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2Xalpha

Iron Sights for IPSC Rifle/ USPSA & 3Gun Heavy Metal Limited

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Also posted on hitfactor.no

This article is going to be an overview of the different options on iron sights for the IPSC Semi Auto Standard division and the USPSA Heavy Metal Limited division, which are rifle divisions limited to iron sights only. I found little information about the subject, but hopefully this will spark some intereset and discussion.

One of the first thing you hear about iron sights for competition use is sight radius. It's generally desirable to keep the sight radius as long as possible for several reasons, primarily to help focusing. If the front sight is further away from the face, the target will appear less blurry when you are focusing on the front sight for precision shots, and vice versa the front sight will appear less blurry if you are using target focus when blasting at shorter ranges ranges. In addition the sight picture will be perceived as steadier, and any errors in sight alignment will have less impact downrange because of the greater distance between the front and rear sight. To achieve longer sight radius many choose a 20" barrel for IPSC Semi Auto Standard instead of the regular 18".

Preferably the front sight should also be attached to the barre instead of the handguard, as most handguards can be flexed to a various degree which will start to have a significant effect at longer ranges.

Mainly two types of front sights are used; post sights and globe sights. Both are very precise, and what you like is a lot of personal preference. You will be able to shoot both fast and accurately with each of them, and many have tried back and forth until they’ve found what works best for them.

Post Sights

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JP Clamp On Front Sight Base. Photo: Brownells

As in the traditional front sight gas block (FSB), but with thinner post for competition use. Front sight bases usually come with the standard mil-spec post insert which is .072" wide, but at longer distances these cover too much of the targets. Usually they are swapped to thinner posts between .030-050" for competition use.

The traditional front sight base is a simple and robust design. For competition use a new front sight may be mounted right behind the compensator to increase the sight radius. “Clamp on” front sights are made for this purpose, attaching by tightening a screw unlike the usual pinned front sight base. Obviously the new front sight can't also function as a gas block due to the location on the barrel, so a separate low-profile gas block (or at least a gas block without a front sight) must be used in conjunction.

The biggest pro of this type of sight is the ruggedness, and due to their shape they are less likely to snag when you pull your rifle out of ports etc. The precision is very good. Not quite as good as a well matched globe sight, but plenty for our use.

Globe Sight

IMG_2872_zpsccb2653a.jpg

A globe sight on a Schuster sight block. Image courtesy of Flickr user "slemmo"

Favored by some Finnish top IPSC shooters, these sights are capable of extreme precision. Sometimes they mistakenly are called diopter sights, because globe sights often are used together with a rear diopter sight for precision shooting.

Among the pros of globe sights is that you can choose from a myriad of inserts to find one you like, and they are easy to change. For instance there are very thin or wide posts, large or small circles, crosshairs, squares (!) and so forth. The outer "tube", or globe, protects the inserts well from damage, but also counteracts change in point of impact due to which direction the sunlight comes from. To achieve extreme precision the front and rear sight can be two matched circles with some air in between, while others prefer a thin post which is both very fast at short ranges and also very precise at longer ranges. Some again prefer a crosshair.

Lee_Shaver.jpg

A pack of Lee Shaver Inserts, Photo: Brownells

Among the disadvantages of globe sights is that the globe itself covers more of the targets, but then again the whole outer globe may be used successfully as a large front sight at shorter ranges. Some would argue that they more easily catch on stuff (i.e. in and out of ports) and that they aren't rugged enough, especially for 3 Gun where the equipment is tossed more around.

Several different sizes of globes sights exist, mainly the 22 mm is the "new” standard, while many older globe sights tend to be 18 mm. The nomenclature refers to the metric threading of the ring used to fasten the insert. Both types attach to the standard 11 mm rail, same which is found on many "traditional" target rifles such as Anschutz. To get the globe sight high enough above the barrel on an AR, an height adjustable base with an 11 mm rail on top therefore is needed, and there are several solutions available.

- JP JPFS-ALS is a kit where you get a 22 mm globe sight, some Lee Shaver inserts, and the most important part which is the adjustable base to achieve the right sight height. The adjustable base is intended for mounting on a picatinny rail, and JP has gas blocks and dedicated sight blocks with picatinny rails available .

- Uronen Precision "diopteritähtäimen jalusta": A barrel band with an 11 mm rail on top. Stepless adjustments with no indication, may therefore be a little more hassle to get sighted in, but once it’s set you have a simple and sturdy sight base. Diameter is .725”, included is a Lyman #93 globe, Lyman 17 inserts and some Uronen inserts.

normal_Uronen_Precision_front_sight.jpg

Photo: Uronen Precision

- Schuster (out of production): A very nice and solid sight block. Standard 11mm rail for attaching a globe sight at the top, gradual adjustment with two set screws for locking. Available in diameters .740 "and .750".

- Lipski (out of production): A barrel band (quite similar to Uronen), with an 11mm rail on top and stepless adjustments without indication. The design is simple and solid, diameters are .750 "and .812".

- Accuracy Speaks (out of production): Quite similar to Lipski, but with some minor differences regarding adjustment.

A possible reason for why so many sight blocks are no longer in production may be that the USPSA Limited division has allowed “one non magnifying optic", which has led to very few still using iron sights. The only USPSA division still restricted to iron sights is the Heavy Metal Limited division (.308 and larger caliber), however internationally the IPSC Standard division continues to be limited to iron sights only.

Mounting

Whichever type of front sight you choose, mounting it to the end of the barrel may present some challenges. There are many different barrel profiles, so check the diameter your barrel before ordering. In general the most common barrel diameter at the gas block is .750", which gradually becomes thinner towards the end of the muzzle to about .740". The idea behind this is that it should be easier to slip on a gas block, but it can cause us some challenges when trying to mount iron sights out there. If there is a gap between the barrel and the front sight base, one solution may be to use brass shims.

Some Rear Sight Options

Many rear sights have two apertures of different sizes, one large for short range and a smaller one for precision long range shots. Carrying handle rear sights are rugged, and usually have two different hole sizes that can be easily flipped. Note that some of the apertures will have different zeroes when flipped which may be an advantage or disadvantage depending on use, just be aware. Many replace the mil spec aperture with a national match that has two smaller apertures, and then drill out one of them. A smaller aperture will be more precise, but require more light and therefore become difficult to use when the daylight starts to go away.

Click values ​​are also influenced by a longer sight radius, becoming proportionally finer with the increase of the sight radius. If a standard rifle length AR-15 with a front sight at the gas block has a sight radius of 500 mm, and it is increased to 667 mm by mounting the sight further forward, the click values can for instance go from 1 MOA to 3/4 MOA. This starts to eat from the long range capacity of the sights, so if the sights originally could be used out to 600 m you will now only be able to reach 450 m without holding over. Therefore you should choose a rear sight that goes a little further than what you need! Due to range availability we rarely shoot above 300 m in IPSC, but it's nice to have the ability to reach out there.

IMG_0134_zpsa16c7085.jpg

Image courtesy of CO-Exprs, using two flip up sights for different ranges

A rear sight that attracts me is the Matech, it has very little occlusion around the rear sight, providing the shooter fast sight acquisition and a good field of view. The rifle in the picture above has two Matech sights, the foremost is drilled up to a larger aperture and is used for short ranges. It is left up all the time, while the rearmost with a smaller aperture is for precision shots, and is popped up when needed. Note however that any flip up sights in general will not be as rugged as for instance a carrying handle.

Many are plagued with the double vision experienced when trying to use use iron sights, and the Orlob Rifle Occluder is a gadget some might find handy. It "hides" the front sight from your "non-shooting" eye so you only see one front sight instead of two while shooting with both eyes open. The invention doesn’t look very advanced, so you can certainly try to make something similar out of cardboard before you order it, to see if it’s something that is going to work for you.

bg_liun.jpg

Orlob Rifle Occluder

More on Iron Sights

This article has focused on the equipment, but shooting well with iron sights is an art that I hope more people now will try to master (at least I’ve been intrigued). As Patrick Kelley rhetorically asks in his article "The Power of One" from Shooting Illustrated: Why would anyone shoot iron sights “when one can slap on a scope and achieve instant mediocrity”? Well, firstly it is more challenging and thus more fulfilling when actually mastering it. Secondly, you will bring the good habits you learn with iron sights over to optics, and will probably become a better shooter. I mention consistent cheek placement every time, which is a must to be quick with iron sights while one can get away with some errors and still get a good sight picture with optics. Have a look at Patrick’s article for more information and tips on techniques when using iron sights on a rifle.

Shooting rifle, it is always important to know your zeroes and the adjustments required to hit at different ranges, but with iron sights it is perhaps even more important. A stage may have a long range target, but due to poor contrast between the sight and target, one must aim somewhere above or below the target to get some good contrast to aim at. Then it becomes handy to have a ballistic table so that you in advance of that stage know how much elevation to dial (mils). Kelley has some examples on the importance of knowing your ballistics, and the only way to find out of your rifle's ballistics is by training and verifying. A ballistic calculator is a good tool, but you still must go out and verify. Don’t be too concerned that for instance the meter marks on the Matech rear sight will become incorrect when you increase your sight radius; you will have to make a ballistic table to suit your rifle and your load anyway. You should have good enough control on the ballistics to know how much to dial as long as the distance is given.

Edited by 2Xalpha

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Thanks enjoyed reading your post; I asked here what most use for there Iron sight set up, and the DPMS rear sight seems to top the list. I'd like to now what the overall opinion here on the matech rear sight would be Ya, or Na

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By DPMS rear sight, do you mean the "FT-RS Detachable Rear Sight"? I've seen some good shooters use it.

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YES, the FT-RS; and for only $70.00 not a bad choice

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The Matech is a really cool sight and I've used them extensively on my heavy rifle. The problem you run into with the Matech is too many moving parts. The set up I use is very cool (you can see my set up in one of his above photos), but it is kind of high maintenance if you want to keep your kit running tack driver. They hold up better on 223, but on 308, the additional vibration causes them to loosen up. I take mine apart and tighten them back up. In the end, if you want a robust and low maintenance set up, the DPMS FT-RS is really a better choice. A little less race car, but more robust and lower maintenance. If you are shooting mostly matches with targets 300yds and in, the double Matech rocks the house. For longer range matches, such as RM3G, a traditional NM rear sight is a better way to go.

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Great info. I would add that PRI makes a same plane clamp on gas block for both Armalite and DPMS rifles. I use this in conjunction with a Troy clamp on front and DPMS rear on my AR-10. Its rugged and works really well.

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Just stumbled on this thread. Nice write up! Thank you for recognizing my contributions.

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Stumbled upon the X-Treme Shooting Products Centra Goliath Front Sight, might be worth checking out. :) Has a 30 mm tube instead og 22 mm.

http://www.x-tremeshooting.com/index.php?page=centragoliath

http://www.brownells.com/rifle-parts/sights/front-sights/centra-goliath-front-sights-prod38268.aspx

l_749008274_2.jpg

Edited by 2Xalpha

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Take a look at Bobby Johnson's iron sight setup.

Does anybody have recommendations on a good clamp on front sight and a thin post?

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Does anybody have recommendations on a good clamp on front sight and a thin post?

Armalite Naional Match A2 base and a .040 post from White Oak Armory.

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I'm so glad I found this forum, I have 45* irons and glass on my AR-10 now.

 

I'll  be putting a set of regular irons on it soon.

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Timely.  After my cataract surgery I'm going to start shooting my AR 22lr upper in steel challenge just for fun.  Told wife I won't shoot in RFRO, her division.  The CMMG conversion is a brick, but fun.  Now I see what might be out there better than the BUIS I currently have on the upper.

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  As a devoted iron sight shooter, I have read and appreciated this thread several times. Sadly, I learned earlier this year that the DPMS detachable A2 rear sight is now out of production when I tried to buy one for a new build. There are still a few standalone rear sights out there, but they are either the A1 type or have the mounting nuts on the left side of the rifle (the DPMS sight has mounting nuts on the right, out of the way of a right handed shooter's access to the charging handle).

  I use the DPMS A2 with two marks on the drum, one for 200 yards and another mark for 300 yards. Anything beyond 300, I just hold over.

Hurley

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1 hour ago, HRider said:

  As a devoted iron sight shooter, I have read and appreciated this thread several times. Sadly, I learned earlier this year that the DPMS detachable A2 rear sight is now out of production when I tried to buy one for a new build. There are still a few standalone rear sights out there, but they are either the A1 type or have the mounting nuts on the left side of the rifle (the DPMS sight has mounting nuts on the right, out of the way of a right handed shooter's access to the charging handle).

  I use the DPMS A2 with two marks on the drum, one for 200 yards and another mark for 300 yards. Anything beyond 300, I just hold over.

Hurley

 

HRider, if you're looking for an excellent solid rear iron, check out Daniel Defense.  I use them on my PCCI for Steel Challenge.  The windage knob is nearly flush with the protective wings, so there's relatively little visual obstruction.  The price is right too.  If you want something with a nice elevation knob on the rears, checkout Lewis Machine and Tool; the mounting nut is on the left, but you could probably reverse it and not look too odd....  Best, J

 

image.thumb.png.d478f70770d4f98ebf9e4c85a5aff3ec.png

image.png.f880569f93b758aecbf337eed3f46b43.png

Edited by jkrispies

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5 hours ago, jkrispies said:

 

HRider, if you're looking for an excellent solid rear iron, check out Daniel Defense.  I use them on my PCCI for Steel Challenge.  The windage knob is nearly flush with the protective wings, so there's relatively little visual obstruction.  The price is right too.  If you want something with a nice elevation knob on the rears, checkout Lewis Machine and Tool; the mounting nut is on the left, but you could probably reverse it and not look too odd....  Best, J

 

image.thumb.png.d478f70770d4f98ebf9e4c85a5aff3ec.png

image.png.f880569f93b758aecbf337eed3f46b43.png

Thanks, I have looked at the Daniel Defense sight, it should work great for a PCC and even a match rifle, it just doesn't have the ability to dial up. The LMT is one of the others that I was referring to, it is fine, just the nut is not in the ideal location. I was able to buy a used DPMS rear from another iron shooter for my new build. I wish that I would have known that they were going to stop production, I would have bought up a few for the future.

Hurley

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On 5/28/2018 at 4:10 PM, HRider said:

As a devoted iron sight shooter, I have read and appreciated this thread several times.

Thank you for appreciating this "resource". :) 

 

It's time to take a look at some new offerings for competition iron sights.

 

Estonian company Nord Arms offers a front-sight in anodized aluminium, either for a barrel diameter of 0.750 in or 0.875 in (19.1 or 22.2 mm). It has bolts for fine tuning the height from the barrel between 44-61 mm (1.7-2.4 in), and weighs 177 grams.

ADC - Armi Dallera Custom offers the same adjustable Sight Riser Block as used by 2017 IPSC Rifle World Shoot silver medalist Sami Hautamäki. The sight block has a numbered adjustment wheel to help with zeroing. Made in Italy from aluminum and stainless steel. Compatible barrel profiles are not listed, but the website appears to say the riser is not for bull barrels(?)

 

na-fs-750-1_1_orig.jpg

na-fs-750-2_1_orig.jpg

ADC-Sight-Riser-Block-ADJ-2.jpg

Edited by 2Xalpha

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Here is a table showing at what distances the target will be covered with some different front-sights. The IPSC Target is 45 cm wide and the IPSC Mini-Target 30 cm wide. "Cover distance" depends on the front-sight width, as well as distance from the front-sight to the eye

 

 

Target_coverage_by_front_sight_width.png

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So I am coming into this kinda late, but I am going to convert my 18" upper to be an Iron sight rifle for limited/factory division. I am really debating on using this- https://www.brownells.com/rifle-parts/sights/front-sights/ar-15-fixed-clamp-on-front-sight-prod85934.aspx?avs|Make_3=AR-15 for my front sight. I like that it is barrel mounted, I can push it all they to the back of the comp. I am just curious if anyone has any reviews or has used one yet?

 

Edited by CJeromeE
Did not finish before I posted.

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I have not used one. I thought about one for my last build, but decided against it because it doesn't use standard AR15 sight posts. For a few dollars more, you can get a JP front sight. It clamps on basically the same way and uses standard AR15 sight posts. Check it out. I have also used Yankee Hill Machine folding front sight gas blocks. I modify them to lock the front sight in the up position. They also use standard AR15 front sight posts.

Hurley

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My second choice was one of the Yankee Hill Machine FSPs, I like that I don't need to remove my comp to install. How do you modify them, if you don't mind me asking?

 

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I drill an tap a hole through the side plate of the base into the top part, then screw in a 6-32 screw to lock the sight into the up position. It is pretty tight as it comes, but with the screw, it is locked together as a solid piece. If you ever want to fold it down, just remove the screw and it works like they intended. 

Hurley

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