5 56 Nato Vs 223 Accuracy

The AR-15 pattern rifle has several design features that have helped it become popular for varmint shooting. First is the detachable magazine, which is usually best in 10- or 20-round capacity versions, as they don't protrude so far down to cause interference with the rifle being rested on sandbags . When sitting on the edge of a heavily populated prairie dog town, the high capacity and quick reloading feature is appreciated and can translate into more hits at the end of the day.

Furthermore, the AR-15 stock is essentially directly behind the barrel , resulting in much of the recoil being directed backward with little muzzle rise. Varmint shooters appreciate these features, as it allows viewing bullet impact through the scope. If a varmint is missed, compensation can be made immediately with a quick follow-up shot without moving from the rest or shooting position. With the correct combination of ammunition, bullet style and weight, barrel twist, along with a quality rifle, accuracy is often under .5 inch at 100 yards. While the 5.56 mm and .223 cartridges are very similar, they are not identical. Military cases are made from thicker brass than commercial cases, which reduces the powder capacity , and the NATO specification allows a higher chamber pressure.

Test barrels made for 5.56mm NATO measure chamber pressure at the case mouth, as opposed to the SAAMI location. This difference accounts for upwards of 20,000+ psi difference in pressure measurements. The 5.56 mm chambering, known as a NATO or mil-spec chambers, have a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet.

The .223 chambering, known as the "SAAMI chamber", is allowed to have a shorter leade, and is only required to be proof tested to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber or the Armalite chamber, which are designed to handle both 5.56 mm and .223 equally well. In 1961, marksmanship testing compared the AR-15 and M-14; 43% of ArmaLite AR-15 shooters achieved Expert, while only 22% of M-14 rifle shooters did. In July 1962, operational testing ended with a recommendation for adoption of the ArmaLite AR-15 rifle chambered in 223 Remington.

In September 1963, the 223 Remington cartridge was officially accepted and named "Cartridge, 5.56 mm ball, M193". The following year, the ArmaLite AR-15 was adopted by the United States Army as the M16 rifle and it would later become the standard U.S. military rifle. The specification included a Remington-designed bullet and the use of IMR4475 powder, which resulted in a muzzle velocity of 3,250 ft/s and a chamber pressure of 52,000 psi. Chambers cut to .223 Remington specifications have a shorter leade area as well as slightly shorter headspace dimensions compared to 5.56 mm "military" chamber specs, which contributes to the pressure issues. Twist rates as a ratio – smaller ratios as more rotationsScience aside, your rifle's barrel length and twist rate makes certain rounds give the best performance. While you might hear that the bullet weight dictates the twist rate , this is not entirely true – but usually true enough for practical purposes.

From a scientific point of view, length of the bullet has more to do with the best twist rate than weight alone. The weight measurement usually still works in our case because heavier bullets are often simply made to be slightly longer in length to achieve the extra weight. So weight is a pretty good practical measure in most cases.

Another common mistake is saying that the weight in grains has to do with the amount of powder in the round. The reality is a heavier grain round might have more powder or it might not. Early Armalite and later Colt AR-15/M16 rifles featured a one-in-12-inch twist rifling with some reports indicating that a one-in-14 twist was also tested and used. I had one during the early 1980s, but they are not especially common. Period military ammunition, known as M193 ball, contained a 55-grain FMJ boat-tail with a muzzle speed of 3,250 fps.

By 1980, FN designed a 62-grain bullet for the 5.56 NATO that featured a lead core with an FMJ in boat-tail form, but it had a steel penetrator tip and was rated at 3,100 fps. This required a faster-twist rifling, with the U.S. military changing in 1984 to one turn in 7 inches to accommodate the newly adopted M grain ball load. Today, however, military ammunition continues to evolve with more specialized bullet weights for purposes that include close-quarters combat, optimized long-range loads and long-range target competitions.

As a result, manufacturers report government contracts for M16 rifles with twist rates that also include one in 9 and one in 8 inches to better optimize accuracy with specified bullets at defined distances. Manufacturers offer the same twist rates for rifles sold to the civilian market, but select companies still offer twists of one in 12 and one in 6.5 inches. The two cartridges are dimensionally similar but are only partially interchangeable.

For example, the .223 was loaded to a maximum average pressure of 52,000 CUP , and pressures are measured in the case body. The 5.56 is currently loaded to 58,500 psi, with pressures being measured just forward of the case mouth in the chamber. This different pressure measurement method translates to approximately 62,000 psi chamber pressure. The chamber throat of the 5.56 is also longer than the .223.

Let's take a look at the recoil energy that is generated from our ten selected rounds and see if this trend holds up or if we see a little more variability. This data was generated using each rounds bullet weight, muzzle velocity, gun weight , and the powder charge. For the powder charge, we averaged several common powder loads from Nosler's load data and kept that charge constant for each round of the same cartridge. These numbers might fluctuate slightly depending on the actual powder charge used by the manufacturer, but the trends between the cartridges should remain . This twist rate was used on early AR-15 rifles, and custom builders can still make an upper to this specification.

It generally stabilizes bullets ranging from 35 to 55 grains but especially thrives with virtually all cup-and-core 45- to 53-grain weights. These bullets have become particularly popular with varmint shooters for their ability to reach high velocity and give explosive performance at common prairie dog shooting distances of 150 to 300 yards. Interestingly, many .223 Remington bolt-action sporting rifles that have earned an outstanding reputation for accuracy with 50- to 53-grain bullets are fitted with this twist rate. The comparatively slow bullet rotational speed permits its use with many of the highly frangible varmint bullets without their disintegration in midflight. Several of the powder manufactures list 5.56 loads seperate from 223, within their on line manuals.

With the common 55gr and 62gr bullets the COL remains the same, this is because the bullet canlures for crimping is the determineing factor. With the huge variety of mostly heavier bullets without a canlure the additional length of the 5.56 chamber can be utilized. You're unlikely to find a 1-in-14 barrel on any AR-15 produced in recent years, but they do exist and you may encounter them on a bolt action rifle on occasion. This is the least-versatile twist rate you'll see in the 5.56x45mm/.223 Remington chambering. Although 1-in-14 barrels can stabilize 55-grain bullets used by the original M16, it's really better suited for bullets up to 50- and 52-grains—most of which fall into the varmint and target category.

If achieving maximum velocity with light bullets is your goal, this may fit your needs — Winchester's 45-grain JHP load is a screamer at 3,600 feet per second. The .223 Remington performed well enough for the military in the 60's and 70's. This meant "suping" up the old round with higher pressure, resulting in greater velocity with a heavier bullet.

In the late 1970s, FN Herstal introduced a new version of the .223 Remington called the 5.56 NATO. It consisted of the SS109, SS110, and SS111 cartridges. The SS109 weighed 62 grains compared to Remington's 55-grain bullet. It used a steel core to provide armor penetration at 600 meters. This round would become the popular M855 "Green Tip" in use today. This heavier bullet generates more pressure and uses a different chamber than .223.

This is why it is not always safe to cross-load 5.56 NATO and .223 Remington in a single AR-15. Let's take a closer look at ballistic data and specification of the two rounds, then we'll answer some common questions. On the other hand, the .223 cartridge can be safely used in any rifle chambered for the 5.56.

Keep in mind, however, that .223 cartridges are not generally loaded with a mil-spec primer and neither are they crimped in place. Depending on how a given chamber is cut – leade angle, etc. – some rifles fail to shoot .223 ammunition to its full potential. For short-range trajectory, we are going to compare our selected rounds out to a distance of 300 yards with the test firearms zeroed in at 100 yards. Data was generated by compiling the numbers from the manufacturer or by a ballistics calculator. With the ballistics calculator, we determined the short range trajectory by using each rounds bullet weight, muzzle velocity, and ballistic coefficient .

By observation, 5.56×45mm NATO ammunition is not as accurate as 223 Remington in many of the AR type rifles extant, even with the same bullet weight. It was designed to increase the accuracy of 5.56×45mm NATO ammunition to that of 223 Remington. Other companies also have chamber designs that increase 5.56×45mm NATO accuracy. Since all AR-15 chambers and 5.56 NATO cartridges have variances in their design, you can never be certain that you're operating at truly safe chamber pressure limits.

Even if your .223 gun seems safe and accurate after firing a few dozen NATO rounds down the tube, the small increase in pressure could climb over the advertised rating of 62,000 PSI. Over time, this would result in added wear-and-tear on your barrel/chamber, receiver, and rifling. That means changing your barrel sooner than you should have to. What I am saying is that I have had perfectly fine, even outstanding, accuracy shooting .223 loads, in both 223 and 5.56 brass, in 5.56 spec chambers.

The 7-inch twist has become a standard for long-range competition and target work and is most often used in conjunction with 60- to 80-grain bullets. These loads exceed industry cartridge guidelines and are too long to function in magazines without the above modification, or they must be fired in the single-shot mode only. Clearly this approach is competition driven and impractical for defense or hunting applications.

From our experience and research, the 7.62x39mm offers a lot more options when it comes to hunting more medium sized game. The increase in bullet energy for these rounds within 100 yards is much better suited for medium sized game. For shots within 100 yards, you have a fair shot at good bullet placement, and with the stopping power of the heavier bullets, you should be able to make a clean kill. These same regions also make it a popular cartridge for close quarters combat. If you pair the correct bullet design, you can easily punch through cover with this cartridge with power to spare.

The 223 Remington and 5.56×45mm NATO barrel chamberings are not the same. While the cartridges are identical other than powder load, bullet weight, and chamber pressure, a significant difference is in barrel of the rifle to be used, not in the cartridge. The 5.56×45mm NATO chambers are dimensionally larger in certain critical areas than 223 Remington chambers. As the chambers differ accordingly the head space gauges used for the two chamberings differ. The external dimensional specifications of 223 Remington and 5.56×45mm NATO brass cases are nearly identical.

When hand-loaded, care is taken to look for pressure signs as 5.56×45mm NATO cases may produce higher pressures with the same type of powder and bullet as compared to 223 Remington cases. Sierra provides separate loading sections for 223 Remington and 5.56×45mm NATO and also recommends different loads for bolt-action rifles as compared to semiautomatic rifles. Shooting a 5.56 NATO cartridge out of an AR-15 with a .223 chamber will result in a greater pressure than the chamber is designed for. Thisover-pressurizationis why many shooters say it's not safe to shoot 5.56 in a .223 gun.

It's not just more powder in the cartridge causing the higher chamber pressure with 5.56 loads in .223 guns. It was designed to be able to shoot both standard 5.56 NATO military ammunition and heavy bullet (75-77 grain) match rounds more accurately than a standard 5.56 NATO chamber. Bill Wylde did this by changing the leade, or the chamber throat so it was tighter than a NATO chamber, but still had enough room to safely accommodate longer bullets.

The .223 is a relatively short cartridge designed for more compact rifles. It is shown here with the larger 6.5 Creedmoor.As a result, M16s got generous chambers. Bolt-action rifles enjoyed tighter tolerances, shorter bullet jump and slower 1-in-12 rifling for popular 40- to 55-gr. But, today's AR's in the civilian market have proven to be extremely capable of impressive accuracy as well. Determining proper twist is a factor of bore diameter, velocity, bullet weight and even bullet construction.

It is not safe to shoot "5.56" "5.56 NATO" or "5.56x45mm" ("5.56") ammunition in a firearm with barrel marked as being chambered in 223 Remington for a number of reasons. This can result in serious injury or death to the user and/or bystanders, as well as damage to the firearm. These rounds are designed with a larger size than the .223 rounds. However, they are incredibly lightweight and travel at ultrafast speed to reach high distances.

These rounds are arguably the best in the 5.56 NATO rounds categories. They are also ideal for many applications, including hunting, target practice, and tactical situations. Importantly, their reliability is also on another level and delivers enviable stopping power. The bullets are powerful and reach a muzzle velocity of 3100fps from a 24-inch barrel. Many gun experts agree it is one of the best ammo for self-defense. Additionally, manufactured 5.56 rounds are made for the longer leade and, therefore, may have the bullet seated differently.

If the bullet from a 5.56 makes contact with the rifling in a chamber designed for a .223 Remington prior to being fired, this too can cause unwanted pressure increases. So what bullets and twist rates are correct for varminting or taking that long-range coyote? First, bullets of the same weight can vary dramatically in length, bearing surface and ballistic coefficient and may require a different twist rate for perfect stabilization. In extreme instances, bullets can become damaged in a poor quality bore and fragment upon exiting.

Reasons for these twist rates have included changes in military ammunition in an effort to improve overall performance, long-range competition and advancements to hunting and varmint bullets. Also, the throat or leade is longer in the 5.56x45 mm chamber. You should not shoot 5.56x45 mm NATO out of a rifle that is chambered in .223 Rem. Ammunition will not reliably cycle through some AR-style .223 Rem. As a matter of fact, I have not encountered any difficulty with current .223 Rem. Comparing averages, we get a 1% difference in muzzle velocity between the two chambers.

The graph above shows amazing consistently between each trial run, too. This indicates with no doubt that chamber pressures are just about exact in both guns. The result is a gun that can safely and accurately chamber both 5.56 NATO and .223 Remington, without sacrificing the performance of either. The real difference between 5.56 and .223 isn't the cartridges, but the chambers and barrels of the guns firing these two cartridges. Remember those reliability issues the M16 suffered in Vietnam? When the rifle got dirty and gunked up, tight tolerances made chambering rounds and cycling the weapon difficult.

Beretta Arx 100 300 Blackout Barrel Kit

This rifle was designed to be completely ambidextrous, and all the critical controls on it may be operated right- or left-handed. These include the 2-position safety, the magazine release, the bolt release and charging handle and the case-ejection selector, which determines whether spent brass is ejected to the right or left. The flip-up backup sights that come standard on the ARX100 are also versatile, offering an easily-adjustable diopter system ranged from 100 to 800 yards. The barrel is also easily replaceable in seconds, making it possible to use different lengths and calibers without any tools required. Lastly, the folding stock is adjustable for length of pull at the touch of a button, using a simple and rugged telescopic construction.

The first thing that comes to mind when I think of the ARX is the keen focus its designers put into creating a truly ambidextrous firearm. The most laborious task when setting this rifle up for a left-handed shooter is nothing more than grabbing a bullet and using it to depress a tab towards the rear of the receiver. This action swaps the ejection pattern to the opposite side of the other side of the rifle.

After this, all you need to do is swap the charging handle, which is as simple as pulling back, pulling outwards on the handle itself, and swinging it across to the other side. The rifle's other notable ambidextrous features include the fire selector, the magazine release, the bolt release, and the interestingly-placed bolt catch on the bottom of the trigger guard. The U22 Neos is designed for field stripping without tools into basic modules for cleaning. The Weaver-style rail incorporates a fully adjustable rear sight and a removable front sight. The grip and trigger guard assembly, made from fiberglass-reinforced "technopolymer", is attached to the receiver with a single bolt and can easily be removed and replaced with an accessory grip. Unusual for a pistol the magazine release is above the trigger guard and is operated by a right-handed shooter's trigger finger.

The magazine holds ten rounds, giving the Neos a total 10+1 capacity. Beretta's entry into the tactical rifle market took the industry by storm with today's ultimate tactical rifle. Creating a hard-use tactical rifle by combining the principles of modularity, simplicity, and reliability was what Beretta set out to accomplish. Beretta made short work of this concept and the futuristic ARX100 was born. Fully ambidextrous controls, replaceable barrels, and countless accessories, make the ARX100 a perfect fit for multi-mission roles.

Utilizing a constant contact, short-stroke gas piston system ensures complete reliability in the most adverse conditions. Endless customization is made possible by the ease of disassembly, allowing the user to swap barrel lengths and calibers in seconds, all without the need for cumbersome tools. The folding collapsible stock can be configured to suit any user or application. A full Picatinny top rail accepts a wide range of optics, lights, and lasers to truly make the ARX100 a formidable firearm.

The mad scientists at Beretta completed their mission by creating the ultimate tactical rifle, now use the ARX100 to complete yours. If you're not a southpaw, the ARX-100 still offers a compelling feature set. First, in a departure from its AR70 predecessor, the ARX-100 takes STANAG magazines. If you have a stockpile of P-Mags in your desk, the ARX-100 will run with those. The ARX-100 has a telescoping and side-folding stock, a cold hammer forged barrel, and operates on a constant contact piston system.

One of the neat features is the quick change barrel system. Remove the standard barrel without tools, and replace with the length of your choice. The gun is multi-caliber compatible, meaning that a change to .300 Blackout would be as simple as a barrel swap. Other caliber swaps are possible with a bolt change. In fact, the select fire ARX-160 is in use by the Special Forces of Kazakhstan chambered in 7.62×39.

This provides an uninterrupted plane to mount any type of carbine-compatible optic, from a red dot to a hunting scope. The gun comes with polymer flip-up front and rear sights that are adjustable for windage and elevation. The rear sight has five apertures situated on a disc that are calibrated for ranges of 100, 200, 300, 400 and 600 meters.

Expanding on the modularity of the U22 Neos pistol, in 2004 Beretta introduced a U22 Neos Carbine Kit that transforms the pistol into a light rifle. The kit includes a skeletonized butt stock that takes the place of the grip on the pistol and a separate fore-end assembly that replaces the pistol barrel. A fiber-optic front sight is mounted on the barrel and the integral Weaver-style rail includes an aperture rear sight. This Neos carbine configuration appears quite similar to the Buck Mark Sporter Rifle, but Browning Buck Mark pistols and rifles are purpose-built and major components cannot be interchanged.

Besides featuring left or right ejection, the charging handle can be quickly changed from one side to the other. The magazine release, located in the same general area as an AR's, can be activated from either side. And the magazine can also be released by pushing up on a button located at the bottom of the triggerguard just to the rear of the magazine well. The bolt can be locked to the rear with the same button.

The bolt catch can also be activated with the trigger finger by a button located on either side of the receiver just to the rear of the magazine well. The safety lever is fully ambidextrous and located in about the same place as an AR's. It is a little stiff and could be a bit longer though for better leverage. The ergonomic design is different than a typical AR-type rifle, and that's OK. Despite the ARX100's light weight, recoil was quite manageable and not uncomfortable in the least. The controls were positive and required only a bit of getting used to.

Magazine changes were quick and easy to accomplish even though there is no bevel on the magazine well. Incidentally, the ARX100 uses AR-15 magazines, so there will be no need to search for special proprietary magazines. Returning the bolt to battery after loading was lightning quick because the trigger finger did all the work without the need to modify the shooting hand's position. During the entire testing period, no malfunctions of any kind were encountered. I used an EOTech XPS3 holographic sight with a 1-MOA red dot within a 65-MOA circle for a reticle.

This sight is very fast for tactical drills or hunting. Its monolithic top rail includes flip up iron sights. The cold hammer forged barrel with two-position gas block regulates the short stroke gas piston and is designed to cycle even the lowest power 223 ammo.

Unlike the AR-15, the charging handle on the ARX 100 reciprocates with the bolt. Therefore, it is easy to simply grasp the bolt-mounted handle and give it a tug. To change the ejected cartridge's path from one side to the other, a bullet nose is inserted into an opening just to the rear of the receiver.

This is a bolt that lets you press the bolt to one side or the other to control ejection. There are two extractors and this cross-bolt activates one or the other. This may be debated at length, and it is what it is, and when being used, cocked and ready for action the rifle will be open.

At the moment, Beretta is simply trying to meet demand. The ARX 100 features a unique design that lets you change brass ejection on-demand from right to left. This makes the ARX 100 a truly ambidextrous rifle, with excellent interchangeability and ambi options. The selector controls and the magazine release are ambidextrous units. If the magazine release does not function correctly, there is another release just in front of the trigger guard for a total of three magazine release buttons! The third lever is actually a lock rather than a button.

It is more like the AK 47 than the AR-15 type release, while the primary release is a close copy of the AR-15. In 2003 new features were added to the U22 Neos product line, in the form of DLX models which can be identified by a special U22 NEOS logo is engraved on the slide. As with the standard models, the U22 Neos DLX was made with blue or stainless steel finish.

DLX barrel length was 6 inches or 7.5 inches (no 4.5 inch DLX model). DLX triggers are adjustable for pre- and overtravel. Front and rear sights have user-replaceable blades in different colors. DLX models have rubber inlays in the pistol grip; these inlays are textured to improve the shooter's grip and are colored for a distinctive appearance. Even with features like removable barrel and piston operation, I was able to get 100 yard groups just over an inch when shooting good ammo with care.

If your primary concern is bench rest accuracy, you wouldn't buy a configurable, piston operated battle rifle anyway – that's not its intent. If you're looking for a defense gun ready for rough conditions, this might be your huckleberry. It'll stay clean, is easy to maintain and can be adjusted to fit any shooter in seconds. Speaking of stripping, to field strip the rifle, you put the bolt in the maintenance position and fold the stock into the pistol position.

Next, rotate the safety lever past "S" while pushing into the back of the receiver, now uncovered because the stock is folded. At this point, you can rotate the pistol grip out of the upper receiver and the major components come apart. It's a lot easier than it sounds and requires no tools.

Make sure to practice with this system to become acclimated. If you're used to shooting standard AR-type rifles, you won't want to be reaching for a bolt release button on the left side as you might drop a magazine. You also will want to train your fingers to find positions of the bolt release levers and magazine release levers, as they are about an inch apart on both sides of the receiver. The ARX100 is the ultimate evolution of the modern sporting rifle. Designed for ease of use and ultimate reliability, the ARX100`s feature set is unparalleled.

The cold hammer forged barrel can be removed and replaced with various lengths and calibers in a matter of seconds. Case ejection can be switched from right to left with the simple push of a button. All of the critical controls on the ARX100 are completely ambidextrous. With a constant contact piston system, the ARX100 can easily feed and fire under the most unforgiving conditions. The lightweight, technopolymer receiver allows for reliable operation with virtually no lubricant. To make maintenance easy, the ARX100 has no pins and can be completely disassembled with no tools at all.

The ARX100 is the next step in modern sporting rifle evolution. This is a minor complaint, especially given the rest of the rifle's stellar features, like the adjustable folding stock and the quick-change barrel system. Initially, I didn't see the utility for most civilian shooters. A skilled person can remove and replace the ARX-100's barrel, sans tools, in under 30 seconds. Simply lock the action open, remove the bottom handguard cover, pull down on the barrel release levers and pull the barrel free. A hell of a feature on a squad automatic or an LMG, but not so useful on a civilian weapon.

At least, that's what I believed until I heard about the caliber conversion kits. I was interested in it and when the price showed up so low, I went to try one on. The lower part of the forearm is ergonomically perfect for a grip. The quick change barrel lockup is rock solid and simple.

Magpul gen 2's fit fine, as do Lancers and good old GI's. Sure, there are some things that could be slightly better, but only slightly. I've seen guys knot themselves up with their sling by having it connected in the wrong place and trying to switch on the fly.

The rifle comes with a folding stock that is adjustable for length of pull. Controls are laid out well and are easy to manipulate and reach for shooters with small hands. The charging handle is reciprocating, but small enough so that it didn't get in the way while shooting from inside vehicles. By design, the charging handle is very small compared to other systems due to the ambidextrous design of the weapon.

One of the nifty features of the ARX100 is the quick change barrel design. The end result is that you can change the barrel completely, in seconds, without any tools whatsoever. Over time, we might see conversion options for things like 300 AAC Blackout, 6.8 SPC and 7.62×39 – not to mention short barrels. First off, it's important to note that 10 rounds at Media Day isn't enough trigger time to offer a real review.

But it is enough time to gain an initial impression of the gun, and the ARX-100 has a lot of positive traits to it. One of the big complaints about non-AR-15 rifles in .223 is that they have an unusual recoil impulse, a trait not shared by the ARX-100. The stock rifle uses a standard birdcage style flash hider, but even with only that the recoil impulse is straight back. The rifle doesn't porpoise and flex when firing, but delivers the recoil in a linear impulse straight back to the shooter. While I've listed many positive qualities of the ARX-100, not everything about this rifle can be viewed through rose tinted glasses.

In fact, some of the baggage brought about by this rifle cannot be spun in a positive light at all. One shining example of a feature that cannot be viewed in any real positive light would be the sling loops. The designers at Beretta opted out of adding QD sockets to the ARX in favor of five metal sling loops molded into the body as well as one sling swivel placed in the gas block. Under normal circumstances I wouldn't have a problem with such an idea, but the problem is that these loops are four strands of angel hair pasta in thickness.

This means that there aren't many good choices for sling attachment hardware which will mount to this rifle. The current sling I've got mounted, a Blue Force Gear Vickers sling, uses MASH loops. These fit through the sling loops but provide almost no freedom of movement meaning that while hanging the rifle does swing around in ways I wish it wouldn't. On top of this, the MASH hooks have a gnarled polymer receiver of the rifle which is something that wouldn't be a problem on rifles with more standard mounting hardware.