mcarterbrown.com  

Reply
 
Thread Tools Search this Thread
Old 10-23-2006, 02:08 AM   #1 (permalink)
a.k.a. FullSpinPaintball
 
SpinDoctor15's Avatar
 
Join Date: Apr 2006
Location: D.C.

AKA Fan
Brass N Wood Fan
Palmers Fan
Bolt-Action MacMurray Marauder

This is a MacMurray Marauder that I acquired off of WhartRat on MCB. It was originally a pump marker that he nickle-plated and did his "Wharf Rat Squiggle" (what I call this unique finish!). A KP bolt was modified to attach the bolt handle. The lower valve tube is a mess right now, I need to get the valve-nut retaining threads repaired (from Palmers), as someone cross-threaded them. Also, the trigger group has a Blue Streak trigger that has the 'sear' part cut down somewhat. I need a new main spring, as the one in here was fine for the original pistol grip, but doesn't work with the trigger group.

10/14/06: This weekend, I drilled and tapped two holes in the trigger group and inserted two small set screws (6NC32 threaded) through the rear-lower part of the body to hold the trigger group in place. I also drilled a hole through the bottom of the stock and put a pringle screw/body retaining nut through there to hold the marker to the stock. It's a nice fit, even though it's not a Sheridan stock! Finally, I plugged the Constant Air elbow that eeks out the right side of the body, and fixed the 12 gram plunger, as the threads were gummed up with dirt. It's now possible to insert a 12 gram and actually have it seal against the chamber-face plug. However, once punctured, the 12 gram vents empty. I've figured out the source of the problem, it's the aforementioned "valve-nut retaining threads." Since the valve nut only holds on for about 1/4 turn when inserted, it doesn't allow the o-ring on the front of the stainless steel valve body to seal properly. Once I fix this thing completely, it's off to the firing range!



Here's a group shot with the other brass:





10/17/06: Well, after much trial and error, the valve-retaining nut actually threads down a full turn (vs. the off-angle 1/4-turn it was doing before).

With this rifle, there is a big challenge with the hammer/spring setup. The throw of the spring is very short, there is NOT much room in there, certainly less than 2". I was having a problem where I would pop a fresh 12 gram and it would vent down the barrel in about 10 seconds. So, I thought it was the cup seal, and put a new pierce pin assembly in there. No joy with that repair, so I replaced a bunch of o-rings. See the pictures below for those nasty original o-rings... No joy on the o-ring repair either though.

Finally, I discovered the source of my problems. I had been putting little spacers in the rear-cap in place of an RVA, since the spring wasn't strong enough to propel the hammer forward in the first place. However, it was pushing on the pierce-pin, and with a weak valve spring, it was keeping it open enough to leak. I finally changed out the valve-pin spring with a stiffer one, and voila! It only barely leaks now. The hammer is still touching the pierce pin. So now I need to find the optimum combination of valve spring to main spring, and I need the main spring to be just long enough that it doesn't allow the hammer to touch the rear of the pierce pin. Even with the strong spring setup in there now, it doesn't produce the required air blast to really propel a paintball (or even sound loud enough!). For information on springs/hammers, etc. there is some excellent reading material on this subject on the Palmers site (http://www.palmer-pursuit.com/techpages/ty_vs_st.htm, read the little 3-line paragraph at the end of this essay). I'll have to work with the space I'm given, but eventually, it'll provide the 285 fps I need!

This is some quick video I shot last night. The first part shows the loading of a 12 gram, and some test shots. The first shot didn't pierce the 12 gram (again, hammer/spring combo not quite right), and I failed to cock it during a quick-firing part, but overall you get the idea. The second part shows a close-up of how the bolt action actually works. The little lug on the bolt that pulls on the hammer is rotated by the bolt handle, and then you can see me remove it entirely by rotating it to align with a slot on the right-hand side of the marker. It's pretty neat, the action is fairly smooth:



Here's the gun broken down into its components. I hope the carpet doesn't cause too much eye-strain, I didn't have a better surface to photograph on last night. But, as you can see, it's pretty much your standard Sheridan setup:



Here's a closeup of the old, cracked o-ring on the face of the stainless steel valve pierce-pin assembly. It obviously needed to be replaced:



Another photo of that same o-ring on the face of the assembly, only this time I stretched it around a 12 gram to show off the extent of the cracking!:



Finally, here's a photo showing that same o-ring (on the right) with the identical o-ring from my old KP2 pierce pin assembly. Let's just say I'm glad the Palmers PGP seal replacement kit includes a few of these, as both guns were in dire need of new o-rings in the valves:

__________________
Jason
Spin Doc

** Spin Doctor's Paintball Page
** MCB Feedback
** PBN Feedback
** PBN Feedback (old)

Agglet re: Frink: "Much like a newborn baby your collection is both beautiful and disgusting."
russc: "PBN is a business, and that's why they prefer thousands of morons to hundreds of intelligent posters"
drum: "Between the ammo shipments and all the long rectangular packages, not to mention regular mail from the Pa. Superior Court, my mailman is pretty sure that I am a freak."

Last edited by SpinDoctor15; 10-30-2006 at 12:30 PM.
SpinDoctor15 is offline   Reply With Quote
Old 10-25-2006, 04:55 AM   #2 (permalink)
Eli
Phat.
 
Eli's Avatar
 
Join Date: Oct 2006
Location: Los Angeles
Send a message via AIM to Eli

That is so freakin' cool...
__________________
MCB Feedback
Eli is offline   Reply With Quote
Old 10-25-2006, 05:19 AM   #3 (permalink)
Post Whore
 
SuperHiQuality87's Avatar
 
Join Date: Sep 2006
Location: New Mexico

Look; Spindoctor; i've fallen in love. Where did you get the bolt handle? I need one. ASAP.

III
__________________
Dr. Jack Barnes says: Science is not for pussies!
Quote:
Originally Posted by Morgenstern View Post
Next time add more yelling and crazy camera angles. Maybe start an episode with you parachuting into your attic, then you immediatley come under fire from the french resistance. I can see it now....
Please read the MCB Rules.
SuperHiQuality87 is offline   Reply With Quote
Old 10-25-2006, 10:41 AM   #4 (permalink)
a.k.a. FullSpinPaintball
 
SpinDoctor15's Avatar
 
Join Date: Apr 2006
Location: D.C.

AKA Fan
Brass N Wood Fan
Palmers Fan
It actually came with the gun from Wharfrat, he told me it was a bolt handle that was welded to a cut-down KP bolt. I'll take a closer picture soon (when I get some more time!). Thanks for the compliments guys. I look forward to getting the springing correct and then making the stock look nicer. I don't like the angle cut under the front area, it has bolts for a duckbill ASA, but I want to keep it 12 gram...
__________________
Jason
Spin Doc

** Spin Doctor's Paintball Page
** MCB Feedback
** PBN Feedback
** PBN Feedback (old)

Agglet re: Frink: "Much like a newborn baby your collection is both beautiful and disgusting."
russc: "PBN is a business, and that's why they prefer thousands of morons to hundreds of intelligent posters"
drum: "Between the ammo shipments and all the long rectangular packages, not to mention regular mail from the Pa. Superior Court, my mailman is pretty sure that I am a freak."
SpinDoctor15 is offline   Reply With Quote
Old 10-28-2006, 12:59 PM   #5 (permalink)
MCB Member
 
Join Date: Apr 2006
Location: Clarksburg, CA

The bolt handle is a Mauser Bolt Handle, made by Advanced Technology (or "ATI"). They are available for under $15 from a variety of gun parts dealers and also appear on Ebay occasionally. The bolt handle is held on by a bolt threaded into a standard speed demon pistol bolt (requires drilling and tapping) you need to redrill the air hole in the bolt so it lines up correctly, but it's easy. This gun has no rifle parts other than the stock and trigger group.

It's a shame you don't like the patterned finish on the nickle plating. Palmer would be glad to redo it for you - they charge $300 for their classic finish.
__________________
Scourge of the Spaceways
Wharf Rat is offline   Reply With Quote
Old 10-30-2006, 12:31 PM   #6 (permalink)
a.k.a. FullSpinPaintball
 
SpinDoctor15's Avatar
 
Join Date: Apr 2006
Location: D.C.

AKA Fan
Brass N Wood Fan
Palmers Fan
I do like the finish! Sorry, I re-read my post, and it didn't make sense. I edited it to read 'unique finish' as I think it's great you're able to do this type of work so effectively and economically. Thanks again for parting with a superb custom piece, I look forward to getting the springs adjusted correctly, and taking it to the field!
__________________
Jason
Spin Doc

** Spin Doctor's Paintball Page
** MCB Feedback
** PBN Feedback
** PBN Feedback (old)

Agglet re: Frink: "Much like a newborn baby your collection is both beautiful and disgusting."
russc: "PBN is a business, and that's why they prefer thousands of morons to hundreds of intelligent posters"
drum: "Between the ammo shipments and all the long rectangular packages, not to mention regular mail from the Pa. Superior Court, my mailman is pretty sure that I am a freak."
SpinDoctor15 is offline   Reply With Quote
Reply

  mcarterbrown.com » Paintball » The Armory » Sheridan

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump


All times are GMT -4. The time now is 12:19 AM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO
© MCB Network LLC