February 15, 2021
The 9mm Luger is the most popular centerfire pistol round in the world. It is used by the military and law enforcement and is well suited for personal defense, casual shooting, and many competitive shooting sports. It is a potent cartridge for its size, producing as much muzzle energy as the .45 ACP when fired from the same-length barrel.
The 9mm is versatile and can be loaded to higher pressures for more speed and power for situations that call for it. The standard maximum average pressure limit established by SAAMI is 35,000 psi. A higher pressure limit, referred to as +P (plus pressure), is 38,500 psi. There is also a +P+ load, but there is no prescribed limit for it. All we know is that it’s loaded to pressure higher than 38,500 psi. NATO has its own 9mm ammunition specification with a pressure limit of 36,500 psi.
Some of us like to wring all the speed we can from a cartridge, and handloading gives us the opportunity to do this. The principal concern is whether the chamber pressure is within prescribed safe limits. I tested several high-pressure and high-speed handloads to see what type of performance they produced. The load data I used was from reliable sources, including Hodgdon, Hornady, Lyman, Speer, VihtaVuori, and Western Powders. The data included standard-pressure and +P loads.
Handloaders have to be careful to make sure their loads stay within safe pressure limits, so it is important to follow published load data closely. Changing components can dramatically change pressure. The important things to watch are bullet manufacturer, overall length, brand of brass, and primer. Changing any of these can change pressure. Case brands vary in their capacity, and cases with less capacity will produce more pressure than cases with more capacity if they are loaded the same because the powder chamber will be smaller.
Cartridge overall length (COL) is an especially important variable. Pressure increases as the bullet is seated deeper in the case, so handloaders must be very watchful of COL. For example, the Speer Reloading Manual #10 showed a 9mm Luger load that produced 28,000 CUP (copper units of pressure) went up to 62,000 CUP when the bullet was seated 0.030 inch deeper—an increase of 34,000 CUP (121 percent). The details of that load have been lost to time; I asked the folks at Speer about it, but they couldn’t provide further information. But it’s certainly a red flag for closely watching COL.
Ramshot used to publish a chart in its manuals that showed a 20 percent increase in pressure in a 9mm load when a 115-grain bullet was seated from 1.155 inches down to 1.082 inches COL (0.073-inch change) using Zip powder. Pressure went from about 27,500 psi at 1.155 inches to about 32,800 psi at 1.082 inches, an increase of 5,300 psi. It illustrates how different powders might act differently with different cases, bullet weights, and COLs.
All that said, the COL has to fit the gun’s chamber, and not all 9mm chambers are the same. That might require some adjustment on the part of the handloader. For example, I have several S&W M&P9 2.0 pistols, and they have short throats that require me to seat the bullets deeper than the recommended COLs in some manuals. When seating the bullet to a depth greater than that listed in the manual, the powder charge must be reduced to keep the pressure the same.
Here’s an example. The VihtaVuori manual has a 9mm load with a Hornady 115-grain XTP bullet with an overall length of 1.142 inches. That COL fits in several of my 9mm barrels, but not in my M&P barrels. The round won’t go all the way in the chamber because the bullet hits the rifling before it can fully seat. The bullet has to be seated to at most 1.098 inches to just fit the chamber of the M&P used for this article. I seated the bullet to 1.080 inches, which is 0.062 inch deeper than the VihtaVuori length. The powder charge has to be reduced, but by how much?
I used QuickLOAD (QL) software to calculate how much to reduce the load. QL uses bullet weight, bullet length, case capacity, and powder type and charge to estimate pressure. Plugging the values in for the 115-grain XTP, a COL of 1.142 inches and 6.7 grains of 3N37 (VihtaVuori’s maximum load for this powder), QL estimated the peak chamber pressure at 31,603 psi. To be clear, this is an estimate, and I’m not saying this is the actual pressure. The values it gives are estimates and are no substitute for actual pressure measurements under controlled lab conditions. I used this estimate only as a baseline. Adjustments were made in the COL and charge weight to try to keep the estimate close to QL’s 31,603 psi. For this load I set my upper limit at 32,000 psi and only used charge weights that produced estimates under that. The QL estimates are shown in the accompanying chart.
If I seat the bullet at 1.080 inches to fit my M&P barrel, QL says I have to reduce the 6.7-grain charge to 5.9 grains. It estimates the pressure at 30,859 psi, which will keep it within my limit.
If I had not reduced the 6.7-grain charge but still seated the bullet to 1.080 inches, what would the pressure be? QL estimates the pressure would jump to 44,630 psi, an increase of 13,027 psi, or 41 percent. That’s a huge increase and is well into +P+ pressures, which could be very dangerous. That’s why charge weights have to be reduced when seating the bullets deeper.
When you have to seat the bullet deeper and then make changes in the charge to maintain the same pressure, the velocity will go down. How much did the velocity change with the shortened COL? I shot both the 1.142-inch and 1.080-inch COL ammo in my 5.0-inch Kart barrel. The 6.7-grain 1.142-inch load produced 1,297 fps, and the 5.9-grain 1.080-inch load produced 1,224 fps, a difference of 73 fps.
Conversely, if you can increase the COL, you can increase the powder charge and velocity will go up. This is a method for getting the most speed from your ammo. Load as long as possible, increase the charge weight as you go, and you’ll get more speed.
The typical speeds for standard-pressure 9mm Luger ammunition are roughly 1,180 fps for 115-grain bullets, 1,140 fps for 124-grain bullets, and 1,000 fps for 147-grain bullets—all from a 4.0-inch barrel. Some loads are a little faster or slower, depending on the manufacturer. +P loads add around 50 fps, again, depending on the manufacturer.
To “calibrate” my test gun’s velocity, I chronographed several factory loads that included standard-pressure, +P, and +P+ rounds.
This will help to determine what speed my gun shoots factory ammo and provides a context for comparing the speeds it shoots the handloads.
My principal test gun was an S&W M&P9 2.0 Compact with a 4.0-inch barrel because most published 9mm ballistic data is from a 4.0-inch barrel. As noted previously, some of the loaded rounds were too long to fit in the M&P9 chamber, so those rounds were fired in a Glock G19 with a 4.0-inch barrel. Based on a lot of shooting I’ve done with both guns, I know that the M&P and Glock barrels produce roughly the same speed.
My other test gun was a hybrid Para Model 1911 with a Caspian slide and a 5.0-inch Kart barrel. Velocity from the 5.0-inch Kart barrel is listed in the chart on page 56. It produced an average of 58 fps more speed than my 4.0-inch barrels. Accuracy was tested with the Para pistol mounted in a Ransom Rest.
The chronograph results of the factory-loaded ammo show that the M&P9 4.0-inch barrel produced speeds close to the published speeds for most of the loads tested. I do not show all the loads I tested, but the ones in the chart are representative of my results. Most of my results were close to, or a bit slower than, the published speeds. A couple of loads were faster than their published speeds. The differences can be attributed to several possible factors, including different lot numbers of ammo and simply using different guns for testing.
Bullets of 115 grains ranged from just below 1,200 fps for standard-pressure loads to close to 1,300 fps for +P and +P+ loads. The 124-grain loads ranged from 1,140 fps for standard-pressure rounds up to just short of 1,200 fps for NATO and +P versions. The speediest round was a Winchester Ranger 127-grain +P+ load, which clocked 1,271 fps from my 4.0-inch barrel. Standard-pressure 147-grain rounds were just shy of 1,000 fps, and +P and +P+ versions from Underwood were at 1,100 fps. The bottom line is that the speeds from my 4.0-inch M&P barrel are fair representatives of what one might expect from 9mm ammo out of a 4.0-inch barrel.
As for the handloads, I included light 90-grain bullets because they are suitable for small game and make shooting water jugs wonderfully entertaining. The standard-pressure 9mm loads with 90-grain bullets produced around 1,300 fps from a 4.0-inch barrel. The fastest was a Speer 90-grain Gold Dot powered by Winchester 572 powder at 1,377 fps. +P loads were over 1,450 fps, which is pretty zippy for a 9mm. The fastest was a Hornady 90-grain XTP at 1,485 fps powered by Ramshot Silhouette. The most accurate 90-grain load from the 5.0-inch Kart barrel was a Hornady 90-grain XTP JHP powered by VihtaVuori 3N37 at 1,459 fps; it put 10 shots in 1.40 inches.
Most of the standard-pressure 115-grain handloads exceeded 1,200 fps from the 4.0-inch S&W barrel, which is a little faster than standard-pressure factory ammo. The fastest standard-pressure load was with VV 3N38 pushing a Berry’s 115-grain plated hollowbase roundnose bullet to 1,321 fps. This is fast!
And it’s faster than any of the +P loads used for this bullet weight. VihtaVuori’s data was tested under methods established by C.I.P., the European equivalent of SAAMI. The C.I.P. pressure limit for 9mm Luger is 2,350 bar, which translates into 34,084 psi. SAAMI and C.I.P. use the same piezoelectric technology for testing pressure, but they differ slightly on how/where the sensor is placed, so pressure readings differ.
The +P loads with W572, Ramshot Silhouette, and Accurate No. 7 showed an improvement in speed from 27 to 93 fps over their standard-pressure counterparts. The Silhouette and Accurate No. 7 loads were over 1,260 fps and close to the range of the +P and +P+ factory loads. The Accurate No. 7 load with the lead IbejiHeads bullet was the fastest at 1,293 fps, matching the Federal 115-grain +P+ load. The best accuracy was achieved with a Hornady 115-grain XTP bullet powered by VV 3N37 with 10 shots going into 0.62 inch. It was traveling at 1,297 fps from the 5.0-inch Kart barrel. Half of the 12 loads surpassed 1,300 fps in the 5.0-inch barrel. The Berry’s 115-grain bullet driven by 3N38 was close to 1,400 fps from the 5.0-inch barrel. Speed freaks will really love that one!
Most of the standard-pressure handloads with 124- and 125-grain bullets were a bit slower than typical factory ammo, though load data from Western and with VV 3N37 posted speeds over 1,150 fps from my 4.0-inch barrels. The fastest standard-pressure load was a Hornady 124-grain FMJ FP bullet at 1,184 fps loaded with VV 3N37. This round was fired from the Glock 19 because the bullet seated at 1.142 inches would not fit in the S&W M&P’s barrel. The next fastest standard-pressure round was the Remington 124-grain Golden Saber at 1,178 fps over a charge of Accurate No. 7. The fastest +P load was the same Remington 124-grain bullet and Accurate No. 7 for a speed of 1,215 fps. It was the only 124-grain load tested that exceeded 1,200 fps in my pistol. While this is not a super-fast 9mm +P load, it’s around the +P speed expected for this bullet weight.
Some of the standard-pressure 147-grain loads exceeded 1,000 fps from my 4.0-inch barrels, those powered by VV 3N38, N105, BE-86, and Accurate No. 7. The fastest standard-pressure load was produced with VV 3N38, and it reached 1,103 fps, which is faster than the +P handloads and as fast as the +P and +P+ factory loads from Underwood. The fastest +P load was a lead bullet at 1,058 fps powered by Accurate No. 7. The accuracy champ here was also the fastest load from VV 3N38 with the Hornady 147-grain XTP, and it put all 10 shots in 1.05 inches.
A few words of caution. It’s no surprise that my handloads might not match factory +P+ loads since my pressures are limited to the +P pressure limit. Competitive shooters loading what is called 9 Major for USPSA and IPSC matches often exceed +P pressures, and those loads are faster than most factory-loaded +P+ loads, but they are intended for specially built race guns.
Not all guns are rated for +P. There are two concerns with +P ammunition. First, the barrel must be strong enough to hold the pressure, and the chamber has to support enough of the case to prevent a case blowout. The second concern is recoil. Faster bullets mean more recoil force the gun has to tolerate. Let’s use our data with 115-grain bullets and Silhouette powder as an example. The maximum standard-pressure load (6.2 grains) at 1,204 fps produces 3.55 ft-lbs of recoil in a gun weighing two pounds. The maximum +P load (6.6 grains) at 1,262 fps produces 3.94 ft-lbs of recoil, a 12 percent increase. It might not seem like much, but it means the gun takes a heavier pounding on every shot. Let’s say you use the very fast load with VV 3N38 (8.7 grains) at 1,321 fps. That produces 4.54 ft-lbs of recoil. That’s a 28 percent increase in recoil over the standard load with Silhouette. That’s a big increase, and the heavier pounding will shorten the gun’s life.
Develop your high-speed loads by starting 10 to 15 percent below the maximum and work your way up watching for pressure signs. If you see pressure signs before you reach the maximum load, stop. Load smart and be safe.