6mm accuracy after barrel worn out?

[dntworry]

I hear a lot about things being wildly inconsistent after 12-1500 rounds just wondering exactly how bad I should be expecting here. I ask because I just rebarreled my T3X to 6CM and once I "burnt out" the barrel was going to use it as a varmit gun with 55gr bullets and build another match rifle.

Is this possible or would things be too bad at that point?

 

[Jerry m]

Define 'Burnt Out'

Someone like David Tubbs may have a different criteria that I do for what burned out means. For my last two 'burned Out' barrels:
1) 7mm Rem Mag would not hold on a 8.5 X 11 piece of paper at 200 yards.
2) 6.5 Rem Mag approximately 8 inch group at 100 yards....

Neither of my barrels could be used for varmints.

Good Luck

Jerry

 

[XLR308]

For precision work it would most likely start with random flyers with the same load recipe that you may be able to prolong with seating longer or uping your charge weight.
Depending on how you run the barrel it may just go South quickly with results similar to what was stated above and be time for a replacement.
The short and best answer is if in doubt or running a caliber that's tough on barrels have a spare spun up and waiting to avoid any wait or aggravation from down time.

 

[Wheres-Waldo]

TAG.

If burnt out = 100 FPS velocity loss and going from 1/2 MOA to 3/4 MOA, I'll be shooting my barrel long after it's "burnt out"

 

[6brshooter]

When it loses 100 fps, it's time to order a new one, unless you only have 1 match rifle, in which you should already have a backup barrel

 

[FUNCTIONAL]

Cost to set back and rechamber a barrel is the same regardless of new or "burnt out". A setback you can get a few hundred more rounds which can vary depending on how bad the bore is and how far you can set back. For the cost and effort its usually easier to get a new barrel done up. Wilson sells blanks at good prices if you want a cheap blank with quality above a factory barrel but might not quite "top tier" barrel maker quality.

As far as when is it burned out...For me when it goes above 1moa or loses consistency. I can adjust for fps loss in dope or added powder but I cant correct for something that happens randomly or cant keep it within MOA. Most of my 6mm barrels have been night and day difference. Shooting .25-.5" one day to shooting 3 inches the next with no amount of load/seating rework helping it. Most have gone in 1200-1500 but I did have a bartlein go past 1800 and still hold 1/4 moa that I pulled because I got scared lol. I took that one and set it back an inch as a test barrel but all others were fire cracked past the point of being able to be set back and be worth it.

 

[Mk32784]

Keep shooting it till the groups are not longer acceptable to you?

I have usually seen barrels live on the edge for a while, 1-2 flyers every 5-8 shots. Then completely let go and shoot 10 in groups at 100 yards.

 

[lts1ow]

My barrel at around 1400-1500 of 6creed decided to finally start throwing shots, groups went from 1/2moa to random flyers well over 1moa. Lost a decent amount of speed too. SD was around 14 and I yanked the barrel. (only pushed it that far cause new barrel had not yet arrived)

 

[Dthomas3523]

Just depends on the barrel and also what you consider shot out. For me, once it takes that first substantial (enough to change dope), velocity drop it’s done for serious match use.

It will inevitably take another drop and I don’t need that to be during a match. Which is most likely as that’s where it gets shot the most.

Here is a 6cm barrel target after 1100 rnds only using hornady 108eldm factory ammo.

The fire cracking was so bad even a set back didn’t help.

This was 100yds ?

 

[dntworry]

Could have phrased the question better but basically got my question answered. By the time it's "burnt out" as in first slows down with a 6mm, it's only a handful of rounds away from starting to fall on its face completely so no. Will not work as a varmit gun after that, just going to get a separate cheaper dedicated varmit rifle then.

Thanks for the input

 

[brianf]

for me, if factory match cant hold +/- 1" @ 100 its time to go
it may still be fine by a lot of peoples standards
but it messes with my head and i loose confidence
i shoot like shit if i loose confidence in a rifle or its components

 

[dntworry]

Just depends on the barrel and also what you consider shot out. For me, once it takes that first substantial (enough to change dope), velocity drop it’s done for serious match use.

It will inevitably take another drop and I don’t need that to be during a match. Which is most likely as that’s where it gets shot the most.

Here is a 6cm barrel target after 1100 rnds only using hornady 108eldm factory ammo.

The fire cracking was so bad even a set back didn’t help.

This was 100yds ?

View attachment 7142405

Out of curiosity, what barrel went out after 1,100 of factory ammo?

 

[Lunchbox27]

Just depends on the barrel and also what you consider shot out. For me, once it takes that first substantial (enough to change dope), velocity drop it’s done for serious match use.

It will inevitably take another drop and I don’t need that to be during a match. Which is most likely as that’s where it gets shot the most.

Here is a 6cm barrel target after 1100 rnds only using hornady 108eldm factory ammo.

The fire cracking was so bad even a set back didn’t help.

This was 100yds ?

View attachment 7142405

God damn, bro... 1100 with Factory??

 

[Dthomas3523]

Out of curiosity, what barrel went out after 1,100 of factory ammo?

Bartlein.

Pretty typical of 6cm. It’s still running 3-3100 fps with factory ammo.

I see people online claiming 15-1800, but I’ve never met anyone down here with that kind of luck. 900-1500 has been barrel life for me and everyone else down this way.

 

[Dthomas3523]

God damn, bro... 1100 with Factory??

Factory ammo still runs 3-3100 fps in every barrel I’ve owned. So the wear and tear is still about the same as loaded ammo.

 

[lennyo3034]

Mine never lost velocity. It just went from 1/2 moa to 3 moa within 50 rounds. Total round count before it went south was 870.

 

[cattleman99]

It totally depends on how "shot out" your barrel is. I had a 6x47 barrel open up from 1/2" to 1.5" at 100 yards, it was done for shooting matches but I would still have enough confidence in it to shoot varmints with it.

I noticed it was done towards the end of a match, took it home and put it on paper and groups were larger, and that was the end for it.

 

[Wheres-Waldo]

If my 6mm CM goes from the ~.55MOA its shooting now to 2MOA+ in under 1K rounds, Ill be switching to a BR or variant quick.

I'm currently at 3100 FPS, wondering if backing it down to 3000 or 2950 will have any appreciable affect on barrel life? Using H4350, load density will be so low that SD and ES will be even higher than it is now.

 

[Dthomas3523]

If my 6mm CM goes from the ~.55MOA its shooting now to 2MOA+ in under 1K rounds, Ill be switching to a BR or variant quick.

I'm currently at 3100 FPS, wondering if backing it down to 3000 or 2950 will have any appreciable affect on barrel life? Using H4350, load density will be so low that SD and ES will be even higher than it is now.

That’s why I’m running dasher now. For 2-2500 rnds.

I have a 6cm barrel for factory ammo if I don’t have time to load.

I’ll probably also be picking up a 6br barrel for even more life for some matches.

 

[b6graham]

could always run a 6XC and get 2k plus barrel life at almost creedmoor speeds

 

[Aaron47pb]

Mine never lost velocity. It just went from 1/2 moa to 3 moa within 50 rounds. Total round count before it went south was 870.

Same. Just had a 6cm go from shooting in the 0.3-0.4s to barely shooting MOA at the 850-900 round mark. Velocity stayed pretty consistent.

 

[Aaron47pb]

could always run a 6XC and get 2k plus barrel life at almost creedmoor speeds

Are you running them slow? My two 6XC barrels were toast at the 1200-1300 round mark.

 

[b6graham]

Are you running them slow? My two 6XC barrels were toast at the 1200-1300 round mark.

3k+

 

[Shutrmgavin]

Fascinating. Tibor Rex of you tube fame got 7k rounds out of a ruger barrel in 243 win. 105 amex at 2900 fps in a 26" barrel the whole time. Criteria was no longer consistently sub MOA.

 

[b6graham]

Fascinating. Tibor Rex of you tube fame got 7k rounds out of a ruger barrel in 243 win. 105 amex at 2900 fps in a 26" barrel the whole time. Criteria was no longer consistently sub MOA.

lol

 

[Shutrmgavin]

lol

lol

Well, I'm at 2k at the same speed with the 107 smk. Still .1 MOA- .6MOA. I see a lot of people claiming some pretty high speeds out of their rounds. Maybe it makes a big difference. Lol

 

[b6graham]

Well, I'm at 2k at the same speed with the 107 smk. Still .1 MOA- .6MOA. I see a lot of people claiming some pretty high speeds out of their rounds. Maybe it makes a big difference. Lol

does it make a difference? yes. does it make it a 308? no.

 

[PinesAndProjectiles]

I tried 6 Creed once. Groups went from 1/2 to 3 moa real quick. Never lost velocity, though. This was just after 700 rounds.

 

[Shutrmgavin]

I tried 6 Creed once. Groups went from 1/2 to 3 moa real quick. Never lost velocity, though. This was just after 700 rounds.

That sucks man. I'm at a lot more than that on my stock rpr. Still less than moa. How fast you running them. I'm at 2850 with the 107 smk.

 

[PinesAndProjectiles]

That sucks man. I'm at a lot more than that on my stock rpr. Still less than moa. How fast you running them. I'm at 2850 with the 107 smk.

105 Bergers at 3010. Not smoking fast, but no slouch, either.

 

[lennyo3034]

105 Bergers at 3010. Not smoking fast, but no slouch, either.

Wow. I had a similar experience but I was slinging 105s at 3180.

 

[Dthomas3523]

Trend seems to be people figuring out speed ain’t that big a deal. Consistency and barrel life are more important. Less time putting rounds on new barrels to speed them up and less time checking dope on a new barrel.

Seeing a lot more straight 6br popping up now for these reasons. 28-2950 with a 105/108/115 is more than fine for this game.

 

[King_beardsly]

Trend seems to be people figuring out speed ain’t that big a deal. Consistency and barrel life are more important. Less time putting rounds on new barrels to speed them up and less time checking dope on a new barrel.

Seeing a lot more straight 6br popping up now for these reasons. 28-2950 with a 105/108/115 is more than fine for this game.

This is half the reason I keep toying with leaving the 6cm and going to a 6BR variant, better barrel life, less having to tune loads as the barrel ages and they seem like they just plain work. Down size is I’ve got a ton of nice fresh ADG brass still in boxes and I’ll need to get new powder/dies and lots of brass