Benjamin 312 RestoMod

[avator]

I might have missed it but, do you plan on anything for the metal finish?

[Tack Driver 10]

I might have missed it but, do you plan on anything for the metal finish?

I like the old world patina on these guns so going to leave the metal as is.
Once it's gone there's no going back.
The bright brass look is nice but just not my style.

The new wood pump arm is going to take time for the finish to cure.
Attached a spare tootsie to the steroid lever for testing in the 312.
Got a little more power across the board.

With 14.3 CPHPs   
05 pumps 613 FPS 11.93 FPE
08 pumps 721 FPS 16.50 FPE
10 pumps 775 FPS 19.07 FPE  (full dump)

With 18.1 JSBs   
08 pumps 657 FPS 17.35 FPE

[avator]

Good call on leaving the metal as is... I'm a big patina fan as well.

[Techie]

With 14.3 CPHPs   
05 pumps 613 FPS 11.93 FPE
08 pumps 721 FPS 16.50 FPE
10 pumps 775 FPS 19.07 FPE  (full dump)

With 18.1 JSBs   
08 pumps 657 FPS 17.35 FPE

Wow, those are some incredible numbers for a 312.  You are the master!

[Tack Driver 10]

With 14.3 CPHPs   
05 pumps 613 FPS 11.93 FPE
08 pumps 721 FPS 16.50 FPE
10 pumps 775 FPS 19.07 FPE  (full dump)

With 18.1 JSBs   
08 pumps 657 FPS 17.35 FPE

Wow, those are some incredible numbers for a 312.  You are the master!

Master skills not required.
A steroid 312/342 is well within reach.

The FT adjustable piston was responsible for the lions share of the gain.
The Delrin valve stem allowed full dump with 10 pumps.

As stated earlier, more valve volume, 24" barrel and larger ports would yield around 830 FPS 21.87 FPE.

[Dave S]

With 14.3 CPHPs   
05 pumps 613 FPS 11.93 FPE
08 pumps 721 FPS 16.50 FPE
10 pumps 775 FPS 19.07 FPE  (full dump)

With 18.1 JSBs   
08 pumps 657 FPS 17.35 FPE

Wow, those are some incredible numbers for a 312.  You are the master!

Master skills not required.
A steroid 312/342 is well within reach.

The FT adjustable piston was responsible for the lions share of the gain.
The Delrin valve stem allowed full dump with 10 pumps.

As stated earlier, more valve volume, 24" barrel and larger ports would yield around 830 FPS 21.87 FPE.

Amazing work, Ron! The best I can get out my steroid Blue Steak with 12 pumps is 727.7 fps 14.3 gr. pellets. Good job! dave

[Tack Driver 10]

I made a new wood pump arm for this gun since the original matched the 342 better.
Modified it a little but basically the same look.

[xcalibur]

This has been an interesting thread. Who would have imagined 19 FPE from that little Benji. Well done