ULW barrel, ESSB and Blitz buffer

[Cam73]

Hey guys-

I've got a new PCC in the mix and I'm Interested to hear the opinion of folks running the same or similar configuration and their favored bullet weight, PF and BCG weight installed/ removed. I've searched the topic quite a bit and it seems lighter bullets with higher PF (in respect to PF floor) are pretty popular. I didn't come across anyone specifically addressing when/why to pull the BCG weight. The plan is to develop a load for the gun but would like the option to shoot factory ammo in a pinch. 

 

Current parts:

Standard Blitz PCC buffer (6.2 oz iirc) 

JP AR-10 Carbine spring in a Zulu 2.0 with their goofy spring thing replaced with the included fixed spacer

Taccom ESSB (weight installed, 14.4 oz) with white short stroke spacer

Taccom ULW barrel

 

The local range is slow fire only so I took the gun out to confirm function and chrono the following loads but was not able to do any doubles for speed/accuracy. Chrono was acting finicky, number may be a little skewed.

 

115gr Everglades V2 JHP- 1.140"- Titegroup 

3.8 126 PF- too close to PF floor (left over for my previous PCC with 16" bbl)

4.0 133 PF

4.2 139 PF

4.4 144 PF

 

124gr  Federal AE round nose 147 PF

 

The 115s and 124s felt very different (snap vs push) but neither were offensive or more disruptive than the 16" PCC  with Taccom adjustable buffer I've been shooting. Dot stayed easily inside the center part of the window. Ejection was pretty weak, especially the lower PF rounds, about 1:30-2:00. I tried an AR-15 carbine buffer spring to see if it would help ejection but it changed the recoil so much I didn't bother watching ejection. In 120 rounds there was 1 stove pipe and 3 double feeds (2 live rounds) so that had me a little distracted from focusing on recoil characteristics.

 

Is it worth exploring heavier bullet weights? Or pulling weight from the BCG? Loading up into the 150 PF range? Different buffer spring? Run 4.0 of TG and practice until this stuff actually matters?

 

I'm not the most familiar with blow back theory in respect to a competition rig, any input is appreciated, thanks!

Edited January 6, 2020 by Cam73