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AR PERFORMANCE

 Frequently Asked Questions 
  • Build an upper? quick tips
    Please, when building your upper use good building procedures it will save a lot of headaches later. Many think the AR is like legos and anyone can slap them together on the kitchen table and they will run perfect. Maybe if you're lucky. It's better to be a good builder than a lucky builder. *When assembling the gas tube and gas block MAKE SURE the gas port in the gas tube aligns with the port in the top of the gas block. Remove the rear set screw and look down through the hole into the top of the gas block. IF ANY part of the gas tube covers the hole in the gas block drill it out with a 5/32" bit. *Use a sealer(not silicone) between the gas tube and gas block to prevent gas leaks. Blue loctite works. *Use a sealer between the gas block and barrel. Any gas leaks in either location will cause problems when the pressure is 14,000psi. *align the rear set screw with the dimple in the bottom of the barrel. That is what makes sure the gas port in the barrel aligns with the port in the gas block. The dimple is exactly 180* around the barrel from the gas port. * If the barrel is a loose fit in the upper receiver use bedding(blue loctite is simple and works, been using it for 27 years)around the barrel extension not the threads. That helps make the connection between the barrel and receiver more rigid. The scope is connected to the receiver and the receiver to the barrel that connection between the barrel and receiver is critical. Use 40 ft lbs minimum torque then turn to the next hole to align it for the gas tube but do not go over 80lbs. *Do not over torque the muzzle device, 15 ft lbs is all that is needed. * OIL the bcg and keep it wet. See below for short stroking problems.


  • Short stroke? Align gas block/ port location and the dimple.
    Most gas blocks have a hole .298-.300" from the rear of the gas block. That matches the port in our barrels +- allowing for a little manufacturing tolerance of holes in gas blocks. If you use a handguard with a cap the cap forces the gas block forward another .033" unless you use a FSB with a hole at .265" from the rear. The rear set screw in the gas block is where the gas port in the top of the gas block is drilled. To align the holes place the rear set screw in the dimple on the bottom of the barrel. Remove the rear set screw, align the hole in the dimple and tighten the front set screw then replace the rear. http://68forums.com/forums/showthread.php?55097-SHORT-STROKING-PROBLEMS-build-tips ***FYI- The hole in the top of most gas blocks is .1495" If the port size in the barrel is .082 you can slide the gas block as much as .034" toward the shoulder on the barrel to close the gap if need be. ARs cycle from pressure created by the ammo. Different ammo and different loads create different amounts of pressure at the gas port which cause the carrier to move at different speeds. If everyone used the same ammo porting a barrel would be easy. We try to port the barrels with the combination most people use(carbine stock, standard springs and buffers with Hornady, S&B and Federal xm68 ammo). Any ammo or handload that produces 4000psi less or using heavy buffers and springs may cause the rifle to not cycle or strip cartridges from the mag. Remington and Federal Eagle ammo and many starting book loads do not produce as much pressure as Hornady, S&B or Fed XM68 ammo.


  • Checking Headspace
    From Forster- GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gage, the chamber will accept ammunition that is made to SAAMI's maximum specifications. The GO gage is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gage is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser. NO-GO: Corresponds to the maximum headspace Forster recommends for gunsmiths chambering new, bolt action rifles. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gage, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gage. The NO-GO gage is a valuable tool for checking a newly-reamed chamber in order to ensure a tight and accurate chamber. FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI's specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin. From PTG website- Exact same wording... Pacific Tool and Gauge offers three lengths of headspace gauges per rifle caliber. In order from the shortest to longest, they are: GO, NO-GO, and FIELD: GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gauge, the chamber will accept ammunition that is made to SAAMI's maximum specifications. The GO gauge is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gauge is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser. NO-GO: Corresponds to the maximum headspace Forster recommends for gunsmiths chambering new, bolt action rifles. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gauge, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gauge. The NO-GO gauge is a valuable tool for checking a newly-reamed chamber in order to ensure a tight and accurate chamber. FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gauge, its chamber is dangerously close to, or longer than, SAAMI's specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gauges are slightly shorter than the SAAMI maximum in order to give a small safety margin.


  • Phone calls -
    We are a small business... Sorry, we have 1 phone line and only a few guys that have many tasks. At this point in time we can't add someone to just sit and answer phones, it's tough to find someone that knows enough about AR15s to answer the questions correctly so it would just being them saying hello and handing me the phone anyway. Emails are the best way to reach us.


  • We will only ship to the billing address of the CC card.
    There are too many fraudulent attempts to allow any other type of transaction. The street address and zip code must match the billing address of the card. This protects the card owner, card issuer and this business.


  • Can I shoot 600 to 1000yds?
    The production barrels we sell for hunters and rec shooters are not made to shoot 600 or 1000 yds. I am not a used car salesman so I'm not going to lie in order to sell a barrel. Very very few people actually shoot that distance and those that do use a high end real match grade barrel like Krieger, Brtlein, Broughton. Our Socom 556 and 20" 556 barrels are very accurate with 69 and 77gr SMKs and they can be shot at 600 but If I was really going to shoot 600+ yds I would use a purpose built barrel and not use a lightweight hunting barrel and be disappointed because of trying to do something that it wasn't designed to do. Buy the right tool for the job.


  • NEW BARREL Cleaning and break in
    AFTER building the upper run a patch through the bore to remove the protective oil, grit and dust that accumulated during shipping and building the upper to make sure there are no metal particles that may destroy your barrel on the first shot. DO NOT try to remove the black surface, that helps keep copper fouling down and provides a barrier between the copper bullets and the bare metal. Clean the protective oil out of the chamber. It will be brown, the oil mixes with the Melonite. Do not leave any excess oil in the chamber or barrel after cleaning or before shooting. Melonite treated barrels usually do not copper foul like stainless barrels and no "break in" is needed. If(IF is the key word) there is a little copper fouling, use a good foaming copper cleaner when you come back from the range. A blue patch means there is some copper fouling in the bore so you should repeat the process until the patch comes out white. 1 patch with solvent to remove harsh copper cleaner thenrun 1 patch with alcohol. Then 1 patch with light oil like Rem oil or WD40. Then follow with 1 dry patch to remove the excess oil. The barrel will copper foul less and become easier /faster to clean each time. When the day arrives that you clean and no blue comes out you can ease off of the cleaning and shoot until the barrel loses accuracy, when it does clean it again with copper remover. Keeping the copper out so a good layer of carbon can coat the bore is the objective.


  • Melonite treated barrels exterior
    If you want to keep the deep black gloss finish do not use a strong solvent on the outside of the barrel, just wipe it off with a light oil. If you want a non glare finish wipe them off with alcohol. It will evaporate quick and dull the finish. DO NOT USE RUST-X or Bullfrog Rust hunter and be very careful with brake cleaners, some will discolor the finish of the melonite treated barrels. Melonite and parkerizing are controlled corrosion processes so any product that removes rust may harm the barrels finish. Solvents and oils used to clean guns will not hurt the finish.


  • Best mags for the 6.8
    #1- Best mags for use with factory ammo-Barrett, they are only avail in hi cap 30 round mags. Great quality, apx $45 #2-C Products Defense, Aug 2012. They have released new inexpensive mags that seem to get good reviews. 25 and 10 round capacity. PRI Gen 1 (old style, non-waffle)if you can find them(Precision Reflex inc), they allow loading to 2.3" very sturdy but no longer made. Stoner, Stag and others are rebranded ASC mags...the old CP mags.


  • military discounts
    We offer a 10% discount to military only IF you send in a copy of your military ID by email. Any orders placed using the military discount code will be cancelled if a copy of the ID is not sent by email to info@ar15performance.com


  • Scope mounts & accuracy
    DO NOT mount 1 scope mount on the receiver and 1 on the handguard accuracy will be poor due to flex in the handguard. Use the proper cantilever scope mount. And torque to 15 inch lbs, not ft lbs. Squeeze the trigger and follow through(hold the trigger back, do not allow it to reset until the bullet contacts the target)to get the best accuracy. Use a good sand bag or rest on a stable platform not the hood or tailgate of the truck. Best accuracy is usually found when the brass is close to the chamber size. When setting up your resize die do not simply follow the instructions on the dies set. Try to adjust the die where it sizes (shoulder location)the brass .002-.004 under the chamber size. Screw the die up 1/4 turn above the shell holder and size a piece. Try it in the chamber, if it doesn't fit screw the die down 1/16th turn. Repeat until the unloaded brass fits and the bolt locks behind it. Size and try several pieces to make sure the size is correct before loading any, pulling bullets isn't fun.


  • Suggest a cartridge for a specific use.
    I sell a lot of different barrels and many different ones to the same people. When they call back and the first words are "holy ****" I know they are happy about the performance. choices in order. Hogs- usually several shot while running---30 Herrett, 6.8, Grendel, 300 blackout- Terminal performance is everything here, BC and SD mean little. Deer- one shot, one deer while not moving---6.8, 30 Herrett, Grendel, 300 Blackout-the 6.8 has many more usable hunting bullet choices and most deer are shot under 300yds. Velocity must be fast enough to make the bullet expand at distance. varmints to yotes- 224 and 6mm Predators, 5.56x42, Tac6, 224 Valkyrie,5.56 they all work well. Long distance paper- 6mm Predator, Tac 6, 224 Predator, 5.56x42, 224 Valkyrie, Grendel. Exterior ballistics and accuracy are the key. CQB- 30 Herrett, 6.8, 5.56- Reliability and terminal performance first. DMR- Tac 6, 5.56x42, 224 valkyrie


  • Why do we sell (Melonite) treated barrels instead of chrome lined barrels?
    Nitro-Carburizing, Melonite, QPQ is a heat treat process for barrels that harden the barrels to apx 60 Rockwell so they last longer, are more corrosion resistant inside and out and it also decreases friction in the barrel which can increase velocity and cut down on copper fouling. Chrome lined barrels can decrease accuracy as it is a built up layer inside the barrel. Nitro-carburizing changes the structure of the metal without building a layer in the bore increasing performance but, not decreasing accuracy.


  • What do you recommend for a piston system?
    None, the piston systems have not proven themselves to be more accurate or reliable than the standard DI system. If you use our bolts in a rifle with a piston system and the bolt breaks at the cam pin hole it will not be covered under warranty. IMO piston systems cause more problems than they fix.


  • Can we use your products with other mil spec products
    YES, all of our products except the 750XD bolt will work with standard mil spec parts. The 750XD requires a matching barrel extension.


  • will you build an upper using my parts?
    Sorry but, No. At this time we are not building uppers. Blackstone Arms builds uppers using our parts.


  • custom 1 off barrel?
    Sorry, we just do not offer any gunsmithing services.


  • will you work on my upper or rifle?
    No, we are not set up as a smithing shop. We do not flute customer owned barrels. ADCO's primary business is smithing try them.


  • do you have reloading data for the 6.8? which bullets work?
    Reloading data can be found at most powder manufacturers web sites. If you are an experienced reloader you can get much more velocity with careful loading. The Speer 90gr TNT and Hornady 110gr HPBT seem to be accurate in every barrel I have shot or made. To get the best accuracy requires hand loading to an OAL of 2.295- 2.3" except when shooting the Hornady 110HPBT (try it at 2.258") Pri mags allow loading to 2.295". We recommend the use of CCI 41 primers, CCI 450 or Wolf Magnum primers, any erosion to the bolt face by the use of other primers will not be covered under warranty.


  • Can I use 5.56 mags in my XXX rifle?
    No, the 7.62x39 requires 7.62x39 mags, the 5.45x39 use 5.45 mags, the 6.8 needs 6.8 mags. In general most cartridges require a special mag except the 6mmx45 or other cartridges based on the .223/5.56


  • FYI- overgassed barrel- adjustable gas block
    If you have a firearm that is overgassed check out Black River Tactical's gas block with inserts to change the port size.- http://www.blackrivertactical.com/store.html#!/~/product/category=2710008&id=18000700 This IMO is the proper way to change the port size instead of a set screw that over time burns away.


  • What is my problem with the Grendel?
    I don't have a problem with the cartridge, I have a problem with the people that surround it and the lies they tell to hype it up and try to make everything else sound bad. They say the .136 recess bolt is stronger...lie They say hoop stress makes anything larger/stronger than a grendel unsafe...lie Any engineer can explain both, Next Arne was the first guy to stick a 6.5 bullet in a PPC case. Lother Walther who was already producing barrels for Arne introduced Bill Alexander to Arne. Arne gave Alexander all of his test data where he had been shooting his 6.5 CSS. Alexander got with Lapua and convinced them to make brass and trademarked the name "6.5 Grendel" That just screwed Arne out of his idea/invention. Alexander made everything about the Grendel different so everyone would have to buy from him. Bolts with a .136 recess, muzzle devices with a 9/16" thread and of course the trademarked name. He thought that would make him more money. It did in a way because now that the Grendel is SAAMI other better manufactures are producing parts and taking the lions share away from Alexander Arms. They repeat daily that the Grendel beat the 308 at Blackwater. They used an expensive Grendel match bullet and compared it to military ammo for trajectory. Then when it came time to shoot through glass they changed the bullet to a 144gr fmj and compared it to the same 308 military ammo. There are a few guys that hang out on the Grendel forum that say you can shoot deer at 6-700yds. Well you could probably hit one but it sure wouldn't be something a responsible hunter would do. They always talk about BC and that goes along with the last thing about shooting deer at 600 yds. They say the 6.8 and Grendel are really close out to 300yds but then the Grendel really pulls away. Most people with any common sense or ethics will not shoot an animal past the distance the bullet stops expanding. So lets say the 123 gr bullets starts off at 2500 fps out of a 20" barrel, 2400 out of a 16" barrel. At what distance does that bullet drop below the expansion threshold? Hornadys BC figures are inflated. The true BC of the 123 SST or Amax is around .465. Using Hornady's info from their website the 123gr bullet drops below the 1800fps expansion threshold at apx 400 yds when fired from a 20" barrel. Apx 350yds when fired from a 16" barrel. They talk about how superior the SD(sectional density) of the 6.5 is. SD doesn't kill animals. The construction of the bullet is much more important, the expansion, velocity and overall terminal performance is what is important. Then there is the BS about hoop stress. Alexander and his followers say that anything more high performance than the Grendel is unsafe. Well how convenient. Ask them (LRRPFT52)to show you the exact formula used to figure the hoop stress of a part that is under stress for 2 milliseconds. They can't because they are using a simple online calculator that only figures the outside wall stress at continuous pressure. The truth is the Savage rifle barrels are 1" dia, same as the AR and they among others are chambered in the 308 and everything else. There are hundreds of people that have been shooting 6BRs, 6BRX, 6.5BR, 22-250s and all kinds of wildcats more powerful than the Grendel since 2009 with no issues. Proves what they have been saying is untrue. The supermod of the Grendel forum and those guys want everyone to think the Grendel is the best and most high performance cartridge to fit in a AR15, it isn't. LRRpfftt or Paul Scott the supermod on the Grendel forum and his little buddy Cory are liars from the first word until the last. He spreads his crap to damage anyone that competes with the Grendel. Now he says I covered my badge at SHOT. Well I've only been to SHOT 1 time many years ago and Alexander Arms was not there the year I went so Paul Scott would have had no place to sit. They put down any one or any company that comes up with a stronger product because they can't figure it out themselves. A .136 recess bolt has less backing/attachment than a .125 bolt. That made the bolts 8% weaker than a bolt with a .124 recess. When Bill A. changed the recess in the bolt to .135 it moved the case .012" out of the chamber leaving more of the case unsupported by the chamber walls. That is why when you push the pressure on a Grendel the cases swell and come out looking like a belted magnum. Google Grendel belted magnum. The simple thing for an engineer or machinist to do is move the extractor pivot hole to allow the extractor to snap over the thicker rim of the Lapua cases. TBC...


  • Are the .136 recess Grendel bolts stronger or the .124 recess?
    A Grendel bolt with a .136 recess is weaker than a bolt with a .124 recess. Walk in any engineers office with the 2 different bolts and they should be able to tell you the bolt with a .124 recess is stronger with just a few measurements and without any calculations. To figure the strength of a bolt if the lugs were attached to a solid rod- LxWxHxYSx7. The lugs should be .277 long minus the recess gives you the important dimension. In the case of the Grendel it is .141". That is the part of the lug that has 100% (strength) attached to the bolt body. .277-.124=.153" that is how much of the lugs have 100% attachment on a 5.56, 6.8, 7.62x39 bolt. There is 7.2% less strength in the .136" recess bolts if you only figure the difference in strength due to the recess. Next because I know it's coming... 2)heat treat- The tensile and yield strength shown in the specs by the manufacturer of the steel is the max strength possible if you use their guidelines. You can't make steel stronger but you can use the wrong heat treat and definitely make it weaker. 3)The out of proportion extractor drawing LRRPFFT likes to post. When Alexander made the first Grendel bolts it was easiest to use a 5.56 bolt and bore it out. The rims of the Lapua brass are thicker than 5.56 so he bored it deeper so the extractor would snap over the thicker rim. That was easiest but if he had wanted to keep the strength he could have moved the pivot hole of the extractor forward .012" so the extractor would snap over the rim and the bolt would have been stronger. The exact same extractors like AA sells can be used on the 7.62x39 or the Grendel. R Guns and AR15 Hardware have both sold them. Our "Enhanced"/superbolt bolts are not a mil spec bolt design just named "enhanced" The radii really are larger to increase the mass and strength. They are not just a name like "Monster" with a funny little logo on them.


  • cartridge stuck in chamber-
    Just an FYI- If you have a cartridge stuck in the chamber and can't get it out by pulling on the charge handle do NOT stomp or beat on the charge handle. Mortaring(tap butt on ground while pulling charge handle) may be the military way but there is another way. Stick a big flat blade screw driver up through the mag well and place the blade between the front of the carrier and the barrel extension and twist it.


  • Black Nitride, Melonite, QPQ,
    All of these processes are the same thing. Melonite is a registered trademarked process but they all do the same thing and should not be used on bolts or barrel extensions. Bolts and extensions should be carburized for heat treat. The Melonite or Black Nitride process should not be used on already hardened bolts and extensions as it will soften and weaken the already hardened parts.


    This business supports AMERICA and its Constitution

    (ARP) AR15 Performance LLC

    Key West, FL 33040

    Hi performance 5.56 & 6.8 SPC barrels and parts since 2007

    The best way to contact is by email
    Email:  tech@AR15performance.com

    Phone: 801-750-4216  8am-5pm eastern time  M- Fri only
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      6mm Predator, 277 WLV,  224 Grendel, 6mm Grendel, 6.5 Creedmoor, 5.56 x 42,
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