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rws_350 · Member

has anyone tried this on a 2240 crosman? what was the speed increase ?

http://www.crookedbarn.com/airgun_books1.htm

rsterne · Moderator

With a stock barrel, you MIGHT get an 80-100 fps increase if you also used a larger transfer port and drilled out the barrel port.... The 600+ fps number in the Ad was with a 14" barrel.... a stock 2240 has only an 8" barrel and shoots about 460 fps under ideal conditions.... Up to at least 18", a longer barrel gives more velocity....

Bob

Mark5043 · Silver Status Member

rsterne · Moderator

Stock a 2240 runs about 35-40 shots to a 12 gr. powerlet.... I've heard Boss equipped guns are in the 17-20 range.... so yeah, about half the shots.... and even more noise.... Rolling Eyes

Bob

Mark5043 · Silver Status Member

Okay thanks.That doesn't sound so hot from an efficiency standpoint.I think I might get mine with the 10 inch barrel,so I can up the velocity a little over the stock barrel,and keep the shot count up.Seems to be a more balanced approach.... Wink

rsterne · Moderator

If you want efficiency, go with the 10" barrel, get a Rear Velocity Adjuster and concentrate on shot count rather than velocity.... My argument goes like this:

1. It's a PISTOL.... intended for close range.... high velocity isn't required....
2. The 2240 wastes about as much CO2 as it uses.... that's why it's loud....
3. Unless you put a 14" or longer barrel on it you won't get a big increase in velocity without wasting even MORE CO2....
4. Crosman doesn't care because they sell CO2....

I built a 1750 (ie a .177 cal 2250) and I reduced the hammer weight and used an RVA to reduce the hammer spring preload.... I ended up with a gun that could be set up for the same average velocity (with less variation) as stock but with 60-70 shots.... or I could dial it down to 80% of stock and get 120-130 shots per powerlet.... It ended up cheaper to shoot than a .22 cal springer because it sipped CO2 so frugally.... Shocked

I never played with a Hammer Debounce Device because I took the route of reducing the hammer strike instead.... Using an HDD will decrease the amount of CO2 wasted if it's set up properly.... something else you might consider....

Bob

Mark5043 · Silver Status Member

Sounds great...I would much rather spend the $50 or so that the Boss valve costs on Co2,and pellets. Thumb Up!

steveR56 · Member

Set mine up with boss valve and 16" barrel, and lighter hammer spring- getting 22 good shots @ 520fps. avg. This at 40 deg. so should go up a bit with temp. increase.

rws_350 · Member

what fps gain can i get with having it ground and polished for better co2 flow? any links how to do this myself?

rsterne · Moderator

Part of the reason for purchasing a Boss valve is that the port is already angled to eliminate the 90* corner....

Bob

steveR56 · Member

Here is the valve mod-just be carefull about going too deep towards the seal seat -dremel works well- and clean all the shavings out(air blaster)
http://www.airgununiverse.net/22xxvalve.html

ellodrith · Member

My favorite shooter right now is a modded 2240.

Stock internals, steel breech, 10" .177 barrel, LPA MIM rear sight, black muzzle break with sight pin (this also makes the balance point almost perfect), and of course the velocity adapter (mine has the end that can be screwed out to change springs), and hand carved grips (need to redo these soon).

I am on spring test no. 4 now, much lighter than stock, getting about 100 consistant shots per cartridge. Change the spring, crank in a few turns and I get 30 or so shots that will take a squirrel down at a reasonable distance Smile

Very, very happy with this rig atm.

link to pic
http://easy.warmland.ca/1740

cheers
Jeff

steveR56 · Member

Nice setup! I'm just getting going on these and having a ball! Got two-trying to set one up"Frankenstein" for PCP the other one stock for basement target shooting- would definately recomend the AOA adjustable sear. drops trigger pull down to Scary light- smack 3 times and it goes off! Tried Hdd- 1st broke- but they are sending me 2 more. Just got chrony and 16" barrel with Boss valve and light hammer spring hitting 520 fps@ 22 shots- like your approach for more shots- 100 is sick! What spring are you using and length? Got an assortment from Ace- just waiting for time to chrony- have leapers green/red dot 3mil, @10 yds is 1/4 " group and dead on @ 30 yds outside

packrat · Senior Member

My 2240 has B&A Boss valve..I get 41 shots over 400 fps....first 20 are all over 500 with a high of 553.87.... 21-30 go no lower than 470.84 (high of 552.94)....31-41 gradually go down to shot 41 of 402.90. Average is 489.58 for the entire string. 11.9 Rws pellets, 71 degrees B&A BOSS valve and 10" barrel, power adjuster 2 turns out.
Stock it never got above 410fps with 33 shots, with the last few(pre-chrony ownership) were weak. After mods, the highest fpe reached was 8.11 (like 2 shots) average fpe was 6.34. B&A valve delivered was $42.00 ...

steveR56 · Member

here's my latest attempt-16" 2240 with full length disco tube and valve- power adjuster and lighter than stock spring-25 shots @725avg.35 fps avg spread