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Author Topic: Benjamin .177 bolt adjustment?  (Read 222 times))

Offline LesStrat

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Benjamin .177 bolt adjustment?
« on: June 21, 2022, 07:40:53 PM »
I have a Benjamin with an American Walnut stock/lower, .177 caliber. I damaged the pump 40 years ago and had it repaired. After the repair, it would eject some of the air rearward, directly into your aiming eye.

I finally got it out of the closet yesterday and realized that the bolt is not remaining seated when firing. I can hold it in place with my thumb, and there is very little leakage.

Is there a way to adjust the bolt so it will remain seated?

Based on an internet search, I think itís a 347 multi pump.. I bought this about 45 years ago. 

I always loved this gun until it was damaged. If I can restore it, this would be great to pass on to my grandsons.
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Offline oldair

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Re: Benjamin .177 bolt adjustment?
« Reply #1 on: June 21, 2022, 08:44:01 PM »

You need to adjust the cam plate (left side of the receiver) to push the bolt fully into sealed position when it's closed with the bolt handle.

Offline bantam5s

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Re: Benjamin .177 bolt adjustment?
« Reply #2 on: June 21, 2022, 10:28:07 PM »
The model is there on the gun, on the rear plug where the bolt is.

To adjust the sealing of the bolt you need to move the cam plate.

If it is a 347 I don't remember if I'll have a cam plate cover or not but it doesn't matter,  theres 2 screws on the left side and those hold the cam plate in place.

Loosen them and hold the plate ( youre pushing on the cover If there is one, or directly on the cam plate otherwise) pushed as far forward as you can against the closed bolt then tighten those screws back up.
W
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PCP? I never touched the stuff !
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Offline LesStrat

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Re: Benjamin .177 bolt adjustment?
« Reply #3 on: June 22, 2022, 10:22:50 PM »
I only see one set screw.

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Offline bantam5s

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Re: Benjamin .177 bolt adjustment?
« Reply #4 on: June 22, 2022, 11:01:06 PM »
I only see one set screw.
That is the bolt lug which is what catches the hammer and pulls it back.

You are missing the cam plate,  it is attached via those 2 screw holes there.
It can also secure a model 273 peep sight, but it's main purpose is to push the bolt forward vie it's angled surface.


That is definitely a 347 for sure.
« Last Edit: June 22, 2022, 11:07:23 PM by bantam5s »
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PCP? I never touched the stuff !
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Oh!, no I don't have one of those.

Offline LesStrat

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Re: Benjamin .177 bolt adjustment?
« Reply #5 on: June 23, 2022, 03:44:23 PM »
Where can I get a cam plate and screws?

I didnít realize it was even missing. Whoever repaired it must have left it off.

 >:(
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Offline Goose

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Re: Benjamin .177 bolt adjustment?
« Reply #6 on: June 23, 2022, 03:50:59 PM »
Where can I get a cam plate and screws?

I didnít realize it was even missing. Whoever repaired it must have left it off.

 >:(

I'd be mad, too...  Check around for a local machine shop.  They can fab one up in a jiffy!

Luck,

J~
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Offline LesStrat

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Re: Benjamin .177 bolt adjustment?
« Reply #7 on: June 23, 2022, 06:17:50 PM »
I was a teenager when this was repaired. I havenít even looked at it closely until the other day when I figured out why I was getting blowback.
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Offline bantam5s

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Re: Benjamin .177 bolt adjustment?
« Reply #8 on: June 23, 2022, 06:54:39 PM »
Where can I get a cam plate and screws?

I didnít realize it was even missing. Whoever repaired it must have left it off.

 >:(

I'd be mad, too...  Check around for a local machine shop.  They can fab one up in a jiffy!

Luck,

J~
They'd need an example to copy.
  • USA CA Arbuckle
PCP? I never touched the stuff !
No, it's a type of airgun !
Oh!, no I don't have one of those.

Offline bantam5s

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Re: Benjamin .177 bolt adjustment?
« Reply #9 on: June 23, 2022, 06:55:28 PM »
Where can I get a cam plate and screws?

I didnít realize it was even missing. Whoever repaired it must have left it off.

 >:(
Check JG Airguns, Baker Airguns, or Ebay.
  • USA CA Arbuckle
PCP? I never touched the stuff !
No, it's a type of airgun !
Oh!, no I don't have one of those.

Offline Goose

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Re: Benjamin .177 bolt adjustment?
« Reply #10 on: June 23, 2022, 07:19:01 PM »
Where can I get a cam plate and screws?

I didnít realize it was even missing. Whoever repaired it must have left it off.

 >:(

I'd be mad, too...  Check around for a local machine shop.  They can fab one up in a jiffy!

Luck,

J~
They'd need an example to copy.

I wouldn't and I'm not a machinist.  Just a welder...

Be safe,

J~
  • Western NC
"There are two types of people.  Those that are interested in controlling others and those that aren't." - R. A. Heinlein

Offline bantam5s

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Re: Benjamin .177 bolt adjustment?
« Reply #11 on: June 23, 2022, 10:57:41 PM »
Where can I get a cam plate and screws?

I didnít realize it was even missing. Whoever repaired it must have left it off.

 >:(

I'd be mad, too...  Check around for a local machine shop.  They can fab one up in a jiffy!

Luck,

J~
They'd need an example to copy.

I wouldn't and I'm not a machinist.  Just a welder...

Be safe,

J~
But you know what it looks like.
If they don't and don't exactly know how it works, I would not expect a very good result.
  • USA CA Arbuckle
PCP? I never touched the stuff !
No, it's a type of airgun !
Oh!, no I don't have one of those.

Offline eeler1

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Re: Benjamin .177 bolt adjustment?
« Reply #12 on: June 23, 2022, 11:17:42 PM »
try mike baker, he frequents this forum and is usually pretty reasonable in his prices;  peter_built78@hotmail.com
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Offline Goose

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Re: Benjamin .177 bolt adjustment?
« Reply #13 on: June 24, 2022, 09:32:07 AM »
But you know what it looks like.
If they don't and don't exactly know how it works, I would not expect a very good result.

It's a small piece of 16 gauge steel.  Easily heated, drilled and formed, then ground down, bent and hardened as necessary.  Measurements are easy to take from the gun.  There are pictures to go from on the internet, too (see the one above).

My Dad is a retired machinist and made many parts for various things over the years.  Including timing and transmission gears for his '59 Panhard Dyna Z and a bolt for his Crosman 101.  Machinists are not stupid people.  Perhaps you should meet one.

J~
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Offline LesStrat

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Re: Benjamin .177 bolt adjustment?
« Reply #14 on: June 24, 2022, 01:40:41 PM »
No go at Baker.

JG has the cam, but no screws.

I guess Iíll order the cam and see what I can find in the hardware stores.

Thanks, gentlemen. I had no idea what was going on with my rifle. After 40 years, my baby will be restored soon (hopefully).
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Offline kelvinator

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Re: Benjamin .177 bolt adjustment?
« Reply #15 on: June 24, 2022, 02:12:54 PM »
Might try this for the screws...
https://www.ebay.com/itm/112654800420
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Offline LesStrat

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Re: Benjamin .177 bolt adjustment?
« Reply #16 on: June 24, 2022, 03:05:50 PM »
Thanks. I searched fleabay and couldnít find them. If I can get logged in Iíll order those.

I ordered the cam from JG, but they have a minimum order requirement. Then they nearly doubled the cost with shipping. Wow.
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Offline eeler1

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Re: Benjamin .177 bolt adjustment?
« Reply #17 on: June 24, 2022, 03:08:53 PM »
Geez, this shouldn't be so hard.  Fabricating the part when it is available at reasonable cost doesn't make sense to me.  So if you haven't ordered from JG yet, and have failed with both Bakers, and struck out with Rick Willnecker at Precision Pellet (airgunshop.net), and can wait a week until I get back home, pm me and I'll send you a plate and screws.  May not have new ones, but surely have a set in the pile-o-airgun-parts.

EDIT: oops, just saw your post, if you can't find the screws, let me know.  Like I said, I'm certain I have them.
« Last Edit: June 24, 2022, 03:11:07 PM by eeler1 »
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Offline LesStrat

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Re: Benjamin .177 bolt adjustment?
« Reply #18 on: Today at 03:26:00 PM »
Your offer is much appreciated. I was able to get the screws from fleabay. 

After I ordered both, eBay showed a link for the cam and screws from the same seller that had the screws.

 ::) :-\

When I searched for the cam before, NOTHING came up. Thanks to kelvinator for finding the link.

Anyway, I should have the parts this week, and I ordered a couple of boxes of pellets as well.

As weird as this journey as been, Iím excited that my favorite gun will be functional again.

Thanks to all of you for your assistance.
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