What is going on???????

[Creedmoor shooter]

Only 172 rounds? If you did load dev wa new barrel, the velocity probably increased as the barrel settled in and you're now out of the node.

I suppose that could be but I chronoed the 143 eld-x with 42 grains of rl-17 and it ran a 2875 with a ES of 8. That was about 30 rounds ago so I'm not sure it would pick up much more velocity as that's already humming for the creedmoor. This was previously my best load that shot a .169moa and several .2 and .3 groups and now it shoots over 1moa

 

[toddc]

As for cleaning products I use butches bore shine. I just find it odd that it will literally put 2 in the same hole then throw one 1.5 -2 in off. I've been watching my accuracy fall off over the past 2 months. I shot it mid November and it had opened up to .5-.6 then I took it out last week and got similar results to what I had yesterday. I thought may even my barrel was alittle dirty so I did run a bunch of patches and made a pass with the brush. I can try a more thorough cleaning to see if that helps. I should probably mention my round count is 172. I went 79 rounds in between my 2 last cleanings. Thanks for all the suggestions so far!

2 in 1 out=Bipod issues, bedding or scope.

 

[Capt RB]

If you have a carbon ring best thing to cut the carbon is yamaha ring free for outboard engines. Next is seafoam again it's for 2stroke outboards to keep the O2 sensors from getting covered in carbon deposits. It will cut the hard carbon very quickly soak a patch wet the bore then use a nylon brush for a few minutes then patch it out. If the patch is snow white your done if not repeat. This will also prevent copper from being removed if it covers some.
I'd check the load first for speed/sd then I would remove the bipod and shoot off a bench/bag set up to see if changing the pressure point helps.

 

[Creedmoor shooter]

Thanks for the help. I had two good loads with the 143 eld-x with rl-17 and H4350. I'll shoot both loads over a chrono and off bags to see if it makes a difference. I'm leaning towards the theory that it could be the rl-17 is very sensitive to temperature since I've noticed a gradual accuracy degrade over the past 2 months as its gotten colder.

 

[MudRunner2005]

My AccuMark was one of the "cheap years" where Weatherby used button-rifled Criterions instead of cut-rifled Kriegers and raised the price, and didn't bother to tell anyone they cut barrel quality significantly...

Anyway, we all know that story, where the barrel started caving-in around 75-100 rounds, and got worse from there.

Not saying that is your issue, but being that mine did the same thing, and they were both Criterion barrels, I'd have that barrel scoped by a gunsmith to be on the safe side! If it's bad, contact Criterion.

Other options, I have heard RL-17 is known to be a bit temp-sensitive... And I have personally experienced this with RL-19 and RL-22. So that might warrant some research.

 

[nddodd]

This may not be your problem but it was a problem I had with one of my guns. Neck tension can be your best friend if it's consistent, if it's not you'll chase your tail trying to figure out what the hell is going on. I don't know if your annealing every couple firings or not but I'd suggest it, just to see if that helps.


Hopefully you'll get it figured out, it can be very frustrating.


Nathan

 

[Creedmoor shooter]

This may not be your problem but it was a problem I had with one of my guns. Neck tension can be your best friend if it's consistent, if it's not you'll chase your tail trying to figure out what the hell is going on. I don't know if your annealing every couple firings or not but I'd suggest it, just to see if that helps.


Hopefully you'll get it figured out, it can be very frustrating.


Nathan

It is extremely frustrating. Took me almost a year to get the funds for this and I sold one of my gunew and this is what I get lol. Like I said before I'll try shooting off the bags and try a less temp sensitive powder. Not to sound stupid but can you explain neck tension to me? If all this doesn't work then as Mudrunner said it's going to the smith for a look over and perhaps a call to criterion. I just don't get how it could shoot so well then just go to crap so quick.

 

[nddodd]

It is extremely frustrating. Took me almost a year to get the funds for this and I sold one of my gunew and this is what I get lol. Like I said before I'll try shooting off the bags and try a less temp sensitive powder. Not to sound stupid but can you explain neck tension to me? If all this doesn't work then as Mudrunner said it's going to the smith for a look over and perhaps a call to criterion. I just don't get how it could shoot so well then just go to crap so quick.

What happens more times then not, as the brass is fired it work hardens more and more with every firing. Some of the pieces will harden more than the others, and when you run them through a neck sizing, full length or bushing die one will have more spring back than the other. When that happens you'll have some that say measures .260 inside the neck and some that measure .255. There's a whole hour or two I could go into this but with that said you've got some cases that seat the bullet real easy and some that have more resistance. Those that are tighter will not group as well as those that were easier to seat.

 

[Creedmoor shooter]

I measured inside my case mouth on a few and they were all .264. I did however discover my brass was .010 too long! Not sure if it would cause those issues but i trimmed them back to book length.

 

[elkaholic]

I measured inside my case mouth on a few and they were all .264. I did however discover my brass was .010 too long! Not sure if it would cause those issues but i trimmed them back to book length.

That COULD cause the issue because it would likely raise pressure and make it inconsistent as well. You will know when you shoot again!

 

[Creedmoor shooter]

I just hope to get to the bottom of this.... I'm losing sleep over it lol

 

[Creedmoor shooter]

Ok note to self..... keep an eye on case length! I was able to get out of work early enough today to try it out again before the sub 0 weather hit this weekend. I was shooting in about 15-20 degrees off my bipod as usual. I loaded 42.5 of rl-17 which was a good summertime load and I loaded 42 grains of h4350 which shot in the .4s in the summer. The rl-17 shot a .75 and the h-4350 shot a even .400. Not this guns best performance but I'll take it over what I've been seeing lately. I wasn't on my A-game today as I was dealing with a ridiculous heart beat that I couldn't slow down lol. Thanks everyone for your help!

 

[AZShooter]

The target you just posted is certainly encouraging.

I have to ask. You said the brass was .010" too long. Compared to SAMMI length? Or .010" longer than your chamber end? I would suggest to you that you are far from the end of the chamber UNLESS you actually measured it. Most chambers, unless made with a custom reamer, have a huge distance to the end of the chamber compared to SAMMI max length specifications.


I would suggest there was something else at play here. Sure if all cases are the same length and diameter then they should have very similar bullet tension/ release characteristics which would help create consistent velocity and better accuracy. Might not be able to see this with a hunting sporter but everything helps.

What Varmint Al says on his site is true, I found the same sort of dimensions:

Quote:
"I usually find that the factory recommendations for case length leave a 0.050 inch to 0.070 inch gap between the end of the case and the actual length of the chamber."

link to how to measure chamber length.
Varmint Al's Handloading/Reloading Page




The question remains, what has the rifle shooting better now? I think you should repeat the testing for a larger sample.

This is the beauty of this site, Len has the notification system so we never miss an entry. We posters offer suggestions to the OP and we all learn. Keep us informed Creedmoor shooter.

 

[Creedmoor shooter]

The target you just posted is certainly encouraging.

I have to ask. You said the brass was .010" too long. Compared to SAMMI length? Or .010" longer than your chamber end? I would suggest to you that you are far from the end of the chamber UNLESS you actually measured it. Most chambers, unless made with a custom reamer, have a huge distance to the end of the chamber compared to SAMMI max length specifications.


I would suggest there was something else at play here. Sure if all cases are the same length and diameter then they should have very similar bullet tension/ release characteristics which would help create consistent velocity and better accuracy. Might not be able to see this with a hunting sporter but everything helps.

What Varmint Al says on his site is true, I found the same sort of dimensions:

Quote:
"I usually find that the factory recommendations for case length leave a 0.050 inch to 0.070 inch gap between the end of the case and the actual length of the chamber."

link to how to measure chamber length.
Varmint Al's Handloading/Reloading Page




The question remains, what has the rifle shooting better now? I think you should repeat the testing for a larger sample.

This is the beauty of this site, Len has the notification system so we never miss an entry. We posters offer suggestions to the OP and we all learn. Keep us informed Creedmoor shooter.

Yes the target is definitely encouraging. Getting more to where I like to see it. As for the case lengthat according to ther hornady manual my max case lengthe was supposed to be 1.920. I was running around 1.930-1.933. I have not measured my chamber length. I will test some more rounds and see if the results are the same. Something definitely changed no doubt about it. As I suspected the H4350 was going to shoot better being so cold out. I'll try some more rl-17 and h4350 to see what I get for results. Any other suggestions are most helpful!