9mm Max Velocity

[1Victor30]

Is there a maximum velocity for 9mm FMJ? Either 115gr or 124gr. Most of my loads have an OAL of 1.15, if not a little bit more. Does this affect velocity? My biggest worry is pressure. Can velocity readings give an indication of high pressure? Will be getting a Chronograph pretty soon, but will be kind of useless if I don't know how to interpret the readings.

[JustSomeGuy]

Although pressure is certainly related to velocity, there are various factors that make it less than a 1 to 1 relationship. Bullet friction related to type (jacketed, plated, lead), OAL, primer effectiveness, powder burn speed, case capacity variances and case neck tension, etc. will all have effects and may cause more or less pressure relative to velocity.

Maximum velocity is only relative to the components involved and barrel length. There is no "absolute maximum", but there are physical limits relative to what you have.

That said, if you are 100fps over what you are expecting for a given load, you are certainly getting more pressure than you should and something should be checked!

I will say this again... If you reload you should own a chronograph. Otherwise you are blind to what you are really doing and no one wants a blind shooter around.

[noylj]

Well, then I have been reloading and shooting blind for a tad over 40 years.
I don't see pressure and velocity as having a 1:1 ratio, though they are certainly related.
The one time I tried a chrono (possibly before you were born, using circuit-printed paper and reading milli- or micro-seconds on display), I found that .44 Mag would hit max velocity and the velocity would be flat or even drop as pressure went up. Marvelous way to determine a max load--when velocity stops increasing nearly linearly, you have just exceeded max load.
Max velocity? What pressure? What is bullet bearing surface? A slightly small jacketed bullet will often show in increase in velocity despite not sealing the bore.
Look in your loading manual and you'll see the max velocity that a given barrel and specific components can provide. Then look in another manual and see what a different barrel and different specific components can provide.

[Bart B.]

Yes, there's a maximum velocity for 115's in a 9mm semiauto pistol. At some point, the pressure will be so high it'll cause damage to the metal parts slamming against each other as well as stretching the chamber area of the barrel to where it cracks.

All 35 caliber handguns have limitations and the 9mm's no different. That's a medium speed cartridge; small case and short barrels are used. If one gets 100 rounds of 9mm ammo, gives 10 rounds to each of 10 people, there'll be 50 to 100 fps spread in velocity as each person shoots a different 9mm pistol.

A good test of how important an extra 100 fps bullet speed really has is as follows. Get a good friend whose opinions you trust, shoot a 9mm bullet into his left leg, then another identical bullet 100 fps faster into his right leg; both wound channels identical in location and axis. Ask him which leg hurts the worst. Then ask the doctors who treat him which wound channel is the most destructive. This will provide the best information on how effective that extra 100 fps speed of those 35 caliber bullets really is.

Most 9mm pistols shoot 115's out somewere around 1100 to 1200 fps. If you want to shoot them a little faster, change to a .357 SIG cartridge. To make 'em leave a lot faster, get a .375 Mag revolver which is a much stronger handgun and withstands high pressure rounds a lot better than semiauto ones.

Most reloaders don't have a chronograph because they feel they don't need them. Reloaders infatuated with highest velocity possible sometimes have chronographs. I don't think all reloaders should have one and most who do have them don't know why their handloads shoot a given round's recipie they got someplace slower than what's stated.

[Chuck Dye]

Get a search engine going and explore results for "9mm major power factor" and variations. Lots of been-there-done-that info, including on The Firing Line.

Firewalling what you have can be interesting and fun. It can also be disastrous. Give some real thought to simply moving to another gun and cartridge.

[Nick_C_S]

This is not an easily answered question, and oversimplifications abound. But I'll take a stab at it:

Because you're a loader, I will assume you're asking the question from a practical, and not so much a theoretical standpoint. For each bullet weight (for each specific bullet design, actually - but for now, we'll just leave it at weight, because that's the primary limiting factor), Yes, there is indeed a maximum realistic velocity.

In 9mm, the practical maximum velocity of a 115g bullet at 35,000 psi, through a 4" barrel is about 1250 fps. And it's about 1150 fps for a 124g. And about 1000 fps for a 147g. I know this from reading load manuals. And I also know that this is just a guideline for basic reference.

This is not to say that these velocities can be achieved with any powder. They cant!

Basically, fast powders expel their energy quickly - too quick for the bullet to gain sufficient momentum for maximum velocity. Slower powders expel their energy more slowly (the difference is but a few milliseconds), giving the bullet more time to gain momentum - velocity (assuming sufficient barrel length).

Here's my approach. And I'll use a real example. I have a 124g JHP bullet that I want to emulate the performance of Speer's 124g GDHP. Through my gun (Kahr CW9, 3.7" barrel) , the Speer round chrono's at 1048 fps. Now I go look at my Speer #14 manual. It shows lots of loadings over 1048 fps. But knowing that it's data for a 4" barrel gun, I know to mentally subtract a few fps from the figures shown - about 20 or so (it's actually non-linear: subtract less for faster powders, more for slower powders. But practically speaking, and for this application, -20 fps will work just fine). Okay, there's still lots of powders that exceed 1068 fps.

There's four powders listed that I have: W231, HS-6, AA5, & Power Pistol. I look at the systematically:

W231 is too fast for the application; it doesn't meet the velocity requirement.

HS-6 doesn't quite achieve the velocity requirement either.

AA5 will do it - just barely. But it's a nice, clean powder, meters very well, and I have a bunch of it.

Power Pistol with do it with ease. But I'm building a defense round; and I know P'P'stl is flashy, and because it's a flake powder, tends to be a bit pressure spikey. I'm loading 9mm, which is a minimal case volume cartridge, which also lends itself to pressure spikes. I'm going to steer away from Power Pistol.

So AA5 it is. It also fits my over-arching criteria for powder selection: "What's the fastest powder that can achieve my desired goal?"

This is a load in progress, btw. Right now, I'm at 6.3g and it chronos at 1033 fps. (In fact, you were at the range with me the day I chronoed this round.)

The brass looked fine. I see no signs of pressure. So I'm moving to 6.4g next time out at the range. 6.4g is the Speer #14 max btw. And if it shows no signs of pressure, I'll probably call it "good enough" and consider the load "set." Even 6.3g's 1033 is acceptable. That's fast enough to make a HP bullet expand as designed.

Clear as mud?

57K really needs to chime in here - giving is technical point of view, with all his SAAMI numbers, etc. And his obligatory recommendation of Ramshot Silhouette Admittedly, he knows more than me. I just know enough to be safe and effective with my loading process - but always learning more.

[1Victor30]

I think it is the pressure thing that has me most confused and paranoid. When you ran some of my loads through your Chrono, Nick, we were getting readings with higher velocities with less powder than in the manuals. For example, Alliant says that 4.7gr of Bullseye under a 115gr FMJ bullet should get 1144 fps. My loads averaged 1204 fps with that load. For 5.0gr of BE under the same bullet, Alliant says 1180 fps. My load averaged 1278. You said I should back down from the 5.0. Should I also back down from the 4.7 to 4.5? I hand measure each load because my powder dispenser is just too inconsistent. I also know I am not using the best powders for pistol, but can't get what I want, so have to make due. Don't want to make the loads too light or I will have other issues. Much more complicated than I thought is was going to be!

[Nick_C_S]

I chose to answer the OAL (or COL, or COAL - interchangeable terms) part separately. OAL is definitely intertwined with my above post, but putting it in the same post gums up the clarity of each (assuming they have any clarity lol)

OAL is something you set before doing any loading. You have a bullet, and ideally, you have the manual for that bullet and therefore, the OAL the manual uses will probably work. Generally, I use the manual's OAL if I have that info. But either way, you mock up some dummy rounds and do the "plunk test" with your gun's barrel. Make sure it's not impinging on the barrel lands; if so, reduce the OAL.

I think many loaders get too wrapped up on OAL. For the above JHP in my example, its OAL is 1.12. It's set. I leave it. I have no reason to change it. So I don't change it. I don't think about it any more. Done.

OAL and pressure: Yes, OAL will most definitely effect pressure. In essence, reducing the OAL will have the net effect of increasing the powder burn rate - almost like having a faster powder in the case. This is why you first set OAL, then go loading. Adjusting OAL is not a means of adjusting your round's performance. At least, not in my loading world.

Set it; and forget it. That's how I do it.

[Nick_C_S]

Nick, we were getting readings with higher velocities with less powder than in the manuals.

Check your manual's test barrel length. You have a (very nice) Springfield with a 5" barrel. Your manual may have a shorter test barrel. Also, Springfield's are well made guns - it could just be efficient at pushing bullets.

That said, the higher readings should definitely get your attention (and did - that's good). We could be seeing the beginning of a pressure spike. Although in this case, I doubt it. The increase in velocity was fairly linear for the powder increases. Also, when Bullseye pressure spikes, it tends to be rather severe, leaving little doubt.

Bullseye is a very fast, flake powder that is quite unforgiving. It has one purpose that it does very well: to make consistent, low to medium power, everyday shooting rounds. And for that reason, I recommended backing down your loads. Going too low will bring about the issue of feeding problems. But long barreled semi-autos - like yours - tend to have a fairly broad operating window. You're not going to run into that; and if you do, just increase the load back up a little. Besides, you're going to "set" that load at 4.5g's anyway It's perfect right there.

[57K]

Although pressure is certainly related to velocity, there are various factors that make it less than a 1 to 1 relationship. Bullet friction related to type (jacketed, plated, lead), OAL, primer effectiveness, powder burn speed, case capacity variances and case neck tension, etc. will all have effects and may cause more or less pressure relative to velocity.

I believe JSG said less than a 1 to 1 relationship. Now, where to begin? I agree and especially with fast burning powders where the relationship between pressure and velocity are more likely to be near the 1 to 1 ratio. Move down to slower burning powders with higher energy potential and things change for the better in terms of the velocity you can expect at a given pressure level like say the 9mm's Max. pressure rating per SAAMI at 35,000 PSI/33,000 CUP. For a very fast burner, Bullseye actually has pretty good energy potential. The problem is that once you hit its Max. potential or slightly exceed it, pressures can spike.

noylj, brings up a good point in his .44 Magnum reference. When you increase the powder charge and don't get any gain in velocity, this is referred to as the "point of diminishing returns." Pressure may be spiking or very close to doing so at this point. As you move to slower burning powders with good pressure stability, the less likely that is to occur and why the IPSC guys use a very select few spherical powders to load 9mm MAJOR. HS-6, True Blue, Silhouette, 3N37 and more lately, AutoComp. Others see some use like LongShot and while it was available in the US, Vectan SP-2 was used quite a lot. With any of these powders you can build fast and safe high velocity 9mm. What you CAN'T do is load 9mm MAJOR for typical 9mm pistols which takes down another street: OACL. Most IPSC competitors use custom built 1911s with long chamber throats where the magazines will allow longer OACL's than the SAAMI Max. spec of 1.169". Some common 9mm pistols have long throats (i.e. S/S P-226/229/228 and G19 & 17s) but OACL is restricted by the magazine. Unfortunately, there are 9mm pistols with short barrel throats like the CZs and XD/XDm, so it is imperative that you learn how to establish the proper OACL for a particular bullet in the pistol it's to be fired from.

So, 1Victor30, Nick has already given a pretty good explanation of things. You're getting higher than load manual velocities for a couple of reasons. Alliant tested with a 4" barrel where you're using a 5" and in my experience, XD/XDms tend to give high velocities in relation to their barrel length. I've always wondered where the Croats are getting their steel, if it's actually produced in Croatia and probably is, it makes for some pretty darn good barrel steel. Getting 1278 FPS with a 5" barrel from a load rated 1180 FPS from a 4" test barrel is still quite an increase. You guys had the chrono about 12' from the muzzle didn't you?

Let's get to a couple of issues that have been raised: lowering pressure by increasing OACL and bearing surface. Typically, load manuals list short OACL recommendations and handloads should never be shorter, IMO. This is stated in a number of manuals and by powder makers who give data for their powders. It's kind of a worse case scenario where the data providers are intentionally using the shortest OACL practical to establish Max. pressure ratings. What JSG was referring to in regards to bearing surface is that different bullets have shanks of differing lengths, and the longer the shank is, the more bearing surface it has with the barrels rifling. As noylj pointed out, velocity in regard to bearing surface can change also and I'll give an example. In my experience, the Montana Gold 124 gr. JHP is about .0005" or 1/2 thousandth gives me higher velocity with a given powder charge than most any other bullet. So with its slightly smaller diameter, bearing surface is decreased as is the coefficient of friction in the bore. For this reason, whenever I work up 9mm +P loads, I tend to use SIERRA's data because their 125 gr. JHP has about the longest shank you'll encounter among the various 124/125 gr. JHPs, and further, SIERRA loads them very short.

Now, I have a couple of questions for you, Victor. Have you established that the 1.150" OACL with the 115 gr. FMJ is safe in the 5" XD's chamber? And, do you really need as much velocity using an FMJ bullet? Again, as Nick pointed out, you can answer the proper OACL question by doing a "plunk" test. A handload of slightly shorter OACL than the Max. allowable will give an audible "plunk" when you drop the handload into the chamber, with the barrel removed and muzzle tilted downward. But you can also establish the Maxx. Allowable OACL for a given bullet in a given chamber fairly easily. I generally find that by using a jacketed bullet, you can just barely start that bullet into a FIRED case. Take this "dummy" and insert it into the chamber and then push on the case-rim until the case stops forward movement. This is where the case-mouth has contacted the forward ledge in the chamber and the barrel's throat is seating the bullet. Make up about 5 of these "dummies" and test them all in this manner. You should get a consistent Max. Allowable OACL. Then, when you make your handloads, shorten them by .005 - .010" below the Max. allowable you established with the "dummies." Part of this will also depend on the OACL variation that your press and dies allow. Typically, I just shorten to the next lower .5mm depending on which or whose pistol I'm loading for, so here's how that shakes out: 1.102"/28mm, 1.122"/28.5mm, 1.142"/29mm and finally, my longest loads are 1.161"/29.5mm which I like to use for 147 gr. JHPs. But again, you have to establish that none of these lengths are too short for YOUR pistol's chamber. For CZs and XD/XDms using my favorite 124 gr. Rem. JHP (not Golden Saber), 1.122"/28.5mm works and is just a hair longer than many factory JHP loads.

The only bullets I load in 9mm currently are JHPs. The 124 gr. Montana Gold does not expand in my testing, so it's little different than using an FMJ. It may be possible that Montana Gold's FMJ bullets use the same nominal diameter I'm finding at around .3545". If so, they'll also produce higher velocity with a given charge of powder as will bullets with shorter shanks. Like I said, bullets like the 125 gr. SIERRA JHP and some other truncated cone shape bullets like the XTP have fairly long shanks in comparison to JHPs that have a rounded ogive. Here's one example of a handload I use: the 124 gr. Rem. JHP in once fired nickel +P cases with a CCI-500 and the +P charge of Silhouette I use with an OACL of 1.142" chronograpks 1238 FPS from the 4.14" barrel in my Rugr SR9.

Now we get to the confusion. Around 1990, give or take, SAAMI reduced the Max. pressure rating of the 9 x 19mm from 35,700 CUP to 35,000 PSI/33,000 CUP while establishing the Max. for 9mm +P at 38,500 PSI. Since loading the 9mm since the mid 80s, I've pretty well concluded through careful study of data and observation of pressure signs that there is little difference between 9mm +P at 38,500 PSI and older data where the former Max. of 35,700 CUP was used. My problem with the SAAMI reduction is in since we know the established Max. for +P, why is there so very little data for it? In fact, I haven't seen anyone give 9mm +P data in over 10 years and the last to do it was Ramshot. So for you guys that may not have seen the older data, here's a FYI specifically in the case of HS-6. Today's standard Max. Standard Pressure loads are a good deal below the older loads when the pressure rating was 35,700 CUP. I won't give a specific charge, but take my word for it that the charges with HS-6 were a good deal higher than anything you'll see today. In the SPEER #11, they used a Beretta 92SB and the data is from the mid 80s. The Max. Charge of HS-6 gave them a velocity of 1315 FPS and supposedly with either their 115 gr. JHP or FMJ and by today's standard's would easily be rated +P and not too far away from what some have rated +P+ using 115 gr. JHPs at 1350 FPS like the Illinois State Police, ISP, or Secret Service loads of yesterday. The ISP used the Win. 115 gr. JHP and the SS load used the 115 gr. Rem.

In summary, whenever your loading close to or at Max. Charges, a chronograph is very useful. And going back to the general discussion, whatever powder you're using, when you observe NO velocity gain with an increase in powder charge, you've hit PEAK pressure or maybe just beyond it and described as the "point of diminishing returns." I don't recommend using anything faster burning than say Unique for higher velocity loads and my personal preference is for spherical powders that have better presure stability. For both the 9 x 19mm as well as the .40 S&W, what I recommend for full power loads are the sphericals starting at V-V N330 down to AA#7 or LongShot depending on whose burn rate chart you're looking at and how they have AA#7 and LongShot placed. They reverse order in different charts. In regard to my own +P type loads, I've never had any issues following the recommendations for powders used in IPSC/USPSA 9mm MAJOR. I don't load anywhere near those levels and the only OACL restriction I have with the SR9 is the magazine. They have long throats and that's why I prefer them personally. I'm not recommending that any of you attempt 9 x 19mm +P handloads because the loading parameters are a good bit narrower and because of the lack of data. I just don't have any need to push an FMJ, or a cast lead bullet for that matter, beyond the velocity that standard pressure loads are capable of. JHPs are a different matter entirely and I do handload my own defense loads at +P levels, at least in terms of velocity. I know that +P is a pressure designation, but sometimes it is used as a marketing tool. In the case of the Win. Ranger 127 gr. +P+, it would require a less than optimal powder selection for it to be +P+ in terms of actual pressure. While there is no SAAMI recommendation for Max. pressure for 9mm +P+, there is the suggestion that it shouldn't exceed 40,000 PSI and I'd really be surprised if the 127 gr. +P+ Ranger is that close to 40,000 PSI. Another example is the SPEER 124 gr. +P Gold Dot. SPEER rates it at 1220 FPS and from my SR9 that load chrono's 1174 FPS. I have a handload with the same Rem. 124 gr. JHP mentioned previously with a charge of Silhouette just higher than SIERRA's recommendation where I'm using a longer OACL of 1.122"/28.5mm where their's is 1.075" and my handload gives the exact same velocity over the chrono at 1174 FPS and because of the longer OACL, I don't believe my handload would actually pressure test above 35,000 PSI for standard presure 9 x 19mm. Of course, to make that definitive, it would have to be pressure tested. The charge I use for that load is .5 grs. lighter than the charge I use in my defense load that chrono's 1238 FPS. Again, there are good and bad powder selections to accomplish such a load. HS-6 is plenty capable but tends to flash higher than the others. Power Pistol is capable but I don't use flake powders and in particular, double-based flake powders like Power Pistol or Blue Dot that will give impressive muzzle-flash if you like that sort of thing. True Blue comes by low flash kind of naturally through it's high volumetric density and very small physical size. 3N37 works very well with low flash and what I used in my defense loads prior to moving to Silhouette with the Rem. 124 gr. JHP. For higher velocity 147 gr. JHP loads, few are better than AA#7 that was designed for such purpose, i.e. high velocity submachinegun loads with heavier 9mm bullets and V-V 3N38 can also work for that.

[Nick_C_S]

57K: We set up the chronograph at 4 yards.

(Great read, btw.)

[57K]

Just as I do. The numbers should be plenty accurate.

[1Victor30]

I have used Montana Gold 115gr FMJ with an OAL of 1.15 and they did fine. I have some reloads that I buy at the local range that are 124gr TMJ and the OAL is 1.142 +/- .002. Not sure what powder they use, but it is 4.4gr. and looks like a ball powder. I can use that data as a basis for the 124gr FMJ and CMJ bullets I have and work the loads to my needs.

[57K]

Thanks, Nick, glad you liked the post and I didn't mean to overlook your comment.

Victor, 4.4 grs. of a spherical powder with a 124 gr. TMJ sounds suspiciously like W231 as common as it is. Ramshot ZIP is very similar and looks very much like W231 so it would be hard to tell the difference just by looking. But, 4.4 grs. is about middle of the load range for either depending on whose data your looking at. I played with both a while back in experimenting to find a soft shooting load for my brother's little Taurus PT-111. I also used WST, although Hodgdon doesn't recommend or give data for it, and a light charge of True Blue as well. I can't recommend WST because of the lack of data, but ZIP and W231 work fine for soft shooters with 124 gr. FMJ or the MG 124 gr. JHP. I loaded some with the ZERO 125 gr. Conical JHP also and like the Montana Gold, it's pretty much a gaming bullet. Zero makes a different bullet in that weight that would be more suitable for defense but I haven't had a chance to try it yet.

[JustSomeGuy]

See... when I said there was no "absolute maximum" I was speaking of theoretical maximums, not what you would do with a normal pistol. Labs regularly fire projectiles at speeds that would shame 9mm Major competitors out of test systems that look like cannons. I did say there are limits based on what you have.

If what the OP was asking is if what is described in manuals is really the maximum SAFE load to use with a specific set of components, then yes... that's it and you should not go beyond that without using a gun designed for it specifically. If you need more than you should be looking into a 9X23 or 357SIG as someone mentioned.

The "diminishing returns" thing is a very good point. Powders become "non-linear" when they are past their pressure maximums, which varies with the powder type, cases (caliber) used, bullet etc. This is why maximums are listed in the books. It is past those listings that the powders in question were found to get "squirrely", spikey, or dangerous with the components used and thus the maximum was established. Whether or not it is below the SAAMI pressure limit is of course another factor. Some powders, like Silhouette, HS6 and a few others will remain linear well past the pressure limit established for the cartridge.