Another question, for my 270, I load approx 90% full of powder, maybe a little more. I am happy with velocity and accuracy. What I'm wondering is, if I use some sort of filler to fill the case to near 100%, without compressing it, should it produce any increase in performance? I wonder this, because then the powder should be in a more consistant column in the case, and not with a small air gap along the upper side of the case when it is chambered? I know its something I need to try, just wondering if anyone else has investigated the same sort of thing?
thanks

If you do an Archives search, you will find a Tech Note on this subject.

Pressures can and sometimes will sky rocket with the addition of fillers. If you are going to add fillers to your loads, I would reduce the load and stert over with the addition of fillers. Even if you drop your powder charge 5 full grains, the use of fillers will still give you your original velocity figures because of the increased pressures....

A

kdub's suggestion is likely a wise one.I 2nd it! Lots of good stuff to read here.

My thinking is that it would be a "bad idea" to use a filler in a bottle-necked case of any flavor. I further don't much care for the idea in straight-walled cases either.
Published data from a known source is the rule of the day.

Save yourself some grief and do a search. Life is already hard enough. No real good reason to get hurt by your hobby.

Iowaloha! Nice to meet ya.

Cheezywan

If your loading density is already 90+%, a filler is completely unnecessary and potentially quite dangerous. Fillers can do a lot of good with very low density loads in big cases, but even then it's safest to stick with a published, tested recipes.

+1 to pisgah, cheezywan and others.
Not only no, but he11 no.

If you use the same caution with fillers that you use with gunpowder,you will not have any problems,at all.Take the given advise and research the subject before trying fillers.
Most of my regular use cast bullet loads use fillers.My 30/30 hunting load,with about 90% IMR 3031 powder has just enough granular filler to fill the case.DO NOT OVERFILL,and compress the load.Even a mild compression will force the filler,over time,to compress into a solid mass,which is not good.Compressing fiber fillers,like Dacron,is less dangerous,but not advisable.
Normally,a 90% filled case does not need any filler;below 60% usually does.
I also feel tha a filler protects the bullet base from the hot gas from the ignited powder.
Frank

Filler does not burn so it will be a added thing to push out your bbl adding recoil and pressure. 90% don't do it. If you want more % go to a slower powder and fill the case.