Yet another parts airgun build.
Select Gate
READ GTA FORUM RULES BEFORE POSTING
GTA Forum Help Desk
GTA Announcement Gate
Dealer Area
GRIP
AirgunWeb Airgun Videos
Airgun Repository of Knowledge
Vendors and Vendor Videos
AirGun Expo 2021
Airgun Expo 2022
Contests and Giveaways!!!
Welcome New Members
In Memoriam
GTA Contributing Members
Shot Show Videos
Hajimoto Productions
Airgun Detectives
Air Gun Gate
BB Guns and Such
"Bob and Lloyds Workshop"
American/U.S. Air Gun Gates
European/Asian Air Gun Gates
PCP/CO2/HPA Air Gun Gates "The Darkside"
Air Archery
Vintage Air Gun Gate
Air Guns And Related Accessories Review Gates
Hunting Gate
Machine Shop Talk & AG Parts Machining
3D printing and files
Buyer's, Seller's & Trader's Comments
Bargain Gate
Back Room
Target Shooting Discussion Gate
Target Match Rules
Shooting Match Gates
Field Target Gates
The Long Range Club
100 Yard Match
Discussions By States
Welcome,
Guest
. Please
login
or
register
.
Did you miss your
activation email
?
1 Hour
1 Day
1 Week
1 Month
Forever
Login with username, password and session length
Home
About
Help
Old GTA
Gallery
Search
Stats
Login
Register
Advertise Here
GTA
»
All Springer/NP/PCP Air Gun Discussion General
»
Machine Shop Talk & AG Parts Machining
»
Show Off Your Air Guns With Mods (SHOW and TELL)
(Moderators:
Rocker1
,
ezman604
,
Tater
) »
Yet another parts airgun build.
« previous
next »
Print
Pages: [
1
]
Go Down
Share This!
Author
Topic: Yet another parts airgun build. (Read 1182 times))
happymecanic
Expert
Posts: 1274
Real Name: Francois
Yet another parts airgun build.
«
on:
March 13, 2022, 11:48:56 PM »
While doing some maintenance and repairs on my pumper airguns, I realized I had quite a few spare parts, enough to build an almost complete air rifle.
I found I had a pretty good Crosman 766 straw barrel, it has 19'' of rifling starting at the front TP edge. I polished the lead-in and re-crowned it. I made a 1/2'' mild steel shroud for it, along with a front barrel support bushing. I also made a steel pump arm pivot block, that also supports the shroud. I shortened a spare receiver 8-32 screw to hold the shroud. That makes a clean, ''factory'' look
. Front and rear sights from a Crosman 760 5th variant (late 70s) are used, and fits like a glove. I found a clean 6-32 screw in my parts bin, just had to turn down the head OD a bit. I still have to cold-blue the parts.
The Cr 760 also gave the metal receiver in very nice condition, trigger group (steel trigger blade
), breech/barrel support and bolt. The bolt will eventually be modified with an Oring and free-flow tip.
A defunct M4-177 rifle provided the pump tube, hammer/spring/guide, de-tuned valve and plastic cup piston and pump arm assy. The rear bottom edge of the aluminum valve was crushed by the boss in the receiver tube, as is often the case. There was at least 0.025'' of compressed material, so pumping efficiency would suffer if I left it like that. I repaired it by making a hardened steel ring 0.100'' thick, shaved 0.100'' off the back of the valve, and pressed the ring onto the back of the valve, creating a new rock-solid ''seat'' for the boss.
I'll be using a hardened steel pivot pin instead of the OEM roll pin, and am thinking about nickel/silver soldering a steel pivot bushing into the pump arm.
I also have made wood blanks for the butt stock and forearm. I don't have an original stock to go with the receiver, and no stock forearm fits with a 760 receiver/ M4-177 tube, so I need to make my own. I'll be using maple from scavenged pallet wood. The wood actually has a pretty nice figuring in it, but is straight enough to have good strength. I'd like this airgun to have a ''slim look'' to it, so the forearm won't be a fatty. Instead I'd like something kinda like the 766/2100/AM77 forearm, sleek and nicely sculpted. Just can't wait to get into that
.
This is where I'm at into the project, hope you like the view
.
Logged
Canada
Motorhead
Field Target Shooter .... Stand em up Shoot em down
GTA Senior Contributor
Posts: 17753
2019 GTA Hall Of Fame Recipient
Real Name: Scott
Re: Yet another parts airgun build.
«
Reply #1 on:
March 14, 2022, 12:01:06 AM »
Very nice ... Done parts & pieces builds a few times myself.
Logged
Northern California ... Old Hangtown
**
Home of MOTORHEADS AG Tuning Services
**
* PM me for further contact & tuning info.
Sacramento Valley Field Target Club
#
https://sites.google.com/site/sacvalleyairgunclub/
happymecanic
Expert
Posts: 1274
Real Name: Francois
Re: Yet another parts airgun build.
«
Reply #2 on:
March 18, 2022, 08:14:44 PM »
Thanks Scott! Yeah I guess you know that road pretty well
.
Today I finished making and cold bluing the steel parts. I made a hardened steel pivot pin for the pump arm, it uses an E-clip to stay in place, will be better than the stock roll pin. The action is now ready to be put back together. Next is the wood stock.
Logged
Canada
happymecanic
Expert
Posts: 1274
Real Name: Francois
Re: Yet another parts airgun build.
«
Reply #3 on:
March 19, 2022, 10:47:30 AM »
I just did the very first chrony test of this de-tuned-for-Canada rifle. It's shooting better than I expected, I guess I did my re-seal job well. I was expecting velocities in the 425-430s, but was pleasantly surprised. Also results are a bit odd, the lighter 7 grains RWS Hobby pellets are flying slower than the Crosman Premier Match 7.9 grains wadcutters, but they do fit tighter in the barrel bore. Also they're much more consistent in shot-to-shot velocity, very curious to see what this will give when I'll shoot some targets.
Here are the shot strings:
Crosman Premier Match wadcutter 7.9 grains pellets, @ ten pumps:
1- 445 fps
2- 452
3- 470
4- 452
5- 472
6- 463
7- 470
8- 468
9- 464
10- 477
Avg: 463.3 fps
RWS Hobby 7 grains wadcutter pellets, @ ten pumps:
1- 448 fps
2- 445
3- 444
4- 445
5- 453
6- 454
7- 454
8- 454
9- 448
10- 452
Avg: 449.7 fps
Will need to test more pellets and check accuracy, but so far I'm pleased with the results
. Now getting into the longest phase of the job: wood work. I must tame my impatience LOL!
«
Last Edit: March 19, 2022, 10:51:55 AM by happymecanic
»
Logged
Canada
Print
Pages: [
1
]
Go Up
« previous
next »
GTA
»
All Springer/NP/PCP Air Gun Discussion General
»
Machine Shop Talk & AG Parts Machining
»
Show Off Your Air Guns With Mods (SHOW and TELL)
(Moderators:
Rocker1
,
ezman604
,
Tater
) »
Yet another parts airgun build.