Last October I installed new barrels on two of my centerfire silhouette rifles. Both are Remington 700's that were bought new. One is a 26" varmint 7-08 bought in 1996 and the other is a 24" Classic 7-08 bought in 2000. They shot great right out of the box, so I decided to use them as is. They only alteration I made was putting an H-S thumbhole stock on the heavy gun and trigger tuning to both. During a match last August my heavy gun's accuracy went right out the window with little advance notice. Only a week prior to the match my benched groups were still around 1 1/2 to 2" at chickens. They were both nickle sized group shooters when new.

I had to quit using it after missing lots of targets and many shots not going to call. I had to finish up the tournament with my Classic. Later that day benching the heavy gun produced nice grapefruit-size groups. The total amount of rounds sent down that 4140 factory barrel was 5460. I've never shot out a barrel before this one; so I didn't know what kind of life to expect from a factory tube. The Classic was still shooting good at 4625 rounds; but I decided to rebarrel them both at the same time since I assumed that the Classic would fail soon anyway.

Being a machinist, I wanted to install the new barrels myself. I placed a call to Douglas Barrels and ordered their XX match grade stainless 24" #3 contour and a 26" #5 contour both in 7-08. Both barrels were chambered with the same reamer at my request. Only $659 and fourteen days after my call , my barrels arrived. Since I work in a machine shop, it only took me a few hours after my shift was over to have both barrels properly installed. They are head spaced within .0002 of each other. I was lucky enough to have both barrels like the same bullet and powder combination (130 and 168 Sierra with Varget). The loaded ammo is interchangable between guns and this is a good thing. I am now back to nickle sized groups at chickens with little down time waiting for someone else to do this work for me. I can highly recommend Douglas barrels for their quality and their quick delivery.

A couple of days later I split open the chambers on the old factory barrels to see how bad they were. On the heavy gun, three inches foward of the throat/leade, the bore was severely charcoaled and eroded. The lands were nearly gone for the same length also. A look under a 50X microscope resembled the Grand Canyon with melted copper and debris in the cracks. This barrel was clearly toast. The Classic wasn't much better, but it was still shooting quite good. I can't complain, the two factory barrels got me thru plenty of shooting seasons.

A combined total of 10,085 match kings were sent to their destruction thru those two factory barrels over the years. This got me curious as to how much money I spent on feeding those two guns (and my habit). I pulled out a calculator and did the best I could on adding up the cost of the MK's, powder, primers and brass. The powder alone for 10,000 rounds is around 55 pounds! Some but not all of the components were purchased in bulk. Over the years, $20 here, $50 there and $100 to $300 at gun shows for eight pound cans of powder, cases of primers and bulk boxes of bullets and brass really adds up. I really couldn't put an exact dollar amount on what I had spent. Suffice to say, it WAS significant.

Then there is my 7X57 with 3600 rounds thru it, my 788 .308 with 3900 and my .30-06 and .243 with a combined total of 5000 rounds thru them. I am doing my part to help keep the people at Sierra and Hodgdon employed! Yes......this is an expensive game we play but worth every penny. I'm looking forward to replacing those new barrels again someday. To date, the new barrels have 600 rds each thru them. The carnage to my wallet continues!.........NOW... I have a question; assuming proper use and care can anyone tell me about how many rounds I can expect to get from the new 416 stainless barrels? My loads are 36 and 39 grs. Varget with 130 and 168 Sierra MK's. I"m sure some of you long time shooters have burned up a few barrels. Tell us about your experiences..................Thanks, ..........Bob M.

You are not convincing me to get hooked on high power to go with my small bore fixation! Having just picked up a .260 Remington to start, I'm having second thoughts...

So, how long does a barrel last and how do you check for wear without splitting it open?

BlauBear wrote:So, how long does a barrel last and how do you check for wear without splitting it open?

Barrel life depends on the load you are shooting and how much accuracy you are willing to give up before before you declare it worn out. Some of the bench rest guys only shoot 1000 rounds or so before changing barrels. From what I've read, 5000 rounds or so as Bob has experienced is in the neighborhood of average for the type of stuff we shoot in HP silhouette. Some say that with everything else equal, the cartridge with the longer neck gives you better barrel life. This is supposed to explain why barrels on the 6mm Remington out last the 243.

You measure it by checking for "throat erosion". Put a dummy cartridge in the chamber that is loaded long and use a cleaning rod to measure from the muzzle to the tip of the bullet. Then take the bullet out and measure from the muzzle to the bolt face. This measurement will grow as you shoot. My gunsmith recommended checking this every few hundred rounds.

You should be loading to a cartridge overall length somewhere between -.020" and +.020" relative to the measurement you came up with above depending on what shoots best in your rifle. Over time, you "chase the throat" by loading your cartridges longer as your measurement grows. Changing COAL effects pressures, so proceed with caution.

Eventually, the throat will have eroded past the point where you can keep up with it. A common practice at that point is to cut a little off the threaded end of the barrel and run a chamber reamer in it. This moves the chamber forward to catch up with the eroded throat. Then you start all over.

So much to learn! None of this is an issue in small bore, of course, since a properly maintained .22 will pretty much last forever.

How much is removed when the barrel is re-chambered, and how many times is a barrel typically re-chambered before it's discarded? Thanks for a very instructional post, Carl!

Bob, thanks for your initial post, and I apologize for hijacking your thread! I'd love to learn machine shop skills, someday... Right now I'm trying to pick up enough high power knowledge to navigate!

BlauBear wrote:How much is removed when the barrel is re-chambered, and how many times is a barrel typically re-chambered before it's discarded?

I have not yet reached this point myself, but as I understand it, "a few threads worth" is all that is removed. I don't know how many times this can be done per barrel.

BlauBear, didn"t mean to concern you with getting into highpower. By all means get that .260 put together and get out there. You will be glad you did. The sad fact of centerfire rifle shooting is that every time you pull the trigger the bore is subjected to over 2000 degrees of flame/gas temperture, erosion, and high pressure impact abrasion from unburned powder kernals. This takes place in only a few milliseconds, but it takes it"s toll on steel over time. Carl"s explanation for checking and adjusting for throat wear is excellent. Rechambering to "catch up" to wear can only be done to a point. In my case, the wear was so extensive that the barrel would have to be re-shanked and fully re-threaded. This is no guarantee that the gun would shoot good for very long, if at all. Remember, the rest of that bore had over 5000 rds thru it. In the case of a sporter barrel, you can only rechamber so deep before you move the chamber closer to the thinning outside contour of the barrel creating a thinner wall thickness condition and lack of material in which to create a new shoulder. Also, the costs involved having this work done, i think, would be better spent on a new barrel altogether.

I've kept track of the throat progression on my 260 Rem with a Kreiger 416 barrel. Surprisingly the amount of progression depends on the bullet and with 123 Scenars it's 88 rounds/mil and for 139 Scenars it's 43 rounds/mil. The barrel now has over 1700 shots and the movement is predictable. Best I can figure is that the point of contact of the throat leade must be moving up the ogive and the ogives are different enough to cause the difference in erosion rate.

Talked to my gunsmith about freshening the throat by rechambering and he said he'd cut a 1/4" off and rechamber anew. Bad news is that chambering a barrel (new or old) ran about $225 (as I recall) or almost the cost of a new barrel. Doesn't seem worth it unless you can do it yourself.

Bob, I'm not discouraged at all, just realizing that there's a lot to learn and I might want to pay real close attention. It's actually fascinating! One decision is how deeply to get in, since without some boundaries I would end up building a machine shop one step at a time!

Instead, I need to learn what is sensible: In this case, I've learned to check for throat erosion by measuring barrel "growth", about how often to expect to replace a barrel (around 5,000 rounds), and that it generally makes sense to replace the barrel but re-chambering is an option.

What matters in a barrel? Crown contour? Chamber cut? Material?

I read recently that benchrest shooters are swearing by 2 groove rifling in barrels for BR comps. Not sure how that would translate over to sils but if they are most accurate of the bench I would tend to think they stand to be more accurate how ever they get shot.

As for .22 barrels lasting forever I think they may depending on the barrals manufacturer and also the bullets diameter and lube type. Talking with Jerry Tureau this past weekend he was mentioning a burnt out barrel he had in a .22 after IIRC a little over 10,000 rounds down it. So many variables to wear on steels it would be hard to predict a failure time with any degree of accuracy for .22 but in time it can be ruined and need replacing. I read that the Ruger .204 is the newest quick barrel burner around and I can see why with speeds 4x's the SB .22

From all I have gathered over the years the most important aspects of a barrel are the twist rate in relation to the length of the barrel in relation to the bullets size and density and velocity. Proper crowning and types of rifle grooving options are also varied as to what best. I am not a HP sil shooter so I am just speaking in general terms about this.

There is an excellent indepth article on barrel making that was first published in Precision Shooting in 1995. . The title is "The Making of a Rifled Barrel". Check it out at www.firearmsid.com Go to main menu - feature articles - scroll down to July 2000.

bob259........hav'nt heard from you in a while. One of your last posts in HP, you mentioned the possibility of getting into HP. I certainly hope we did not scare the hell out of you!

This post doesn't seem so scary to me. The loads in HP silhouette can often achieve half minute or so accuracy. To achieve the same in smallbore silhouette, even in the best custom rifle, it's not uncommon to have to use the highest (and most expensive) Eley ammo, which can easily hit $14+ per 50 rounds. What's the big deal about what HP ammo is costing?

Jason, ammunition cost is less intimidating when friends will help with reloading. Also, I don't personally know anyone using $14 a box ammunition - I spend $3 a box and everyone else thinks that's too much.

The learning curve intimidates me, although the set up cost for another expensive sport is non-trivial. It doesn't chase me off - that would require sense I lack - but it does make me think!

BlauBear,
There are few of us out there that do shoot accurate ammo in the larger matches. While I tend to catch the tenex when I can find it on a bargin i.e. less than $12 a box I'll buy it. BTW tenex was $3.90 a box when I was a junior and we still used it then in bigger matches.

Mary

Innocent;

I got a case of the downgraded stuff and am plotting how to stretch it.

All;

One thing to love about this sport is that everyone shares their knowledge generously - it's a fascinating and awesome community ethic. It is my nature to enjoy intellectual challenges, and silhouette has that in spades. Add the metal discipline side and I'm hooked! And I'm even looking at the possibilities of a serious academic paper on the subject. (One of my academic mentors specializes in muscle memory, that is, deep training that becomes reflexive and automatic.)

Never thought of yourselves as an academic community before, huh?