I've lost my Mrod barrel!!

I've lost my Mrod barrel!!

Joined: July 24th, 2009, 4:33 pm

October 28th, 2011, 7:43 pm #1

I last saw it in this extended P-rod shroud! Overall length is 41 inches. The custom shroud spacer is the work of Jim Gaska (of course!).
Testing comes tomorrow at the SW Ohio Fun Shoot at the Middletown Sportsmans Club. I've drilled the TP out to 3/32" (0.09375) so I don't know quite what to expect. I'm using H&N FTTs @14.66 grains, with the 5.53mm pellet head. It's been a fun project so far. I wanted something a little different, and maybe pick up a few FPS with a longer barrel (my exploits with fitment are documented on this forum).
darryl
?t=1319830665
?t=1319830738
?t=1319830777
Quote
Share

Joined: February 15th, 2007, 2:07 am

October 28th, 2011, 10:05 pm #2

Guess tomorrow we'll see if she lives up to the look.
Gary
Quote
Share

Joined: July 24th, 2009, 4:33 pm

October 29th, 2011, 1:20 am #3

thanks Gary,
now the whole world won't be satisfied unless I post 983FPS with 18.1 grain JSBs. I won't be able to show my name here again! Oh. Wait. It is still a P-rod. I'll be happy if it hits 700FPS with those H&Ns I bought! LOL!! See you tomorrow, G!
darryl
Quote
Share

Joined: August 20th, 2008, 3:27 pm

October 30th, 2011, 2:28 pm #4

Nice job, I'm interested in what speed you get out of that (.09375) 3/32 T/P, because I'm going to be using the same size on a stock length Prod barrel.
Quote
Share

Joined: July 24th, 2009, 4:33 pm

October 30th, 2011, 7:02 pm #5

The P-rod tested out as follows (didn't record the whole 10-shot string)
lo = 716 FPS
hi = 738 FPS
av = 729 FPS
Es = 21.92
Sd = 7.81

These numbers with both adjustments full on, and a stock hammer spring; starting fill was 2600 PSI. My next testing won't come until I buy a chronograph, and install the Disco hammer spring I got from Gary. Overall, I'd call these numbers mediocre. But the advantage is not a lot more air being used versus the stock TP, so the shot count is still good; three magazines is livable for 17FPE.
Darryl
edit: I forgot to post the video here so you can hear how quiet it is with Jim's shroud extension (spacer) at the breech end. It's very quiet for an average of 729FPS, imo. http://www.youtube.com/watch?v=EEbVmWK5tPg
Last edited by turbodt on October 31st, 2011, 2:40 pm, edited 1 time in total.
Quote
Share

Joined: July 24th, 2009, 4:33 pm

October 31st, 2011, 2:45 pm #6

video posted in prior reply
Quote
Share

Joined: August 20th, 2008, 3:27 pm

November 1st, 2011, 11:15 am #7

Darryl did you try a higher fill pressure like 2900 and record a string of 24 shots? I'm interested in how many good shots are available with that 3/32 TP ?
Quote
Share

Joined: July 24th, 2009, 4:33 pm

November 1st, 2011, 3:38 pm #8

as is the 0.09375 (3/32") is good for 24 shots with good POI in my rifle. I didn't really try beyond that shot count, but before I drilled the TP I could count on 32 good shots. I may still be able to get that now. I just didn't see the need. I guess I figure 24 is a lot for such a small air reservoir. Fits my shooting needs OK (or a t least it did until you put the demon-thought in my head! LOL!!!!) .
darryl
Quote
Share