224V after 2500 rounds: Might need new barrel.

[Subwrx300]

Well I'm sad to say I might have hit the dreaded "wall" with my 224V. It's put 2500+ rounds down range in the last 6 months and I noticed some random flyers starting to creep in around 2000-2100 rounds. Last week, I zeroed rifle, shot 85 rounds for practice. The next day, rifle was 2" high and left; zeroed again but groups were 1.5"-2" at 100yds. Normally, it shot .5-.8" at 100. This load is with 88 ELDs, CFE223 and both Federal/Hornady brass.

I was understandably perplexed, so I took it home, scrubbed it down completely and back to range. Things seemed to tighten up around 20 rounds in and all was well. Back to 1000yd range on Sunday for practice and things started well but towards end of day (120 rounds) not so good, shots missing left/right a few feet at 700yds without change in wind. In fact, my buddy brought some factory Hornady ammo to test in my gun for different reasons and the first round of two 10 shot groups completely missed 12x18" target. Next 9 landed in 1.5"-2" or so.

Back to range today at 400yds: of (2) 10 shot groups at 12x18" paper, only 10 landed on target. Watching trace, I could visibly see rounds wildly flying 2-3' high, low right, left and on and on.

Barrel throat looks pretty good through borescope but I can't explain the erratic flight and it's never done that prior. I'm going through a few trouble shooting steps to see if I've inadvertently caused this issue. I changed dies recently and may have too much shoulder bump (.005-.006 currently, which I normally set to .002 for ARs). Also, have shot this rifle suppressed for last 1500 rounds, so that could have impact on longevity of barrel (blowing gas and carbon back into barrel, increasing errosion/wear).

I should point out that I'm using same lot of bullets and powder, along with both new and once fired brass. All combinations are producing flyers about 2 out of 10nshots or slightly more.

I'll be testing three things to see if I can restore accuracy/remove flyers.

• Bullet change: moving to 80gr Berger and 77 SMK to test if 88 ELD bullet is simply no longer stabilized.
• Shoulder bump: reducing bump back to .0015" to reduce possible issue with bullet run-out/flyers.
• Last resort: Tubbs TMS and Final Finish system. I've used this in past with good results but I'm curious if the above doesn't work, if it can restore barrel for next 1000 rounds.

In the interim, I'll likely be putting a new barrel on order from Paul at Craddock. Current barrel is 26" +3 but I will probably move to a 22-24" plus 2 and shoot non-suppressed.

Any of you guys had barrels start throwing flyers later in life? I'm talking real flyers (like missing targets completely and wild trace downrange). Am I missing anything in front of my face?

 

[Scotts556]

Im gonna venture to say you've cleaned the barrel real good? Got all the nitro and copper fowling out? have you checked the rifling at the muzzle?

Scott

 

[bfoosh006]

New "lot" of bullets ? ... maybe thinner jackets ?

 

[Subwrx300]

Im gonna venture to say you've cleaned the barrel real good? Got all the nitro and copper fowling out? have you checked the rifling at the muzzle?

Scott

Yes. Cleaned completely with bronze brush and swabs then JB bore paste to remove carbon in throat. Squeaky clean no copper 200 rounds ago. Had issues within 100 rounds.

Rifling at muzzle looks good/great. Sharp and clean. No apparent dings, dents scrapes or anything visible though bore scope.

 

[Subwrx300]

New "lot" of bullets ? ... maybe thinner jackets ?

Well that's the odd part. I've had three lots of the 88ELDs. I'm on lot #2 and these have shot well for last 700 of 1000 bullets in the lot.

I do have another 1000 sitting from different lot, which I can try also. I don't see it fixing issue but will definitely give it a try. Also going to test other bullets (have several other loads that showed promise) to rule out issues with bullet shape/throat erosion, which is entirely possible with VLD shaped bullets.

 

[bfoosh006]

Well... something is making some of your bullets "wooble" wildly out of your barrel, while some are fine.

I would try some of the other lot, just to eliminate the bullet as a variable.

And spend a bit of time with the borescope, looking for shallow rifling ( ? )

 

[Subwrx300]

Well... something is making some of your bullets "wooble" wildly out of your barrel, while some are fine.

I would try some of the other lot, just to eliminate the bullet as a variable.

And spend a bit of time with the borescope, looking for shallow rifling ( ? )

I've been going over it with fine toothed comb and if rifling is shallow, I can't tell with my eyes. Its worth pointing out that there is a very VERY slight keyhole like appearance of holes in paper at 400 (very slight/ and in different orientations).

This barrel is right on marginal stability line with these bullets anyway, so I'm going to drop down to 77/80s to potentially rule out the barrel. If it shoots consistent with lighter, shorter bullet, I've probably reached the limit of the barrel with the heavies.

If I still get flyers, I'll have another barrel spun up in short order.

 

[Rimfiremike]

With slight keyholing mentioned, it will be interesting to hear how the lighter bullets behave. Maybe the heavies were just barely being stabilized and now some are just not stable anymore.
Order for a new barrel sounds like a good idea regardless.

 

[DJL2]

I'd be curious as to an assessment once the lighter bullets get a go. I'm wondering what might be behind degradation if the throat and muzzle both look good. Assuming the velocity hasn't changed significantly, what else might impact stability? From a longer term perspective, do the pros of the 88s justify either "trashing" a barrel sooner or switching to a lighter load to get all the life from it?

 

[brcook03]

Not necessarily with a .224V rifle but I had a coworker who started seeing accuracy issues with his 6.5 Creed JP barrel. He did the same things you did but saw similar results (increased groups, random flyers, etc.). It turned out that he had a lot of build up on the barrel crown. Once he cleaned it up, the rifle went back to reliably sub-MOA.

Cleaning the crown may be worth trying.

 

[Rudy Gonsior]

Cleaning the crown might help, I’ve had similar build up from certain brakes, so it’s worth double checking.

Conversely, who’s barrel are you running, it it a button or single point cut? Also what twist rate is the rifling? And last roughly what temperature are you working in? You mentioned you started 6 months ago, was that in the summer ?

Without knowing much about your set up or situation, I’ll throw out this idea because just because I had a similar issue with some .224 barrels we were testing not long ago.

Barrels (x2) where Rock Creek .223REM 1/8 twist, 14.5”. Barrels shot ok (0.75-1.0 MOA with 73gr ELD-M factory) in early testing but over the course of 900+ rounds (spanning several months) during 100m accuracy testing, accuracy trends developed similar to what your describing. Under standard atmospheric conditions (nearly identical to actual test conditions when started) we should have had a stability factor of 1.4. However our test site is located in norther NH and as testing progressed though the fall temperatures dropped and stability fell to about 1.28-1.32 which is marginal. At a loss to the cause of sporadic accuracy we looked at everything and eventually it was discovered that the twist rate was actually decelerating from a 1/8 to a 1/8.8ish which drops the stability factor to 1.06-1.08 in the cooler conditions, which perhaps explains the sporadic accuracy.

Again it’s a shot in the dark but actual twist rates and atmospheric conditions may be something to look at if you exhaust your options.

 

[Subwrx300]

Cleaning the crown might help, I’ve had similar build up from certain brakes, so it’s worth double checking.

Conversely, who’s barrel are you running, it it a button or single point cut? Also what twist rate is the rifling? And last roughly what temperature are you working in? You mentioned you started 6 months ago, was that in the summer ?

Without knowing much about your set up or situation, I’ll throw out this idea because just because I had a similar issue with some .224 barrels we were testing not long ago.

Barrels (x2) where Rock Creek .223REM 1/8 twist, 14.5”. Barrels shot ok (0.75-1.0 MOA with 73gr ELD-M factory) in early testing but over the course of 900+ rounds (spanning several months) during 100m accuracy testing, accuracy trends developed similar to what your describing. Under standard atmospheric conditions (nearly identical to actual test conditions when started) we should have had a stability factor of 1.4. However our test site is located in norther NH and as testing progressed though the fall temperatures dropped and stability fell to about 1.28-1.32 which is marginal. At a loss to the cause of sporadic accuracy we looked at everything and eventually it was discovered that the twist rate was actually decelerating from a 1/8 to a 1/8.8ish which drops the stability factor to 1.06-1.08 in the cooler conditions, which perhaps explains the sporadic accuracy.

Again it’s a shot in the dark but actual twist rates and atmospheric conditions may be something to look at if you exhaust your options.

I may measure actual twist rate in last 8 inches vs first 10 to see if any difference.

It's a 7.5 twist barrel that has run 88s very well down to 30deg F so I don't think it's atmosphere related.

I've already spoken to mfgr and they would like to see the barrel for testing. They are likely replacing the barrel as they haven't had any low round count failures so they are interested in testing for future development.

While I'd like to keep testing barrel, I just don't have time to tinker this time of the year. I may run some 80s through it to see how they shoot but might not have time before sending it back.

 

[RFutch]

@Subwrx300 Any new developments?

I mean you've had a week to figure this out...

 

[Subwrx300]

Lol. Sent barrel to mfg for testing/inspection. They don't have a lot of customers that have put 2500-3000 rounds through these yet, and the few that have, went beyond 4000-5000 with good precision.

The odd aspects in my case are that I'm using same lot of powder, brass, bullets, primers. Barrel looks good overall: good rifling, very minimal heat checking, gas port erosion seems within norms and throat/lands have only moved. 012" since new.

They wanted to see it in person so I obliged. Hope to have update end of next week or so.

In the interim, im getting ready to build/buy a 224V bolt gun. A lot of guys here seem to think a 224V doesn't really fit a bolt gun because other options push the same bullets faster. But I think it has a place. A 2900fps 88/90gr bullet is virtually identical to my 6.5 Creed to 1000yds in terms of drop and drift (slightly less drop). And barrel life should be significantly better than 6.5CM/243 route, lower recoil, no need to fireform like a 223AI and doesn't eat barrels like a 22-250 (which doesn't have 1:7twist anyway nor throat to allow long bullets.)

I'm excited to test a bolt gun to simply test the cartidge precision without the variables of a gas gun.

 

[Shawn1492]

Would you be so kind as to do a write up and review of your bolt gun build when you get to that point.

 

[Subwrx300]

Would you be so kind as to do a write up and review of your bolt gun build when you get to that point.

Definitely. I usually do write ups for all new builds and this one would be very high on my list. I think it will prove the cartidge is very precise (few random flyers, consistent groups etc) and issues are likely with gas guns simply aren't as accurate consistently as bolt guns.

Perfect example: my 223 Kreiger AR15 just shot the following targets on two separate days:

Last Saturday, shot 1, 2, 3 etc with 69TMK first then 77 SMK and repeat with 5-10 min between groups.

Sunday same weather, fired in sequence shown 1,2,3 etc but shot 77 SMK load first, followed by 69 TMK. 5-10 min between groups.

69 TMK shot two .65" groups but also a 1.4" groups; overall average of .877" for 8 groups.

77 SMK shot best of .5" but shot a .92"; overall average of .696". Notice it shot a 10 shot group of .59" on Day 2 group #5... This is statistically much better than average and stars aligned.

This is pretty much what I see with my 224V gas gun too. .6-.9 with occasional 1.2-1.5" every so often. That never happens with my bolt guns. I'm certain it's something to do with semis just being hard to shoot and even harder on build quality because of stacking tolerances.

Will be cool to test though!

 

[Subwrx300]

Have update much faster than expected! Have a new barrel 26" non-Fluted (a.k.a. oneheavysonofabitch) barrel on its way.

The company (Rainier) was awesome to work with! I mean, seriously, I put a LOT of rounds through this barrel over the last 6 months and it shot AWESOME through 2300 rounds before starting to show signs of degrading performance.

I decided on the non-Fluted 26" (last barrel was fluted 26") for these reasons:

1. Want to test performance of fluted vs non in same barrel profile. (I.e. rigidity)
2. the extra weight out front should balance rifle better for matches.
3. test known loads to see if in same spots
4. After 2500 rounds, I want to *potentially* cut this barrel back to test suppressor use and dwell time. Think dissapator build on a 224V. It has a 15" gas system (+3) which works great but dwell time is very long with suppressor, so cutting back 1-3" might improve cleanliness of barrel and reduce need for heavy buffer springs and decreasing gas too much with AGB.

Will be a two weeks or so before I can get it out to shoot but will post back link to any review once I have something to report.

 

[RFutch]

Did they cover the replacement?

If so does that mean there was something amiss with that barrel and barrel life should have been 5000+ like other reports?

 

[Subwrx300]

Did they cover the replacement?

If so does that mean there was something amiss with that barrel and barrel life should have been 5000+ like other reports?

I bought new barrel at a discount. It was worth it; original shot very well and I didn't expect anything after the time/round count since I purchased.

Their CS team is top notch and it was a great opportunity for me to given them some data for barrel life and condition after 2800+ rounds.

I'm pretty sure that shooting it suppressed shortened the barrel life and the next barrel will be shot mainly unsuppressed through this match season. Only time will tell, but I would wager it will go 3500-4000 rounds before starting to drop off a bit.

The results I had with previous barrel were worth giving it another shot (who's going to complain about a 1/2-3/4 moa gas gun barrel???). I bought this barrel just to test the 224V and use it as a learning platform for the caliber. Pumped to try the heavy version to see if the nodes are wider.

 

[Subwrx300]

Update: new barrel 26" +3 gas barrel installed, brake time and ready to hit the range. Some subjective and objective points.

• The old barrel was 3.6lbs, this one is 5lbs but it's very difficult to feel the extra weight on the rifle.
• I'm very surprised at how much stiffer it feels being non-Fluted compared to the same barrel fluted. There is an easily noticeable reduction in ability to deflect the barrel by hand.
• Balance: I went with non-fluted to move balance point slightly further forward. Old barrel balanced exactly in from of mag well, which was good before I put on the Arcalock. However, with new barrel, it's about 1-2" forward of mag well, right at beginning of the Arcalock rail. Dead nuts spot on where I wanted it.

Excited to get some rounds through it soon; may be a week or two though due to travel, work and match schedule.

New balance point:

 

[Shawn1492]

Is that a griffin arm as parading break? Does it maintain good accuracy?

 

[Subwrx300]

Is that a griffin arm as parading break? Does it maintain good accuracy?

Nopre; Thunder Beast CB Brake for suppressor.

 

[Subwrx300]

Update: 150 rounds through new barrel. It's starting to come into it's own now but I really don't think precision can be judged until 200-250 rounds through new barrel.

I just ran an H4350 OCW test over weekend and have great velocity results. Charges ranges from 26.2-27.4 at .2 grain intervals. Will post complete results next week, but velocity ran from 2700 - 2802 over the 1.2 grain spread. SDs were generally around 10-12 with with two charges at 8-9. That means about 10fps per .1 grain and with temps so cold, I expect better consistentcy once I get to 50-60 deg.

I found a couple a good nodes but I think seating depth is still an issue so I need to run depth test on two different nodes to confirm.

Getting occasional crazy flyers though which are likely a product of seating depth, gas port still breaking in, marginal stability from the crazy low temps (7.5t barrel with 88s in 10deg weather just above sea level).

Hoping to put up full results by end of Feb.