308W 220gr Berrys J-words w/Trail Boss subsonic success

[Lksdmachine]

I have several thousand 308 steel case 147gr fmj Berdan primed surplus ammo sitting around from years ago. Not a fan of it unless I was just making dirt fly, which I don’t do anymore with the cost of such silliness.

Anyway, I started disassembling some of it. I thought it would be nice to have some throw away cases to experiment with 308W subsonics and make good use of the surplus ammo. I had some 220 grain Berrys plated for the 300BO laying around and some TB powder, so I started playing…..

11.7gr of TB under the Berrys 220 and WOW…. What fun! The case is full near the bottom of the neck. Running them through a Ruger Predator with a can, I can keep them easily in 1.5” at 100yrds. I was shocked as I saw many reports of tumbling results with those long heavy boolits. Next time out, I’m sand bagging that baby to see what she will really produce.

My thoughts were if this “test” was successful with the throw away cases with Berry’s 220’s, I planned to pour me some comparables and hope to get similar results.

I’ve also acquired a Rem 700 AAC to try out too…..

I’m wondering if anyone has transitioned from similar weight J-words subsonic loads to similar cast and had successful accuracy.

Looks like I’m busy for a few weeks now!

[BunkTheory]

how are you seating the bullets? How deep in the case?

[Gamsek]

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I (and few of my friends) use MP 311-235 BLK bullet for subs, we don’t use GC’s for up to 1200fps.

9.6grs of TrailBoss or TinStar is a starting point for those 220grs HP (224grs with GC) if you look for subsonic velocity
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[Lksdmachine]

how are you seating the bullets? How deep in the case?


I’ve seated to an OAL of 2.78” and it feeds from the Ruger magazine nicely. I’m sure that long stick is well below the neck. But I sure can not argue with how it prints holes.
I often see folks opening up the flag hole using TB….maybe the Berdan double hole priming flash works better to ignite TB like this? I have not taken a boxer primed case with the same recipe to try yet and compare performance. Might be worth it to compare.