quote:

Originally posted by sig229owner:
Materials influence it as well...

Stainless steel won’t last as long as CHF.

Non chrome lined won’t last as long as chrome lined.

I’ve read others say that about stainless steel, but traditional benchrest shooters have the opposite. While most stainless barrels are softer than cro moly barrels, they’re more heat resistant so “burn out” slower. They generally have a longer competition life.

Stainless erodes at a slower rate than chrome moly does. CM barrels start to loose their accuracy slowly and sometimes it's difficult to pinpoint exactly when they stopped shooting up to standard. You just kind of notice it one day. A stainless barrel will shoot well right up to the moment when it stops meeting standards. Groups will start opening up immediately when the barrel looses it's accuracy at a given distance.

quote:

Originally posted by fritz:
snip

-308 Win will definitely last longer, but few precision guys use this round anymore. Maybe 5k to 8k rounds before the required accuracy isn't there. My 308 is still doing well at something like 4500 rounds, but it seems to be getting a little picky about bullet type. For now I have decided to shoot only loads with SMK and Amax bullets. I'd like to do more testing of TMK and ELD bullets, but I will wait until I install the new barrel.

Virtually all F-TR competitors use .308 Win to 1000 yards, there are a few hardcases who shoot .223. Then you also have all Palma shooters the world over, all .308 Win. We use that caliber because that's what the rules call for. I'm sure PRS shooters eschew the .308 in favor of other calibers.

In F-TR virtually every rifle I ever see has a stainless steel barrel, as do all the F-Open rifles. I can't speak to Palma, it's been a long time since I've been to a pure Palma match. Maybe I'll go to SOA next year, prior to FCNC and see what's what.

We prefer stainless steel barrels to Chrome Molybdenum barrels because of wear patterns. Both type can produce great precision but over time, Chrome-Moly degrades slowly whereas the SS barrel tends to keep its precision until it let's go. I have seen people have their SS barrel go from great precision in the morning match to shotgun pattern by the end of the day. This is due to the fire-cracking in the throat of an SS barrel. At one point it looks like dried up clay with cracks all over and then one or more pieces (or flakes) let's go and the accuracy leaves the barrel with it.

I roll off my SS barrels at 4,000 rounds. I always have at least one barrel ready to replace it as I buy them in pairs and get the chambered at the same time. When I roll off the barrel I retire its accompanying 500 Lapua cases, and start another batch.

Chrome-Molybdenum and SS have about the same precision lifespan.

ETA: Whoops, just saw SgtGold's post. Sorry for the duplicate information.

I have no were near the experience or level of SgtGold, Fritz or Nikonuser,

However I can say from personal experience that they are spot on as far as SS Barrels,

when I was shooting Service Rifle, my AR had a heavy SS barrel, 1:9 for 100yrd matches,

I could do 1/2-3/4" groups prone slow, and 3/4-1" prone rapid,

then suddenly one day, it didn't , group size doubled,

I had loaded a crapton of ammo for it, all at the same time, same powder, same type brass, same lot of bullets, as in nothing had changed,

thought of it as a bad day,
next match, was the same,
took the gun down, cleaned it very well, and for giggles used my M16 throat wear gage on it,

it swallowed it, well past the reject line, and when I looked down the bore, no noticeable lands/grooves for a few inches,

took it to the range one day before I rebarreled and shot of a bench, and still got about a 2-3" group, (not good enough)

A few days ago I posted that my 16" Wilson Combat 1/9 twist SS carbine barrel was approaching end of life. Well, it's here. Accuracy at distance was....bad. I suspect the barrel took a nose dive on its prior outing, late this summer. The barrel has 4,800 rounds.

I shot from prone with bipod, the Leupold Mark IV set at 5x, reticle held at the top edge of an 18" tall by 24" wide steel plate. Winds 7-13 mph from my 8-9 o'clock. The first clue that something was amiss was the need to dial 1.0 to 1.5 MOA more than normal to attain impacts near the vertical center of the plate.

Due to the large vertical variation of impacts on the plate, I began to seriously question if my head was firmly planted in my backside. I shot ammo that always seems to work well in this upper. Vertical in MOA, for 8-10 round groups:
2.7 MOA Federal GMM 69
1.5 MOA Australian Outback SMK 69
3.2 MOA Lapua Scenar 69
2.2 MOA Hornady ZMax 55

I put dots at 50 yards on paper. Every group of 5 rounds showed vertical stringing. Only the FGMM 69 showed a little side-to-side variation. Vertical sizes of each group of 5:
.72" Lapua Scenar 69
.60" FGMM 69
.60" Aussie Outback 69
1.1" Hornady ZMax 55
.97" PMC 55 FMJ
I felt I was shooting well, which should have produced 1/2" or smaller groups.

So I put a 14.5" LWRC piston upper, wearing a 1-4x Vortex Strike Eagle, on the Wilson lower. Not the best optic for precision shooting. At 50 yards I produced groups of .6" with both Lupua 69 and Aussie Outback 69 -- not my best shooting. But I settled down with Hornady ZMax, producing a group of .3". Back on the 440 yard plate with Hornady 55 Zmax, the LWRC put 8 rounds in 3-3/8" vertical (roughly 3/4 MOA), with much lower horizontal than the Wilson barrel, under similar winds.

The Wilson 16" barrel is toast. On to something new.

Based on what I'm reading here, if we show up for MOAC-R with a just barely broke in barrel, we will need to toss that barrel at the end of the class.
One more line item for the expenses, I guess.

Bruce

quote:

Originally posted by RNshooter:
Based on what I'm reading here, if we show up for MOAC-R with a just barely broke in barrel, we will need to toss that barrel at the end of the class.
One more line item for the expenses, I guess.

Bruce

.

not sure what that is,
however my SS barrel mentioned above had approx. 8K rounds thru it,


ETA I know a guy that had a few seasons on a Colt HBAR chrome lined barrel shooting rattle battle ,
no idea of round count, but it was used for practice at Quantico and comps at Perry,

quote:

Originally posted by RNshooter:
MOAC-R description

Precision rifle barrel life is different than standard carbine use. You may well get 15k+- 5k out of a typical carbine where 2-3 MOA is sufficient.

That being said, 3k rounds in 4 days sounds like a bit much.....

Best barrel life is obtained with a hammer forged, chrome lined barrel.

quote:

Originally posted by RNshooter:
Based on what I'm reading here, if we show up for MOAC-R with a just barely broke in barrel, we will need to toss that barrel at the end of the class.
One more line item for the expenses, I guess.

Bruce

I don't know. I would not show up to one of these classes with one if my match rifles. I'd bring a chrome-lined AR-15.

quote:

Originally posted by NikonUser:

quote:

Originally posted by RNshooter:
Based on what I'm reading here, if we show up for MOAC-R with a just barely broke in barrel, we will need to toss that barrel at the end of the class.

I would not show up to one of these classes with one if my match rifles. I'd bring a chrome-lined AR-15.

Exactly.
Given the high number of rounds in just a few days, with a red dot instead of a low powered optic -- precision and long range accuracy shouldn't be on the venue. Therefore I wouldn't go into the course with a barrel I intended to use for accurate shooting afterwards. A chrome-lined CHF barrel sounds like the ticket.

I suspect my "shot out" barrel would work just fine for MOAC-R. I actually considered MOAC-R for a moment, until I realized the Team Safari match occurs about the same time.

I doubt you'll burn out a barrel at MOAC.

Even so, back to the math.

3000 rds 5.56 = $900 plus shipping / $40 handgun ammo
MOAC-R = $900
5 nights hotel = $500
Rental Car = $250?
Airfare / Ground Transportation? = $200-750?
Food / misc = $100

Likely $3K all in with the misc stuff that you'd need.

Decent Chrome Lined Barrel = $200?

Probably a good reason to have a solid 'training carbine' that is useful for high round count courses like this - say a basic Colt with a RDS or something like that.

How do the QPQ or nitride processed barrels fare?

quote:

Originally posted by badcopnodonut!!:
How do the QPQ or nitride processed barrels fare?

I'm still trying to wear some out.


The consensus so far is:

Quite a bit better than naked steel but not quite on par with chrome lined for absolute durability.


My last 4 barrels I purchased have all been nitride, very happy with them so far.

quote:

Originally posted by IndianaBoy
The consensus so far is:

Quite a bit better than naked steel but not quite on par with chrome lined for absolute durability.

Some poeple advocate breaking in a stainless barrel, then haveing it nitrided. They seem to think you get the best of both worlds. I don't know what affect this has on absolute accuracy but it should work well with longevity.

FWIW: Many years ago the American Rifleman had a short article covering experiments done at the Finnish State Rifle factory covering barrel life.

It was found in this series of tests that if the bullets were mated to the groove depth, accuracy was maintained up to 35,000 rounds. Yeah, 35,000 rounds of 7.62x53R ammo. Accuracy standard was with the M39 rifle 3 cm for 3 shots at 100 meters IIRC. Not what you guys are getting from your target rifles, but certainly demanding enough to expose the validity of the test.

It would be interesting to take a worn out 7.62x51 NATO barrel on one of your AR's and slug it and then shoot groove depth bullets in it to see what performance could be obtained. I size .375 diameter bullets for use in 366 caliber rifles and very good accuracy can be had in spite of the severe reduction in diameter. As long as adequate neck relief exists in the chamber and the bullet diameter equals the groove depth and the load is safe, it is a safe practice.

It would be no trick to use ".303" cal {.311, .312} bullets and mate them to a worn bore with the use of push-thru dies such as those I use to see what level of accuracy could be obtained.