I have had occasional, erratic stringing of loads down and left....

175 TMK - 175 TMK, 42.8 gr R15, Hornady cases
110 Varm - 110 gr Nosler Varmageddon, 50 gr BLC-2, PRVI cases

Rifle - Trued Rem 700, 20" varmint contour with AE30 can





I have a theory of why…

I have not always been diligent at cleaning lube off of the cases.  I could feel the lube still on these cases, and it would account for why it has happened erratically with other loads.  

I have cleaned off the remaining loads and will go back and shoot them some more.  

I need a chronograph!  The Labradar is calling my name.

Thoughts on the impact of cases with lube still on them?

It is a little difficult to follow what your were trying to accomplish on this range visit. It appears your 175 gr bullet shoots well, and your 110 grain bullet shows a very pronounced tendency to print a diagonal string on the target. Because of the order that you preformed your tests, it appears that it is not a mechanical issue with your rifle. You report that at other times, this 110 grain load has also performed very well.

To test your case lube theory, you should compare the difference between careful cleaning and your normal procedure without changing any other variable. Depending on your procedure, maybe you will find the improvement is not worth the extra effort. I usually rinse my brass after resizing, but that is because I like my hands to feel clean after handling loaded ammo.

Another thing to consider is the effects of residue in the barrel from different kinds of powder. It adds another variable if you are intermittently switching between powders. Just like copper fowling, you should give the barrel some shots to reach an equilibrium before expecting it to be extremely consistent. I don't know if anyone has done extensive research on this topic, but there are many competitive shooters that avoid switching powder without cleaning because the accuracy results are sometimes unpredictable.

Sorry I don't have a definitive answer. I would certainly be very interested to see what other people say about it.

Thanks, that is very interesting about switching powders.  I did come home and clean the rest of the 110 gr rounds I have loaded.  

As far as what I was trying to occomplish, I have a long range match next week and the groundhogs are starting to come out, so I was trying to get both loads zeroes so I can get after it.

Here is a 3 round group of the 110 gr load from last year.






Here is another example of the down and left stringing from a different 175 gr TMK load.  

Does this exist with the can off? Do you have to continuously rezero (ie; it's not a short term drift)? Check your crown and can? Time between shots & is it cold to start with?

Perhaps something to do with neck tension on your 110's not being set right and moving while firing...?

Answers to your questions are in bold.

I checked the tightness of the can, that has caused me issues before; it was tight.  

The stinging is so weird.

Yeah that is odd. The 175's staying the same would lead me to think it's something with the 110 ammo. Too much room in the case and inconsistent burn? If you're neck sizing, perhaps try increasing the tension 0.001" or something? Best of luck.

I was digging through some of my old posts and thought I'd give an update to this.  

I believe the issue was a dirty bore.  It had been a while since I had cleaned my rifle and I go by the adage of don't clean until your groups suffer.  The dirty bore didn't affect my 175 TMK load, but it seemed to adversely affect the 110 Varminter load.  I cleaned the rifle and the load went back to grouping well.

Good to hear.