Just added a RP valve to my Crosmann 1322 with 14.5 barrel. It has the steel breech and transfer port looks to be the same size as my 2240xl mod port. At 20 pumps getting about 570fps with Crosman Premiers. This sound about right?
Crosman 1322
- Thread starter robich22
- Start date
I have a 1322 that also has a 14.6" barrel with nothing else done to it and I get 550 at 10 pumps with 14.3 crosman cphp
Upvote 0
The Alchemy RP valve has a larger volume than the stock Crosman valve. With a short or medium length barrel, unfortunately it's just going to require more pump strokes to achieve a given pressure. To benefit from the added volume in a meaningful way, you would need to pair it with a long barrel.
The principle at play here is the valve volume relative to the barrel volume. The stock Crosman valve is around 1.5cc whereas the 14" long barrel in .22 cal is 8.5cc. So the valve has about 1.5/8.5 = 18% of the volume of the barrel. The sweet spot in somewhere in the vicinity of 25% so there should be some benefit but it won't be dramatic.
The principle at play here is the valve volume relative to the barrel volume. The stock Crosman valve is around 1.5cc whereas the 14" long barrel in .22 cal is 8.5cc. So the valve has about 1.5/8.5 = 18% of the volume of the barrel. The sweet spot in somewhere in the vicinity of 25% so there should be some benefit but it won't be dramatic.
Upvote 0