Modern Sporter - Build Discussions
- Thread starter ATRS Shaun
- Start date
ATRS Shaun
Business Member Rep.
- Location
- Calgary, AB
The rear metal block holding the 'arms' on that trigger needs to be modified.
My upper and lower had quite wobble between with each other, the sound of upper and lower clashing with each other is quite loud as well (moving front and back). Checked with my mr223 and stag 10, they do have wobble feeling as well, but is very minimum. I put the strike industry enhance lower kit into the modern sporter, maybe the takedown pin is too small for the MS? Any help would be great, thanks!
- Location
- Saskatchewan
I would be interested to know more about this as well as I’m using the same parts kit.
Although my M&P15 has a slight wobble between the upper/lower and it doesn’t appear to hurt my accuracy. But this Sporter I’m hoping for further range with a better and longer barrel then the M&P
Shorerider
CGN Regular
- Location
- British Columbia
My slick side upper has some side to side movement. I used a BCM LPK and it was there. Swapped to a strike extended pin and it’s no worse. Someone else had mentioned putting a piece of hockey tape on the hook got rid of their play. I have a FA upper that I haven’t tried yet so no idea if it wobbles or not.
ATRS Shaun
Business Member Rep.
- Location
- Calgary, AB
With only utilising one pin, the dimension of that pin can be quite critical. If you have a set of calipers, try measuring the pin and ensuring it's 0.249-0.250". If you have further issues, please send us a detailed email to info@albertatacticalrifle.com
Thanks
View attachment 317655Measured from groove to cylinder, wish i made sense...
View attachment 317657Meaured from cylinder to cylinder.
View attachment 317658If i push the upper all the way to the front, as you can see the there is a quite gap between each other, pink light in the back.
- Location
- calgary alberta
Have you tried a different front pin? If so did it make any difference? Given the hole in the lower is drilled .249 with max of .250 your pin should not fit if it truly is .251.
As Shaun requested, email the shop directly please so we can try to work with you to resolve this.
Watching this thread close, my set has a lot of play in it(more than any AR I've owned) and have been playing with ideas of how to fix it.
I just measured my Strike Industries front pin at 0.247" with a mitutoyo micrometer. Randon pin I had in my parts bin was 0.249"
I also took a 0.250 pin gauge and it has play in the upper receiver hole. I don't have any pin gauges bigger than .250 so cant check that.
I just measured my Strike Industries front pin at 0.247" with a mitutoyo micrometer. Randon pin I had in my parts bin was 0.249"
I also took a 0.250 pin gauge and it has play in the upper receiver hole. I don't have any pin gauges bigger than .250 so cant check that.
- Location
- calgary alberta
Many of the issues we have encountered seem to come back to out of spec pins and parts. Most of which we believe to be off shore sourced parts hence the dirt cheap pricing on these parts.
Patt08
CGN Ultra frequent flyer
I was planning on using my BevBlock, but I’ve seen some posting that you need a reaction rod? Maybe ATRS can chime in.
Mumbles Marble Mouth
CGN Ultra frequent flyer
- Location
- Lower Mainland
I’m curious now just how loose the fit is. Is it S&W M&P Sport II loose or worse? Something that maybe interesting, I changed the barrel on my Sport II to a 20” M16 barrel and the receiver doesn’t feel loose like it did with the 16”. The only idea that came to mind is the extra weight of the barrel puts more pressure on the rear takedown pin.
- Location
- Saskatchewan
Due to the location of the front takedown pin being lower than a standard AR-15. A Bev block will not fit the upper receiver.
You’re best bet is a reaction rod or the cheaper barrel torque tool from TNA. Unless you have a vice block but remember that putting too much pressure on the upper itself can cause damage if you’re placing it in a vice. This is why the barrel torque tool is your safest option.
PinaKaleada
CGN Regular
- Location
- South of most
100% Torque tool, TNA is a good place to find it. It's 1 tool you wont regret buying, it'll last you a few life times of building!
I used a bev block. I removed the roll pin that holds the metal barrel extension torque tool in the plastic block and slid it up until it lined up then used a 1/4" pin in the upper pin hole and bev block hole. I then clamped the bev block in the vise and it doesn't move. It still acts like it was designed to other than the back of the bev block where you push your bolt carrier over the spigot with the oring on.
My second upper I used a wheeler delta series upper vice block that has the picatinney clamp in it. Bought it from TNA for 55 dollars. I really like how it holds the upper. I think it is a very good way to hold the upper instead of 2 pin or the barrel index pin. Reaction rods are amazing for muzzle devices as it introduces no stress into the upper.
Here is the wheeler upper clamp
ht tps://www.brownells.com/gunsmith-tools-supplies/rifle-tools/bench-vise-blocks/delta-series-ar-upper-picatinny-rail-vise-block-prod126528.aspx
It works for anything with a 1913 picatinney rail and leaves absolutely no marks or indications that the upper has ever been in a clamp. It also has pins for an ar10 and ar15 upper so you can take the upper off and hold it securely for cleaning or whatever you want to do
