Primary Arms prism scope

[Caveman Jim]

I was lucky enough to snag one of these last week while it was on sale for $99 with free shipping.
Primary Arms SLx 2.5 Compact 2.5x32 Prism Scope - ACSS CQB-M1 Reticle
While unboxing I noticed that there were more than a few handling marks than normal but seeing as it was $150 off so I figured it was a blem sale.
I went to sight it in this morning, got it on paper started to dial it in then the groups started widening. The two screws on the bottom that hold the mount to the scope loosened up, I can't believe that those were not torqued from the factory.
I put some thread locker on and torque them both to spec.

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[Snip]

I had a 5X prism scope from PA, but the Holosun 510 and 3x magnafier looked better and clearer at 100 yards than the 5x. Sold the 5X.

 

[Aero Denezol]

I've been eyeing one of those to mount on a carry handle. You got a really good deal. Congrats.

The PA prism and red dots are pretty good. My only complaint against PA is the small hardware/fasteners on the mounts are of very poor quality and strip easily.

*Not the screw that goes on the pic rail, but the smaller screws.

 

[Caveman Jim]

Thanks Aero D. Will have see how they hold up with the Locktite.

 

[Koda]

I picked one up from the sale but haven't installed it yet.
I did notice the small screws under the mount. I'll have to check they are torqued right.

Otherwise the scope is fine, no bless.

 

[Caveman Jim]

I would remove and install with Loctite, just to be sure they aren't going to loosen up.
Hell for all I know mine was probably made on a Monday or a Friday, do you remember back in the day when the Detroit cars rolled off the assembly line a little off?

 

[Koda]

I would remove and install with Loctite, just to be sure they aren't going to loosen up.

After reading g this thread that was my thought.
Primary Arms optics get good reviews, but they are still a budget brand and this model I think was their line made in China.

 

[Caveman Jim]

Yep that's one of the first things I noticed when I unboxed it, made in China and my heart sunk.I would really be upset if I would've paid full price for a China item.

 

[Koda]

Yep that's one of the first things I noticed when I unboxed it, made in China and my heart sunk.I would really be upset if I would've paid full price for a China item.

It's perfect for my spare parts "frankenrifle" build though. As long as it works and is reliable and PA optics have a solid reputation.

Not all their optics are made in China, I just can't find out which ones in their lineup are made elsewhere... I hear their top end models are made in Japan.

 

[Koda]

So definetely loctite the base screws to the scope -before- even using it.

I finally got around to sighting in... I even remembered this thread and checked the screws, they were tight. So I didnt think to loctite them anyways.

Zeroed the scope. It shot well. got home, and its slightly loose.
frustrating. Wasted day.

so what does everyone recommend for this, blue or red loctite? I dont plan on ever not using the base that came with it so maybe red loctite?

 

[Camelfilter]

So definetely loctite the base screws to the scope -before- even using it.

I finally got around to sighting in... I even remembered this thread and checked the screws, they were tight. So I didnt think to loctite them anyways.

Zeroed the scope. It shot well. got home, and its slightly loose.
frustrating. Wasted day.

so what does everyone recommend for this, blue or red loctite? I dont plan on ever not using the base that came with it so maybe red loctite?

I use blue, don't recall using red on anything. Don't think I even have any red.

Have little bottles of harbor freight blue in ziploc bags several places (kitchen junk draw, shop, truck box, range bag etc). However I'm not a mechanic, machinist or gunsmith.

I don't have this scope, just mentioning what I use.

 

[Aero Denezol]

Zeroed the scope. It shot well. got home, and its slightly loose.
frustrating. Wasted day.

so what does everyone recommend for this, blue or red loctite? I dont plan on ever not using the base that came with it so maybe red loctite?

It should not be coming loose, that is definitely unusual. It should not require loctite on the base if it is torqued to spec.

The little screws that switch between different spacers/risers are the consistency of play-dough - torque those at your own risk. But the big cross-bolts *should* hold zero.

If you send it back to Primary Arms, their warranty dept. is pretty good.

 

[Koda]

It should not be coming loose, that is definitely unusual. It should not require loctite on the base if it is torqued to spec.

The little screws that switch between different spacers/risers are the consistency of play-dough - torque those at your own risk. But the big cross-bolts *should* hold zero.

If you send it back to Primary Arms, their warranty dept. is pretty good.

The little screws are the ones that came loose.
The instruction manual says to torque to 30in lbs.... which I didnt. I only checked they were tight.

 

[Caveman Jim]

It should not be coming loose, that is definitely unusual. It should not require loctite on the base if it is torqued to spec.

The little screws that switch between different spacers/risers are the consistency of play-dough - torque those at your own risk. But the big cross-bolts *should* hold zero.

If you send it back to Primary Arms, their warranty dept. is pretty good.

I sent mine back and they said that they torqued the two small screws and replaced one of the base cross bolts that I inadvertently snapped.

They definitely have excellent CS.

 

[Aero Denezol]

The little screws are the ones that came loose.
The instruction manual says to torque to 30in lbs.... which I didnt. I only checked they were tight.

Ah I see now. Yeah those little screws are the weak point of the PA product. If you use Loctite use blue only.

I do like PA. I think there is stuff is thoughtfully designed with shooters in mind. Unless you're headed to the Ukraine, PA stuff is good enough for sport/competition and home defense.

 

[Koda]

Those two little screws are the weak point of the product and disappointing but if blue loctite solves the issue then it will be a great scope. I still need to buy the proper driver bit to torque them, not certain what size, i think its metric....

Whats surprising is how well the scope held zero. I shot about 20ish rds thru it and never once suspected the scope was loose. My final target of the day was a .4" group on bullseye at 50yds.

 

[Caveman Jim]

Those two little screws are the weak point of the product and disappointing but if blue loctite solves the issue then it will be a great scope. I still need to buy the proper driver bit to torque them, not certain what size, i think its metric....

Whats surprising is how well the scope held zero. I shot about 20ish rds thru it and never once suspected the scope was loose. My final target of the day was a .4" group on bullseye at 50yds.

Your experience is a total opposite of mine, as the rounds multiplied mine got noticeably worse. That's how I noticed something was wrong with the scope itself.
The first pic is of my first target that got sighted rather well then walked the second out to 50 yards. The second one is my last.

 

[Koda]

Your experience is a total opposite of mine, as the rounds multiplied mine got noticeably worse.

Its odd for sure, but i have 2 theories what happened in my case...
1, the scope sits in its base with a V groove, so it would find "home" after every shot. The problem with this theory is I should have noticed it loose as I adjusted the turrets. But it probably didnt actually come loose until maybe after those....
I do recall now after my final zero (see pic) i fired 8 rds of some factory ammo to see if it held the same 50yd zero (it did). I bet it " finally" came loose then...

2, it held just enough to get thru the days shooting, but came fully loose from the vibration of driving out on the bumpy gravel forest road.

Heres my final target and shots for the day. I made my last adjustment at 50yds, hit 4rds bullseye, moved out to 100yds and held a group 1.6" high with the 50yd zero.

 

[Member 34319]

Had a couple of the older ones over the years. Mostly back when they were the current model. The new lightweight small ones are a completely different optic compared to these.

I never had an issue with the 3-4 I had on various AR15s. Mostly 556, I think maybe briefly on a PCC.

@Caveman Jim Have you ever strapped a high magnification optic to this gun and tested its groupings that way?

 

[Caveman Jim]

Had a couple of the older ones over the years. Mostly back when they were the current model. The new lightweight small ones are a completely different optic compared to these.

I never had an issue with the 3-4 I had on various AR15s. Mostly 556, I think maybe briefly on a PCC.

@Caveman Jim Have you ever strapped a high magnification optic to this gun and tested its groupings that way?

Thanks for the mention @Reno. I have only had a Vortex red dot on this rifle which is a 16 inch barrel with a 1/8 twist. It's always grouped -1.5" out to 100 yards.
The reason I switched from a red dot is because I have astigmatism in both eyes and I'm seeing way too many dots to concentrate on one.