to listen too.
Myself, if I were concerned I would drop back on charge weight, load and have fun. If not concerned I would load and have fun.
You will have to make that call.

[JonB_in_Glencoe]

Are you loading for semi-auto pistol?
Many times when working up loads, besides accuracy, I judge a load by how far the gun throws the spent cases. I'd be less concerned about FPS, as long as you aren't seeing signs of over pressure or launching the brass into the next zip code.

[PonchoHobbes]

One other possibility could be the load data itself if it's form just one source. I have probably 5 different loading manuals plus all the online options and none of them agree but they do give a consensus of an approximate range. I was loading for 45 Colt last week and the max charges for Unique with a 250 grain cast bullet were from 7 to 9.5 grains and advertised velocity was between 850-950 fps.

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[GARD72977]

I say load away. You are within published data and not showing pressure signs. Some barrells are faster than others. The powder coat could account for some increase.

I would be aware as the summet temps increase.

[chutesnreloads]

Not all chronographs agree with each other. Are you sure yours was set up correctly? Just a slightly shorter or longer distance between the "eyes"
will make a much bigger velocity reading. Suggest you try a few more after setting up chrony again. Also.... How many rounds of this load did you fire through the chrony?

[MT Gianni]

Looking in Hogdsons data center max for 124 gr is 4.7 max for 147 is 4.1 gr. I would cut it back some at least until the velocity approaches the listed 1088 fps.

[jim147]

I don't see what size you are using. And have you slugged the barrel? I would think if the boolits are too small, you would need to push them harder to seal up.

That's my thought at the moment but I've been sick for two weeks and woke up at 3:30 this morning so I could be wrong.

[NATJAC]

The Barrel length is 3.5", the load data, which is from Winchester's webpage, uses a 4" barrel for testing. They are using CCI-500 primers and I'm using WSP primers.

[NATJAC]

Are you loading for semi-auto pistol?
Many times when working up loads, besides accuracy, I judge a load by how far the gun throws the spent cases. I'd be less concerned about FPS, as long as you aren't seeing signs of over pressure or launching the brass into the next zip code.

Yes both semiauto, a g19 and MP9c
From 4.3 to 4.7, all of the cases landed in the same spot, roughly.

[NATJAC]

Not all chronographs agree with each other. Are you sure yours was set up correctly? Just a slightly shorter or longer distance between the "eyes"
will make a much bigger velocity reading. Suggest you try a few more after setting up chrony again. Also.... How many rounds of this load did you fire through the chrony?


This is kinda what i'm thinking.. I've shot these before with the only difference being a different lot of powder and those were right in line with the published FPS.
I fired 8 rounds of each increment:
8ea 4.0gr, 8ea 4.4gr, 8ea 4.7 thru two different handguns (g19 and MP9c)

[NATJAC]

I say load away. You are within published data and not showing pressure signs. Some barrells are faster than others. The powder coat could account for some increase.

I would be aware as the summet temps increase.

I've looked in all the manuals I have for loads, none really showed anything for WSF and 9mm except for the Lee book and Hodgdon website (which are the same load data)

[NATJAC]

One thing to consider is that you are casting a hollow point. So, that boolit WEIGHS 130 grain but if it was a round or flat nose it might be like a 135 or 140 grain boolit. That's the load data you want with a HP. We kind of get fixated on weight of the boolit but the load data is really based on case capacity with a boolit seated. So if you have the same boolit at max col vs one a couple hundreths deeper the one a little deeper will generally have higher pressure. The grain weight kind of gives us a general idea of where the boolit is going to sit in the case, so we use that as a starting point...

You are correct, this is a HP bullet and the net weight of the boolit is ~130 grains. So you are saying that I should look for load data for ~135-140 grains?
I had to seat these to a COAL of 1.11", otherwise the boolits would touch the lands.

[NATJAC]

These are air cooled. ~ 8 bhn

[Driver man]

I think powder coating affects chamber pressure. i have had similar results to you .

[Daekar]

I have an Encore barrel that is creepy fast with every load I put in it... sometimes things work out that way. If you're not exceeding max loads, your brass is fine and your gun is acting normally, I wouldn't worry.

[chutesnreloads]

This is kinda what i'm thinking.. I've shot these before with the only difference being a different lot of powder and those were right in line with the published FPS.
I fired 8 rounds of each increment:
8ea 4.0gr, 8ea 4.4gr, 8ea 4.7 thru two different handguns (g19 and MP9c)

Are you sure your new lot of powder is WSF and not WST? That could make a difference from what you loaded previously.

[racepres]

I have an Encore barrel that is creepy fast with every load I put in it... sometimes things work out that way. If you're not exceeding max loads, your brass is fine and your gun is acting normally, I wouldn't worry.

This^^^
No two Chambers are ever the Same.
Like believing that if our Velocity is under published velocity... We can go ahead and Increase the Charge!!!!
It don't work that way either...

[popper]

I don't see a problem with your load, have fun. it's a slower powder so you probably get a lot of flash.

[jsizemore]

9mm case shows sharp rise in pressure with small changes to powder, seating depth, etc. You went from 4.4 - 4.7 and got good burn at 4.7. Did you try 4.5 and 4.6? Might be worth a try and give you a margin for safety if dropping charges with a powder measure. My buddy uses VV powder in his 9mm's. Depending on what component manufacturer's manual he uses with the same components, he'll see charge and velocity variations. Even in VV's own data. Since I started loading for the 9mm I've switched powders, primers, coating/sizing method and have matched cases from the same lot to ride herd on my 9mm's. It sure ain't like loading for a 38spl or 45acp.

[charlie b]

9mm is a very small case and a small amount of change in OAL compared to the book will dramatically affect the pressure.

Me? I would not exceed max load for the weight of the bullet listed and I would try to adjust OAL so the case volume is same as the book load (if you can figure it out). I use the velocity measured by my chronograph to be a check against the book, ie, if it is faster than the book max, then I am over pressure and I need to reduce the charge.

When I cannot find an exact book match to bullet weight I use the next HEAVIER bullet charge data. I will also extrapolate between bullet weights, eg, 120gn bullet lists 5gn of powder, 140gn bullet lists 9gn, so a 130gn bullet I would not go above 7gn. And I would check vel to make sure I am also halfway in between. No, this is not exact and you could still be overpressure, but, probably not by much.

Yes, you are probably over pressure. I would back off until the measured vel matches book (if the book uses same length barrel).

PS do not bother with looking at primers. By the time they flatten out you are way above max levels for the pistol.

[Burnt Fingers]

The pressure signs are all based on rifle brass at rifle pressures.

By the time you see the classic pressure signs in pistol brass you're DEEP into danger.

Hodgdon has data for both a 130 gr and 135 gr bullets. Both are plated bullets. Neither set of data has WSF listed.

[1eyedjack]

I shoot an MP359125 hollow point powder coated in 9mm as well as 38/357 . It as been very accurate in both. The hollow point affects OAL & powder capacity because it is longer than a round nose or SWC for the same weight so it gets seated deeper in the case. Had a bad experience with BE-86 & this bullet in 9mm , started @ 5.0gn with Alliant max @ 5.7gn for a 125gn lead bullet...shot 10 rounds with recoil like +P self defense rounds ! Also had a broken ejector when I got home.
I contacted Hodgdon once about power coated bullets & got a reply that they couldn't test powder coated bullets in their equipment. I also inquired about a Lee 105gn SWC for data for 38 special & was told use the 125gn lead data -a heavier & longer bullet

[NATJAC]

Spoke with Hodgdon, the guy said i'm probably running pressures around 40,000 psi and that was extremely dangerous (38,500 psi is max for +p loads) and your typical overpressure signs, such as flat primers etc, are for rifle cases and not pistol cases. He also said there are "no loads" for 130 grain and that "i'm just guessing, which is very dangerous". When I asked him why he doesn't have any loads over 125 grain boolits using WSF powder he said "there is probably a reason" but couldn't comment as to why.
I've only got WSF powder, guess what I should do is just use EXTREMELY conservative data and live there.

[Larry Gibson]

"9mm is a very small case and a small amount of change in OAL compared to the book will dramatically affect the pressure."

charlie b nailed the probable reason with that statement.

Your 130 gr bullets are probably seated deeper than the 124 gr bullets the data was developed for. In the small 9mm case it doesn't take much of a change in seating depth to increase pressure dramatically. The increase in pressure equivalates to a probable increase in velocity.

[popper]

1997 winchester lead data, 147gr = 3.7-4.1gr, 124gr lead = 4-4.7 gr WSF. 4 gr should work for you.

[fredj338]

You must be new to the chrono. What a given data source gets is almost never what you or I get. Diff testing conditions; guns, components, temps, humidity, elevation, all of it matters. Even shooting the exact test gun, you can be off 30-40fps or even more.
I use lead data with coated & work my own loads up. If the bullet is not what I am loading, I go to the next heaviest data & work that up.

[fredj338]

9mm is a very small case and a small amount of change in OAL compared to the book will dramatically affect the pressure.

Me? I would not exceed max load for the weight of the bullet listed and I would try to adjust OAL so the case volume is same as the book load (if you can figure it out). I use the velocity measured by my chronograph to be a check against the book, ie, if it is faster than the book max, then I am over pressure and I need to reduce the charge.

When I cannot find an exact book match to bullet weight I use the next HEAVIER bullet charge data. I will also extrapolate between bullet weights, eg, 120gn bullet lists 5gn of powder, 140gn bullet lists 9gn, so a 130gn bullet I would not go above 7gn. And I would check vel to make sure I am also halfway in between. No, this is not exact and you could still be overpressure, but, probably not by much.

Yes, you are probably over pressure. I would back off until the measured vel matches book (if the book uses same length barrel).

PS do not bother with looking at primers. By the time they flatten out you are way above max levels for the pistol.

YEs & no. OAL affects small volume cases more but the boogyman of OAL isnt what many think. Powder burn rate matters, more so in small cases like 9mm. Use a slower powder, you are probably compressing the charge anyway, & without pressure indications.
In my own chrono testing with WST & Unique, shortening the OAL with medium range loads showed very little affect on vel, thus pressures, until I hit 0.060" shorter. Sp yes OAL matters, but not as much as some think.
Considering all the factors that go into reaching a given vel, I wouldn't get too worried about being over pressure unless my loads were significantly faster than a given book load. Like more than 100fps. I have had that much deviation between loads in revolvers with the same 4" bbls.

[charlie b]

Not new to the chrono. I have many loads that track book data almost exactly, when the book data has same barrel length as my gun.

[Forrest r]

I like shooting test loads over a chronograph myself. Gives me an idea of what the firearm is doing compared to the "book velocities". It also lets me know how individual powders ack with that specific firearm. After a little testing (10/15 loads) I get a pretty good idea of where that firearm is compared to the published data.

100fps+ from a 1/2" shorter bbl would of scared the heck out of me!!!

FWIW:
Hercules used to put this out about bullseye powder and the 38spl/wc combo. They used to have a lot of kabooms & bullseye was the bad boy on the block back then.
https://i.imgur.com/uIUZpPE.jpg

Ramshot put this out in their reloading manual using their fast burning powder Zip
https://i.imgur.com/UlcjxB5.jpg

Using unique in the 9mm with the lee 120gr tc bullet
https://i.imgur.com/iVohJkW.png

That lee bullet is .555" long. A mihec 359-125 hp is .695" long and will seat .140" deeper then the lee 120gr tc bullet. See data above for the tc/unique load.

[NATJAC]

Thanks for all of the replies! I am definitely going to back off the load and use a smaller charge. To reiterate Forest R's point's regarding OAL (which is a great bit of information and very eye opening!), the overall length is EXACTLY why i'm in a overpressure situation. I've loaded this round before (at 1.15" and it had velocities very close to the published data but I had purchased another 9mm pistol in which the published overall bullet length wouldn't work with the coated bullets do to the bullets getting pushed into the lands. I then had to shorten the oal from 1.15 to 1.11" which jumped my velocities ~125 fps.. once I noticed the spike in velocity it did worry me that I may be in overpressure situations. Always better to be safe than sorry, especially since my boys are going to be shooting these rounds.. not to mention the increased wear and tear on my handguns do to the violent cycling. I did NOT think about the hollow point bullet, even though being the same weight as a round nose, would still have to be seated deaper into the case so i'm glad "44Blam" pointed that out. Thanks for all the feed back guys!

[Burnt Fingers]

RCBS used to have a warning about seating depth in the 9mm and how a slightly deeper seating could more than double the pressure.

Slightly in this case was 0.030 deeper.

I'll have to look through my manuals to see which one it was in but it was page 385.

283892

[fredj338]

Not new to the chrono. I have many loads that track book data almost exactly, when the book data has same barrel length as my gun.

My experience is pretty much opp. I rarely get book vel with anything. There are just too many variables. Then again I reload for like 35 diff calibers & even more diff guns.

[fredj338]

RCBS used to have a warning about seating depth in the 9mm and how a slightly deeper seating could more than double the pressure.

Slightly in this case was 0.030 deeper.

I'll have to look through my manuals to see which one it was in but it was page 385.

283892

That single line from the Speer manual confuses more people about OAL. IT is sooooo misleading. Yes, with certain powders & max loads, one could dramatically increase pressures, though I doubt double. Yet as a general rule, that just doesn't happen. Slower powders can go 110% compression without pressure issues. Uber fast powders may start showing signs at deeper seating, but 0.030" isnt going to do it IMO. That is 1/32". Some factory ammo will vary that much round to round in a given box. My own chrono test show pretty much what Forrest chart shows. Not much going on until you hit 0.060" deeper & even then, 20% increase in vel isnt a double pressure vent.