Jumping bullets a mile!

[rckendall]

223rem with what bullet?

I came back to add to this, and see your reply. Thanks.

It is a WOA AR-15 Varmint upper. I'm trying to use 69 gn SMK, LC brass (04 headstamp) and Varget, because I have plenty of these right now. I am getting no consistent results. It has about .200 jump at max mag length.

Richard

 

[eric32]

Good deeper in .005 increments , also i cant really say sonce i cant see your groups.

 

[338 dude]

After reading the article, it all sounds very good and logical, but I'm still trying to process (in my mind) all that's actually going on as the bullet is seated deeper at each interval. For example, if one is starting with a load that fills the case to something like 102% of case capacity when seated at the lands, how far can one keep reducing the the seating depth until there's a major pressure problem? If one is starting with a load that only fills 94% of the case capacity, then there's plenty of room to not have much worry about too much pressure as one seats the bullet deeper. This issue wasn't mentioned in the article. I know this process is really all about POI, but as a bullet is seated deeper and deeper, one is changing MV and pressure curves (given the same powder load). So to some extent, MV data can be telling you something too as it relates to POI, isn't it . . . ??? Or maybe it just doesn't really matter???

I've got some more mulling to do.

Anyone else have any thoughts along this line?

Here’s something else to consider yes as you seat deeper you have a smaller combustion chamber so you are raising pressures but with longer jumps it handles the pressure better so is anything really changing

 

[rckendall]

Good deeper in .005 increments , also i cant really say sonce i cant see your groups.

Two groups that stood out to me had 3/8" vertical and 1 1/2" - 2" horizontal. These made me think I should change seating depth. But I also did not see any patterns of groups having the same POI, which I was looking for.

 

[eric32]

Then either change powder or bullets. ARs have the added element of the gas vlowback and cycling. So i cant really talk to the load development of them.

 

[rckendall]

Thanks, I have plans to do both. First will be powder as I have RE-15 which is known to work with those bullets in ARs.

I had mediocre results with bolt gun in 223 Rem before using Varget and the 69 SMK. I went to 8208 and had great results.

 

[eric32]

Yea 8208 will also work in a gasser as well try that powder too.

 

[1911nut]

In my Swift, 55g Berger flat base bullets 0.20” in the neck jump 0.162”. It shoots the load in the 3’s - 4’s.

Its a SAAMI spec chamber.