Barrel Break-In

P

phan108

Member
Rating - 100%
9   0   0
Location
Ontario, Canada
Just recently picked up my first AR, a brand new Bushmaster XM-15.
I been reading alot about a break in procedure.
I was wondeirng, if it is really necessary or just a myth?

Thanks
 
yes and no.

there is a break in period for sure, gotta give the springs a chance to get worked in and everything a chance to settle into a good fit.

as far as a procedure goes, not so much, but dont overheat it for the first few 100 rds, clean it well even if non corrosive ammo and i like to run them nice and wet with lube for the first 1000 rds or so, and if you hand load, take it easy at first, dont load super hot til things settle in and til you know nothing is off spec etc...

thats what ive always done and its always worked out well for me
 
Ain't nothing to break in on a factory AR barrel. Break in procedure as Canmic pointed out is to get all the parts worn in ie shoot lots and then shoot some more. Field strip clean and repeat.

What's the deal with not letting it overheat for the first few 100 rnds?
 
These aren't fancy sniper rifles which need to be run in. :). If your AR is 'mil-spec' grade with chrome bore, etc, just shoot as per normal routine. I've never heard of a 'break-in' period for an AR platform. Clean/maintain afterwards as you would after any range time.
 
1feral1 said:
These aren't fancy sniper rifles which need to be run in. :). If your AR is 'mil-spec' grade with chrome bore, etc, just shoot as per normal routine. I've never heard of a 'break-in' period for an AR platform. Clean/maintain afterwards as you would after any range time.
Click to expand...

even the fancy sniper barrels should not be broken in, IT DOES MORE HARM THAN GOOD. mcmillan had a few things to say about that, and well he's mcmillan so I think we should all listen to what he has to say right?
http://www.6mmbr.com/gailmcmbreakin.html
I wish this myth would just die!
 
Myth? Speaking as from my own experience as a Fitter, Armament, when I was rebuilding the Parker-Hale M82 sniper rifle in Australian service (c,1997) with Robertson barrels. During this timely process, a series of ball rds were fired, Hoppes was used, and was allowed to eat as much copper fowling as possible, the barrels were thoroughly cleaned and this process was repeated as per Australian Army Electrical and Mechanical Engineering Instructions.

It should also be noted that this was also done with earlier PH barrels.
 
1feral1 said:
Myth? Speaking as from my own experience as a Fitter, Armament, when I was rebuilding the Parker-Hale M82 sniper rifle in Australian service (c,1997) with Robertson barrels. During this timely process, a series of ball rds were fired, Hoppes was used, and was allowed to eat as much copper fowling as possible, the barrels were thoroughly cleaned and this process was repeated as per Australian Army Electrical and Mechanical Engineering Instructions.

It should also be noted that this was also done with earlier PH barrels.
Click to expand...

yes myth, do you want to listen to Einstein when it comes to relativity or your high school physics teacher?
Mcmillian is Einstein
But believe what and who you want.
 
'But believe what and who you want'... 'yes myth'.

Dude, in professional militaries, for maintenance of equipment including weapons, we follow guidelines set forth at command level, which are adhered to to ensure quality of maintenance and modification of such equipment, where the 'running in' of barrels in specific weapons is required. There's no myth about that.

McMillan has an opinion, which is not followed by those far above my paygrade, who are indeed the 'Einsteins' of mechanical engineering, who write policy based on more than one man's view.

As for my experience, I've been an armourer longer than you've been alive. I see according to your profile, you strictly shoot as a hobby, I did it for a living.

But thanks for your input anyways.
 
Last edited:
Before I start, I don't think that was directed at you 1feral1.

I have to side with Mike on this one...hahaha, not often eh?

I've looked at everything presented on this subject that is readily available on the web and all I can gather from it is a barrel break in procedure only reduces copper fouling. I say reduces because advocates of what I call Voodoo will pretty much all agree that a fired round is a fired round, the first few don't gain some magical properties that damage barrel steel. I think anyone that has had a barrel badly fouled with copper will agree that it can be a serious pain in the ass to remove, but no one has been able to convince me that cleaning the bore at the range ten times for a total of thirty shots is going to do anything other than wasting an hour at the bench when I could have been shooting. Anyone that states that I can't just give it a thorough cleaning at days end because it's going to somehow change how a burning charge interacts with the steel is in my opinion misunderstanding the Chemical/Physical process's behind the firing of a cartridge. I'm also pretty sure no engineer dreamed up some of the recommended procedures I've seen...none I've worked with anyway.

If you want some comic relief go read some of the battles over this topic in Precision Rifles...
 
Me, I just follow maintenance procedures prescribed for the type of weapon I was working on. If that written policy states when rebuilding sniper rifles, with a new barrel replacement, to fire 5 rds of 7.62mm ball, clean using bore solvent, and repeat for a total of 50 rds, I do that, for as a professional soldier, I am entrusted to do so. It's my name that goes on the serviceable tag, and electronically on file should something nasty happen later on in the service life of the rifle. None of us would ever short-cut policy, when other's lives matter down the road. If some one else has a better idea, based on fact, the onus is on them to forward this information on for further investigation, which may lead a policy change, but until then, policy must be followed. To have some clown (Mike) seem to call me out for something he has only read about... well, that answers pretty much why after 11 yrs on this site, I rarely post and only observe. :). Cheers.
 
1feral1 said:
These aren't fancy sniper rifles which need to be run in. :). If your AR is 'mil-spec' grade with chrome bore, etc, just shoot as per normal routine. I've never heard of a 'break-in' period for an AR platform. Clean/maintain afterwards as you would after any range time.
Click to expand...

I never broke in my fancy sniper rifles loather Walter barrel, mostly cause the manufacture never said to. It still is deadly accurate, grouped 1.6" at 300 yards with 10 rounds.
 
Just because a military does it does not mean it is correct or that there is an evidence based reason for doing it.

Old, non-chromed sniper rifle barrels are not the same as modern chrome lined AR15 barrels.

As a professional soldier, master armourer and company rep for a large barrel making concern, I can say that there is no reason to attempt to break in a chrome lined AR15 barrel. Wipe out the preservative oil and commence firing.

The break in procedures detailed by the internet only serve to move your barrel that number of rounds closer to replacement and help clean out nothing but your ammo vault.
 
Bsand -We follow policy laid down by Defence Force governance, and 'running in' was policy on M82 sniper rifles with barrel replacement. As a private citizen, you can do what you want with your personal property.

Milspec AR barrels require nil breaking in. Policy was replace/test fire to confirm function. Nothing more
 
Long time no see, on the forums Matt. Thanks for piping up.
Matt K said:
Just because a military does it does not mean it is correct or that there is an evidence based reason for doing it.

Old, non-chromed sniper rifle barrels are not the same as modern chrome lined AR15 barrels.

As a professional soldier, master armourer and company rep for a large barrel making concern, I can say that there is no reason to attempt to break in a chrome lined AR15 barrel. Wipe out the preservative oil and commence firing.

The break in procedures detailed by the internet only serve to move your barrel that number of rounds closer to replacement and help clean out nothing but your ammo vault.
Click to expand...
 
Google is your friend. read and note the very last sentence!

quoted from Krieger Barrels FAQ said:
BREAK-IN & CLEANIN

With any premium barrel that has been finish lapped -- such as your Krieger Barrel --, the lay or direction of the finish is in the direction of the bullet travel, so fouling is minimal compared to a barrel with internal tooling marks. This is true of any properly finish-lapped barrel regardless of how it is rifled. If it is not finish-lapped, there will be reamer marks left in the bore that are directly across the direction of the bullet travel. This occurs even in a button-rifled barrel as the button cannot completely iron out these reamer marks.


Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file.


When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat.


If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat “polished without allowing copper to build up in the bore. This is the reasoning for the fire-one-shot-and-clean procedure.


Every barrel will vary slightly in how many rounds they take to break in For example a chrome moly barrel may take longer to break in than stainless steel because it is more abrasion resistant even though it is a similar hardness. Also chrome moly has a little more of an affinity for copper than stainless steel so it will usually show a little more color if you are using a chemical cleaner. Rim Fire barrels can take an extremely long time to break in, sometimes requiring several hundred rounds or more. But cleaning can be lengthened to every 25-50 rounds. The break-in procedure and the cleaning procedure are really the same except for the frequency. Remember the goal is to get or keep the barrel clean while breaking in the throat with bullets being fired over it.

Finally, the best way to tell if the barrel is broken in is to observe the patches; i.e. when the fouling is reduced. This is better than some set number of cycles of shoot and clean as many owners report practically no fouling after the first few shots, and more break-in would be pointless. Conversely, if more is required, a set number would not address that either. Besides, cleaning is not a completely benign procedure so it should be done carefully and no more than necessary.
Click to expand...
 
I have found break in with MY Ar's have required lots of lube and some hotter 556..especially my LMT to get it functioning properly with lighter 223 loads.
 
So we have krieger that says to do it
Mcmillan that says it is useless
John Noveske that says that its useless
Colt Canada that says its useless
 
You must log in or register to reply here.
Back
Top Bottom