Question for you reloaders on Load Dev

[champ198]

Been working on reloads for a 6.5CM.
First ill say I am still new with a lot of this and this is a hunting rifle. Not a precision rifle or a really super high end rifle either. But one that I do enjoy to shoot and hunt with.

Finally starting to get somewhere with help from one of the members here. Has been a huge help.
But I also have another question.
When you head to the range and start shooting. Do you start out cold. and record those groups.
Or do you run some sighters or foulers through the gun to get some heat in it before shooting groups for recording data?

The reason I ask is the 3 charge groups I shot last night all were somewhat consistant.
But the first group the first shot I made went low and opened the group up.
taking that one shot out the group and mean radius of the group would be much much smaller.
So just got me thinking if I should run this group again to see what it does if the rifle has some heat in it first.
Here is my original target.

Here is the same target with the 1st target shot dropped. Which was the first shot made with the rifle cold.

Right now just trying to get a charge weight found so I can start working on seating depth tests to see if I can get a smaller group.

 

[rustyinbend]

When the purpose of shooting the string is to determine velocity, SD, ES and trying to nail down an optimal charge and case configuration ... I use the top-3 outliers from seating bullets with my AMP Press as "barrel warmers". If I'm just plinking for fun, then I either don't measure velocity, or don't particularly care if there's an early shot variance. I've found that three shots is plenty to prep my barrel for accurate load development data.

 

[acourvil]

Agree with rustyinbend, but if this is for hunting you also want to track what that first shot does. Some rifles/loads will have a repeatable difference on the first shot, and if that is your kill shot you want to know exactly where it will go. You can also try to work for a load and/or barrel treatment that does not do something different on the first shot.

 

[diggler1833]

Been working on reloads for a 6.5CM.
First ill say I am still new with a lot of this and this is a hunting rifle. Not a precision rifle or a really super high end rifle either. But one that I do enjoy to shoot and hunt with.

Finally starting to get somewhere with help from one of the members here. Has been a huge help.
But I also have another question.
When you head to the range and start shooting. Do you start out cold. and record those groups.
Or do you run some sighters or foulers through the gun to get some heat in it before shooting groups for recording data?

The reason I ask is the 3 charge groups I shot last night all were somewhat consistant.
But the first group the first shot I made went low and opened the group up.
taking that one shot out the group and mean radius of the group would be much much smaller.
So just got me thinking if I should run this group again to see what it does if the rifle has some heat in it first.
Here is my original target.
View attachment 8650243
Here is the same target with the 1st target shot dropped. Which was the first shot made with the rifle cold.
View attachment 8650244
Right now just trying to get a charge weight found so I can start working on seating depth tests to see if I can get a smaller group.

Man, you went in .1gr charge increments. I'd fully expect your next group - if you repeated the test - to be just a touch over 1 MOA.

You have a fairly consistent load there, and that isn't a bad thing...other than it isn't giving you the accuracy you're after. It also testifies a bit to your own shooting consistency.

.1gr increments are a quarter of a single percent difference in charge weight for that cartridge. To expect significant difference in results with minute difference in inputs is a good way to expend extra ccomponents. Maybe try .75 - 1% increments (.3 - .4gr), and you'll be able to cover a much wider range of potential charges that work well in your rifle.

Or, you can keep it at 41.0, and try some seating depth tests if your happy with the velocity results from your initial test.

There's more than one way to be successful at this, which is why we argue in these forums all the time. I've just never had a "good" load that was a quarter percent away in charge weight from a mediocre load - hold up.

 

[champ198]

These targets were shot after originally doing .02 gr increments.
These 3 charge weights were the node I wanted to look at coming from those earlier results.
right now I think the 40.9 is going to be my load. So I have another 10 rounds loaded to verify. Then I will work on seating depth tests if needed.

 

[RegionRat]

These targets were shot after originally doing .02 gr increments.

Did you mean to say you went from a 0.2 grain increment, then narrowed the test and ran in 0.1 grain steps?

Because 0.02 is going to take a lot of steps to make a velocity/charge sweep.... obviously a typo.

Anyway, just take the following advice with a grain of salt....

If this is a hunting rig, keep your focus on the type of shooting you actually care about and practice that kind.
In other words, if your cold bore shot is important when you are hunting then that is your focus.

To test a cold bore shot, is not to say that every test is from a cleaned bbl, but it is still a matter of your choice how you clean and how many fouling shots you take before you go into a situation with a cold bore for a critical shot.

When we are lucky, our rig will shoot a cold bore shot into the same group as a warmed gun once it is fouled after a cleaning.
When we are not lucky, the cold bore shot is out of family with the warmed gun. This isn't the end of the world, but it means be patient and honest with the testing to determine if the shots will be predictable.

Yes, that is a total pain in the ass compared to shooting a warmed up bbl. The best field shooters know this is the price of being good at this type of shooting. Knowing the typical probability of a cold bore shot in field shooting is not the same as shooting PRS, F-Class, etc.

Getting in and out of vehicles, heated buildings, carrying the gun in weather for many days before a shot, etc., are all part of the game and you will just have to test your rig, and yourself.

I think the only "competition" game that comes close is when an XTC shooter attends a EIC match. An EIC match has no sighters, and depending on the attendance and size of the relays the gun will be cold. You inevitably take shots from a "cold gun" that count, including shots at 600 yards. Some ranges have a place where you can take a blow-off shot before the match, most do not.

The type of shooting you are doing means you work on your cleaning interval and the philosophy of how you will carry that gun in terms of always clean, or cleaned and some fouling shots.

A rookie shooter has to pay attention to weather and practice shooting in winds much more so than worrying about perfecting their loads.

While you are perfecting that load, just remember to balance your efforts with shooting cold bore shots and keeping score. The difference between a fractional improvement in group size will not be as great as the shooter errors in the field.

The bad news is, it takes a long time to test cold bore shots realistically. The good news is, that gives you an excuse to take more guns to the range to shoot while you rest this one to cool off. Good Luck and in for the range reports.

 

[Csafisher]

Did it drop because it was cold or because it’s just part of your shot distribution?

 

[diggler1833]

That single low shot is perfectly within the normal dispersion one could expect within a 1 MOA load, especially when just a tenth or two more dropped one even lower.

 

[Hawk in WY]

Cold bore or cold shooter?

 

[Im2bent]

Keep in mind you should try different powders. It may not like that powder. Playing with seating depth can make a difference, but a different powder can be a game changer. And are you shooting the bullet you want to ultimately use. A different bullet can also make a big difference