Rifle Scopes 1-piece rail vs 2-pieces set

[spawn_mm_jtf2]

Looking for you opinion here. On the net, some say its better a single piece picatiny rail then a 2-piece set, some say the oposite... My action is a mossberg long (use same base as a m700) and the scope is a millett lrs-1. I want to know because the cheap aluminium bases that came with the rifle seem to always get loose.. so I'm looking for new bases...and a bottle of locktight.. heheh

I like the look of the picatiny rails, but not their price...

Thanx for your advices gens!
Steph

 

[roggom]

Re: 1-piece rail vs 2-pieces set

There are pros and cons to both. I see the dual bases more for a hunting application, where you want to reduce weight and have a bit more access to the chamber. Also the dual bases tend to keep the scope and rings a bit closer to the receiver.

The single base are more rigid, can have an integral recoil lug, are usually better aligned and you have more adjustment fore and aft. Only thing is the scope tends to sit a little higher, so you may need a cheeck pad, but in a long action might be more comfortable.

Weaver makes a decent aluminum rail, other than that you may have to give up some pop or beer money for a month and get a premium set.

.

Afterthought: some blue loctite is fine, but you may want to look for a decent 5 to 75 inch pound torque driver.

 

[spawn_mm_jtf2]

Re: 1-piece rail vs 2-pieces set

yeah.. the adjustable torque screw driver start to feel like a necessity... not the kind of thing you find in local stores here... I'll look for it on the internet, which one are you using? I saw a black and yellow one once in a scope review video ...

 

[roggom]

Re: 1-piece rail vs 2-pieces set

Yes, you probably saw the Wheeler FAT wrench http://www.amazon.com/Wheeler-Firearms-Accurizing-Torque-Wrench/dp/B0012AXR4S

I use a Proto that I got a good deal on. It is industrial grade but the price was right.

Another popular one is the Borka Tool http://www.borkatools.com/pages/atd12/mtsd.html

Just remember it is inch lbs, not foot lbs.

 

[servicepuke]

Re: 1-piece rail vs 2-pieces set

Would better access provided by two piece bases be more important in a tactical rifle that would be used in a high stress environment?
I like two piece bases, but I just plink and hunt.

This is the torque wrench I use, but I wouldn't have paid this much if I didn't use it for work.
http://www.sears.com/shc/s/p_10153_12605_SPM6628589102P?prdNo=23&blockNo=48&blockType=G48
The Snap On guy told me that when using the click type, they should be clicked a few times at the desired torque setting before torquing your fastener to achieve more accurate torque.
(Be interested to know if others agree-not trying to derail)

 

[spawn_mm_jtf2]

Re: 1-piece rail vs 2-pieces set

wow! I get so much information since I'm on SH forums! Thanx guys.. I just realize that the manual state torque measure in inches/lbs too, not ft/lbs... I must admit that 30 ft/lbs on those small srews would have been....scary.. heheh

About the acces to the chamber, for moose and bear hunting here, we rarely fire more then twice... 5 rounds in the magazine...

The height of the rail might me an issue though...Even with the low millett ring, my scope is 1/4 inche above my barrel, making my cheek weld only okay, no better.. so that kinda answer my question..I'll check the thikness of that Weaver rail...

 

[Killer Spade 13]

Re: 1-piece rail vs 2-pieces set

1 piece. Structural integrety and rigidity.

 

[servicepuke]

Re: 1-piece rail vs 2-pieces set

How much does the increased rigidity of the one piece base matter?
The two piece bases are also attached directly to the action which is pretty rigid.
Has anyone quantified the difference in group size between the two types?
Is the decreased access to the magazine and action area worth the added rigidity?

 

[roggom]

Re: 1-piece rail vs 2-pieces set

SP,

Here is the deal, long range target/ and tactical "line" scopes are twice as heavy as a normal hunting scope. Folks who shoot competition or even plink at long range tend to put thousands of rounds down a tube. Shooting a 308, 7mm mag, 300WM, 338 without a brake or can transfers a lot of recoil down the rifle.

Some single base mounts have a recoil lug integrated to the bottom of the base. This lug butts again the receiver and keeps the mount in place. Other single piece bases (Leupold MK4) come with 8-40 screws so the smith can mount the base more securely to the receiver (similar to dangerous game rifles). Even the single piece standard will allow the equal transfer of the energy across the entire piece of the base.
Also for a true tactical rifle, there are better options for receiver access, as many rifles have detachable magazines that are loaded from the bottom.

As for quantifying, no need. It is a personal choice. If anyone want to put a $3k S&B scope, or a $700 Weaver, on a dual base system, they can pick it up off the deck when it eventually pops off.

For a hunting rifle, especially a thicket or walking rifle, the dual bases are perfect. Better cheek weld because the scope is lower, and you dont shoot as much. Maybe 10 or less shots on a hunting trip and a couple of boxes for sight-in.

Also: There are some decent 1 piece bases that sit lower, but are designed more for hunting applications, like the Warne 1 piece weaver. http://swfa.com/Warne-Maxima-1-Piece-Bases-C1275.aspx

 

[SKS Guy]

Re: 1-piece rail vs 2-pieces set

Check out the egw one piece pic rails. Good quality with an affordable price.

 

[servicepuke]

Re: 1-piece rail vs 2-pieces set

Hi Roggom,

Would the #8 screws be adequate with two piece bases for the heavier scopes and high round counts on a 308?

Thanks
Kev

 

[Aries64]

Re: 1-piece rail vs 2-pieces set

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: servicepuke</div><div class="ubbcode-body">Hi Roggom,

Would the #8 screws be adequate with two piece bases for the heavier scopes and high round counts on a 308?

Thanks
Kev </div></div>
<span style="font-weight: bold"><span style="font-style: italic">servicepuke</span></span> -

8-40 screws are fine for two-piece bases and big, heavy scopes on .308s'. 8-40 screws have also proven perfectly capable on Tac Ops .300WMs' as well as on other Magnums that Tac Ops has built for TEAMS around the world, despite Tac Ops Two-Piece Bases lack of built-in recoil lugs. None of these rifles are babied, they're run hard and knocked about daily.

<span style="font-weight: bold"><span style="font-style: italic">Tac Ops X-Ray 51 in Birdsong Green & Black-T with PMII 5-25X[56mm] Mark 4 Steel Rings on top of Tac Ops 40 MOA Two-Piece Base:</span></span>

Keith

 

[spawn_mm_jtf2]

Re: 1-piece rail vs 2-pieces set

Well, I tried a 1 piece rail at my local gun shop and it doesnt fit my action. the two piece set for m700 fit, but space between the front and aft holes on the rail for m700 long action is too short for my mossberg.. that disapointing, there is probably no compagnies that make one for my action... The good new is they did have a Weeler FAT wrench in stock, so I bought it with some blue loc-tite and I have reinstall every single scew from action to rings with proper torque and loc-tite.

If this doesn't hold, I guess I'll have to order a set of very expensive steel bases and rings on the net...

How do you know if your screws are 8-40? is this the standard in the rifle industry for taped holes on receivers?

 

[roggom]

Re: 1-piece rail vs 2-pieces set

Standard screws are 6-48, as for other bases I would think you can get something in a Redfield or Leupold. http://data.hodgdon.com/main_menu.asp

For your current bases you should be good once you get your torque wrench, it is just good practice to prevent stripping out your screws, yet get them tight enough to hold. Also Luepold recommends using loctite on any optics over 28oz(from the install instructions for MK4 bases).

 

[spawn_mm_jtf2]

Re: 1-piece rail vs 2-pieces set

Thank you very much for the info sir! Thanx for the link to reload data, that might proof very useful in the future...

As for loctite, hehe, my LRS-1 is more in the weight class of a 15lbs sledgehammer then a 28ounce scope, so it's mandatory, I just didn't knew it before the thing started to get loose...twice... Yeah, by tightening screw with the FAT yesterday, I realise that I was far far from the 30 lbs/in recommended...

 

[roggom]

Re: 1-piece rail vs 2-pieces set

Oops meant to post the Leupy ring and mount chart
http://www.leupold.com/_pdfs/BaseFit_RingHght.pdf

You are right, not much around for the Mossberg.

 

[MWDG3]

Re: 1-piece rail vs 2-pieces set

One issue I rarely see discussed is the wide variation in manufacturing tolerances. Put a pair of quality rings on a one piece rail and the ring bores will stay more true. Alignment of the rings on two piece mounts can be sloppy, inducing stress into the scope tube.

 

[Aries64]

Re: 1-piece rail vs 2-pieces set

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MWDG3</div><div class="ubbcode-body">One issue I rarely see discussed is the wide variation in manufacturing tolerances. Put a pair of quality rings on a one piece rail and the ring bores will stay more true.</div></div>
There <span style="font-style: italic">can be</span> a wide disparity in manufacturing tolerances on many parts and from manufacturer to manufacturer. However, while machining the surfaces in perfect alignment on one-piece bases is typically easier than machining those same surfaces in perfect alignment on two-piece bases, your comment about putting quality rings on a one-piece rail and <span style="font-style: italic">the ring bores staying more true</span> is largely dependent upon the receiver. If the base holes aren't all drilled on-axis, the base doesn't mate with the receiver, and/or the receiver dimensions vary you can have an alignment problem - whether one-piece or two-piece. <span style="font-style: italic">Potential</span> and <span style="font-style: italic">actual</span> problems can be eliminated by bedding the base to the receiver, lapping the rings after mounting to the base, or both.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MWDG3</div><div class="ubbcode-body">Alignment of the rings on two piece mounts can be sloppy, inducing stress into the scope tube.</div></div>
<span style="font-style: italic">Potential</span> receiver and/or scope tube stress - like ring alignment, is largely dependent upon the receiver. If the base holes aren't all drilled on-axis, the base doesn't mate with the receiver, and/or the receiver dimensions vary you have a <span style="font-style: italic">potential</span> alignment problem whether the base is one-piece or two-piece. And as mentioned above, to eliminate any <span style="font-style: italic">potential or actual</span> stress to either the receiver or the scope tube <span style="font-style: italic">when using a one-piece or two-piece base</span>, the base can be bedded to the receiver, the rings can be lapped after mounting to the base, or both.

The debate between one-piece versus two-piece bases has been beaten to death any time over here and on other firearms sites. While I can't speak with absolute certainty myself about the subject, the absolute and dependable accuracy delivered by every Tac Ops rifle is absolute proof that two-piece bases work extremely well on expertly machined and crafted rifles.


Keith

 

[MWDG3]

Re: 1-piece rail vs 2-pieces set

Good points Keith.