Tell me about 20moa bases,,,, with recoil lugs.
- Thread starter EotS
- Start date
Respectfully, I disagree.
The majority of base/base screw failures I have seen over the years were on light/medium recoiling rifles (700LTR and similar) that were mounting heavier scopes while using bases w/o recoil lug.
The light gun produces a quick/fast recoil that is trying to run out from under the scope pkg every shot. This is exaggerated with the light gun/heavy scope combos even in 308/30-06 class cartridge chamberings. In the last few years the Bergara rifles showing up in classes were repeat offenders.
Same reason we have seen so many MIRS rails start to fail at the mounting screws when the users actually practiced and trained with their clip-on I2 NV in place.
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I have a HMR in .300WM with a Leupold Mark5HD 5x25 mounted with an MPA BAM on a Leupold Mark4 20MOA rail with 6x48 screws. Was at the range shooting at a 500M steel target and I could not hit the target. Shoot over, then under then 3m left and 3m down.
Started checking my rifle and found that all four of the torqued and blue Loctite screws came loose. In a big way. The front screw was the worst, and the rear screw was the “best” in that it was not nearly as loose as the others. Was round 267 on the rifle when it got bad enough that this happened. I had a gunsmith drill out the rail receiver screws to the larger 8-40 and remounted everything. Only have fired 20 rounds since with no issues. Have never had a rail fail like that.
Started checking my rifle and found that all four of the torqued and blue Loctite screws came loose. In a big way. The front screw was the worst, and the rear screw was the “best” in that it was not nearly as loose as the others. Was round 267 on the rifle when it got bad enough that this happened. I had a gunsmith drill out the rail receiver screws to the larger 8-40 and remounted everything. Only have fired 20 rounds since with no issues. Have never had a rail fail like that.
Think a lugged base would have prevented that?
Or, should I plan on having larger base holes drilled/tapped?
Both?
The larger screws and lug will help, but is not need in most applications, like hunting. The lug does help if you plain to shoot allot and the larger screws help if you plain on having a lot of weight attached to the base.
The biggest mistakes people make is not cleaning the oil or old Loctite out of the screw threads in the receiver and/or torque them correctly, so they back out. I have this happen to me on factory rifles and when I rushed to get every thing mounted. I have also seen that the screws are a tad long and bottom out on the barrel threads. You should always measure the screw length and make sure they will not bottom out before they are tight.
my self, I do run several 20 MOA lug base's made by MDT, but with the 6-48 screws with blue Loctite with out issues. As long as I do it right, I don't have issues. I also run there rings as well, for the price, you can not beat them for the quality.
The biggest mistakes people make is not cleaning the oil or old Loctite out of the screw threads in the receiver and/or torque them correctly, so they back out. I have this happen to me on factory rifles and when I rushed to get every thing mounted. I have also seen that the screws are a tad long and bottom out on the barrel threads. You should always measure the screw length and make sure they will not bottom out before they are tight.
my self, I do run several 20 MOA lug base's made by MDT, but with the 6-48 screws with blue Loctite with out issues. As long as I do it right, I don't have issues. I also run there rings as well, for the price, you can not beat them for the quality.
Also not a bad idea to epoxy bed a rail to a receiver, In the case of a rail that is not from the manufacturer. I have had more than one with a rail moumted, then pull the rail and see very little contact. They seem to stay in place after epoxy bedding them. Make sure to have release on anything you don't want permanant.
I do think a lugged base would have helped. I went looking for one and had a hard time finding one I wanted in stock so I ended up keeping the base I had, plus it accepted both screw sizes already. I will be buying lugged bases from here on out. From what I have read on SH Seekins is a very good option so I will try one of them in a 20moa next time I buy one. I need one for my .300 Weatherby MarkV.
FYI: It cost me $200 to have the receiver drilled out for the 8x40 screw size. Lugged base is cheaper.
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