Note: Using propane instead of 134a gas will increase the wear and stress in your internal mechanisms and is not recommended.  The purpose of this test is to show you the gas consumption and the consistency of the shots using a higher output gas therefore any inconsistencies will be made clearer.

The initial differences you will see on this magazine is that it's substantially bigger (stating the obvious here) and holding almost twice as much ammo as the regular 5.1 magazine does, this also provides a much bigger gas reservoir to hold your propellant in.  The markings are also different from the regular 5.1 magazines as shown in the pictures below along with the 50 round magazine showing a more shiny black finish as compared to the 5.1 magazine having a less glossy dark grey color.

As you can see from the pictures, the magazine dimensions are slightly different from the magazine lip being taller on the 50 round mag having a circular internal lip where the standard 5.1 magazine has a square lip.  This may prove to be useful for those that have a habit of handling their magazines a little more rough causing the magazine lips to break as we all know corners mean a weak point.  By changing the internal corner into a smooth edge, this will spread any forces exerted on the magazine lip reducing the chances of any breakage.

Furthermore, due to the elongated magazine lip, the upper part of the magazine have been made slightly shorter to accommodate the longer magazine lip with the magazine latch recess placed slightly higher so that the overall dimensions stay compatible with the HiCapa series.  Towards the back of the magazine lip where it usually hides between the top sides of the magazine shell, this is not the case with the 50 round mag as it has an enlarged outlet valve bracket.  Upon closer inspection, you will also see that the rubber seal on the outlet port on the magazine is slightly different to the regular 5.1 magazine as the 50 round magazine has a cornered seal as compared to the square seal, reducing the friction that comes in during the blowback valve sliding along the port.

If you look at the base plate between the two magazines, you will also notice the 50 round magazine has two locking pins towards the bottom of the magazine.  That is used to hold the base plate in where the regular 5.1 magazine's base plate is held in by a screw hidden underneath the plastic base plate cover which the 50 round magazine cannot be slid out as you would with the regular magazines.

We were curious of how many shots it can fire on only one single charge of gas as well as showing you the main differences between this extra large mag to the regular 5.1 magazine, so we took it for some gas capacity tests as well as seeing if there would be any differences on the power output on these magazines.

Gas capacity vs cooldown test

We understand that the more gas you have reducing pressure, the lower the temperature will get as it will absorb the energy around it.  Using propane that has an expansion ratio of 1:270 any cooldown effects will be seen with a bigger effect as compared to using 134a with a much less expansion ratio hence the power output differences between the two gasses.

Test conditions: firing on quick semi-auto mode using propane and KSC perfect .20g ammo with an ambient temperature of 27celcius.  Fire using a TM 5.1 HiCapa at quick semi automatic successions until the magazine is fully expended, reload more ammo immediately and expend the ammo.

On the 50 rounds magazine tested 5 times in total, it was able to expend on average of 87rounds per charge of gas (25degrees surface temp before testing and reaching 16celcius after)

where the regular 5.1 mag was able to expend 42rounds average per charge of gas (25degrees surface temp before, 19degrees after)

Note: Power reduction more noticeable on the standard 5.1 magazine as cooldown effects take its toll where shots become increasingly weaker along with its recoil, where the 50round mag is less noticeable but power drops very abruptly in 3-4shots from high kick to hardly any remaining energy to cycle the slide.

At longer ranges it is easier to achieve a better grouping due to its additional weight and weight distribution, the 50round magazine adds more stability by weight and its weight distribution on the lower part of the pistol on the frame (as compared to a heavier slide where the added weight will be on the recoil rather than on the body itself)

In a nutshell, if you want to shoot more in one session without reloading as much but doesn't mind carrying the extra weight on your gun or your pouches.  The 50 rounds magazine has a little more advantage in terms of firepower without compromising your maneuverability much along with being able to stabilize your shots for longer ranges due to its increased weight around the frame making it more manageable to control its recoil due to the weight balance being more bottom-heavy.