Bolt Catch issue with Pmags + Mag Catch differences says S&W

*I would love to somehow ask this to someone in the M&P technical department if any industry people from S&W are on the forum, over the phone, it's hard to speak to the VERY technical support people*

I'll try to make this as short as possible, but please read it all, as all advice will help me greatly!!!

Question 1- Bolt Catch issues

I have an "Original Gen 1 SPORT" and also a "Standard M&P15 lower" that I built into another rifle.

Well, just added "Strike Industries- Extended Bolt Catches" on both so was my first time really checking out the "Bolt Catch and Follower" relationship. (I also put the original Bolt Catches back on and it's still an issue, just for the record).

My "Standard M&P15" has a lot of wiggle in the bolt catch between the ears, as if the cut iut in the receiver may be too wide, although I would assume the Roll Pin would keep it stationary (it doesn't oddly, and both rifle's Bolt Catch "Tooth" tend to only engage the edge of the follower if I insert Pmags!

After pulling apart the upper and lower so I could see what is happening, I see that some Pmags just Bypass the Catch all together, making the bolt catch on the ridge of the follower instead, can baaarely catch as the tooth sometimes covers only a little of the follower, or sits binded against the rear edge of the follower and will the follower down when you hit the release button, which if assembled, feels as if its working. (Unless the bolt carrier is pressing against the Catch when it's fully installed to push the tooth further forward).

Makes me wonder if it would even cleanly stripped a round at full force and chamber it without an carrier binding if it doesn't lower the follower low enough, even though the bolt can slam home when the mag isn't loaded.

I have a LOT of Pmags, so this concerns me greatly!

If it does catch it, if I rock the mag forward in the magwell by pulling back on the mag, the Catche tooth slides off of the rear of 9 times out 10.

I've tried this on about 30 Pmags of all gens, 20s, 30s, and 40s.

I've heard of Issues with Pmags and ARs due to Pmags having more material on the rear of the mag opposed to a USGI mag, creating more distance between the follower and the Bolt Catch tooth, and wondering if it is just that and a Pmag issue, or tolerance stacking also being my Catch has so much wiggle room on the Standard M&P. It also would NOT catch a D&H aluminum mag with Magpul follower being the mag was much looser than a Pmag in the magwell.

Again, with the USGI bolt Catches back on, iy does the same.

Question #2- "Mag Catch"

So I started thinking hard! Being every single M3 and M2 fit differently in the magwell and yield different results and fitment (all pmags are 2013 production btw) even if they were produced in the same month, they yield different results (could be if the follower is slid forward or rearward being only a tad of play and the bolt will not catch it).

I was thinking if the Mag Catch gripped the mags tighter, or differently, if that may help. (I adjusted it as tight as to where the nipple sticks out of the "Mag Catch", but figured any further was going too far.

So I called S&W, leading to my final question/ bit of confusion after what I was told.

Question 3 (Final)- Gen 1 vs Gen 2 SPORT Mag Catch

I CALLED "Smith & Wesson" yesterday, and was told that the "Sport" Mag Catch and the "Standard Mag Catch for M&P15 rifles" are 2 different part numbers.

Right now, My "Original/Gen 1" Mag Catch is in my standard M&P15 lower, and a DPMS LPK's Mag Catch in the Sport. Which, makes me wonder if that is causing some abnormal lockup, even though they fire/feed fine

They are sending me 2 mag catches, a "Sport 2" and "Vtac" mag catch to try out, and I feel this MAY help, BUT, I'm worried that the SPORT Gen 2 Mag Catch may not be the same as the Gen 1 Mag Catch being the Gen 1 Sport's receiver was made "In-House".

Not sure if the Gen 2 is much different, but if so as far as the lower.

It makes me wants to put the Original Mag Catch back into the Sport, but, I remember the DPMS one making a clanking noise so I cannot for the life of me remember if I may have switched it in the past, or if the Sport's original Mag Catch is still in my Standard M&P, which is likely but it's not like they are marked, unless the finish is different or any other tell tale sign of which is which.

Anyone know why the Mag catches would be different part #'s between a Sport and regular M&P??? If so, wonder what is different about the specs.

Hopefully someone from S&W can chime in!

Would be great if this remedied my issue, but I've read dozens upon dozens of people with Bolt Catch+Pmag issues. Have no clue why a company will not just make a catch (maybe a normal one and an enhanced style) with a tooth that is a hair longer and market it as "Pmag Compatible" and make Bank!

Magpul should be the ones making one being their mags have the most issues with Mil-Spec Bolt Catches.

I pulled out my Sport so I could "follow along" with your post.

Qustion 1 - Bolt catch issues.
When I insert a mag, the tooth on my bolt catch covers about 1/16" of the rear of the follower. Appears roughly the same with PMAG or GI mag.

There should be a little play with the bolt catch... but not sloppy loose. When you separate the upper from the lower and are rocking the magazine and such, are you putting some force on the back of the stop to simulate the pressure from the bolt?

I am not able to duplicate your issue of rocking the magazine and causing the catch to lose engagement with the follower, with or without pressure.

You state that "Makes me wonder if it would even cleanly stripped a round at full force and chamber it without an carrier binding if it doesn't lower the follower low enough, even though the bolt can slam home when the mag isn't loaded."... A trip to the range would provide you with this knowledge. Have you shot this rifle yet?

Are both rifles doing this, or just the one? Does it do this with every PMAG, or just a few?

Mag Catch - Question 2&3
Your magazine catch should be adjusted so that the magazines lock into place and can fall freely when the magazine release is pressed.

I have several PMAGS and have not experienced your situation of inconsistency in fit.

As far as the magazine release for the Sport 1 having a different part number than a magazine release for a different M&P 15, that suprises me too... However, remember that the Sport 1 was built as a budget rifle and things were changed to save costs. If there are truly differences between the two, I would guess that it would be in materials, or how they are hardened... or possibly the ones for the Sport don't have the same QC requirements.

Not sure if you noticed, but the "mil-spec" trigger in your Sport 1 is also not the same as in other rifles. The hammer is MIM, not forged.

cyphertext said:

I pulled out my Sport so I could "follow along" with your post.

Qustion 1 - Bolt catch issues.
When I insert a mag, the tooth on my bolt catch covers about 1/16" of the rear of the follower. Appears roughly the same with PMAG or GI mag.

There should be a little play with the bolt catch... but not sloppy loose. When you separate the upper from the lower and are rocking the magazine and such, are you putting some force on the back of the stop to simulate the pressure from the bolt?

I am not able to duplicate your issue of rocking the magazine and causing the catch to lose engagement with the follower, with or without pressure.

You state that "Makes me wonder if it would even cleanly stripped a round at full force and chamber it without an carrier binding if it doesn't lower the follower low enough, even though the bolt can slam home when the mag isn't loaded."... A trip to the range would provide you with this knowledge. Have you shot this rifle yet?

Are both rifles doing this, or just the one? Does it do this with every PMAG, or just a few?

Mag Catch - Question 2&3
Your magazine catch should be adjusted so that the magazines lock into place and can fall freely when the magazine release is pressed.

I have several PMAGS and have not experienced your situation of inconsistency in fit.

As far as the magazine release for the Sport 1 having a different part number than a magazine release for a different M&P 15, that suprises me too... However, remember that the Sport 1 was built as a budget rifle and things were changed to save costs. If there are truly differences between the two, I would guess that it would be in materials, or how they are hardened... or possibly the ones for the Sport don't have the same QC requirements.

Not sure if you noticed, but the "mil-spec" trigger in your Sport 1 is also not the same as in other rifles. The hammer is MIM, not forged.

Click to expand...

Hi,

When the upper is installed, only a few Pmags do it by bypassing the Catch altogether, but when it is just the lower, I can see what is going on.

The Bolt actually presses the Bolt Catch tooth forward to help it sit over the follower more, but on an off chance that after the final round in a mag is fired, if the follower doesn't engage the catch (making it not sit on the follower), if I release the bolt, even by using the charging handle, it makes me wonder if the top round would actually chamber, or if a round is only capable of being chambered if it is lowered by the Bolt Catch lowering it a tad before the bolt flys forward?

I say so being I can engage the lock position manually on the catch even if it isn't contacting the follower so that it stops the bolt. But wondering if the round would actually chamber properly being yhe round in the mag isn't lowered by the follower.

When fully assembled, it seemed to fully bypass it on maybe 5 out of 20 Pmags, yet when just testing with the lower, a few would bypass the Catch, and the others would either barely catch onto the follower, or if the follower is slid a tad forward or if I rock the mag to self induce it, the bolt catch will sit right behind the rear edge of the follower, and the pressure can still drag the follower down.

, I guess all in all, if one mag bypasses the catch altogether and the bolt catches on the hump of the follower and the bolt catch doesn't work, but if I pull the charging handle back and then lock the Bolt Catch upward, even if it is not contacting the follower, but is indeed holding the bolt in place, if the round will chamber once the bolt is released, yet the follower does not get depressed?

Btw, can't get to the range to try this anytime soon.

As far as the mag catches, I wonder if the sport is an MIM part and that may be the difference, opposed to size of function.

Also, the replacement catch is for a "Sport 2", but my Sport is a Gen 1, which the receivers were made "In-House", so hoping the specs are not different.