Improved BLT tune from the M-Rod Forum

This was not my finding, stumbled on this over at the Marauder Rifle forum. Posted by RayK, here’s a link: http://www.marauderairrifle.com/forum/viewtopic.php?f=24&t=9251

And the contents of the post for those who just want to get to it:

New improved BLT (24 shot 2500 psi fill with 3% ES) for 25

Postby RayK » Tue Apr 08, 2014 6:09 pm
After consulting with our guru – Dave HisOwnSelf, I got the initial settings for a 24 shot string with 3% extreme spread from a 2500 psi fill.

This is a great tune for squirrel hunting especially if you fill from a hand pump (way easier to pump to 2500 than to 3000) or from a 3000 psi SCUBA tank – you still get lots of full fills.

We called this the BLT, but this new tune has higher energy AND lower extreme spread than I’ve seen in the past.

I’m getting shots peaking at 790 FPS (35 FPE) with JSB 25.4 grain Kings and 25 FPS extreme spread across 24 shots – and it still hits very hard.

This is where I’m keeping my second 25 M-rod for a while. I’ll get a chance to shoot next Saturday.

The initial settings were very close at HS preload 3 CW, HT +6 CW, and VMS +5 – wide open. I just tweeked HS a little (1/4 turn more) CW until velocity at 2100 psi (middle of shot string) was 790 and I was right on.

Then I got the same good string Dave got on his 25 M-rod, so his hammer spring may be a little stronger than mine is.

Note to Dave, you have to try this. It is just 3 out on HS from your favorite +6 +6 +5 tune and it is so much easier to hand pump to 2500 psi. And 790 is not much slower than 830 FPS when shooting squirrels.

Ray

I tried this out on my own 25 M-Rod, and sure enough got a full 24 shots at 35 FPE with no noticeable change in POI. Best number of shots from a 2500 PSI fill I have found so far. My second was a bit hotter at 43FPE, but only provided 16 shots from 2900 – 1600 PSI, so this was a massive improvment, and no o-rings to mess with. Hope some of you find this useful.

Casey