• Frank's Lesson's Contest

    We want to see your skills! Post a video between now and November 1st showing what you've learned from Frank's lessons and 3 people will be selected to win a free shirt. Good luck everyone!

    Create a channel Learn more
  • Having trouble using the site?

    Contact support

Rifle Scopes Let's talk about objective bell sizes

Djstorm100

Sergeant
Full Member
Minuteman
Feb 5, 2010
193
0
36
Bell/objective lens size on rifles are there to help to collect and transmit light through the scope we can agree on. When talking about design of the scope and objective lens/ bellsizes what are the things consider on how big the bell is? Example. Vortex makes a 2.5-10x44 Sfp and 2.5-10x32 ffp. Why have the two different sizes?

Does bell housing size really matter?


Using tapatalk
 
Last edited:
Bell size on rifles are there to help to collect and transmit light through the scope we can agree on. When talking about design of the scope and bell sizes what are the things consider on how big the bell is? Example. Vortex makes a 2.5-10x44 Sfp and 2.5-10x44 ffp. Why have the two different sizes?

Does bell housing size really matter?


Using tapatalk
are you talking about the size of the objective lens? If so, the two you listed are the same size.
 
The objective size allows more light to get into the scope and will enable you a 56mm objective longer into the day/dusk than a 50 mm objective, even more so with a small 44mm obj. The only positve is the smaller obj. allows you to mount the scope lower but that is not enough of a good reason for me.
 
So why would Vortex (which makes great products) use two different sizes for the small scope. I say same because of the specs other than one is FFP w/ parallax adjustment and the other is SFP.
 
Why not? Better light gathering and it's actually a bit shorter optic. Not to mention the new features on the x42 NF.

I'm stuck on vortex because of the bang for the buck. Granted we in NC do not have any ranges longer than 300 yards, some are 1000 yards but you have to be a member and pay this and that.

Anyway
2.5-10x32 is FFP with parallax adjustment

2.5-10x44 is SFP with parallax being at 100 yards. Would this mean that the scope is parallax free at only 100 yards OR at 100 yards +? I do like being able to range with scope and I can range with SFP just adds one more step.
 
The FFP in a power range under 14x is a waste of time and space. So that for me takes that (advantage) out, the 32mm over 44mm is all about mounting. Both optics will not have a level of built in quality that will show up in the middle of the night, so I would just go with the largest bell housing you can clear on the rifle and be done with it.

John
 
The FFP in a power range under 14x is a waste of time and space. So that for me takes that (advantage) out, the 32mm over 44mm is all about mounting. Both optics will not have a level of built in quality that will show up in the middle of the night, so I would just go with the largest bell housing you can clear on the rifle and be done with it.

John

Thanks John.

The FFP appealed to me simply because of FFP and the parallax adjustment. FFP is not THAT important but does eliminate one step but since I was using the 1-4x at the class I dial it up to 4 (mag where the reticle is true) and run it. No need for the extra step if ranging. I did like the IOR fixed 6x.
 
So why would Vortex (which makes great products) use two different sizes for the small scope. I say same because of the specs other than one is FFP w/ parallax adjustment and the other is SFP.

I'm going to take a stab in the dark and say its a price point thing. Side focusing parallex is more costly to manufacture and so is adding FFP. So how do you cut cost to make sure the optic comes in at your target price point? Maybe cut materials cost? Yes its only a small cost savings but those small savings might be big when you start talking the number of scopes manufactured?
 
See, with FFP in less then 14x to me is a non-point for use, the reticule gets so small, its hard to use in a 2.5-10x or a 3.5-10x. Even then with a 1-4x, 1-6x, 2.5-10x we all know most of the time we all will run the optic at 4x, 6x, or 10x. So it defeats the point of the FFP.

Anyways, both will work for normal day time use.
 
forget to add,

Parallax adjustment is a nice to have item but is not a needed item. All brands of fixed parallax scopes as long as you keep a repeatable cheekweld parallax will not kick your butt. The parallax adjustable system is great for when you are in shooting positions that make it hard to have the same cheekweld you used when you zeroed the rifle.

If the fixed parallax can be set, I always ask for a 300yd fixed parallax.

John
 
MrBoyette: Fixed parallax is great for hunting at 100-400y, but when you shoot different range out to 1000+ then parallax adjustment will be essential. Even with the same cheekweld, the parallax will only be correct for a small range (at around the 300y on your scope). The parallax error below or above that will only increase as range increases/decreases, with no way to dial it out.

Useless to some, necessary to others.

32 vs 44 would be less of an issue. If you have the height, use it.
 
Got the scope and first thing I can tell is the reticle is not 100% workable.






So now curious if 4-16x50 FFP would be any better, doubtful. I assume I'll have the same problem at low magnification and this is the same through all FFP with a low magnification. But then again at 2.5x I don't see where I would be using the reticle for ranging or anything of that nature. I see it more as a point and shoot type thing, correct?
What I was trying to accomplish was to was have a scope that I could use in 3 gun and still reach out effectively to 600-700 yards, very doubtful since most guys use a 1-4/6x.

.1 milrad adjustment
EBR-1 reticle or something very simliar
enough magnification to do close work out to 600-700 yards. Recently found some land to go out that far.
Budget $800-900
Great Customer service (why I went with vortex)
30mm tube
uncapped turrets with zero stops
 
Last edited:
^ Vortex has a piss poor FFP low mag reticle, but that's not FFP's fault.
FFP is beneficial at ALL mag ranges. The scope maker needs to design a usable FFP reticle.

thats not 100% true.

Any reticle subtends to the unit of measure its designed for. so the only modification you can make is adjustment to the field of view. Yes you could go the route of the bolder stadia lines like I did with the A5 on the IOR 3-18x42mm.

Djstorm100,

Do not assume that the 3-gunners that use 1-4x or a 1-6x know how to use that optic. most do not, and to be honest, if its a 3 gun setup I wold run a AimPoint Micro 2 MOA or I hate to say it a EoTech with 3x magnifier and be done with it. Show me two stages in the same 3-gun match at or over 400yds......

The 1-7x Sightron is the best buy for what you are trying to do. Look up Liberty Optics if thats the route you want. For my 3-gun setup, 200yd zero and a H1 AimPoint. Rock it all day and have faster times on longer stages then most people with a 1-4x or even a 1-6x.

One more quick edit,

That Vortex you have is a great optic for a 18" AR15. I would keep that and build a 16" 3-gun upper based on iron sights. Shoot that for a bit, then later on add the Sightron if yo need it.

John
 
Last edited:
One thing that has been bugging me about the Vortex since I want the 2.5-10x32 is the fact that the posts are three times thicker on the MOA version than they are on the MRAD version. Personally, on an FFP scope at any magnification a tapered reticle makes the most sense, but on a low powered scope, thin lines seem relatively less effective for rapid engagement. Since I want the MRAD version, I'm ticked that it has the thinner posts. That being said, I've never had much of a problem seeing thin crosshairs on other scopes I've owned (while hunting), but I can imagine situations with busy backgrounds that might be tricky. I actually had a hard time seeing the reticle in the vortex on 2.5x just looking through it at sportsman's warehouse, but that was a REALLY busy background....
 
MrBoyette: Fixed parallax is great for hunting at 100-400y, but when you shoot different range out to 1000+ then parallax adjustment will be essential. Even with the same cheekweld, the parallax will only be correct for a small range (at around the 300y on your scope). The parallax error below or above that will only increase as range increases/decreases, with no way to dial it out.
I sure am glad there was no internet when I went to sniper school, otherwise I never would have qualified with my fixed parallax scope we focused at 300yds but shot it out to 1000yds, and with 173gr Special Ball hitting transonic around 850yds at that.

Fixed parallax scopes very much have their place, when shooters want durability and simplicity versus absolute accuracy. When 1.5-2moa wins the day while beating the hell out of the system, I'll take fixed parallax every time. Not everyone is shooting F-Class.
 
As you state not everyone shoots F-Class, similarly not everyone is happy with 2moa. You hit the nail on the head when you state you will take the simplicity over accuracy. That is all I am saying; I'll take accuracy over simplicity. Same coin, different side.
 
6Dasher, the OP isn't talking about running the scope where absolute accuracy dominates (he wants a scope for 3-Gun), so simplicity and durability carries the field because you can run it harder and faster. He hasn't said what rifle he's running it on, but I'm assuming standard 3-Gun type build, lightweight 5.56 with a 16"-18" barrel, light single stage short throw trigger. Not exactly what you take to run at distance, but hits on 75-100% IPSC are easily achieved at 600yds with a <6x scope.

It's all about the usage and context. I may not shoot 3-Gun Nation, but I have a fair amount of time doing run-and-gun shooting. Quick while being accurate enough for hits rules the day, along with being able to take the running, rolls, climbs, crawls and other abuse involved. Shooting 2moa out to 300yds under the ticking clock (or 2-way) pressure is more than sufficient in that discipline. I shoot precision too and those scopes are appropriate for that, but we're not talking about precision shooting.

OP, in your budget range and intended use, I would listen to Boyette on this one. I've never seen the Sightron 1-7x, but it does sound like a sweet scope that will fulfill 98% of your shooting desires and he recommends it. I would run straight irons before I ran anything that didn't have 1x as a feature on it. There is no such single scope that you're really wanting, but there's some that are pretty dang close. Luckily for us mounts and/or uppers detach and swap.
 
6Dasher, the OP isn't talking about running the scope where absolute accuracy dominates (he wants a scope for 3-Gun), so simplicity and durability carries the field because you can run it harder and faster. He hasn't said what rifle he's running it on, but I'm assuming standard 3-Gun type build, lightweight 5.56 with a 16"-18" barrel, light single stage short throw trigger. Not exactly what you take to run at distance, but hits on 75-100% IPSC are easily achieved at 600yds with a <6x scope.

It's all about the usage and context. I may not shoot 3-Gun Nation, but I have a fair amount of time doing run-and-gun shooting. Quick while being accurate enough for hits rules the day, along with being able to take the running, rolls, climbs, crawls and other abuse involved. Shooting 2moa out to 300yds under the ticking clock (or 2-way) pressure is more than sufficient in that discipline. I shoot precision too and those scopes are appropriate for that, but we're not talking about precision shooting.

OP, in your budget range and intended use, I would listen to Boyette on this one. I've never seen the Sightron 1-7x, but it does sound like a sweet scope that will fulfill 98% of your shooting desires and he recommends it. I would run straight irons before I ran anything that didn't have 1x as a feature on it. There is no such single scope that you're really wanting, but there's some that are pretty dang close. Luckily for us mounts and/or uppers detach and swap.

I'm trying to kill two birds with one stone. Something that I can effectively shoot out to 600-700 yards but then turn it down and run 3 gun. I'm going to give John's advice a try since I have a Aimpoint H1.

When would you want fixed parallax? Under what situations?

I'm doing 3 gun for fun and using a rifle that really fulfills a different role I built (on the heavy side) that was for a longer range/precision work (man size target) at distance. 18 SS barrel, STR stock, SSA Trigger, Bi-pod, AAC Brakeout 2.0 (runs a can) Spr-ish build, yes.

This picture is with a Primary Arms 4-14x FFP that I had to get warranty out. Got it cheap and is now on my .22lr trainer and works surprisingly well.

IMG_2402_zpsa3218523.jpg
 
Last edited:
Durability and simplicity. We focused the Unertl on the M40A1 at 300yds. Running under 100yds in urban settings we would encounter some noticeable parallax, but at that distance the deflection was negligible as far as effect on impacts and still fell inside the brain "T". At the grand you wouldn't notice it there either.

1x-? scopes don't have adjustable parallax for a reason, they don't need it. Their purpose is to be thrown around more, be rapidly used at varying ranges from in a room to inside effective small arms range, and to do it without further adjustments.

Fixed parallax magnified scopes I currently own include Leupold Mark 6 1-6x, Mark 8 CQBSS, Mark 4 2.5-8x32 MR/T, USO MST-100 and I just added two NF 2.5-10x24s to the mix. All are on/destined for durable rifles that see field time, are not for seeing how small of groups I can shoot, and are ones I want to ensure will perform quickly when necessary. Notice they're all at or under 10x.

My variables include a pair of S&B PMII (3-12x and 3-20x), SWFA 3-15x42 (rimfires, 7yd minimum parallax), and a SWFA 5-20x50. They're precision setups that see more range time than field, more distance than close range, and shoot more for score and groups than for game or HD. The lowest magnification on any of those is 12x (PMII).

When you say "effectively shoot out to 600-700yds", what size targets are you talking about? Do you mean 75-100% IPSC silhouettes or similar? That is easily done with a 7x, hell 50% IPSC is viable, but you're not going to be very efficient with group shooting or finding small targets.

The perfect scope is still a unicorn. Myself and many other shooters have chased it, thrown hard earned money at it, and in the end we ended up with another rifle and scope to do the other side of the spectrum. Figure out what optic will perform at the vast majority of your shooting spectrum, get the best scope for that which you can afford, and have fun pushing the limits for the rest.
 
Durability and simplicity. We focused the Unertl on the M40A1 at 300yds. Running under 100yds in urban settings we would encounter some noticeable parallax, but at that distance the deflection was negligible as far as effect on impacts and still fell inside the brain "T". At the grand you wouldn't notice it there either.

1x-? scopes don't have adjustable parallax for a reason, they don't need it. Their purpose is to be thrown around more, be rapidly used at varying ranges from in a room to inside effective small arms range, and to do it without further adjustments.

Fixed parallax magnified scopes I currently own include Leupold Mark 6 1-6x, Mark 8 CQBSS, Mark 4 2.5-8x32 MR/T, USO MST-100 and I just added two NF 2.5-10x24s to the mix. All are on/destined for durable rifles that see field time, are not for seeing how small of groups I can shoot, and are ones I want to ensure will perform quickly when necessary. Notice they're all at or under 10x.

My variables include a pair of S&B PMII (3-12x and 3-20x), SWFA 3-15x42 (rimfires, 7yd minimum parallax), and a SWFA 5-20x50. They're precision setups that see more range time than field, more distance than close range, and shoot more for score and groups than for game or HD. The lowest magnification on any of those is 12x (PMII).

When you say "effectively shoot out to 600-700yds", what size targets are you talking about? Do you mean 75-100% IPSC silhouettes or similar? That is easily done with a 7x, hell 50% IPSC is viable, but you're not going to be very efficient with group shooting or finding small targets.

The perfect scope is still a unicorn. Myself and many other shooters have chased it, thrown hard earned money at it, and in the end we ended up with another rifle and scope to do the other side of the spectrum. Figure out what optic will perform at the vast majority of your shooting spectrum, get the best scope for that which you can afford, and have fun pushing the limits for the rest.

Anywhere from 50-100% IPSC. Since I only have a max range that I can go to is 300 yards. I took IPSC targets that are smaller (25% for example) to make it harder, but it nothing like shooting out to 600yds. I'm not a group shooter per say, yes I like to shoot nice little groups at 100 yards to improve skill set but at the end of the day shooting man size targets is what I'm after. Grouping shots is more of a "hey I can shoot this small with X ammo" or "I built this 0.xx moa rifle, yea!"
 
I'm trying to kill two birds with one stone. Something that I can effectively shoot out to 600-700 yards but then turn it down and run 3 gun. I'm going to give John's advice a try since I have a Aimpoint H1.

When would you want fixed parallax? Under what situations?

I'm doing 3 gun for fun and using a rifle that really fulfills a different role I built (on the heavy side) that was for a longer range/precision work (man size target) at distance. 18 SS barrel, STR stock, SSA Trigger, Bi-pod, AAC Brakeout 2.0 (runs a can) Spr-ish build

These "best scope" threads tend to thrash around with lots of good information but never seem get anywhere unless the OP's purpose for the rifle is clear. Had no idea until this post that 3-gun competition was a consideration. Read through the thread a couple of times, forgive me if you mentioned it earlier and I missed it.

For multi-gun, 4x on the low end is way too much. Doesn't matter if it's FFP or SFP, adjustable for parallax etc. You need 1x (or as close as you can get to it) on the low and 4-6x on the high end. This should enable you to hit "man size targets" at 600-700yds pretty easily once you figure out the needed holdover or elevation setting. On 1x you'll be able to hose down the close in stages. As John said, the benefits of FFP are lost on low power variables.

If you don't want to buy a new scope, just use your H1 for 3-gun and your Vortex for trips to the range to shoot further out since you already have both. QD mounts for each would be nice, but not necessary. You could sell both and have enough scratch to buy a Vortex Razor 1-6x (SFP) or even a Leupold Mark 6 1-6x (FFP) either of which would seem to fit your needs.

This thread has come a long way from the opening question about objective bell sizes:)
 
Got the scope and first thing I can tell is the reticle is not 100% workable.






So now curious if 4-16x50 FFP would be any better, doubtful. I assume I'll have the same problem at low magnification and this is the same through all FFP with a low magnification. But then again at 2.5x I don't see where I would be using the reticle for ranging or anything of that nature. I see it more as a point and shoot type thing, correct?
What I was trying to accomplish was to was have a scope that I could use in 3 gun and still reach out effectively to 600-700 yards, very doubtful since most guys use a 1-4/6x.

.1 milrad adjustment
EBR-1 reticle or something very simliar
enough magnification to do close work out to 600-700 yards. Recently found some land to go out that far.
Budget $800-900
Great Customer service (why I went with vortex)
30mm tube
uncapped turrets with zero stops

i think you are overlooking something. that is the exact optic i would want on an AR platform which is what you have. the reason being at 2.5x the illuminated reticle works great as a "red dot". make a nice little plus sign for quick and easy target acquisition. then you have the benefit of using the reticle for which it was intended above 5/6x or so.
 
i think you are overlooking something. that is the exact optic i would want on an AR platform which is what you have. the reason being at 2.5x the illuminated reticle works great as a "red dot". make a nice little plus sign for quick and easy target acquisition. then you have the benefit of using the reticle for which it was intended above 5/6x or so.

I wish. In daylight, the illumination isn't visible. Under cloud cover it is though.


I finally had a chance to compare the MRAD and MOA versions side by side, and the thicker posts on the MOA version are WAY more visible. Sure wish the MRAD version was like that...
 
Last edited:
I haven't bought mine yet, but the local gun shop was nice enough to put a new battery in one and let me take it outside. Even on full power, I could only see red against dark backgrounds. Maybe our mountain/desert sun is brighter than where you live...
Our maybe it just was a sub par scope. It's the only one I've tried outside so I have no comparison to make. Definitely not nearly as bright as any of my red dot scopes. I was actually planning to add a red dot on a 45 degree mount along with the PST, but maybe I'll hold off...