Frequently asked questions
STI/SV/Para/Bul/Caspian magazines
How can I tell if I have a Gen 1 or Gen 2 tube?
Follow the below link to the the image describing the difference
Click Here
What is the difference between 9mm and 38 Super Comp?
9mm is a tapered casing, 38 Super Comp is a straight wall cartridge and is longer than 9mm
What should my 9mm Major feed lips be?
The front of the feed lips should be .340 to .350. The rear are not adjustable.
What should my 38 super comp feed lips be?
The front of the feed lips should be.345 to .355. The rear are not adjustable.
What is the recommended OAL for 9mm Major?
9mm Major is best suited at 1.155 and 1.165 based on your barrel setback upon unlocking and individual needs.
What is the recommended OAL for 38 Super Comp?
38 Super Comp is recommended to start at 1.225 based on your barrel setback upon unlocking and individual needs.. The maximum OAL is dependent upon the bullet profile and how it fits within the body of the magazine.
My gun is chambered in 38 Super (rimmed case), what is the recommended OAL?
We recommend loading to 1.220 OAL so the case rims can stack appropriately.
What should my 40 caliber feed lips be?
.370 to .380 at the front of the feed lips. The rear are not adjustable.
What is the recommended OAL for 40 Caliber?
We recommend loading from 1.135 up to 1.200 based on your barrel setback upon unlocking and individual needs.
What is the "Ambi" selection on the magazines?
The mags with the Ambi cut can be used with either right or left side magazine release button.
New MBX 171.25 / X7 30rd Competition Magazine
The New X7 combination
This New combination is designed specifically for maximum competition to hold 30rds +1 and allow the slide to cycle reliably once broken in this means we had to find some extra room, the new X7 shares DNA with our very successful 141.25 limited optics 24 rds X follower.
Remember All MBX tubes/springs and followers Will break in naturally making the max or 30 rds much easier trying to force this processes to happen on the kitchen table never seams good, load as recommended on insert and video when new shoot 2-3 practice sessions if needed and normally the tubes are good for matches.
MBX Tubes, Quality checks and how we strive to get you the highest quality product
Each tube and base pad will go through specific checks to assure fit and function feed lips set before stress relived & heat hardening this ensures they remain extremely stable for years of use, after heat treat/ stress relief the tubes go through a 3 stage surface finish process that is specifically designed for our tubes in three different machines each tube will spends a total of 6hrs in finishing with concentration on the internal tube smoothness that gives our tube unparalleled reliability and performance
Before final assembly and after heat treating the feed lips are checked again and adjusted if needed, mag catch fit checked in fixture and drop free checked in test gun, slide lock check in actual gun if required then spring cycled 4-5 times on our spring fixture to help with spring “set” then check follower fit and hight remember the competition follower Must sit low to avoid being struck by the slide after the last round is fired we then apply a light coat of oil to the mag before packing
VERY IMPORTANT So remember to follow the competition spring follower break in process instructions to load to capacity 4-7 times before use listed on the insert card.
Reload specs & More on the tech side
The tube and follower is specifically designed for maximum capacity and fast bullet presentation in 9mm. max OAL 1.170 we tested various components for almost a year in development with 1.160-1.165 open 170 pf ammo Montana Gold 124 factory crimp specs around .372 and also factory minor American Eagle/ Winchester ran fine in Limited optic guns getting slide back for reliability with 31 rds start after magazine break was completed holding 30rds.
We only offer in silver tube currently the natural finish that is achieved with our internal polishing media lends itself very nicely to quicker break-in, resulting in loading and bullet presentation quickly becoming smooth and fast.
Loading to capacity
You will need to use a loading tool (uplula) and watch our loading to capacity video if you are not familiar with this technique, remember this a competition design and just like a formula 1 car the magazines going to break in and then maxed out, it will perform fine please keep Ammo clean/primers set into pocket and crimp to factory spec is very important around .372.
Can I just replace spring and follower in my existing tube?
Yes you can! But we can't guarantee results we found in testing mixed results with existing tubes and depending on many factors follower may need modification to present last round, Gen 1 tubes the follower will need custom fitting if tried.
So as this new X7 follower was not designed as a replacement for all previous tubes rather a ready built complete magazine option for those who want to have the ultimate capacity available if needed.
If trying just the spring and follower it will be your choice we can't accept returns on springs and followers and we can not problem solve if you choose to try and not do feel the results are what you wanted with new x7 spring and follower set in a previous 170 tube.
Failure to feed section:
My bullets are slow to rise, why?
1. There are multiple causes for this such as:
1. Dirty magazines
2. Flared crimp
(incorrect crimp)
3. Incorrect OAL
4. High primers (affecting OAL)
5. Damaged, worn or kinked mag spring
6. Damaged or incorrectly installed follower
2. We recommend you check the above list to ensure the greatest reliability of your firearm and magazines.
My gun is out of battery or will not chamber, why?
There could be several causes.
1. For any hand load over factory length the projectile may make contact with the lands and grooves. Some bullet profiles are more prone to make contact than others. Check your extracted round for marks on the projectile and adjust your load or projectile selection accordingly.
2. Check your crimp with a case gauge
3. Check your primer seating. High primers can drag on the breach face reducing clearance between the rim and the extractor.
4. Excessive tension on the extractor can bind the casing from rising up the breach face.
5. Check your extractor to breach face clearance. Installing a new extractor or firing pin stop will have an affect on the contact surface of the extractor claw and the rim of the case.
6. Riding the slide. It is possible for your flesh to make contact with the slide causing friction and interfering with the operation of the firearm. Thumb shield safeties can help alleviate this issue.
7. Worn or inadequately sized recoil springs can cause the slide not to strip and chamber a round. Check your springs and replace as necessary. 8. New magazine springs and often minor loads can cause a reduction in slide speed. Download the magazines for a few cycles until your springs have broke in.
Failure to extract or stove piping issues:
My gun is out of battery or will not chamber, why?
The magazine is designed to present the round correctly for the slide to chamber. When the round has chambered and ready for ignition, the magazine has completed its purpose. Stove piping is generally caused by
1. Incorrect ejector length or fitting
2. Damaged or broken ejector
3. Incorrect tension on the extractor
4. Damaged or broken extractor
5. Reduced power load
6. Incorrect recoil spring
7. Incorrect grip
8. Riding the slide (making physical contact with the slide and interfering with the operation of the firearm)
Double feed misconception:
On the 1911 single or double stack configuration it is impossible to have a double feed. The magazine shape is designed to hold the second round from moving forward enough to exit the magazine at the same time as the round above it. Common items that are mis-diagnosed as a double feed:
1. There is discharged brass in the chamber
a. The round is fired and cycles the slide enough to pick up a fresh round without ejecting the discharged brass. See the "failure to extract" FAQ
2. There is a live round in the chamber
a. Incorrect extractor tension
b. The extractor may not have hooked the rim of the chambered round. When cycling the slide no round will extract but the slid will pick up the next round. Check the extractor tolerances.
c. The ejector must be of recommended length to ensure early and clean contact with the discharged casing to leave the chamber at the correct time during the cycle. Check the ejector tolerances.
Routine mag maintenance items:
When should I change out my springs?
We receive a lot of input on this issue. We recommend that you replace springs annually at a minimum. For avid shooters we suggest biannually.
When should I replace my followers?
The follower is an integral part of the magazine. We recommend changing followers annually.
What do I need to do to maintain my basepads?
We recommend applying light silicone or oil to the pin on your scheduled cleaning cycle. Minimally we’d recommend every two months.
What maintenance do I need to do to my tubes?
Check your feed lip tolerances as needed. Routinely clean your tubes to ensure proper function.
MBX Glock steel mags:
What OAL do you recommend for my load?
For purchased ammo, anything within SAAMI specification will work. The maximum OAL for SAAMI is 1.169.
- Our PCC reloads are traditionally set for 1.145 to 1.155 for best results.
- For pistol we recommend SAAMI specified length.
How much crimp do I need?
We set our crimp at .372 - .374
What is the difference between the "slide lock" and "competition" follower?
- The slide lock follower will lock the slide back
- The competition follower will not lock the slide back which affords the shooter 1-2 more rounds in the magazine.
PCC gun section:
What is the weight on the MBX PCC with the lightweight barrel?
It’s one of the lightest weight PCC’s on the market at 6 lbs.
What bullet profile should I use?
We highly recommend using round nose bullets. They provide the most consistent feed and reliability of all bullet profiles.
There are 2 setscrews, one on the left hand side and the second behind the front takedown pin on my MBX PCC lower. What are they for?
The set screws were installed to improve magazine alignment into with the chamber. By adjusting these screws you ensure correct alignment and thus the highest reliability of your mags in your firearm.
Can I tune the buffer system?
Yes! We have several videos that show how to tune the buffer system along with a tuning kit that can be purchased separately.
What is short stroking?
Short stroking is reducing the rearward travel of the bolt carrier group.
What are the benefits of short stroking my gun?
The bolt travels less distance, resetting faster. The perceived recoil disruption of the sight movement is shorter as well.
What should I know about short stroking?
The stroking kit spacers, shims and ammo load must be tuned for consistent trigger reset. You will lose the ability to lock back the bolt carrier when empty and on the last round. We highly recommend you watch the short stroking video on the website
Click Here.
What do I need to know about maintaining my PCC?
Keep your hammer and trigger clean and free of debris. Lightly oil as necessary. Remove and clean the firing pin. Clean and oil the firing pin tunnel often. Keep your upper and lower receivers clean and lubricated. Remove your buffer system and clean it. Light lubrication is necessary. Replace buffer springs between 15,000 and 25,000 rounds. Clean comp as necessary. We use using an ultrasonic cleaner for the comp. Regularly clean the bore and chamber.
Hiperfire trigger shoe:
What is the difference in size between the trigger shoes?
The numbers represent the distance from the existing trigger face to the face of the new installed MBX shoe.
1. The small flat shoe is 0.200"
2. The medium flat shoe is 0.350"
3. The large flat shoe is 0.450"
4. The small curve shoe is 0.100"
5. The medium curve shoe is 0.200"
6. The long curve shoe is 0.300"
7. The half curve shoe (up or down) is 0.200"