Can anyone answer why?

[JDL]

I worked up a pretty good load for my Savage 99 in .300 caliber, consisting of a 165 grain Mountain Mold boolit and 23 grains of Rx7 plus about 1 grain of poly fiber. Velocity was 1873 fps and the average of 4 groups was less than 1 1/2 inches although the ES was big. The cases were very clean, except one in the second group, which had bits of semi-melted poly stuck on the neck and shoulder. Not all that much but, with the other cases so clean, I was wondering what the cause may be? I've used poly in certain loads since the middle 70's and had never had this occur. Any thoughts? -JDL

[felix]

Joe, you very well could be permitting a SEE situation, especially with and ES over about 50 or so. Use the same load with 4198, but without the filler. If none, then try altering the filler a little. Just how, I can't advise. SEEs seldom have a chance to occur with "packing" material having a very irregular shape. Make sure of that. In other words, NO WAD effect. ... felix

[stocker]

I'd guess you haven't got quite enough pressure to fully expand the case neck to create a seal. Perhaps the cases that showed this were a little harder than the rest and expanded less . Were they older or had been reloaded oftener?Something about 300 Savages, they seem to like cast boolits and shoot well with them. Mine give very good results with little effort in getting there.

[Bass Ackward]

Joe,

My guess is that you just didn't expand the neck to seal. Look at the causes in this area. My guess would be a weaker primer.

[JDL]

The cases were once fired factory rounds but, I could feel a couple offering more resistance while seating which were probably the harder ones. So, the problem could have been hard necks not obturating or, as BA thought, a weak primer.

Felix got me wondering about pressure excursions, so following his advice,loaded some up with IMR-4198 w/o the poly filler. The accuracy was only ho-hum at around 3.5", but with an ES of 5 I decided to try the same 23 grains of Rx7 w/o the filler and compair. My findings wasn't as expected.

Yesterday, the poly inhanced loads produced an average velocity of 1873 fps; SD 28.9; ES 111 fps; the 4 groups averaged 1.495".
Today, without poly, the average velocity was 1889 fps; SD 29.9; ES 89 and the 4 groups opened slightly less than .2" at 1.693".

I had reasoned the poly fiber would have offered more consistant results but, as I have seen in other loads, this isn't necessarly true. -JDL

[Bass Ackward]

I had reasoned the poly fiber would have offered more consistant results but, as I have seen in other loads, this isn't necessarly true. -JDL


Joe,

This was the "personal" debate I always had about fillers. They are NOT automatic. It seems that they work if they solve a problem. When there is no problem to solve, they can have a negative effect.

While I have seen dramatic group shrinkage as a percentage and rediculous patterns return to group structure, all this has done is make a bad load .... acceptable for someone just wanting to get shooting. I have NEVER had a filler load turn out to be my best effort in any caliber I ever had or used.

In almost 2/3rds of my filler trials, fillers had neutral to reverse effects. I have spent time trying to isolate conditions that might draw a pattern for their use. In the end, none was seen. Therefore, I have no idea of how to establish a criteria that might predict success. So it remains a trial and error mystery to me that I avoid only with full case loads using a solid filler and soft lead where the positive atribute is increased velocity before leading begins.