6.5 creedmoor load development help

[sprink21]

I just got a Tikka CTR and have been working on finding a load for it the last three weekends. First weekend I did a latter test and picked what I think was an accuracy node. Second weekend I played with seating depths. Now this weekend I took my magnetospeed sporter that I just got two days ago to get some numbers. I loaded up 40rds and ran the first 20 over the chrony and shot 5rd groups with the last 20. The load is

42.3gr H4350
CCI BR4 primers
140gr ELDM
Brand new Lapua brass
OAL is 2.865" (puts me .02 off the lands)
Avg. FPS 2666
SD 4
ES 11

I thought these numbers were really good but when I went to shoot my four 5rd groups I was struggling to keep 1" groups. Best was about an inch and worst was 1.75". Is it time to move to a different bullet or is there something else I can do to tighten group sizes up? Any help or ideas would be appreciated, thanks.

 

[bruddah]

I just got a Tikka CTR and have been working on finding a load for it the last three weekends. First weekend I did a latter test and picked what I think was an accuracy node. Second weekend I played with seating depths. Now this weekend I took my magnetospeed sporter that I just got two days ago to get some numbers. I loaded up 40rds and ran the first 20 over the chrony and shot 5rd groups with the last 20. The load is

??

 

[Darkside-Six]

Did you shoot the 5 round groups with the Chronograph attached? if so, then that can mess with your point of impact and group size. if not, then I would play with seating depth some more to try and get them to tighten up.....assuming it's just not you. Those numbers are good aside from it being a little on the slow side.

 

[sprink21]

??

I accidentally hit the post button on my phone before I was finished typing lol

 

[sprink21]

After I shot the first 20rds I removed the magnetespeed and then shot the last 20rds from a lead sled.

 

[padom]

Did you shoot the 5 round groups with the Chronograph attached? if so, then that can mess with your point of impact and group size.

this is a myth. Myself and many others have shot 100's of load development tests with a MS v3 on. POI shift Yes, but as long as you have it on for your entire test then POI is consistent across all charges. Group size being affected, no. I can post target after target of groups in the .1's to .5's across bolt guns, AR15's and AR10's in every major caliber out there.

I do not shoot seating depth testing with it on. Why? Because I already have all the chrono data from the OCW test. The point of seating depth testing is strictly group size.

I will then shoot a 25rd string over the chrono once I have selected my OCW and found my optimal seating depth for a final velocity and SD check.

 

[sig2009]

Well with SD 4/ES 11 I have never gotten those results out of my Tikka CTR. That is a winner as far as I am concerned. And I have done ladder tests with over 400 rounds. Gave up on this 20" Tikka barrel and am now swapping it out for a 26".

 

[sprink21]

Well with SD 4/ES 11 I have never gotten those results out of my Tikka CTR. That is a winner as far as I am concerned. And I have done ladder tests with over 400 rounds. Gave up on this 20" Tikka barrel and am now swapping it out for a 26".

Were your velocities low also in your CTR? Mine has a 24" barrel and was hoping that I was going to be at least in the mid 2700s with 42.3gr of H4350

 

[J McGriddle]

That definetly sounds slow. What was temp and pressure during testing? Also, what is the round count on that barrel?

 

[sprink21]

120rds on the barrel, 40deg F and around 400ft in elevation. Not sure what the barometric pressure was.

 

[J McGriddle]

Your barrel is just getting broken in, it might speed up some. As far as the grouping, I would clean the hell out of the barrel, shoot 10 or 20 fouler rounds and try get a decent group again. I know some guys say their barrel won't start shooting tight groups until after 40 fouler rounds.

 

[J McGriddle]

This is the test method I use and have talked to others who have had good results also.

http://www.6mmbr.com/laddertest.html

 

[sprink21]

Your barrel is just getting broken in, it might speed up some. As far as the grouping, I would clean the hell out of the barrel, shoot 10 or 20 fouler rounds and try get a decent group again. I know some guys say their barrel won't start shooting tight groups until after 40 fouler rounds.

I'll give this a try next weekend to see if it helps, thanks

 

[Darkside-Six]

this is a myth. Myself and many others have shot 100's of load development tests with a MS v3 on. POI shift Yes, but as long as you have it on for your entire test then POI is consistent across all charges. Group size being affected, no. I can post target after target of groups in the .1's to .5's across bolt guns, AR15's and AR10's in every major caliber out there.

Yeah same here. I've never had an issue with it personally but always hear about others so I thought I'd throw it out there.

 

[sig2009]

Were your velocities low also in your CTR? Mine has a 24" barrel and was hoping that I was going to be at least in the mid 2700s with 42.3gr of H4350

Upper 2500 to 2600fps. Josh at PVA is swapping out a 26" for me next month.

 

[nexusfire]

maybe try a different bullet. I have a 22" barrel and I am getting 2875 fps with a 130 HVLD and 42.8gr H4350.