Breaking in an AR-10

More
12 years 5 months ago #11829 by Mister_TSquared
Breaking in an AR-10 was created by Mister_TSquared
Hi. I'm looking for ammunition that's ideal for breaking in my new AR-10 A4. I've heard that the best break-in ammo is 7.62x51 NATO (or something similar to it). I was wondering if either of these would fit the bill:

www.luckygunner.com/pmc-308-win-ammo-for-sale-308147fmjbtpmc-20

www.luckygunner.com/federal-308-win-ammo...ale-308150fmjbtae-20

They seem to be what I'm looking for: they're both Full Metal Jacket (like NATO) and they're either 150 or 147 grain (NATO uses 150 grain). If, for some reason, neither of these are what I'm looking for, can anyone make a recommendation as to break-in ammo?

Please Log in or Create an account to join the conversation.

More
12 years 2 months ago - 12 years 2 months ago #12433 by sonogun
Replied by sonogun on topic Re: Breaking in an AR-10
Wow. I was looking for some help here on breaking in my AR-10T 20". I'm ready to site in my irons and break in my barrel at the same time. I have 200 rounds of Black Hills 168g Molly BTHP's and 200 168g Federal Match. I did some reading on the moly loads and it seems that the moly needs to build up in the barrel to produce an improvement in accuracy. I would not be able to achieve the molly advantage if I am cleaning the barrel per the break in directions so I was thinking of starting with the Federal, see how it feeds and then switch over to the molly and evaluate the same. I understand that you should not buy large quantities of any ammo until you see how it feeds but I want to try the M118 that is available now at target Sports in bulk. If I do that, I will wear out my molly coating??? Should I just wait and send 500 M118 down range?
Last edit: 12 years 2 months ago by sonogun.

Please Log in or Create an account to join the conversation.

More
12 years 2 months ago #12458 by mormonsniper
Replied by mormonsniper on topic Re: Breaking in an AR-10
Read this some time ago and it makes sense.

www.snipercountry.com/Articles/Barrel_BreakIn.asp
The following user(s) said Thank You: 10-76

Please Log in or Create an account to join the conversation.

More
12 years 2 months ago #12459 by sonogun
Replied by sonogun on topic Re: Breaking in an AR-10
Great article. I have a 10T which comes with a 20" triple lapped stainless steel match grade barrel. I do engine work so lapping to me is something you do to valves when you don't want to do a valve job. I took that to mean that some smoothing of the final grind took place. Being a newbe who up until this weekend had only spent time on the pistol range, I went by the book if not for the only option I had but because I thought it could do no harm. I also expected the AR-Factory Manual to be an authority on the AR. It could use some revisions. When I give instruction to the machinist on how I want the bore to be pushed out, I specify a certain smoothness as measured by a MarSurf Roughness Gauge. www.mahr.com/index.php?NodeID=10483 . Any time metal is cut, there will be microscopic folding of the metal. During normal break in of an engine, the piston rings removes these folded pieces of metal at the cost of increased ring wear and loss of cylinder seal which reduces horsepower. To prevent this loss in a blueprinted engine, I follow this process which involves using a hone in the opposite rotation of the boreing bar. www.goodson.com/blog/2012/01/13/a-new-finish-in-honing/ . This makes a few more horsepower and adds life to the engine. Which brings up another issue; brushing the rifle bore in the opposite direction without damaging the exit of the bore. I used a bore guide on both ends so that I would not have to reverse direction inside the bore. I also used a brass brush. I was at the range Monday for 5 hours in which time I fired the weapon 70 times. I did not see one person doing what I was doing (by the manual cleaning). My thoughts are that I could have skipped the lengthly process but at least my warranty is intact. If I ever get to the point of ordering a custom gun/barrel, I will expect the thing to be ready to go as advertised right off the back of the UPS Truck. I was taking the opportunity at the same time to adjust my M1 Iron sights. Everything was on paper but I can not honestly say I grouped anything. I will give accuracy another shot when my scope gets here. I figure if I can get on paper at 100 yards then with a scope, I should be able to get a decent group at 75 yards.
I went with Armalite because I thought it was the best product on the market and I could not go wrong. WRONG. I live in California so my choices were limited. We have crazy gun laws. I will end up with a unit that looks very similar to a SASS and have lots of leftover parts laying around. I am sure I would have been better off by building it out in the first place which would have brought additional pleasure in owning an Armalite just the same.
Thanks again for the post!

Please Log in or Create an account to join the conversation.

More
12 years 1 month ago #12461 by BUILDING MY SASS
Replied by BUILDING MY SASS on topic Re: Breaking in an AR-10
Well I can't go into all the specs but I can suggest two or three things...
1)...Use High End Ammo...Hornady, Federal Match, any of the top names... Stay away from Winchester...just my opinion of course :whistle: :dry:
2)...use what is recommended for your rifle by your manual...The A4...168 grn
The T I believe in the 170 to 175 range...I think...
3)..and this one is very controversial...Break it in as the Manual States...Yeah it Takes some time and is a Bit of a Pain,,, but well worth it in the end...I think anyway....
Again...Just my .02 worth...
BMS
The following user(s) said Thank You: 10-76

Please Log in or Create an account to join the conversation.

More
12 years 1 month ago #12468 by Redscout02
Replied by Redscout02 on topic Re: Breaking in an AR-10
ditto on the pain but worth it

Please Log in or Create an account to join the conversation.