Author Topic: Early benjamin 317/300 hybrid (Read 926 times - 1 votes)
)

Bigsal · « **on:** February 04, 2020, 12:50:12 PM »

I recently picked up a Benjamin Arms 317 its complete but in need of serious maintenance. So I gave her a shot of oil, all was good until the leather pump cup let go, this is where the fun starts, called Baker airguns this morning to get some information and order a kit, Dennis informed me that the 317 did not have a leather pump cup..."well I told him mine does I'm staring at it" best we came up with is my rifle must be a very early 317 and still used some of the parts from the 300, it has a 300 bolt and breech, but it has a rifled barrel, but is a pumper like normal with the "tootsie roll " handle. Any ideas what I have going on over here? Any info is welcome. Dennis also said they make a conversation kit to upgrade to a synthetic cup...I ordered it hopefully it will get the old girl up and running again. When it did kinda pump up it held air and functioned normally.

xcalibur · « **Reply #1 on:** February 04, 2020, 05:50:50 PM »

Benjamin did use leather pump seals until they changed to a rubber hy-car pump cup in the late '40s.

An original 312/317 from 1940-1950 would have a two piece solid bolt. The 310 from same era would have a two piece flow thru(hollow) bolt.
By two piece I mean the handle was separate and screwed into the bolt.

Bigsal · « **Reply #2 on:** February 04, 2020, 06:30:00 PM »

Appreciate the help, I didn't know what year it was made, I found out with no serial number that it was a pre 1957 so I'm guessing it's a early 40s rifle...nice! I hope the conversion kit works for it, are the leather cups still available? Just in case the conversion kit is a bust, I'd like to have a backup plan for it. Thanks again for the info.

DanD · « **Reply #3 on:** February 05, 2020, 09:16:13 AM »

I have a pre serial, nonadjustable rear sight 312 that had the cup fail after working for a little while.
It had a leather cup where the bottom separated from the side.
I emailed Mike Baker to order a replacement and sent him the pic below to ask him how to install it. He informed me that my rod is for a rubber cup and sent me one. It snapped right on and is working great.
I don't know if a previous owner installed the wrong cup or if it was a mix and match of parts from the factory.

eeler1 · « **Reply #4 on:** February 05, 2020, 11:49:28 AM »

Good point Dan. With a 60 to 70 year old rifle, you may not know whats original vs. who's been in there or what they've done. That said, Benjamin (and others too) hated to waste parts. They may have found a bunch of old leather seals stashed in a drawer at the factory, and made a run of a few rifles just to use them up.

Regardless, I would agree that the conversion is best. Synthetic seals are plentiful, while a leather seal to fit would probably be hard to find.

Bigsal · « **Reply #5 on:** February 05, 2020, 01:25:35 PM »

Man you guys are awesome! I'm assuming it was built in the 40s...I'm currently waiting on a trigger mount from Rick at precision pellet, the mount was broken and Rick reproduces them in steel, talking with him it's a common problem. Once that part gets here and the rebuild kit and pump head arrives from Dennis, I should be in business. I love restoring these old air guns, I just finished restoring a 1965 Blue Streak with the Williams peep sight on it. I used one of Dennis's kits and it worked beautifully. My other restoration is a '65 Crosman model 99 that I got up and running after rebuilding the valve in it, not a powerhouse but a load of fun to plunk with.

xcalibur · « **Reply #6 on:** February 06, 2020, 12:10:16 AM »

Quote from: DanD on February 05, 2020, 09:16:13 AM

I have a pre serial, nonadjustable rear sight 312 that had the cup fail after working for a little while.
It had a leather cup where the bottom separated from the side.
I emailed Mike Baker to order a replacement and sent him the pic below to ask him how to install it. He informed me that my rod is for a rubber cup and sent me one. It snapped right on and is working great.
I don't know if a previous owner installed the wrong cup or if it was a mix and match of parts from the factory.

Wow, I don't even know what to think of that hodgepodge. Would have been confusing to tear into that mess. LOL

Below are photos showing the difference between the earlier leather seal and the rubber hy-car seals. The leather one has a slotted screw and washer holding it on. The hy-car slips over the boss on the pump head like shown in DanD's photo above. They will not interchange.

Bigsal · « **Reply #7 on:** February 06, 2020, 03:08:32 AM »

Yup, the 2nd photo is exactly what I have, it adjusts on the hinge end only, I hope the conversion head works with the rod I have, I dont want this to turn onto a parts buying free for all...lol...I'm pretty confident that it will work. Trying to explain stuff over the phone a lot can get misconstrued.

The broken trigger mount really bugged me, although not 100% my fault I probably shouldn't of torqued it as tight as I did but I guess it would of eventually failed at some point due to being cracked in the first place...

Bigsal · « **Reply #8 on:** February 07, 2020, 05:29:31 PM »

Got the conversion and rebuilt kit today from Dennis, it was a Hycar style head and it seems to be working good. The rebuild kit I purchased as a precaution that way if I need it I'll have it..I also recieved the trigger mount from Rick and it worked beautifully! Upgraded the trigger mount to steel (which is what it should of been made of in the first place in my opinion) now to enjoy shooting her for a while...lol

Thank you to our advertisers!

Early benjamin 317/300 hybrid