View Full Version : Barrel break-in advice

01-01-2008, 11:03 AM
I just picked up a Remington 700 Sendero in .300 ultra mag and I am in the process of setting it up. In the course of my last few rifles, I have taken the time to break-in the barrel. Doing research for this project, I am now hearing that break-in, is either wasting time, or if using JB or Iosso, you are actually damaging the barrel. I have posed my question to you folks because of the vast experience you collectively have. I also expect to get conflicting answers; what ever your experience is, please share it. I get one chance on this and I want to do it right.

Also, this rifle has a HS Precision stock. When taking it off for the first time, I was not happy with the fit of the stock in relation to the recoil lug. This stock has a full length bedding block. Should I put a skim coat of bedding compound on this, specifically in the recoil lug area or not? If so, how far do I carry out the bedding compound? My other rifles that I have bedded, I carried the bedding 1-2" down the barrel. Would this rifle be the same, or should I bed the receiver only?

Thanks for all your help-Happy New Year,

Gene Beggs
01-01-2008, 11:10 AM
Barrel break-in? In my opinion, complete waste of time.


Jay, Idaho
01-01-2008, 11:19 AM
I follow Dan Lilja's break-in procedure.

Along with what Mr. Beggs said, I've read that Tony Boyer does not do a break-in on his barrels. Maybe the short bearing surface and short barrels are less prone to copper, I dunno.
I've never had a barrel shorter than 27" so that may be a factor.

01-01-2008, 02:49 PM
When we talk about barrel break in, it's not talking about a 300RUM either. That thing burns a huge amount of powder compared to a PPC. I have loaded for a 7 RUM and it had 91g of powder in it. There are book loads that contain much more than that. I would try and keep the rounds through the barrel as low as I could. Just my opinion.


01-01-2008, 03:50 PM
My personal belief is that barrel break in is a waste of time, bullets, and barrel wear. I've done it and not done it and can't tell the difference. My practice now is to clean a new bbl very thoroughly before I ever fire it and then clean every 20 shots or so.

On bedding your stock, it may shoot fine like it is--some do. Both mine shot better after I skim bedded them.

01-01-2008, 05:48 PM
Just want to point out most folks here, Tony Boyer included, are shooting custom hand lapped barrels. Not much need for any break in there.
Factory barrels can be a different story.
Seeing how much powder that 300 is burning I doubt a break in will be needed. As long as the bore is slightly oiled on the first shot there should be enough carbon laid down to coat the bore for the next shot. This is assuming a bore in relatively good condition. If its a cheesegrater break in wouldn't help anyway.

If you roll your own Reloader 25 might be a good place to start. Alliant powders usually burn pretty dirty.

I've seen reports of people cleaning the throats right out of their rifle with JB. Total Hogwash. Try putting some on a cotton patch and rub your way through a piece of steel. Let me know when your done;)

Enjoy that beast.

01-01-2008, 08:37 PM
Here is Speedy's opinion on barrel break-in and cleaning procedures for everyday use: http://www.varminthunters.com/tech/sgycleaning.html. Can't hurt to listen to what a Hall-of-Fame inductee has to say on the subject.

01-01-2008, 09:59 PM
Whether one believes in barrel break-in or not, one cannot deny the fact that somewhere in the break in process the number of patches it takes to come clean is reduced on shot "X" and the amount of cleaning time inbetween shots is reduced. And throughout the process, the POI changes. Now, one can ignore it or not believe this happens but that still does not make it untrue.

And custom barrels are no more immune to it than factory barrels because both have chambers and both have burrs where the reamer stopped no matter how well the rest of the bore was lapped if at all.

Now, if you shoot out as many barrels as Tony Boyer in a year, you simply would not have the time to do break in and since you could cherry pick barrels anyway, why worry about something you don't have time for? For the rest of us (or at least myself) who don't own stock in Krieger, taking care of the barrel or two per year we use should be important.

I have broken in many of 300 ultra mag factory barrels and can testify to the worthiness of the endeavor. I have never used Iosso or Jb paste in break in so I cannot comment on that. However, I have used just about every other solvent with varying results. Some certainly work quicker than others.

Bottom line is this:
Everyone everywhere breaks in barrels whether they do it intentionally or not. The difference is some of us break them in right at first, and the others break them in over time with many more shots inbetween cleanings. It is my belief that the latter bunch are the ones who chase tunes and struggle with keeping up on it because the barrel is being seasoned during this time.
Just my 2 bits.

01-01-2008, 11:06 PM
Erik, Why not use a barrel break-in procedure,what else have you got to do?It's not like your gonna sit down and crank out 20 shots in 20 minutes with that monster!
Most factory barrels are real rough and the chambering job is not much better with rotational scratches in the lead area where the rifleing begins.This area and the rest of the barrel tear up the bullet jacket as it goes down the bore,leaving copper imbedded in the steel.They behave better if you polish them a little bit.I would wet patch, brush, wet patch,then JB the new barrel paying attention to any rough spots in the bore,then wet patch,brush,wet patch till the solvent runs clean,one dry patch and shoot damp.(I like shooters/kroil mix)Do this for one shot and clean,two shots and clean,three shots and clean,four shots and clean,five shots and clean.You will feel the barrel get smoother and foul less as you go along! Just 15 rounds and you're all set! Now was that so hard?
The bedding on most Senderos and VSSF's I have seen needs a lot of improvement. I would scratch up everything in there except the pillar areas and re-bed,tape the front and sides of the recoil lug and bring the bedding compound out one inch in front of the lug(more than that and it will influence your barrel vibration,not good).Float the rest of the barrel.
Have fun!

chuck furniss
01-02-2008, 09:38 AM
I have checked many HS stocks for fit between bedding block and receiver and have found that the fit is very poor.I feel that skim bedding is a must do thing.As for bedding up the barrel channel goes,anywhere from 1/2 to 3 inches depending on the barrels weight and then trim back as needed if vertical stringing occurs.


01-02-2008, 11:10 AM
Thank you everyone for your insight and experience. Like Joel says, what do I have to lose? My goal is to coax the most accuracy possible from this rifle. The more accurate for me, the more confidence, thus the longer shot I will be able to take, within reason. Thanks again for your help. Since I found this forum, I'll be keeping an eye out and learning more from you all.