How to build a Positive Slam Dow

[Trader Dan]

I also have this posted in the Gunsmithing forum.

Pards,

I put some lighter lever and carrier arm springs in the Golden Boy. It works great but I would like to be sure the carrier goes all the way down after extensive shooting as I have dedicated myself to shoot the Holy Black out of the 1866. I have my first match today after a summer of not going to the matches for one reason or another. I installed the spring kit and took the gun to the range and ran about 100 rounds, 50 black and 50 smokeless, through it with no problems. BUT, because Murphy and I are besties, I just have a feeling he will show up today at the match and cause problems for me. He does that ya know. 

I have searched here and I have searched the Internet and I cannot find even a bad picture of what a PSD looks like and no where did I find out how to either modify my lever arm or buy a new one and modify it.

Would someone be so kind as to either provide me with a link or post instructions and pictures of how to modify the lever arm so it will act as a PSD.

[john boy]

Would someone be so kind as to either provide me with a link or post instructions and pictures of how to modify the lever arm so it will act as a PSD.

The topic was discussed in detail on the SASS Wire recently ... do a search

[Coffinmaker]

Trader Dan,

You will need > A Carrier Block Arm.  A package of 8-32 Set Screws (2 per pack).  An 8-32 Tap and Drill set.
Looking at the back of the carrier block arm, your going to drill a hole at the TOP of the flat surface, all the way through the Carrier Block arm.  Insure you drill through the CENTER of the arm, and at a right angle to the flat (90 degrees).
Carefully Tap the hole for the 8-32 set screw.  Be sure to use plenty of oil on the tap.  If it breaks off, in the hole, your screwed.  Clean out all the swarf, run the set screw in with the hex socket DOWN so you can adjust it.  With about two threads showing above the flat surface of the Carrier Block Arm, file the set screw Flat.
Adjust the set screw so the Carrier Block is fully DOWN in the mortice with the lever against the lower tang.  If you can just feel the finest movement, your OK.
Take it all apart, clean the hole and the set screw with alcohol.  Apply Blue LocTite to the set screw and put it back in, quickly reassemble the Carrier Block, Carrier Block Arm and Lever and re-adjust.  Let the LocTite set up.  Done.

Coffinmaker

If this is beyond your skill set, send me an IM

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[Bunk Stagnerg]

I have an 1866 and a 1860 both in .45 "blowback" Colt fitted with the positive Slam Down modification.
When the lever is closed the carrier is solidly down. The 1866 was shot in a match last weekend. Smoky Pete and I shared the gun through 5 stages (100 rounds) and it closed with authority, and never missed a beat.
 We were shooting 2.7 c/c FFFg and a 200 grain BL bullet. No smokesomewahtless powde for this child.Positive slam down makes a toggle link rifle very reliable especially when shooting real Gun Powder.
Yr' Obt
 Svt'
Bunk
. 

[Trader Dan]

Shot the match and used BP for 3 of the 4 stages and my 44-40 1866Yellowboy performed flawlessly! Which is more than I can say for my shooting!!!!! So maybe I don't need the PSD mod after all.

But, I am going to order a new carrier lifter arm and do the mod on that one and install it. Never hurts to be on the safe side!   

Coffinmaker was kind enough to provide the instructions as you have seen and I can handle that.  Thanks, Mr. Coffinmaker!

[Pettifogger]

Shot the match and used BP for 3 of the 4 stages and my 44-40 1866Yellowboy performed flawlessly! Which is more than I can say for my shooting!!!!! So maybe I don't need the PSD mod after all.

But, I am going to order a new carrier lifter arm and do the mod on that one and install it. Never hurts to be on the safe side!   

Coffinmaker was kind enough to provide the instructions as you have seen and I can handle that.  Thanks, Mr. Coffinmaker!

Over in your other thread I asked what caliber you are shooting.  .44-40 does not suffer the blowback of the .45 Colt or even the .38/.357.  I am running my new production Winchester in .44-40 without the slam down.  All if has ever fired is BP or subs.  It has never balked.

[rbertalotto]

Picture in this thread:

http://www.sassnet.com/forums/index.php?showtopic=255126

[Coffinmaker]

Thanks Roy.  That's one of my arms for slam down.

I must also "Pile On" with Pettifogger ........ again.  Positive Slam Down is intended to provide reliable function with Straight Wall cartridges that are known to "leak."  Blow-By is seldom if ever a problem with bottle neck cases.  Most 44-40, 38-40 and 32-20 will complete a match as clean as when they started.  Cleaning is just running a wet snake through the bore.

Of course, if one just must have insurance, the Slam Down modification will not affect performance.

Coffinmaker

[Trader Dan]

Got my brass out last night after the match and inspected each case prior to clean. No blow by at all. Interesting.
The problem, or at least I interpret it as a potential problem, is that after I installed the spring kit, IIRC, they were Slix Springs, I can move the carrier up just a tad and it does not always drop back down. I can "jiggle" the rifle and the carrier will go back down. While this did not cause any problems during the match and like I said, I just know that ol' Murphy is a waiting for me. So yessir Mr Coffinmaker, I am thinking that the insurance of a PSD would be comforting!   

[Coffinmaker]

Trader,

Slix are an excellent choice.  They work very well indeed.  I have had several shooters in my neck of the woods who consistently grab their rifle by the frame, just ahead of the lever.  Inadvertently pushing the carrier block up just far enough to jam the action.  PSD will prevent that annoying little problem.

Coffinmaker

[Trader Dan]

Thanks Coffinmaker. I will get one on order. How hard is the steel that the carrier lever is made off? Will a standard high speed drill bit work or do I need a colbolt drill bit?

[Coffinmaker]

Pretty normal steel.  NOT real hard.  I use standard drills and standard taps.  Just take your time and keep lubricated.

Coffinmaker

[Cliff Fendley]

They're easy to drill and tap. Easier than you would think actually for a part like that you would think would be hardened more.

[Cemetery]

Trader Dan,

You will need > A Carrier Block Arm.  A package of 8-32 Set Screws (2 per pack).  An 8-32 Tap and Drill set.
Looking at the back of the carrier block arm, your going to drill a hole at the TOP of the flat surface, all the way through the Carrier Block arm.  Insure you drill through the CENTER of the arm, and at a right angle to the flat (90 degrees).
Carefully Tap the hole for the 8-32 set screw.  Be sure to use plenty of oil on the tap.  If it breaks off, in the hole, your screwed.  Clean out all the swarf, run the set screw in with the hex socket DOWN so you can adjust it.  With about two threads showing above the flat surface of the Carrier Block Arm, file the set screw Flat.
Adjust the set screw so the Carrier Block is fully DOWN in the mortice with the lever against the lower tang.  If you can just feel the finest movement, your OK.
Take it all apart, clean the hole and the set screw with alcohol.  Apply Blue LocTite to the set screw and put it back in, quickly reassemble the Carrier Block, Carrier Block Arm and Lever and re-adjust.  Let the LocTite set up.  Done.

Coffinmaker

If this is beyond your skill set, send me an IM

Oh boy.............good thing this discussion came up. 

I've been having troubles with my '66, and I noticed last night, for whatever reason, my lever doesn't push the lifter arm down all the way.  I've got a small gap there, which won't allow the carrier arm to go all the way down unless the carrier springs are almost totally disabled.

[Trader Dan]

Oh boy.............good thing this discussion came up.  

I've been having troubles with my '66, and I noticed last night, for whatever reason, my lever doesn't push the lifter arm down all the way.  I've got a small gap there, which won't allow the carrier arm to go all the way down unless the carrier springs are almost totally disabled.

[Trader Dan]

Got my lever lifter rod from Cimarron and immediately put in my Cowboy gun parts drawer until I have time to modify it. Between a house remodel, garage cleaning, fixing my truck  and reloading, , smokeless rifle cartridges, just have not had time to modify it. 

Speaking of smokeless cartridges, what would you pard's think about shooting the holy black out of a 1945 Australian Lithgow No.1 MKII SMLE? Couldn't be any worse that Cordite.

Ever read the Destroyermen Book series?