Switching back and forth between ball and extruded powders.

[markm87]

My buddy has a really exceptionally accurate Geissele Super Duty AR with a Great NF ACTAR scope. It's an easy sub MOA gun, so we test a variety of loads in it.

We've been jogging in and out of Ball.. specifically TAC and H322 with some random factory loads like Norma 77 gr (ball) and Outback 69gr (extruded).

Last weekend the POI dropped 3 inches and right 1 inch for no reason. We shoot this gun every weekend. Do you think the Heinz 57 barrage of powders could be the cause?

 

[joshb]

If all shots changed POI, I’d be suspicious of the scope or mounts.

 

[markm87]

They definitely all moved low right.

 

[Ned Ludd]

Did the velocity change markedly? If not, it's likely something other than the powders used, such as a loose scope mount (or similar) as joshb mentioned. Otherwise, changing Lots of powder can easily cause this, as can Lot-to-Lot differences in other reloading components, or even between different Lots of commercial ammunition.

 

[Doom]

I have had some issues with shooting extruded then ball. In particular this happened in 308 with IMR 4064 and 2000MR. Don’t remember if POI changed but after about 4 or 5 rounds the rounds became hard to chamber. When cleaned it seemed as if the rifle was full of oily gunk. Ever since I clean before switching powder type or after shooting factory ammo.

 

[David Milisock]

My buddy has a really exceptionally accurate Geissele Super Duty AR with a Great NF ACTAR scope. It's an easy sub MOA gun, so we test a variety of loads in it.

We've been jogging in and out of Ball.. specifically TAC and H322 with some random factory loads like Norma 77 gr (ball) and Outback 69gr (extruded).

Last weekend the POI dropped 3 inches and right 1 inch for no reason. We shoot this gun every weekend. Do you think the Heinz 57 barrage of powders could be the cause?

Sounds mechanical to me.

 

[markm87]

Thanks guys. We'll dig into the mounting situation.

 

[Tesoro]

h322 isnt a 'ball' powder fyi

 

[K22]

Not saying this is the issue for the problem posted, in fact I don't think it is, but I'll offer my thoughts on ball powders.

While I've shot some of my tightest groups with ball powder in years past, I stop using them some time ago. The problem I encountered was significant POI changes with temperature changes from spring, 50's to 90's in the summer hunting varmints.

It was easy enough to adjust for these POI changes by just spending some time on the range to recheck sight it, but I also encountered pressure surges, especially with H380 in the 22 250 in the field. That wasn't so easy to adjust for since it required a load change and all the testing that goes into that.

I also experience some POI changes with "stick" powder also but much less than ball powder and I had no pressure surges and no need to change the loads.

 

[markm87]

Yeah. I definitely like extruded better for stability, but we were working up the 85gr Match Burners, and the only appropriate powder (burn rate) on hand was TAC.

We're heading back out this weekend to see where the zero might be sticking with H322.

The mount fasteners all checked out as being tight.

 

[markm87]

h322 isnt a 'ball' powder fyi

Yeah, but we were going back and forth between TAC (ball) and H322 extruded... as well as other ball and extruded powders. I was worried we had a chemistry experiment going in the bore fouling.

 

[markm87]

Barrel cleaned, no loose mount hardware, and the POI moved back up and left to exactly where it was two weeks prior. What the heck? This high/left POI is an exact reversal of the POI we had last week.

https://imgur.com/eDXmLoj

 

[DGP4]

Did you have a lot of copper fouling? Maybe removing it brought you back?

 

[Delfuego]

Gold Bond is the best Ball Powder I have found for jogging.