Frame-Mounted vs. Slide-Mounted Red Dot Sights?

Why do most bullseye shooters have slide mounted red dot sights instead of frame mounted dots?  I would think the frame mounted ones would be more reliable and less picky about ammo.

A lot has been covered about the topic in older posts.  Quality mounting options for frame mounts are few and they cost more $$ than a slide mount.

Some also prefer the way the recoil feels on the slide mount vs frame.

KC cuts the slide so scope mounts literally on top of the slide.  That puts it on almost the same plane as the barrel.  Frame mounts put the scope on a much higher level.

Chip

I've been building BE pistols since 89. Less than 1% are frame mounted. I've recently built several frame mounted pistols. My observations fired side by side with slide mounted guns:
Frame mounted are a little snappier because slide velocity is faster; it's lighter. Recovery back to next shot seemed faster with slide mount because recoil felt smoother. I just did a 50 rd each pistol comparison on a frame mounted pistol R&D gun I'm building and a slide mounted pistol. I felt like I could be more successful with the slide mount because my recovery to center was better. I'm now lightening the slide on the frame mounted pistol to see if I can improve felt recoil by going lighter; works in IPSC.  Another thing I've noticed over the years is most BE guns aren't built with good lock up. So in this case a slide mounted scope almost always will recoil less because of its mass. I've shot many tired frame mounted pistols and hated them: just recoiled too much. I don't mind recoil, but don't want to lose points on shortline because of excessive recoil.
So in the near future I'll be commenting again when I finish lightening the slide and shoot it again.
Jon

ChipEck wrote:KC cuts the slide so scope mounts literally on top of the slide.  That puts it on almost the same plane as the barrel.  Frame mounts put the scope on a much higher level.

Chip

KC also has one of the lowest frame mounts too, because it has integral rings it puts the optic just as low as any rail type slide mount.

- Dave

Photo from KC's Facebook page

mpolans wrote:Why do most bullseye shooters have slide mounted red dot sights instead of frame mounted dots?  I would think the frame mounted ones would be more reliable and less picky about ammo.

The frame mount was before the slide mount.. There's more than one bullseye pistol smith that vigorously  advocates the frame over the slide..David Sams is one of the best.. Talk with him.. He converted me, and I have never looked back, and regret my reluctance to pursue it earlier.  
The pictures below are the first one.. Oxford white dot.. Wish I still had mine..
I shot with Joe at league nights and matches... We were not friends, but I was acquainted with him. He won Perry with a 2657-139X.. so the frame mount is more than capable, considering technology was no were near then, what it is today. Plus he used a grip mount.. Today we attach directly and securely to the frame.



These are on the down low..The mounts and bases are very similar to David Sams',  with some variation to suit these guns.. 

mpolans, thanks for asking this question. I have been wondering the exact same thing myself.  I'm new to the BE game and took part in my first NRA Regional last month.  While watching the relay before me shoot, I noticed 20 of the 23 pistols on the line had dot optics. Of those 20, only 2 were frame mounts.  That struck me as rather interesting.  

This thread started out with an acknowledgement that slide mounts are most common, perhaps due to cost, perhaps due to less perceived recoil. The thread then took a turn and seems to be defending the frame mount, citing historical precedence and the work of some very high end gunsmiths.

While I respect the knowledge and opinions of gunsmiths like David Sams and KC Customs, not all of us have the coinage for a high end custom build like that.  Personally, I'm dreaming of a mid-level (based on price) like Springfield Armory Custom shop, RRA, or Les Baer, but might just end up with an entry level Springfield RO with a dot attached somehow. But setting aside the financials for a moment, what other practical impacts does one's choice in mounting solution have?  I would love to see an engineer run a comparative analysis between a slide and a frame mount. Seems to me like recoil could be broken down to a simple Force = Mass * Acceleration equation.  At what point does the faster speed/acceleration of a frame mount over take the decreased mass?  

In my other shooting endeavors, I have a bolt action rifle that I run with a suppressor.  Several people have run experiments comparing suppressors to muzzle brakes (the videos are fairly easy to find on youtube).  It is pretty clear that a modern muzzle break decreases the over all force slightly better than a suppressor.  However, the suppressor applies the force of the recoil over a longer period of time.  In the end, I prefer the suppressor because the recoil feels more like a push where as the muzzle break feels more like a jab/kick.

For what it's worth and because everybody seems to make reference to them, the AMU what at that match last month.  They were using slide mounts.

AMU has been spotted using slide and frame mounts.  Don't forget they have a fully supported team.  They have time,people and $$ to experiment with different setups. 

I recommend you shoot well built pistols with both setups and figure out what works best for you. Or you can buy a frame mount gun and and slide mount gun.

JWelch,

The F=ma equation is difficult in this case because we have barrel locking lugs that slow the slide velocity; also dependent on how deep lugs were fit to slide, bushing lockup, slidestop pin fit, mainspring weight, recoil spring weight, etc.
I don't know of one current 2650 high master using a frame mount? Does anyone else? I recently spoke with a multi-winning Perry champion and high 2670 shooter buddy and asked them both why they didn't shoot frame mounts. They both basically said recoil was too snappy in comparison to slide mounted scope.
I'm by no means putting down the frame mount, I just haven't shot one I like more then a slide mount YET (Jerry ;l).
That's why the one I'm building now I'm trying to see if I can get it to recoil less. I used 3.2 gr 700x and 3.8 gr 700x in both pistols I shot side by side. In both cases I liked the slide mount better. 700x is snappy, so I will be using BE next time I make comparison.
Unless something is done radically different a frame mount pistol is no different than shooting a ball gun. At this point I'm under the impression that Jerry's pistol is only gun running a lightened slide out there for BE; I'm working on #2 
Jon

For 99% of us, it's like a 17-handicapper dithering over what brand of golf ball to use, instead of working on his putting.

Testing today.. 2.9 grains of bullseye for 45 short line.. Runs like a Swiss watch..One of the High Masters who shot both the 45 and 38 swears the 45 recoil is less than the 38..it's hard to tell.. Both are low recoil..The 38 slide is a little lighter..
This year, she has averaged in the high 2570s.. another 2600 is in the near future..
Caution, when the speed goes down, the rpms must go up..

john bickar wrote:For 99% of us, it's like a 17-handicapper dithering over what brand of golf ball to use, instead of working on his putting.

+1

Jerry's guns are like Formula cars

Jon

There is another reason to choose frame mount over slide mount. My 52, like it seems everyone else's likes 2.7 to 2.8 gr of Bullseye powder behind a 148gr HBWC. I can use that to justify going with a frame mount (don't have to find a new load). But in all honesty I just didn't want to drill any holes in that pretty old gun. I found the perfect match (for me) with the Leupold QI mount. They have 4 secure points, require no drilling, cost under 50.00 and they are Leupold. Leupold makes/made mounts for the 52 and the 1911 https://www.cheaperthandirt.com/product/leupold-qi-scope-base-for-government-1911-matte-black-52137-030317521370.do . If you don't want to drill holes in that old or shiny new pistol then spending less than 50.00 is a good way to find out if a frame mount is right for you. NFI in Leupold (I wish I did)

I just thought it was interesting. I come from an IPSC/USPSA background, where everyone shoots frame mounts in Open and folks like to lighten slides so their guns cycle faster. The only slide mounts are the mini dot sights like the Docters and similar ones, most of which have had durability problems or problems holding zero. It's a different game with different ammo requirements, but I wondered if there were similar concerns with holding zero, durability, and reliability. I've never shot a slide mount before, and I'm thinking of getting back into bullseye a little after shooting my first bullseye match in over 15 years.

IPSC has minimum power factors that are much higher velocities than what we want for BE. As a result of those hotter loads they have found that lighter slides have less felt recoil. I swiss cheesed a slide last year for a limited pistol and it did make a difference. IPSC pistols are not typically built to the tolerances of a BE pistol. Since IPSC pistol has looser barrel fit they cycle faster because of less lockup/dwell time. Also shooting 2 handed vs 1 handed makes a difference to felt recoil as well. And since your an IPSC comp gun guy, women's national record aggregate was shot with comped 45
Jon

Shredded slides look good though.

It's perhaps interesting that in Jerry's post of that old photo of Joe Pascarella and his gun, even though he used a grip mount the slide still wore a Bomar rib with extended front sight, which weighs about 6 ounces if memory serves me.  So he got the recoil smoothing anyway.

Jon Eulette wrote:

john bickar wrote:For 99% of us, it's like a 17-handicapper dithering over what brand of golf ball to use, instead of working on his putting.

+1

Jerry's guns are like Formula cars

Jon

Yeah; shit, I need to be adopted by a Jerry

Standing here in 2016, the most incredible thing about that American Rifleman cover is not Pascarella's dot mount, nor his Bo-Mar rib, nor his awesome cop 'stash, nor the aviator glasses, nor the khaki uniform; it's the fact that American Rifleman had competitive shooting in it at all, let alone on the cover.

john bickar wrote:Standing here in 2016, the most incredible thing about that American Rifleman cover is not Pascarella's dot mount, nor his Bo-Mar rib, nor his awesome cop 'stash, nor the aviator glasses, nor the khaki uniform; it's the fact that American Rifleman had competitive shooting in it at all, let alone on the cover.

+ A BUNCH!

Jerry and Dave both had good words that I absorbed when I was ordering my wad gun.  So as a new shooter when it was time for a mount, I went with what both recommended.   The disclaimer, is that I normally shoot my ball gun for service competition so I'm ecstatic with the lower recoil of the wad gun in general, but if I could I would like even less. 

Until I get a Master/High Master card and start making top notch 1911s I'm not going to tell anyone what works best, but a slide mount is easier to fit in your box...lol




Dot is off center so it looks lower than it really is.

JWelch wrote:
For what it's worth and because everybody seems to make reference to them, the AMU what at that match last month.  They were using slide mounts.

I wouldn't read too much into this.  Previously they had Aimpoint H2s on frame mounts, until they changed to the Aimpoint 9000SC.  Most of us would be very happy with an H2.  They're using some very "peppy" loads with the 9000SC.  I'm heading back to interservice this June and will be there early to practice so I'll get an update.

Catching up on this thread after the holiday weekend...

From what I read, slide mounts are still the most common, yet the frame mounts continue to be vigorously defended. 

Jayhawk, Mr. Keefer, both of you mentioned Mr. Sams swayed your opinion but you didn't articulate why.  Will one of you gentlemen mind sharing the reasons Mr. Sams gave in favor of the frame mount?

David is retired AMU ..Originator of the Beretta ball gun.He has a loooong history of building great bullseye guns.
I sponsor a lady shooter who suffered a major repetitive recoil injury to her right arm. She's good enough, 2600 shooter,  that I was determined to build a low recoil set up to keep her in the game. The H1 had not been set up for frame mounts at this point.. Dave gave me his base and mount drawings, and I designed the H-1 scope mount for the frame. Dave is now making and selling them..The weight on the slide, plus the recoil is absorbed by the shooter. She is not the only shooter who has been injured in this game..Lead can be shot accurately at much slower velocity, than jacketed. Much slower. Her short line 45 is presently 2.9 of BE. You can't do that with optics on the slide. David helped me with the frame mount he designed for the AMU, and Chuck Warner provided much input on race gun light slides.. Fast twist barrels have a little something to do with it also..

As Jon said find me a 2650 shooter using frame mount. Checking the top shooters at Perry you will find most are using Slide mount. Yes the first mounts were frame mounts, typically grip mounts that were worthless and shot loose after a few matches. Every year at Perry someone had a newer and better mount.
 First the shooter must understand it is what he likes and can shoot best with that will result in good scores. I can assure you that the top shooters tried both slide and frame mount. The majority have determined that the slide mount preforms best for them! I do NOT care what any gunsmith said! Most can't shoot competition! Their main interest is to sell their product! Top shooters I know tell their gunsmith what they want not ask what they should shoot!
 I suggest you try both, I'm sure shooters at you local club have both types and will be happy to allow you to try them. Simply put you can shoot Zins's gun, stand like Zins, shoot the same load and do everything exactly like Zins but not get the same results simply because your not Zins! Every top shooter will tell you that shooting a great score is up to you to find what works best!
 Asking questions like which is best Slide or frame mount is the same as asking which is better Ford or Chevy! You will get the same answers all the time!
 If you don't think so, go back and read old posts!

Mr. Keefer, thank you for your reply.