5 shot groups 3 together and 2 fliers?

[memtb]

….. I live in the USA so it's Fahrenheit. I don't like Celsius or the metric system!

Well……now we know that you're not a Disciple of the 6.5 CM cult! memtb

 

[A A Ron]

A lot of variables can affect group size and heat. Barrel mass, barrel stress, barrel quality, suppressor, temperature, sunlight, (if your ammo and barrel start at 130 degrees because they are sitting in the sun, it will have an impact) ect.. With hunting rifles it's usually a waste of components and barrel life to shoot 30 shot groups to achieve statistical significance. On the other end of the spectrum 3 shot groups only tell you what you don't have. What I mean is that if 3 shots yields a two inch group, the group will never be smaller with more shots. A strategy I have used is to aggregate multiple small groups at different times to control heat and shooter fatigue. It does introduce environmental variables.

 

[bultinkle]

It's possible your barrels heat treat wasn't perfect and if so then it's definitely possible that's the issue. It's also possible you have a 1.5" load and low sample size and simple chance has led you to believe it's a 1/5moa load that opens up. In a consistent manner. How many times has this been observed and have you documented every group that wasn't like that? Sometimes we trick ourselves looking for an answer and forget when it didn't fit our concept.

Further testing is likely in order, I would try giving a lot more time in between, I would also try doing a 5x5 target and a few 10 shot groups to see if the trend you have seen is anecdotal or holds up.

For me I have not noticed heat based walking in my thinnest barrel, a tikka stainless light. This is a .8" 10 shot group with breaks only given towards the very end for mirage off my suppressor to die down enough to get a good enough view of the aim point.

 

[Shane Lindsey]

Are you getting mirage in the scope from your barrel. I am starting to believe some of my groups open up due to bad mirage (started noticing it when I started shooting suppressed without the shroud). Mirage gets so bad that the cross hairs and target blend together. FWIW, may not be barrel (well sort of).

Also agree with shooting slower and letting longer cooling periods between shots, especially if it is a hunting rifle. Shoot one and a follow up. Put it up and wait then do it again.

Heavy barrels are for targets, humping them sucks...

 

[chrisb97]

What powder, brass, bullet. Was that target at 100? I assume yes. How did you arrive at your node? What twist is your barrel? Type of support used? Is this a crowned muzzle or braked muzzle? These pieces of information will help diagnose your issue. P

Using ramshot magnum, lapua brass, 200 eldx. The group was shot at 100 and I just went up half grain increments till a couple of them hit the same POI with decent grouping and then tuned my seating depth. It's a 10 twist barrel with a muzzle brake shot off bipod with rear bag. I have a leupold mk5 7-35 on it.

 

[dustbag]

Did load development on 300 win for a friend. 199 HH with H1000. 3000fps. Always two tight and a flier. Changed to RL23. 3000fps. All 3 together. IDK? Another way to get a better group is shoot seven and make an excuse for the outliers. Oh I pulled that, that's the bullet I dropped in the ground etc. works for some guys anyways

 

[Mike6158]

Metric is just a number for people that can't handle fractions. I can switch back and forth if I want to. I don't want to (I hate to admit this but metric is about as simple as it gets. We gum it up when we try to "convert" it)

On topic. When I ladder test (3 not 5) I set a CZ457 .22LR next to me if nobody else is at the range or I replace the rifle that needs cooling with it. Either way, I shoot it until the other rifle is cooled off. If there's nobody else there I shoot 3, walk down and check the target(s), walk back, shoot the .22, walk down and look at those, walk back. If I'm feeling the need for adventure I'll walk down to the 300 steel plates and paint them for later. If anyone shows up all of that goes out the window. Some range sessions I can get 10,000 plus steps (5 miles) just walking down to targets and back.

 

[Mike6158]

Using ramshot magnum, lapua brass, 200 eldx. The group was shot at 100 and I just went up half grain increments till a couple of them hit the same POI with decent grouping and then tuned my seating depth. It's a 10 twist barrel with a muzzle brake shot off bipod with rear bag. I have a leupold mk5 7-35 on it.

Half grain increments might cause you to jump right over a node. My ladders are all done with .3 grain steps. I look for "the flat spot" then load .1 gr steps for the fine powder test. It's real easy to see when it comes in. I bought a scale the measures in 100th's of a grain but only to let me fine tune the 10th of the grain value. I tested my RCBS Chargemaster 1500 drops and sometimes it was .1 grain off (read 64.1 on the RCBS and 64.23 on the other scale). I step my seating depth test in .003" increments.

 

[Darryle]

Thanks for the replies guys. It's a savage 110 high country so it's got a decently thick fluted barrel on it but it was about 75° when I was shooting. I'll try 5 minutes between shots and see how it looks later this week

I had a custom rifle that would put 2 in the same hole, 3rd just outside regardless of how long between shots or shooter. Rifle was skim bedded, took it to another gunsmith and he said that the bedding was the culprit. He machined out the the original bedding, bedded the action, bottom metal and installed new pillars. The issue went away.

If this is a bone stock factory rifle, I would have it properly bedded before I went any further.

 

[Mike6158]

Rather than edit the last post I'll add the target photos here. These are the two targets that I used for my seating depth test. They look like they've been wet because they have. It rained off and on during the test. It took about 3 times as long to shoot this one. 5 groups of 3 plus the sighter target at the end. Which one would you pick? I've already loaded 5 of the one I like and I'll shoot that at 200. If it holds up ok I'll load 5 and shoot that at 300. At this point I'm testing the 150 gr Barnes TTSX for it's ability to fly straight and give me reliable first round performance.

 

[Mark37082]

I think everyone will agree that cold bore first shot is the most important in a hunting rifle. However, I really like shooting my hunting rifles. Some are more suited to multiple round sessions. If I can hold five shots in 1 MOA or less within a relatively short time span, I'm happy. Three shot groups need to be closer to 1/2 MOA, for me to be happy. This time of year it gets hot in TN. I never really shoot long strings with my rifles with pencil barrels. I shot 30 rounds in one rifle earlier today. This was all within an 1 1/2 hours. My last 5 shot group was .9 MOA. Mirage was a little tough to deal with, but my ES and SD was very good. This was on a CF Sendero barreled rifle. I probably would have thrown some fliers with a thin barrel.

 

[chrisb97]

I appreciate all the responses guys. I'm currently loading more rounds for shooting this Friday. I'm going to do a few more groups of 5 with waiting 10 minutes in between shots just to see what happens. If that doesn't work I'll take it to my smith and have him bed it past the aluminum block it has now

 

[Shane Lindsey]

@Mike6158

Does the gun shoot better dirty or clean? If you don't know, then it may be hard to tell as they start tightening up as it is getting fouled or other factors, fatigue, mirage, heat...etc.
Leave the gun dirty. I would shoot .587, .588, and .589. Have to see it repeats that .588 or if it was a "lucky group".

Do you have any other primers? Maybe load the nine above and do another nine with a different primer at the same depths???

 

[Mike6158]

@Mike6158

Does the gun shoot better dirty or clean? If you don't know, then it may be hard to tell as they start tightening up as it is getting fouled or other factors, fatigue, mirage, heat...etc.
Leave the gun dirty. I would shoot .587, .588, and .589. Have to see it repeats that .588 or if it was a "lucky group".

Do you have any other primers? Maybe load the nine above and do another nine with a different primer at the same depths???

All good questions. It starts clean. Clean, btw, how clean is a whole nuther rabbit hole. F class shooters clean differently than Benchrest shooters. Then there's borescope clean. No borescope clean is a clean patch. Borescope clean is a clean patch AND a nice visibly clean barrel. That comes well after the clean patch did. I was in the clean when it isn't accurate camp. Until the last year or so I shot maybe 5 rounds out of this rifle a year. Those were shot to tune up before deer season and deer season. So the rifle got a quick clean then something to prevent rust at the end of deer season.

Fatigue, no, not on the day the target was shot. It was hot when I got there then showers went through and cooled things down a little before I got set up. No mirage for a change.

I keep an eye on the velocity for each shot (LabRadar). That usually correlates to a "flier". Of course I'm not a robot (as far as we know) so of course there are my little errors (little LOL) here and there. I recently had to reset the Jewell trigger in the 7mm back to factory adjustments. It's a little heavy for my liking. I'm going to check the weight and drop it back to 2 - 2.5# today.

It shoots better clean. I can see a noticeable improvement from when I started (patch clean) to now (borescope clean). When I shoot it at deer season, it'll be clean. Now I clean every time either at the range before I leave or when I get home.

At the distance we shoot deer here in TX it'll kill with factory ammo if I was inclined to buy factory ammo. I'm just checking performance of the 150 gr Barnes TTSX.

I have Remington, CCI, Federal, and <cough> Wolf primers (they go bang if I need them to). I really should test with different primers. I hand prime with a Sinclair tool. I can feel when a primer is different than another (high for instance) and I usually set that case aside to use as a sighter (fouler).