2020 M4 vs 2023 M4 T-PRO

[Plinkingaway]

I thought it might be interesting to do a little comparison between my Dad’s 2020 M4, and my new (2023) one.
After taking them both apart I took some pictures of the most prominent differences I found, so here they are:
 

The piston plugs have a very different finish.                                                         The old ones have a polished steel look, and the new are a more opaque finish.
Perhaps they tried to reduce visibility as they’re slightly exposed by the t-pro hand guard.                                                       The pins are also a little different, the old ones being a polished steel look, and the new ones having an bronze like coating. 

 

I found that the finishing work to the piston housing was slightly more refined on the older model, but this could be because of the difference in colour. 
 

 

 

There are some differences in the barrel assembly.                                                You’ll notice that the pins are miss stamped in the newer model, I did see this on another fde t-pro, so it might be a prevailing change/mistake.  
Overall I would say the finishing work is close in terms of quality.                              I wish I had an even older model to add for more reference.

 

 

None of the firing pin pictures quite show the finish change, but it’s much like the pins in the piston plugs. 
The old on has a polished steel finish, and the new one is a sort of bronze finish. 
 

 

 

The bolt head retaining pin has a larger notch in the new one. 
 

 

 

 

The bolt heads have slightly different identification marks, but in terms of workmanship they seem pretty close. 
My new one has some nicks on the bolt face that the old one doesn’t suffer from however. 
 

New

Old

 

There was a slight discolouration in the finish on the metal parts of the new trigger grouping in places. 
(New trigger group on top.)

 

 

Everything else seemed to be pretty similar. 
The old pistons finish seemed like it had a more grey tinge, while the new ones had almost a green tinge.                               You might be able to see it in some of the previous photos, but I had a hard time getting a good photo of it otherwise. 
 

I’d be interested if anyone else has an old one they wouldn’t mind rating these against in terms of workmanship. 
Also, if anyone else has a t-pro I’d be interested to know if you’ve found that the internal parts of yours share the same finishing differences as mine. 
 

Cheers, and thanks for reading! 
 

[CEBEP]

Thanks for comparison. Are hand guards totally interchangeable? Can you out new one on the old M4 and polymer M4 on a new one T Pro?

Thanks

[Plinkingaway]

On 3/19/2024 at 7:23 PM, CEBEP said:

Thanks for comparison. Are hand guards totally interchangeable? Can you out new one on the old M4 and polymer M4 on a new one T Pro?

Thanks

I haven’t tried yet, but I believe that you can. 
I’ll borrow my Dad’s gun later and give it a try. 

[CEBEP]

18 hours ago, Plinkingaway said:

I haven’t tried yet, but I believe that you can. 
I’ll borrow my Dad’s gun later and give it a try. 

Apparently there is a difference. I have just received Toni System forend designed for M4 which I was planning to install on my M4 T Pro ro reduce it’s weight. But I noticed that I can’t install it as there is a part of the forend that interferes with this spring in the pictures. I noticed there is no such spring on M4 but it is on my M4 T Pro. If I remove it the forend installs flawlessly. My question is what this spring is for and is it ok to remove it, thinking if it would affect shotgun operation in any way? 

[m4prime]

11 hours ago, CEBEP said:

Apparently there is a difference. I have just received Toni System forend designed for M4 which I was planning to install on my M4 T Pro ro reduce it’s weight. But I noticed that I can’t install it as there is a part of the forend that interferes with this spring in the pictures. I noticed there is no such spring on M4 but it is on my M4 T Pro. If I remove it the forend installs flawlessly. My question is what this spring is for and is it ok to remove it, thinking if it would affect shotgun operation in any way? 

My OG M4 most definitely does not have that. I assume it interfaces with the new railed handguard in some way? I'd say remove it and install the new forend and shoot it. It definitely isn't an energy bearing part judging from it's construction. Looks more like a way to clamp / compression fit the new foreend.