RM 377 #2
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
»
American/U.S. Air Gun Gates
»
Crosman-Benjamin Air Gun Gate
»
RM 377 #2
« previous
next »
Print
Pages: [
1
]
Go Down
Share This!
Author
Topic: RM 377 #2 (Read 3383 times))
avator
GTA Moderator
GTA Senior Contributor
Posts: 50121
The best "Bad Dog" I ever had.
Real Name: Bill
RM 377 #2
«
on:
August 10, 2014, 08:17:26 AM »
A while back I was browsing around in our local flea market and stumbled across a break barrel air rifle. I didn't really know what it was but, it felt pretty solid. They wanted $35 for it and I offered $25 and they accepted after I explained that we had no idea how many times it had been dry fired by shoppers that didn't know any better. I brought it home and it turned out to be an RM377 made for Crosman by Mendoza. If you don't know the story, a Mexican company named Mendoza made airguns for Crosman for about 3 years in the early '80s. Crosman decided to go with the Chinese gun makers after that for cost reasons. My opinion... big mistake. Mendoza is now sold in the US by Pyramid Air under the license of Air Venturi. The gun is absolutely original and complete. I pulled it apart and did all the routine sanding and lubing. It's very solid and accurate and under rated. IMO. My only complaint is the trigger pull. Cocking and shooting cycles are as smooth as butter after my modest tuning. It has very minor surface rusting on the barrel and action that I will clean up in the future. The wood could use a re-clear coat but is in really good shape. Betty Lou claimed it for her own the first time she shot it. Betty Lou pretty much gets what Betty Lou wants. To be fair, so do I.
A while back, another member posted a thread about an RM377 that he bought new some years ago. His gun finally broke and he didn't have any intentions of repairing it. (other members offered to fix it for him) I contacted him and told him that I may be interested in buying his RM377 to pair with the one we already had. We struck a deal and he sent me the gun. Neither of us knew what was wrong with the gun at the time. He suspected a broken mainspring. While the gun was in transit, I went on the search for replacement parts without much luck. Basically all I was able to find was a mainspring at PA. I decided to wait until I got the gun and determine exactly what it needed. When the gun arrived I was blown away by it's condition. The OP's thread was titled "Buried an old friend today". He must have really loved this old friend, the condition was amazing.
I tore the gun down to find a broken trigger torsion spring lodged in the trigger group. I removed it and after several attempts to find a replacement I realized that a factory part was not going to be had. I finally found some close torsion springs at McMaster and Carr and ordered 6 left hand and 6 right hand. The original springs were #40 wire with 3 coils. The new ones were #25 wire with 2 coils but the legs were plenty long enough to modify. After some trial and error, I finally got it right. I wrapped another coil around a screwdriver shaft and bent the hooks at the end of each leg. Note: this little spring is a pain in the butt to install. Not only did it fix the gun but, it reduced the trigger pull by more than half. Over the years the original owner had misplaced the front and rear sights so he sent the gun with a one piece mount and Bushnell scope. More failed attempts to locate original sights led us to remove the sights from Betty Lou's gun and scope them both with a couple Ruger scopes we had laying around from a couple Airhawks we no longer own.
The new gun was just as accurate as Betty Lou's but it was a bit loose and twangy. It didn't feel quite a solid as her's. It felt like it had at least double the shots put thru it. The barrel had some side to side play, the cocking was grindy and the shot cycle was clanky. Power was good tho. Yesterday when I got home from work it was raining so outdoor shooting was not an option. A good time to tear the new RM377 down and give it bit of TLC. The internals were surprisingly clean. Seal in good shape, Mainspring had plenty of preload and was real straight. Piston was nice and shiny. I proceeded to polish, sand and lube. I put a generous amount of heavy tar on the mainspring. I tweaked the fork to remove the side play. Polished the spring guide and spring ends until they floated against each other nicely. I put it all back together and stepped out on the back porch to toss a couple downrange between raindrops. WOW !!!! JUST WOW!!!! So solid. It just feels like quality. No wiggle, no wobble, no clank. Lock up is a solid "click". Shot cycle it a very quiet, low throated "clunk". No torque at all. And the pellet smacked the steel blank at 25yds with a commanding "gong" . Darkness fell and I was unable to sight it in. I woke up at 3:30 this morning and I'm sitting here like a kid on Christmas morning waiting for the sun to come up so I can open my present. I will definitely be spending some time with this jewel today and I'll get some pics and results to share. 60% chance of rain be dammed.
Kudos to the gentleman that allowed me to breath new life into his old, and my new friend. I hope your new replacement rifle treats you as well as this one did.
Logged
From deep within the Rabbit Hole, Alabama
Charter Member Of The Secret Squirrel Society 20FEB202
mafatone
Sharp Shooter
Posts: 633
yes
Real Name: Dennis
Re: RM 377 #2
«
Reply #1 on:
August 10, 2014, 11:06:26 AM »
Nice write up. Thanks. I have a RM877
Logged
Southern Jersey Shore
avator
GTA Moderator
GTA Senior Contributor
Posts: 50121
The best "Bad Dog" I ever had.
Real Name: Bill
Re: RM 377 #2
«
Reply #2 on:
August 10, 2014, 09:29:07 PM »
Pictures of the pair as promised....
Logged
From deep within the Rabbit Hole, Alabama
Charter Member Of The Secret Squirrel Society 20FEB202
avator
GTA Moderator
GTA Senior Contributor
Posts: 50121
The best "Bad Dog" I ever had.
Real Name: Bill
Re: RM 377 #2
«
Reply #3 on:
August 10, 2014, 09:36:44 PM »
Now things are going to get interesting...... The following 2 pictures are the muzzle ends of the barrels. As far as I know (waiting for a response to confirm) the gentleman I bought the #2 rifle from bought it new and it has not been modified. Betty Lou's gun is .177 cal all the way to the end of the muzzle. The one I recently bought from a GTA member is counter bored at about 5/16 diameter and about 4 1/2 inches deep down into the muzzle
? what the heck is that about?
?
Logged
From deep within the Rabbit Hole, Alabama
Charter Member Of The Secret Squirrel Society 20FEB202
avator
GTA Moderator
GTA Senior Contributor
Posts: 50121
The best "Bad Dog" I ever had.
Real Name: Bill
Re: RM 377 #2
«
Reply #4 on:
August 10, 2014, 09:39:44 PM »
The barrel has original bluing in it....
??
Logged
From deep within the Rabbit Hole, Alabama
Charter Member Of The Secret Squirrel Society 20FEB202
Marco2021
Marco 2021
Plinker
Posts: 224
yes
Real Name: Mark
Re: RM 377 #2
«
Reply #5 on:
March 30, 2019, 05:12:08 PM »
I came across a Crosman Mendoza RM 377 about 6 months ago on Trade me. It caught my attention immediately when I read it was made in Mexico for Crosman. On checking out some reviews I was delighted to note they were very well made. I have missed the opportunity to aquire one until this weekend, a guy was selling 3 guns as a bundle. The RM,a Hatsan M55S and a Winchester 1000. I asked him if he would sell the RM separately he said yes. I bought this little beauty for $125 kiwi. In the pictures it looked tidy with the description saying very good condition. When I arrived I was gobsmacked at the condition, tiny bit of rust on the stock screws but other than that..perfect, even the breech face was like new and the breech seal was perfect also.
I took it round to my mate Keith who is a very competent gunsmith and we stripped it. Spring like new, everything as it should be and the stock screws looked like they had never been off, they cracked upon removal with just a little dry rusty powder. No rust present anywhere else. The spring was dry so a little grease added..job done. Shoots beautifully, trigger is fine about 4lbs pull and it latches with a loud click. I haven't chronied it yet but I'd say about 700 fps. I'm particularly fond of my Mendoza as our close family friend Bobby Cassilas gave my wife away at our wedding so him being Mexican I feel kinda close to this gun.. sentimental I guess.
Final thoughts? Beautiful gun the wood is burnt dark orange with black Tiger stripes and she is a cracker. Thoroughly recommended it.
I understand Mendoza is now name Air Venturi.
Logged
New Zealand
AA TX 200 22 FAC. Hawke HD 3-9*40.
BSA LIGHTENING XL SE .grt .25
HATSAN 130S .30 x2
Benjamin Regal .177
Benjamin Prowler .177
Benjamin Varmint .22
avator
GTA Moderator
GTA Senior Contributor
Posts: 50121
The best "Bad Dog" I ever had.
Real Name: Bill
Re: RM 377 #2
«
Reply #6 on:
March 31, 2019, 05:08:09 PM »
Congrats..
I still have both of my Mendoza Rm377.
If you guys tore them down then I guess you know how tuff that floating torsion spring is to get back in there... gave me a headache.
The Air Venturi Bronco is basically the same gun.
Logged
From deep within the Rabbit Hole, Alabama
Charter Member Of The Secret Squirrel Society 20FEB202
Print
Pages: [
1
]
Go Up
« previous
next »
GTA
»
All Springer/NP/PCP Air Gun Discussion General
»
American/U.S. Air Gun Gates
»
Crosman-Benjamin Air Gun Gate
»
RM 377 #2