Break-in Ammo

S

s2kguy

Private
Minuteman
Feb 27, 2011
9
0
63
#1
I will be taking delivery on my first long range rig, in about a week. I've spent the last year and a half shooting a Savage MKII TR and decided to move up in caliber and range. My new rig will be a Savage 10FCP HS Precision in .308. It will be wearing an HDMR H59 on a 20 MOA base. I've picked up a Tipton Carbon Fiber Cleaning Rod and Mike Lucas Bore Guide to help with cleaning chores.

In anticipation of getting this rifle, I purchased some Federal Gold Medal Match Sierra Match King BTHP 168 Grain ammo (200 rounds) when it went on sale a few months ago. I paid about $200.00, at the time.

From what I understand, I should commit about 50 to 60 rounds to a "break-in" period. My question is, what ammo should I use during this "break-in" period?

<ul style="list-style-type: disc">[*]Shoot what I have[*]Get the cheapest stuff I can find, since the primary purpose is "break in" (as opposed to accuracy) and save the "good stuff" for after the break-in period
[*]Use some "decent stuff" to get through the break-in period while giving me "some" level of accuracy. If this option, what would you recommend? [/list]

Thanks in advance for your suggestions.
 
#3
Re: Break-in Ammo

I was told to use high-end bullets like your FGMM 168's for break in. SOmething about training the bore for that specific load. I used the same Fed Gold Med MSMK that you have to break in my barrel. Bit now I use Federal American Eagle. it's a bit dirtier, but it's not too bad. American Eagle is not even that much cheaper than the Gold Medal.
 
#5
#6
Re: Break-in Ammo

Never bothered to "break in" my AI AW .308. It's driven tacks from day one. Same with my precision AR-15.

There's certainly a period of getting comfortable with a new rifle, but that's a whole different matter.
 
#7
Re: Break-in Ammo

If you insist on wasting money by "breaking in" your barrel, you can shoot whatever load you want to.

If you want an accurate, lower cost load so you can dial in your scope and be almost spot on for your FGMM, I recommend the american eagle 168 OTM load.

This is NOT the load linked above. The 168 OTM load is a match load for the M1A. It can be had for about 16 a box from palmetto state. The brass is excellent, the primers are crimped in. You'll need to remove the crimp for reloading.

ALL barrels will break in to some extent, especially factory barrels. You don't have to do anything special to make it happen. Sending bullets down the pipe will polish it. If you wish, clean it after 10 rounds or so for the first couple of range trips. Do yourself a favor and buy some foaming bore cleaner and don't use metallic brushes.

I had a savage 12 in .243 that coppered badly, but shot very well. I cleaned it fairly regularly and it eventually smoothed out, though never as good as a quality barrel. My better barrels, I only clean when I think accuracy is suffering.
 
#8
Re: Break-in Ammo

with my AR, 24" bull barrel, it shot like crap.
I did the whole break in routine, shoot 5 & clean for 10 Strings, shoot 10 & clean for 10 strings.
I used some of the Tubb polishing rounds (kit, loaded into my brass) it cut my groups in half.
I still believe I got screwed on the barrel though.
at it's best, it shoots 3/4 @ 100. that's with 50 grn hand loads. I did make the mistake of buying a 1-10 twist barrel.
It will soon be replaced with a 1-7 twist barrel.
Some people talk bad about the Tubb "break in" products but although I didn't get optimal performance out of my rifle, I did get positive results from the product.
I just started out with a crap barrel.
 
#9
Re: Break-in Ammo

After reading, doing, pondering, borescoping, and performing a bunch of less worthwhile endeavors associated with initializing a new bore over the preceding few decades, I have come to a few conclusions.

A copper jacket does not abrade a steel bore.

Cleaning does not do anything that can be of significant positive impact during the initialization of a bore. Done improperly, it can be harmful.

Bores do not learn.

Rifling will wear with time and use. I suspect that the primary factors in this wear are hot propellent gasses and semi-abrasive bore crud, probably largely composed of primer combustion products, which are apparently similar to glass. This accomplishes a process similar to lapping with a lead slug, and could be called firelapping; but is an ongoing and gradual process that occurs throughout the barrel's entire lifespan. As bores wear, copper and carbon deposition decrease. Bore friction and rifling wear are factors, but not primary factors, in bore extinction. They do as much good as they do harm.

The breaking-in is a real issue, but I believe it is concentrated mainly in the process of ablating/abrading the sharpness from tool markings resulting from the throating process.

It's not so much that this sharpness is harmful to accuracy, as that the marks will not endure through initial firing. Until that wear is accomplished, the bore's transit time is in transition. Since load development is a process that attempts to match load transit time to barrel harmonics, load development during this period of transition is problematic.

Therefore, break-in is necessary so that the transit time can become stabilized enough to make load development meaningful. I believe it s mainly accomplished by the ablation from hot gasses and burning particles of propellant as they exit the cartidge case. I imagine it as something rather like an incandescent hailstorm. I seriously doubt that the passage of copper bullet jackets or cleaning helps this process in any meaningful way.

To hasten this process, reduced strength loads are probably counterproductive. High quality ammunition is probably only equally as effective as basic ball equivalent ammo for this process, and less economically sound. I would employ a commercial ball equivalent load that uses brass I would intend to reload.

I'd look at this period in the barrel's life as a good opportunity to fireform brass to fit the new chamber, and to do load pressure testing. But I would withhold load development until I could be reasonably certain that the throat polishing process was essentially complete.

I also believe that premium aftermarket barrels are likely lapped after throating, and that for most intents and purposes do not require any further action. I would still fireform my brass and do load pressure testing before attempting meaningful load development.

Greg
 
#10
Re: Break-in Ammo

Hi All,

Thanks for the recommendations. Based on your input, I think that I will forgo the break-in period and check out the American Eagle 168 gr. OTM to zero my scope.

As for cleaning, I've been using the Wipe Out product for my .22lr. I've been told that I should consider switching to Gunzilla. My local range is out of the Gunzilla product. I hope that they get some in by the time I need to clean the .308. If not, I think that Wipe Out should be sufficient.

Thanks Again and Kind Regards,

S2KGuy
 
#12
Re: Break-in Ammo

Most don't know but Bass Pro Shops has decent pricing on ammo. If you google coupon codes for them its possible to get free or discounted shipping.

Just a thought
 
#13
Re: Break-in Ammo

since this thread came up and i'm picking up a 700 sps tactical tomorrow i wanted to ask, is there any reason to stay away from south african PMP hunting ammo (150 gr psp in 308) to run through for the brass? friend has a few hundred rounds he is selling me for 10 bucks a box (hell of a deal imo). not expecting much in the way of accuracy i just want to familiarize myself with the rifle and get the brass for reloading.


oh crap just realized that was my first post on this website...um hi i'm Psubond and i'm an alco....wait wrong meeting. anyways hi....back to lurking
 
#14
Re: Break-in Ammo

Wipe out is a very good product, no need to go to something else.

As mentioned, clean the rifle before taking it to the range for the first time. A couple of wet patched of #9, let it sit for 10 or so minutes, then dry patch. That's all you really need to do.
 
#15
Re: Break-in Ammo

I believe that cleaning .22LRs is overdone. There is no signficant downside to leaving them uncleaned between sessions.

One thing; lead will slowly build up in the extreme forward end of the .22LR chamber, and will slowly degrade accuracy.

I used to keep a .2LR chamber reamer and use it to periodically chase out those lead deposits.

I later found out that this can be more easily accomplished by soaking the Rimfire's chamber area with Shooters' Choice Lead Remover Solvent, followed by substantial brushing of that chamber area with a bronze cleaning brush.

Most of my C/F bore cleaning needs are served by Gunslick Foaming Bore Cleaner and patches. Some of my better C/F bores have never seen a bronze brush.

Greg
 
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