No POI change during load development.

[keen.on.it]

Hello everyone!

Just did my first ever load development today for my Tikka t3x in 270 win, only 3 rounds per powder charge as I have very limited primers as I'm sure you may be aware, and I really wasn't expecting to get any results on my first go at it anyways.

I was wondering, is it at all normal to have such little point of impact change between powder charges? Well, until it opened up a little bit on the last 2 charge weights. (Excuse the random target selection haha, no method to my madness) I would have thought that increasing velocity and barrel harmonics would have thrown it around a little bit more between each charge weight?

Thanks in advance for replies. I've read a whole bunch on here in the last few days leading up to this and over the years on various topics so I owe a thanks to all of my questions that have already been answered as well! Super excited to finally be reloading and looking forward to learning more!

 

[Aloeus]

Others here will have far more experience then I do, but anytime I've done powder charge tests on my 270wsm tikka they've ended up very similar to what you have, some group variations and a small amount of walking but no great changes in poi despite quite a lot of velocity change.

 

[keen.on.it]

Ahhh good to know I'm not alone haha, I wasn't expecting that at all, and couldn't find anything on it online. If nothing else I instantly see the need for a chronograph hahaha. I'll have to take that out to 400 to at least get an idea of consistency and get a rough idea of velocity until I either find someone with one or get my hands on one.

 

[Shane Lindsey]

Test your seating with that 53gr load. Center of it and 51, 52gr are pretty close to same impact with regards to elevation. Once you have your seating depth. Test it again, if you can use a linear target that will show you a little better how the charge weight affects the elevation with regards to the tuning.

Little elevation change over a wide range of charge weight will show you a forgiving load range. This allows for changes in atmosphere as well as slight variations in charge weights.

 

[Tiny Tim]

If your not seeing pressure, you may have to increase powder charge a little more. It seems your starting to see a poi shift at 54 gr, and Nosler lists a max of 55 gr. That said, it also appears to be opening up at that point. I Had a Remington 700 that would shoot starting loads extremely well, but as pressure increased, accuracy decreased. I was leaving about 300 fps on the table to get accurate loads. And like you said, get a chronograph.

 

[Mark37082]

Welcome to the forum and to the world of reloading. I'm not an expert by any means, but have learned a great deal from the fine members here as well as my own testing. POI shifts at short range (eg. 100 yards on flat shooting cartridges) can be minimal on powder charge testing. Keeping development as simple as possible is my preferred method. Without knowing actual velocity, it is difficult to make any clear determinations. You can work on barrel harmonics by observing group size and repeatability, but you are missing one key component in the equation IMO. However, as Shane mentioned, you can work on seating depth on a safe charge level and different bullets/powder combinations to determine what your rifle prefers. Good luck and be safe.

 

[kgunz11]

FWIW, your powder charge is going to be around 52.5gr. Adjust your seating depth 0.010" in both directions to see if the groups shrink up.

 

[DoneNOut]

You are off to a good start. Gun & scope want to shoot! Like Shane said, give 53gr some more attention with seating depth. As stated above, .010" depth changes.

Did you find your distance to lands?

 

[MagnumManiac]

There are cartridges that often show this, then there are those that will have a POI identical with different weight bullets, 270, 338-06, 338WM and many 375's do this, as do 416's.

Cheers.

 

[kgunz11]

Test your seating with that 53gr load. Center of it and 51, 52gr are pretty close to same impact with regards to elevation. Once you have your seating depth. Test it again, if you can use a linear target that will show you a little better how the charge weight affects the elevation with regards to the tuning.

Little elevation change over a wide range of charge weight will show you a forgiving load range. This allows for changes in atmosphere as well as slight variations in charge weights.

53.5gr starts to come apart, that's why I suggested exploring 52.5 a little more. Both 52gr and 53gr show promise so at 52.5 it should be in the middle of that range which will allow some room for environmental changes, be it temperature, humidity, or altitude.

 

[bultinkle]

Not surprising at all imo

I would go to 53 and start shooting more shots per group personally

 

[keen.on.it]

You are off to a good start. Gun & scope want to shoot! Like Shane said, give 53gr some more attention with seating depth. As stated above, .010" depth changes.

Did you find your distance to lands?

I got a rough idea of distance to the lands, will have to watch more videos on it and get it more accurate. For these I went for an OAL of 3.346 which JUST fits in the magazine, being a hopeful hunting round that was priority number one there, but I will still adjust both ways to note any changes.

 

[memtb]

Hello everyone!

Just did my first ever load development today for my Tikka t3x in 270 win, only 3 rounds per powder charge as I have very limited primers as I'm sure you may be aware, and I really wasn't expecting to get any results on my first go at it anyways.

I was wondering, is it at all normal to have such little point of impact change between powder charges? Well, until it opened up a little bit on the last 2 charge weights. (Excuse the random target selection haha, no method to my madness) I would have thought that increasing velocity and barrel harmonics would have thrown it around a little bit more between each charge weight?

Thanks in advance for replies. I've read a whole bunch on here in the last few days leading up to this and over the years on various topics so I owe a thanks to all of my questions that have already been answered as well! Super excited to finally be reloading and looking forward to learning more!

Presently doing the same thing, for some of the same reasons! My photo shows two groups, shot on different days, with 1 grain difference in powder charges!

So…..it's not that uncommon! In fact, with a total of 4 different powder charges, spanning 4.0 grains of powder ….the shots would pretty much superimpose over each other! The groups weren't significantly different than my old load with a different bullet….the old load group was only about 1 1/2" to 2" above all of the new test groups!

My old load was with 250 grain Barnes TTSX's…..the new experimental loads are with the 270 grain LRX's, fired from my .375 AI! memtb

 

[keen.on.it]

If you're not seeing pressure, you may have to increase powder charge a little more. It seems you're starting to see a poi shift at 54 gr, and Nosler lists a max of 55 gr. That said, it also appears to be opening up at that point. I Had a Remington 700 that would shoot starting loads extremely well, but as pressure increased, accuracy decreased. I was leaving about 300 fps on the table to get accurate loads. And like you said, get a chronograph.

I will be posting on some Facebook groups in my area to find someone nice enough to take me out with their chronograph for the time being, shouldn't have an issue I would imagine. No pressure signs but it sure did seem like it was getting pretty spicy starting at 53.5gr. 54gr kicked some good, not sure I've had my 270 kick like that, but I might just have been overthinking it being the top of my powder test on my first load?