vgdvc

Ah ha. What gen do you have and what issues? What are the weak links you heard of for the short life span? I'm new to them so trying to learn about them. I was using an ATI mil-spec with Hiperfire 24c trigger, Blitzkrieg hydraulic buffer, .308 carbine spring,MBX comp and Titan Rocket Magwell. Has been flawless with reliability,makes 130 pf with 145gr with way less powder than needed for the MPX,weighs 6.75 lbs with a Cmore Slideride,is accurate and inexpensive. Shoots predictably but not as soft compared to the MPX. Once I got to M class I told myself I was upgrading to an MPX PCC Model,hope I made a smart choice.....

Almost sounds like extractor is not riding over rim of case to engage it for extraction and keeping bolt out of full battery. If they can't diagnose the problem better hopefully ATI will send you a new extractor ,extractor pin and extractor spring to try. What trigger assembly question was for Ken Shoot Fast since he mentioned having firing pin breaking issues.

I have had positive experience when dealing with them in the past. You may be able to get in contact directly with one of their gunsmiths or have a representative to talk to a gunsmith on your behalf. As long as the bolt is seating flush with the breech face in battery perhaps there is something that out of spec with the extractor or lack of proper extractor spring tension. Keep us apprised.

What trigger assembly do you have in it?

Regarding an optic not made in a developing country the Sig Romeo 3 is made in Japan and mine seems to be excellent quality. Can be had with co witness mount for good price if you hunt around. New Sig Romeo Max is due out soon with enhancements,not sure of build origin.

I'm doing the opposite and in the process of moving from a blowback to an MPX PCC with some upgrades. If you don't mind commenting,why are you transitioning from your MPX?

Thumb pointed at target, fingers gripping handguard? If so that's what I am doing but I added a finger rest for additional force with my index. Looking to experiment with index finger pointing at target for better reference. May or may at not work for me but noticing some top shooters using a form of this. I know it's popular in the shotgun/clay sports world for quick index/point shooting.

Thanks for the specifics. Looks solid.

Hey PCC Shooters splitting hairs on technique style but that sometimes what we do here. Been playing with different support hand positions. I have been using a finger rest with thumb pointed at the target resting alongside the handguard. Good control but I felt as I shot faster I had a tendency of pulling shots low. I recently started trying to point my index finger at target with thumb on top of handguard seeing if that gave a more natural feel and point referencing. Also been trying to see which gives a better natural pointing reference with the dot turned off and shooting targets simply by referencing feel. With a little practice is kind of amazing what can be done. Anyone experiment with any of these techniques and learn to capitalize on it on stages?

What trigger assembly do you have? Something that may be able to help lock/dwell time a little bit longer is a Hiperfire 24c with the heaviest toggle springs.Puts a lot more hammer resistance on a bolt coming out of battery than your average AR hammer spring keeping the bolt closed slightly longer. You also get about a 2 lb trigger pull just keep some extra firing pins as some have claimed the increased hammer force can damage tips or mushroom strike point at the rear.

Since it's a pistol with the brace instead of a stock wonder if you can shoot it in open class LOL!!

With some minor practical competition tweaking I bet that thing would be badass to shred through some tight quarter stages in 9mm.

Good to hear. I put one in place of the factory black housing 683. The 681 is breaking at a consistent 3lbs3oz with digital guage measured at the trigger bottom tip. I did use the factory plate that comes with the 683 for the set screws to push on. I would consider trying a slightly lighter hammer spring if I can find one (JP Yellow?) In hopes of getting 2.5lbs

Yeah,with my AR9 it is easier with limited choices to just run the poly body Cmore slideride as far possible on the receiver and be done. Setting up to the MPX PCC with an aluminum C-more slideride there is more options with a heavier optic and more receiver rail room.

So, with the options of moving accessories and dot/mount to and fro where do you like to have the weight balance point of your carbine fall?

Also pull in and tight with the pistol grip. That will help keep things stabilized and allow the support arm to be a little more flexed and relaxed for transitions ,indexing Etc

Hello. So typical forum disclaimer of YMMV but I have put some efforts into counteracting the up right torque and how to negate it for a right-handed shooter with the carbne. For human influence I have found that a grip such as the BCM mod 3 allows me to get my hand higher up on the receiver and a little more straight up and down forcing me to keep things tighter into the shoulder. It also allows me to get on the safety up high so I can actually "ride" the safety when shooting. The other thing I have done ,and I'm continuing to experiment with is, using a small finger stop on the bottom handguard in which I hook my support hand trigger finger over the stop and thumb pointed at the target parallel to the barrel, similar to how I would grip a pistol. I have used the DPMS Miculek brake on 5.56 caliber carbines and yes that is designed to index as you wish so the 1:00 position does do some help. According to Adrian at MBX the compensator they make is most efficient in a straight up and down position and not designed to be indexed. If you are able to have your own load development keeping the bolt velocity to a minimum we'll also aid substantially in a predictable and minimized dot movement pattern. These have been my experiences so far. Hope it helps and I look forward to learning from what others are able to contribute.

If this is a concern I guess that's one benefit of having an enclosed housing trigger system such as a Timney since the factory pins are there to keep the unit in place and the hammer rotates on it's on hollowed pin.

Yes,good point. I didn't know if the additional force added by the Hipertouch system moving the hammer forward would also contribute to the enlarging hammer pin hole condition.

Thanks for the response. That is what I was concerned of when I heard the rear bolt geometry is different.

Hello. Are any Gen 3 MPX shooters running a Taccom recoil cushion? I am only familiar with the Gen 3 bolt and was told that the Gen 2, when the recoil cushion was designed, has a somewhat different profile on the contact point at the rear of the bolt. For those who might be using one have you noticed advantages or any disadvanages over the stock setup? Thanks.

That is good to hear,thanks for the response.

From what I understand the Hipertouch trigger design puts a significant amount more energy on to the hammer pin than a traditional design, especially with the heaviest toggle springs. Since Hiperfire advises against anti rotational pins,and stock pins do rotate,has anyone experienced elongated/ widened hammer pin holes in their receiver after extensive use with a Hipertouch?

Yes that is what I learned also however I have seen many competitors with the gold 681 that have been using it for thousands of rounds. Since the bolt comes back so fast and puts so much quick Force onto the hammer eith the MPX it is a challenge for a typical AR trigger to hold up. I do believe however with some of the mild loads ,especially 147 grains at about 135 PF, the bolt velocity is substantially less then with 115 and 124 so that may lend itself to longer hammer/sear life.

In my opinion compared to other comps the mbx seems to have a design that actually does something. If Popples were a good idea they probably do it. Not enough gas to make use of Popples.It was described to me that the way the baffles are designed it makes use of what little gas there is in conjunction with the bullet force when exiting.