Home Forums Hunting & Shooting Hunting Optics Question for newer Weaver Grand Slam owners

Have a question for any of you that have a higher powered, newer version of Weaver’s Grand Slam. I picked up a 5-20x50 Multistop in the fall and just got around to mounting it on a Tikka Varmint. Had it out yesterday and noticed some pretty wicked purple color fringing/chromatic aberration. I have a plethora of older Grand Slams, Classic V series, T-series, Super Slam and none suffer from this. I’d like to know if this is just an unfortunate characteristic of this scope or whether I have a bad one. Thanks.

Anybody out there?

I have a few of these Weavers. I haven't experienced anything like what you see.

I have a couple V9's and K6's and optics are fine for the price, certainly no purple colors....Hb

I have a newer style GS 4-16x44, no issues. I'm thinking you got a bad specimen.

I have a one in 4-16x and one in 5-20x and I haven't noticed anything like that.

I bought one 4 years ago and the windage adjustment worked backwards from what the dial indicated.I managed to get it set for my son to hunt with.
He hunted with it a couple of years and managed to make his shots with it. Then it was off and wouldn't adjust. Their repair shop Bushnell has it now. The view was.pretty good through it. I imagine they are thinking WTF is this. Backwards weaver sheit. I always wondered if it was a Chinese counterfeit.

Are you familiar with chromatic aberration/color fringing? The reason I ask is I had a friend look through my scope and he couldn’t see what I was talking about until I pointed it out to him. Lots of people have no clue what it is and/or are not sensitive to it. I also noticed some pretty severe fringing in a pic posted of a grand slam 5-20 in another forum...the post was about how clear the image was. Lol

The fringing can only be seen over 10X and when looking at contrasting images such as tree branches or a telephone pole against the sky...white target on a dark backboard...etc.

Problem is I’m reluctant to send it back as they told me it can’t be fixed and they’d give me a Bushnell Forge as a replacement. Doesn’t appeal to me. The fella I spoke to had no idea what chromatic aberration was. Not sure how they can tell me it’s defective without understanding the issue.

I can deal with the CA issue if it’s a normal characteristic of these scopes....I’m just trying to determine if that is, in fact, the case here.

I'll get my rifle out this afternoon and check it out. Maybe it's something I just haven't noticed.

Thanks man...I’d really appreciate it. Would certainly help with keeping my OCD in check. Lol

LOL. Glad to help.

Here’s an example of CA in a scope...not mine but you get the idea. You can see the purple fringing/bleeding from the white border on the sign. Most noticeable at high power (15-20X).

Second pic is from a grand slam 5-20 I found online. You can see the purple fringing around the white targets. This is similar to my findings. I suspect they’re all the same. Other than this issue, which is not uncommon even on high dollar scopes ($1500+), my scope is perfect...clarity, resolution, brightness.

Hey Seawood...I'm sorry, but I didn't get around to it this afternoon. I remembered and thought about it when I got to the house, but got sidetracked. I just came outside to sit a while and noted the failing light, which reminded me again.

I'll do my best to remember and check it out tomorrow afternoon.

No worries. Love to get your feedback if you have the chance. Thanks.

Seawood, I did manage a look this afternoon. What I did see was that the image is just a bit blurry right at the edges of the view. I couldn't see any of the fringing, but that may have been due to the lack of contrasting colors to be seen in back of my house this time of year. If I understand this phenomenon correctly, what I would need is some good color contrast. It seems to me that alternating bands of blue and red would make it show because they're near the opposite ends of the visible color spectrum.

I'll see if I can create such a thing on my PC and print it out, then I can place it 70 or 80 yards out and take a close look to see what I can (or can't) see.

Whether I can detect chromatic aberration or not, I really like my scope, at least for low recoil cartridges. Eye relief seems to be on the short side, but my 5-20x is on a .222, so it's not going to be a problem. I have a Grand Slam in 4-16x on my Winchester 52 and I like it just as much.

So it's bad enough to complain about, but you'd rather keep it than accept a free replacement. Makes total sense.

Here's what I created for chromatic aberration evaluation:



Unfortunately, I have an HP printer that's giving me fits and I cannot print a usable reproduction. That HP printer is about to receive the 12-gauge treatment.

Seawood, I managed to get a halfassed printout...three adjacent bars of blue-red-blue, just not near as brilliant as the pic I posted above. I looked at it through the scope, and I have to say that while the image is quite good, there is a "little bit" of aberration between the blue and red.at 20x. I did not turn the magnification down from 20. I also looked at it with my Nightforce 4-14 SHV, at 14x of course. It actually looked about the same to me. If I had a S&B or a Swarovski available to look through the differences might be stark but as it is, none of this bothers me much at all...to me the scope is an aiming device, not an observation device, The NF and Weaver (and others) serve me satisfactorily for aiming.

I might think differently about spotting scopes and binoculars though.

I have much more definite feelings about printers, just now.

Weaver GS - $1400 retail. MADE IN JAPAN
Bushnell Forge - $1200 retail. MADE IN CHINA

Would you trade a BMW for a Kia?

Thanks for the info, RR. I find the best test is a white target or piece of paper on a black or dark backboard. Not sure if it would be as noticeable on. the striped printout?

The idea was to use the colors that are at either end of the visible spectrum, thinking they'd bleed into each other and reveal it. That was my own idea, and maybe not such a good one. I'll try black and white tomorrow and see what I can see.