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Sightmark OPMOD™ G.U.M.B. 1.0 Limited Edition Green Universal Boresight OP39025 w/ Free S&H
$74.99 $95.99 Save 22%
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(10 reviews)
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Most Helpful Positive Review Good idea
For what it was designed for, it is what it says. "It helps get you sighted in". It doesn't make an AR a tack driver at 1K. But at 50 yards it got ...
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Gets you close

by Hman, from United States, OK Written on December 5, 2014
This laser magnetically attaches to the end of the weapon's barrel. Very easy to see when changing the weapons windage and elevation. Only thing left to do then is fine tune on a range with live ammo....
Would recommend: Yes
0 of 0 found the following review helpful.
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Great Product

by Rick, from United States, WA Written on December 4, 2014
This is a great aide as a quick bore sight. I own and shoot many different types of handguns. I use it as a quick sight test when going from one pistol to the next. Green dot shows up easily at 40yds. Have not tested it beyond the 40yds. Well worth the money and a nice tool to have....
Pros:
  • Very easy to setup and use
  • Very strong magnet
Cons:
  • None
Best Used for:
  • Quick bore sighting
Would recommend: Yes
0 of 0 found the following review helpful.
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easy to use

by bobbybeegood, from United States, FL Written on December 4, 2014
Easy to use. Snaps easily on the end of the barrel via magnet. The laser could be a bit brighter. Difficult to see in the bright sunlight. It gets you on the paper but you have to walk in the zero. I spun the Boresight in a circle on the end of the barrel & the dot never moved from the same spot. For what it is; it does very well....
Pros:
  • Easy to use. Attach to muzzle and go!
  • Keeps zero.
Cons:
  • None
Best Used for:
  • Boresighting
Would recommend: Yes
0 of 0 found the following review helpful.
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Breakthrough in Bore-sight Technology

by Doc Sparks, from United States, OH Written on November 18, 2014
I own and have experimented with, a lot of gadgets to help align sights and point of impact for long rifles, carbines and handguns. The Sightmark G.U.M.B is truly in a league by itself. It works on the simple premise that the muzzle of your gun is exactly perpendicular to the bore of the rifle ... a pretty good assumption for new or well treated guns. Prior to this my go-to bore sight was one that was fitted into the barrel at the breech. They used a ruby laser to shine down through the barrel and an project an alignment mark on a target. You then dialed-in iron sights, red-dots or scopes. Works well, but each caliber requires a separate laser bore sight and the ruby laser doesn't project all that far. The Sightmark G.U.M.B. changes the game. It simply attaches to the muzzle with a very strong magnet and projects a green laser beam visible up to 50 yards! I had just acquired a new scope for my Henry Golden Boy and used the Sightmark bore sight to zero the scope. Ata range of 50 yards the first shot was well low of the crosshairs (.22LRs drop about 4" at that distance) but the windage was within 1/2" of the bullseyeI I could hardly believe it. Two more shots and I was sighted in!! This thing will pay for itself in ammo cost especially on hunting rifles. I tried it on my 30-30 Winchester. At 100 yards the first shot was 1.5" left of the crosshairs and 4" low. Again the scope was aligned in three shots. I am very very happy with this product. Well worth the money. However, i...
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Would recommend: Yes
2 of 2 found the following review helpful.
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Why wouldn't you save ammo by using this?

by Jesse Tischauser, from United States, OK Written on October 2, 2014
This is the first laser bore sighter I have ever used. I love it! I build 10-15 new AR15 type rifles a year. Why I didn't have one of these in the past to site these new guns in I don't know.

The only complaint is the battery compartment is a little flimsy....
Would recommend: Yes
1 of 2 found the following review helpful.
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Good but...

by Kish, from United States, IN Written on August 30, 2014
The battery compartment is awkward. Battery is held in by a spring. Only motivation, I am guessing here, is to keep the battery out of the device when on in use. They have succeeded.
This is not a deal killer at all just odd, otherwise it is a well made substantial product....
Would recommend: Yes
0 of 0 found the following review helpful.
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Best on market and universal!

by Legacy Reviewer, from United States, WA Written on June 5, 2014
This is simply put, the best universal boresighter on the market, at the best price. A boresighter is simply to get you on the paper so you can get a final zero with your ammo. Boresighting saves time, money, and your shoulder. This used a large magnet that clips to your muzzle. I have used in on everything from .177 airguns to 12 gauge and a .54 caliber muzzleloader. It excels for different sighting planes like the AR platform, and it will work great with handguns, as well. It is absolutely as advertised and is very visible in daylight. Great design, the best price on the market, lifetime warranty, and another exclusive OPMOD product you can't live without.
Pros: Daytime green power for visibility!...
Would recommend: Yes
4 of 4 found the following review helpful.
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Opmod Limited Edition Green Laser Boresight.

by Legacy Reviewer, Verified Owner from United States, CT Written on April 21, 2014
accurate, bright, simple to use, works on virtually any firearm
Pros: bright laser, attaches strongly, can use with rifles or pistols
Cons: possible to bs slightly innaccurate because of manual attachment by magnet and no rod or pin to center the device in the firearm's bore...
Would recommend: Yes
4 of 4 found the following review helpful.
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Opmod Limited Edition Green Laser Boresight.

by Legacy Reviewer, from United States, WA Written on January 23, 2014
I have other bore sights but none work as easy as this on so many different guns. I was very sceptical at first but soon realized I could trust this product. It is so fast and accurate enough to put you on any target at all ranges that dialling the bullseye in after using it was simple. Last season I sighted approximately 30 rifles with this product and was very, very pleased.
Pros: Quick, simple to use, works everywhere.
Cons: The On/Off switch will turn on accidentally if your not very careful....
Would recommend: Yes
14 of 14 found the following review helpful.
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Good idea

by Legacy Reviewer, Verified Owner from United States, TN Written on November 21, 2013
For what it was designed for, it is what it says. "It helps get you sighted in". It doesn't make an AR a tack driver at 1K. But at 50 yards it got me 2" off the "X" ring. Sighted it there then moved back to 100 yards. It was close enough from 50 yards that 100 didn't need it to get on paper. It was already very close. It just needed a little to fine tune it. All in all a good idea if you have troubles getting on paper. Be sure your crown is cleaned and doesn't have carbon buildup on the face of the muzzle. If your rifle has a flash hider you may have to remove it. But try it first with it on first. Just remember to remove it before pulling the trigger. Good luck.
Pros: simple to use, gets you on paper the first shot
Cons: not exact, but it isn't advertised as such....
Would recommend: Yes
14 of 14 found the following review helpful.
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Comments on 10 User Reviews of Sightmark OPMOD™ G.U.M.B. 1.0 Limited Edition Green Universal Boresight OP39025 w/ Free S&H