700mm Superior Heavy Liner on .30 Impact ?

I recently got an M3 .30 with a Superior Heavy liner. It had the slug power kit installed, but I was using the pellet probe. I added the carbon fiber sleeve- unglued. I don't know if there was any benefit over the standard liner as I ordered it with the mods. I will say I have a .25 MKII, Power Plenum with the slug A liner, and I feel it is every bit as accurate. I converted my .30 700mm to a .22 Compact, but when it was a .30, I was shooting the NSA 49.5gr slugs at 930 fps. My first reg was set to 200 bar, the second was set to 150 bar. The macro wheel was on number 16. I left the regs as set for the .22, but dialed the macro wheel down to number 8 to shoot at 928fps.

I look forward to your conclusion. I only went with the SH in case I wanted to shoot heavier slugs.

I have a stock M3 700mm with the new standard 1:22 and also a 1:18 heavy. Every slug I tested up to 54gr did better in the 1:22 standard liner. All of my testing was in the 910-960fps range, 138 and 150 bar. Sample size of each liner is only 1, though.

I have a good guess on the change from 1:26 to 1:22, and that is that the hybrid slugs needed faster twist than was originally anticipated. The heavy change to 1:18 I'm unsure of the reason there. Maybe it was just because the old heavy became the new standard, they needed something to offer in the heavy slot? Your example of shooting 66grn in the 1:22 just ads to the doubt about the 1:18.

The only really good slug for me was the FX hybrids, and I settled on those at 960fps at 150bar (in the 1:22 liner).

Has anybody put barrel liners next other liners. I have 3 that look to have same twist. One looks choke one 1/4 longer.

I just got a new 1:18" 700mm Heavy in hopes it'll shoot the NOE 46gr cast pellets better than my 1:22" superior that actually shoots them pretty well, hopefully even better with either liner when I have enough to sort for the best accuracy (new mold on the way).

I measured the new liner (1:18") probably three times the internally way with a good ball bearing cleaning rod with some tight fitting patches and I kept coming up with 18.75 to 19.25. Doing it carefully the externally way and following one of the grooves for a complete wrap around I kept getting closer to 19.5". Either way, no where near the 1:18" that I could determine.

Current I have my PP MKII tune at 123bar, the power wheel set on Max although it's not actually tweaked to "max". I haven't really tried any slugs to any extent but it'll shoot the JSB 44.75 really well at 905-910. The NOE's that I have a limited supply of unsorted so far are not doing as well as the standard superior but like I said there will be further testing on those. My hopes are to find another alternative to the JSB's and Vortex for a fraction of the price and availability.

Heavy, how did those NSA 66gr shoot comparatively in both of your liners? I'm not planning on going all in on extensive 30cal slug shooting since I know the 1:22" and Hybrids will fill that niche in case I want to hunt with the 30cal.

jking

Keep us posted heavy, curious if you find it to be a better liner or not.

jk

I’m running the superior heavy on my mk2 and it loves the NSA 54.5gr at 990fps and the 61.5gr at 945fps. Regulator is set to 155bar with Max on power wheel and valve adjuster to 3 and 1/2.

I haven’t tried this .30 in my M3 because it is setup for .35.

I’m running the superior heavy on my mk2 and it loves the NSA 54.5gr at 990fps and the 61.5gr at 945fps. Regulator is set to 155bar with Max on power wheel and valve adjuster to 3 and 1/2.

I haven’t tried this .30 in my M3 because it is setup for .35.

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What kind of groups and how far are you shooting? Flyers?

Jking

I’m running the superior heavy on my mk2 and it loves the NSA 54.5gr at 990fps and the 61.5gr at 945fps. Regulator is set to 155bar with Max on power wheel and valve adjuster to 3 and 1/2.

I haven’t tried this .30 in my M3 because it is setup for .35.

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Which superior heavy? The original 1:22 or the latest 1:18?

What power mods does that gun have?

@jking, my groups are from 35yards out to 75yards for my real world hunting and I have not had flyers while I shoot 10 shot groups at each distance for dialing accuracy on my turrets. Group size is extremely consistent at each distance with the heavier 61.5’s doing better at 75yards; typical group being 2 to 2&1/2 inches at distance.

@tdk the MK2 is the power plenum version with slug kit and fx harmonic tuner is installed with carbon fiber barrel wedge to stiffen barrel even more. This is also the newer version with the 1:18 twist rate as well.