Rapid fire in a non chrome lined AR15 barrel

[Peter83]

Hi guys

I have a question about rapid fire with a AR15 in a non chrome lined barrel. The barrel is a Lothar Walther, dont know the material.

Will it wear a barrel quicker than normal, if i rapid fire, but dont let the barrel get hotter than i normaly would? Is there anything specifik in rapid fire, other than heat from the fast firing that "hurts" the barrel in a way, that non rapid fire from a equal hot barrel dont do? Will the rapid fire somehow heat up/wear the troat in the barrel in a way normal fire wont do, even if the barrel feels equal hot to the touch?

Also, is it possible to see without a borescope if the throat is worn, just by looking through the barrel?

Btw, when i say rapid fire, i dont mean mag dumbs or anything. More like 4 rapid shots, then some at slower pace, then 4 rapid shots and so on.

Best regards, Peter.

 

[bfoosh006]

IMHO, think about like your cars motor... redlining it will wear it out fast, driving like a Granny will ( with decent maintenance ) make it will last a long time.

So if you occasionally run it hard, it can take it... and given your firing schedule, you should be fine.

 

[pmclaine]

You will not harm your barrel.

I think of chrome lining as a corrosion protection treatment - helps with environmental issues militaries subject their gear to and operations may not allow proper cleaning.

Chrome lining does allow some wear protection in full auto rifles.

Rapid fire in cross the course firing is ten rounds in one minute. Those barrels last a long time.

The use you describe does not indicate it would hurt your barrel.

Do not use a borescope on your barrel unless you are mentally prepared for what you will see.

The camera will show you all sorts of stuff that will indicate to you your rifle barrel is junk but your reality will be that it shoots fine.

 

[Fig]

For 99% of people out there rapid fire on an AR means 30 rounds as fast as you can pull the trigger. That is hell on any barrel, period.

My rule of thumb is that if the barrel is too hot to grab and hold onto with your bare hand then it's too hot, and it's definitely wearing it out an order of magnitude faster than slow firing. Heat makes the metal softer ergo it wears faster. The heat is what destroys the barrel rather than the friction alone.

Although there is a ton of disagreement about certain things across barrel makers (all say something different it seems), they are all unified in saying that heat is the enemy and wears out a barrel fast.

 

[PusherX11]

This day and age AR barrels are cheap. Build a dedicated mag dump upper and have a blast.

 

[RTH1800]

Slightly off topic. Alan Brown from Crane once told me that the Douglas barrels for the Mk 12 rifles lasted longer under full auto fire than the chrome lined Colt's. He was in a position to know.

 

[308pirate]

Hi guys

I have a question about rapid fire with a AR15 in a non chrome lined barrel. The barrel is a Lothar Walther, dont know the material.

Will it wear a barrel quicker than normal, if i rapid fire, but dont let the barrel get hotter than i normaly would? Is there anything specifik in rapid fire, other than heat from the fast firing that "hurts" the barrel in a way, that non rapid fire from a equal hot barrel dont do? Will the rapid fire somehow heat up/wear the troat in the barrel in a way normal fire wont do, even if the barrel feels equal hot to the touch?

Also, is it possible to see without a borescope if the throat is worn, just by looking through the barrel?

Btw, when i say rapid fire, i dont mean mag dumbs or anything. More like 4 rapid shots, then some at slower pace, then 4 rapid shots and so on.

Best regards, Peter.

Yep, barrel life will go down from 10000 rounds to 9500 rounds.

It's a barrel. Throw it away when it's done.

PS, no you can't see throat wear by looking at it with the undaided eye. LOL

 

[DangerRanger]

I’ll baby an AR barrel when hell freezes over

 

[Peter83]

PS, no you can't see throat wear by looking at it with the undaided eye. LOL

I asked because i can see that where the lands starts is pretty defined/sharp, i thourgt that maybe if there was much wear, the start of the lands would appear more gradually. Also, no part seeems to miss any rifling. Can i make any conclusions based on that? Its kind of hard to desecripe for me in english, hope it make sense ;-)

 

[Peter83]

Thanks for all the reply guys, its much appriciated

 

[308pirate]

I asked because i can see that where the lands starts is pretty defined/sharp, i thourgt that maybe if there was much wear, the start of the lands would appear more gradually. Also, no part seeems to miss any rifling. Can i make any conclusions based on that? Its kind of hard to desecripe for me in english, hope it make sense ;-)

By the time your naked eye can see a difference, it's done.

Really, worry about something else. This is a non-issue.

 

[RTH1800]

PS, no you can't see throat wear by looking at it with the undaided eye. LOL
[/QUOTE]
Yes, bore wear can be clearly seen with the unaided eye. Some will look black for several inches with no trace of rifling. Others the rifling will have a slightly rounded appearance just at the throat. The first sign is the throat looking dull when the rest of the bore shines like a new dime.

Not laughing.

The guys who promote abusing a rifle barrel must have never had a treasured super accurate rifle they actually used for more than a range toy. My .204's often shoot amazing groups out to 600 meters. I use them for crows, coyotes and bobcats. I NEVER send a round down range thoughtlessly. They still wear out all to soon. Back to an Alan Brown quote. "The reason most folks don't realize a barrel is wearing out is that they cannot shoot well enough to tell and they only shoot at 100 yards and less."
Bore wear and accuracy loss shows up first at longer range. Vertical dispersion. I have never had a precision AR in 5.56 go beyond 5300 rounds for MOA accuracy at 600 meters. Exact same results as Crane found.

 

[DangerRanger]

Sometimes I throw it on the ground so it knows who it’s daddy is

 

[RyanScott]

Heat kills barrels. But, barrels are consumables and readily available. Would I do mag dumps with an expensive barrel? No, I have hammer forged chrome lined barrels for that. I wouldn’t shoot a precision barrel fast unless I had to.

 

[Greg Langelius *]

I have a little bit of experience with a L-W barrel. It's a 28" SAAMI Chambered LW-50 Stainless 260 Rem barrel. If your AR's L-W barrel is Stainless, odds are it is made of LW-50.

LW-50 Stainless is a bunch tougher than generic Stainless. It's on my original (2001) Customized SH Ghost Dancer Project 260 Savage 10FP rifle.

I make no suggestions about 30rd mag dumps. Mine has stood up to 1000yd F Open Competition of several years, 20rd strings at a 1 shot/min firing cadence. It's been on the rifle since 2003.

As long as you treat your rifle like it's an actual friend; you should have little or no issues with reasonably hot barrels.

The problems with heat are centered around heat cycles. Do a lot of them, extreme ones, and the barrel's throat area expands and contracts enough to get heat cracking. The pattern looks looks a checkerboard through the bore scope, and is called, oddly enough, "Checkering". It beats up the bullet as it passes, and detracts from accuracy. Eventually, flakes detach, and the barrel becomes a good candidate as a stake for growing your tomatoes.

You can do better by simply treating the barrel like your favorite lady.

Use her; but don't use her up like favorite ladies are in great supply.

Greg

 

[Peter83]

I actually got a one of theese small endo scope things. However, lens is a little too big for the chamber. To me, the rifling seems fine and intact, however i have no idea if i am looking at the right place ( throat ). Is it actually possible to see the throat in theese pics? It is my first time looking in a barrel like this, so please forgive me for not being sure where the throats begins and end... Is it the very first part of the rifling that is the throat, or is the further back towards the shooter? I can see that there is some small black spots at the beginning of the lands, but i dont know if its just the "edge" of them you can see, or possible wear?

 

[RTH1800]

It’s a little blurry but from what I can see it appears to be in great shape.

 

[The DFC]

Heat kills barrels. But, barrels are consumables and readily available. Would I do mag dumps with an expensive barrel? No, I have hammer forged chrome lined barrels for that. I wouldn’t shoot a precision barrel fast unless I had to.

My feelings as well. My ARs w/stainless barrels are all DMR types shot often but low unt slow volumes. My 14.5s are all Cr plated-most are hammer forged as well-grip and rip-and what I used during classes.

 

[Peter83]

It’s a little blurry but from what I can see it appears to be in great shape.

Thanks for the feedback. I cant really figure out where the throat starts and ends. I have made 2 pictures to explain. Maybe you can clear it out for me?

 

[pmclaine]

Thanks for the feedback. I cant really figure out where the throat starts and ends. I have made 2 pictures to explain. Maybe you can clear it out for me?
View attachment 7246449View attachment 7246450

There's a thread in the equipment forum titled something like "Game changer, Teslong bore scope"

Find that thread and you will get to see bore scope views of new barrels, old barrels, shot out barrels, rifling, gas ports, throats and muzzles.

 

[Constructor]

LW50 stainless is very close to 410 stainless, 416R stainless is softer and will wear faster. Chromelined and Melonite/Nitride barrels will last longer.
I had a new but junk stainless barrel and decided to use it to test a new piston design. I shot 820 rnds as fast as I could pull the trigger semi auto. The barrel turned blue and everything on the rifle smoked. After it cooled off enough to hold it the bore scope showed the lands about 8" up had fire-checked and pieces of the lands right in front of the chamber had been blow out.
A few weeks later I run the same tests after mods with a Melonite treated barrel. That barrel turned from black to blue also but the lands were not fire-checked and it didn't blow chunks of the lands out.

 

[skinnj1]

Rapid fire in cross the course firing is ten rounds in one minute. Those barrels last a long time.

The same shooters sometimes shoot the National Tropfy Infantry Team Match (NTIT) aka "rattle battle match". Most teams shoot a 30 to 40 round cadence in 50 seconds. A rifle purpose built for this match and used only in this match or practice for it has a lifespan of about half of a across the course service rifle (2k vs 3-5k)

@Peter53 almost all the rifles shooting this match are non chrome lined with most being SS vs 4xxx series carbon steel.

 

[pmclaine]

The same shooters sometimes shoot the National Tropfy Infantry Team Match (NTIT) aka "rattle battle match". Most teams shoot a 30 to 40 round cadence in 50 seconds. A rifle purpose built for this match and used only in this match or practice for it has a lifespan of about half of a across the course service rifle (2k vs 3-5k)

@Peter53 almost all the rifles shooting this match are non chrome lined with most being SS vs 4xxx series carbon steel.

Yep heat hurts but that doesn't seem to be the service the OP will tasking his rifle with.

 

[RTH1800]

Thanks for the feedback. I cant really figure out where the throat starts and ends. I have made 2 pictures to explain. Maybe you can clear it out for me?
View attachment 7246450View attachment 7246451

What you mark as black spots are the ends of the lands. That is the start of the throat. Bore appears ok form what I can see.

 

[zeroz]

Pay attention to when accuracy drops off. Check your BTO measurement when it does. Adjust accordingly. If accuracy doesn't come back, burn the fucker up with mag dumps if thats your thing and get a new barrel.

 

[Peter83]

What you mark as black spots are the ends of the lands. That is the start of the throat. Bore appears ok form what I can see.

Thank you so much for your patience, and time to explain. As said, i dont have any experience with looking inside a barrel. The black spots on the lands, are that something you can find in most bores? Thanks again, i really apriciate it

 

[Peter83]

Pay attention to when accuracy drops off. Check your BTO measurement when it does. Adjust accordingly. If accuracy doesn't come back, burn the fucker up with mag dumps if thats your thing and get a new barrel.

Thanks, i dont reload ammo myself, but i am thinking about it