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Problem w/ Burris Bases and dovetail rings

Posted: Wed Feb 21, 2007 7:12 pm
by dannybracy
Hey guys... i am getting kinda impatient b/c i haven't even gotten to fire my new LRPR yet!! Been waiting on the rings and bases for about the last week, finally got them today, but the dovetail wont spin in the front base. The base is a burris trumount universal base and the rings are Burris Sig. Univ. Dovetails. It gets stuck as if the milling on the base wasn't deep enough to let the dovetail spin in it. Has anyone else had this problem???? I am SO anxious to get a few rounds in w/ this gun as it has been SUPER warm the last 2 days. I tried filing the base a lil bit and it allowed it to spin a lil further but it still has a ways it needs to turn. I will try to call Burris tomorrow, as I only assume that it is usually a tight fit when the dovetail spins in the front base.....ANY IDEAS GUYS??? Thanks ahead of time. -Dan

Posted: Wed Feb 21, 2007 7:34 pm
by skipper
I don't have any experience with the Burris bases and rings but if they are like the Leupold they are supposed to be tight. I used a wrench across the flat portion to turn mine into place. Then Rick told me about a wrench that Leupold has that you use to do the job. Too late. The wrench worked anyway. You want it to be tight. Don't file on it any more.

Done Deal

Posted: Wed Feb 21, 2007 8:09 pm
by dannybracy
Thanks for your help. It worked great! Got it mounted now all i need is daylight! I didn't file very much at all as i am very ANAL and didn't want to mess it up very much! Thanks again, much appreciated

Posted: Mon Apr 16, 2007 7:27 pm
by Varmonter
for waht it's worth.
i put a one inch dowl in mine and put it in a vise to turn it.
worked well.

Posted: Mon Apr 16, 2007 8:08 pm
by Silverfox
A small amount of grease on that dovetail makes it a bit easier to turn the dovetail into place and might prevent galling of the metal.

The suggestion to use a 1" dowel is and excellent idea.

Too late now for your application, but I have given up on the dovetail mounts. I will use nothing but the Burris Signature Zee rings and Warne Maxima 2-piece steel bases. I DO NOT TRUST those dovetail mounts.

Thanks

Posted: Mon Apr 16, 2007 10:57 pm
by dannybracy
Hey Silverfox, Thanks for the advise. I will probably pick up some to replace as I will be going to SD for my first PD hunt in mid June. Loaded up 850 rounds about a month ago and i sure don't want any problems once i get out there. Do the Burris Zee Rings have the plastic inserts? Thanks again -Dan

Posted: Tue Apr 17, 2007 10:19 am
by Silverfox
dannybracy--The Burris Signature Zee rings DO HAVE the plastic inserts. The Burris Zee rings DO NOT HAVE the plastic inserts. You have to make sure the ring set says Signature on them to insure that they have the plastic inserts.

The plastic inserts are fantastic for saving the "hide" on your scope and saving labor in that you don't have to hone the inside of the rings for burrs, etc. Another thing I really like about the Signature rings is the fact that you can buy additional offset inserts with +/- 5º, +/- 10º, and/or +/- 20º of correction in a kit or separately. That way you can shoot three or five shots after you have rough bore sighted your scope and then use the various offset inserts to walk the crosshairs of your scope to the center of the group you just shot. It sounds complicated, but is quite simple. That way, if your windage and elevation settings are at the center of the total adjustment possible, you can just use the offset inserts to maintain those settings.

I have had scopes that required a full 20º rise under the back of the scope to get the crosshairs where they belonged.

Posted: Tue Apr 17, 2007 3:22 pm
by rayfromtx
I believe the +20 that you are referring to is in thousands not degrees or more accurately in minutes. The distance between your rings will determine what moa is possible with .020" of offset. On my rifle, +20 in the rear and -20 in the front will net me around 15 moa if I remember correctly.

Posted: Wed Apr 18, 2007 9:32 am
by WT
[quote="Silverfox"]

Another thing I really like about the Signature rings is the fact that you can buy additional offset inserts with +/- 5º, +/- 10º, and/or +/- 20º of correction in a kit or separately. That way you can shoot three or five shots after you have rough bore sighted your scope and then use the various offset inserts to walk the crosshairs of your scope to the center of the group you just shot. It sounds complicated, but is quite simple. That way, if your windage and elevation settings are at the center of the total adjustment possible, you can just use the offset inserts to maintain those settings.

Silverfox,

This is great information! I was wondering just the other day about this. After mounting a new scope and sighting it in at 25 yards, I was concerned about how many clicks in elevation and windage it would take to get the crosshairs on track. I was able to correct the windage using the windage adjustment screws on the base and fine-tuning with the scope windage adjustments. The elevation was about 2" low at 25 yards which took a lot of adjustment to bring it up. If I understand this correctly, I would use a negative value insert in the front ring (or a positive value in the rear ring) to lower the front of the scope to correct this problem. Two minutes of angle at 25 yards would be 8 inches at 100 yards, so would I need to use a 10 minute of angle insert to zero the scope at 100 yards and keep the elevation adjustment at close to the center of the adjustment range?

Posted: Fri Apr 20, 2007 9:35 pm
by Silverfox
rayfromtx--You are 100% correct on the +/- numbers in that they are not degrees but thousandths. My BAD!!! :oops: :oops:

WT--Fortunately, when you get the offset inserts, Burris is kind enough to include a set of instructions that tells you where to put the negative and positive inserts. In my case, my rifle was shooting high and just a tad to the right at 100 yards, so I placed the positive insert in the bottom of the front ring. Because I needed to move the front end of the scope up and slightly to the right, I turned the insert slightly clockwise in the bottom ring so the left edge was up at about 10:00 a.m. and the right edge was at about 4:00 p.m. as I was looking at that front ring from the butt end of the rifle. I hope that makes sense.

Since your rifle was shooting 2" low at 25 yards, you would proceed as you suggested by placing the negative 10 value insert in the bottom of the front ring and the positive 10 value insert in the top of that front ring. You can also accomplish the same thing by placing the positive 10 value insert in the bottom of the rear ring and the negative 10 value insert in the top of the rear ring. That will give you 10" of change at 100 yards.

ALWAYS use inserts in sets--that is one positive and one negative of exactly the same value in the same ring. NEVER use two positives or two negative inserts in the same ring.

Oh most honorable Silverfox

Posted: Sat Apr 21, 2007 9:59 am
by rayfromtx
I really hate to disagree twice. It just ain't nice but I gotta do it.

WT- The inserts are in thousands as was previously stated. How much the offset will adjust your POI downrange will depend on the distance between your rings. The closer your rings are together, the greater the offsets will affect your POI. I got around 15" at 100 yards by using a -20 in the bottom of the front ring and a +20 in the bottom of the rear ring. It is often repeated that you will get 40" by doing that but it just isn't so. My rings are 5.460" from center to center.

On the second point, Silverfox is right about using a negative half on top of a positive half and vice versa. I did however use a +10 on top of a -20 and a -10 on top of a +20 and I have had good results. It is cheating a little but it avoided purchasing another set of inserts since they only come with one pair of +/-20s. I will do the same thing again next time but I wouldn't try to cheat any more than that and I would not use plus with plus or minus with minus. This will all make a lot more sense when you have the kit in your hands.

They seem to be a great product and I will continue to purchase them for my rifles.

Posted: Sat Apr 21, 2007 10:48 am
by Silverfox
rayfromtx--You can disagree all you want, that's part of the beauty of these forums and if I am giving totally erroenous information, I certainly want to know. My reply to WT was in "general terms" and based on the instructions that come with the offset inserts. Clearly, you have first-hand experience with various offset inserts and have determined exactly how much affect specific inserts have on your particular rifle. I think the information I gave WT will get him in the ball park for his particular application. However, Burris clearly states that you SHOULD NOT MIX inserts with different numbers in the same ring, nor put two + inserts or two - inserts in the same ring. I guess I'm a dim enough bulb to believe there is some important reason as to why they include those warning in their instructions.

I'm not enough of an engineer to know exactly why they clearly state that in their installation instructions. Maybe they want to force you to buy extra sets of inserts?? However, maybe they include those instructions because of some possible problems that may occur from such applications. Is it possible using two offset inserts with different numbers might not allow the rings to grip the scope properly???? Just wondering???

Posted: Sat Apr 21, 2007 11:34 am
by rayfromtx
I'm guessing they are concerned about proper tightening and I had some concern as well but I looked it over carefully and it seemed to want to work from my inspection and tightened well without bottoming out. I have maybe 500 rounds through the rifle since then and groups hold around 1/2 moa. It is a .243. I guess .010 difference was still within working tolerance. I'm not sure how close the tolerances are on 1" scope tubes but I would be surprised if it didn't vary more than that between manufacturers.

If I was a manufacturer, I would give instructions that kept people way back from the edge. I would personally go much closer to the edge if there was a good reason to venture there. This is far less "experimental" than routine handloading practices.

You should always do only those things that you are comfortable with. (unless of course you are young, bold, adventurous, or foolhardy) I may fit at least a few of those descriptions.

Posted: Mon Apr 23, 2007 7:21 am
by WT
Silverfox & rayfromtx

Thanks for the tips!

Silverfox,
That tip regarding rotating the insert to correct windage is great! It all makes perfect sense.

rayfromtx,
Now that I know that the inserts are in thousandths of an inch, it will be a simple matter to apply Pythagorean's theorem. With the elevation change being "A" squared, the distance between the rings being "B" squared and the hypotenuse being "C" squared..... no, that's not quite it, :?

If I lower the front of the scope .010" and the distance between the scope rings is 6", the distance to the target is 100 yards, then, theoretically, my elevation would change by 6". Here's how I came to that conclusion. The elevation change between the rings is .010" over a distance of 6". The distance to the 100 yard target is 3600". By using a ratio to compare the .010" change in 6" to the unknown change in 3600" , I divided 3600" by 6" and then multiplied the result by .010" which gives a change of 6" at 100 yards. So, a change of .005" should be pretty close to what I would need.
Yes, No, Maybe?? ;)

Okay, now I need to lay down for awhile. :wink:

Posted: Mon Apr 23, 2007 8:44 am
by Gmoney
I've got a solution for you... :wink:

Get some Talley Lightweights and your problems will be over.... :wink:

-Greg