Bolt Shroud Fit

Zebra13

Member
Gents,

Over on the "Secrets of the Houston Warehouse" thread, Alinwa talks about using epoxy on the barrel tenon/receiver joint to eliminate lateral movement of the barrel upon firing. I had a similar thought about using epoxy on a threaded joint a while back...to wit:

Some time ago, there was a thread about correcting loose bolt shroud fit that is common on some actions. The general consensus was that this loose fit was not condusive to accuracy. Some posters used teflon tape to tighten this fit up. When it wore out, they replaced it.

Do you think using epoxy on the bolt shroud joint to cure this ill has any validity? I'm talking about using epoxy to build up either the bolt shroud or bolt threads...epoxy on one, release agent on the other. I'm thinking epoxy on the bolt shroud. It may come out purdy tight, but I would think cycling the bolt would get you the working tolerances needed. If that don't work, how bout' running a loose die over it (for the epoxied bolt shroud) to make it a wee smaller?

Whilst I am no epoxy expert, I see wear being a problem. However, I do see it lasting longer than teflon tape. And if it does wear out, it would be easy enough to clean up and re-do.

Am I off the reservation again? Your thoughts are welcome.

Justin
 
I would think that it could work, but you would have to be very careful not to get the epoxy where it might interfere with operation. Have you tried the teflon tape? It is really easy to apply, and it should let you determine whether your rifle is more accurate with a tighter shroud. If it is, then you can set about fixing it in a more permanent fashion.
 
Don't forget, the tighter the bolt plug, the heavier the bolt lift.
 
Howdy. Being a wannabe who is new to the forum, I am reluctant to clutter things with ignorant comments, but I can't resist saying that for years I have wondered how to hold the bolt lugs against the receiver when the firing pin is released (wasn't conscious or mature enough to worry about alignment as ya'll recently introduced me to....) Have unsuccessfully dreamed of how to have a secondary spring catch and hold the rear of the bolt when tension of fp spring released. How about an o-ring at bolt face or even in a recess at rear of receiver to catch a rib or tabs on bolt? I rekon the more pressure, the harder to close bolt as mentioned previously. Compress the o-ring just enough to hold lugs against receiver? Shouldn't take much. Could one of you real smiths/manufacturers make this work?

Shouldn't be too hard to completely redesign/produce/market an action around this..........;)
 
I have also thought about a hook and spring. Another thought, some actions have shroud threads that are such that the shroud to bolt gap closes as the bolt is closed. Left bolt actions with Remington style shrouds have this feature. Some manufacturers have use LH shroud threads for right bolt actions, and RH for left bolt. You might think about how this feature could be used. It can be difficult to impossible to know how important various conditions are to accuracy. One can spend too much time on a thing that is not that important. If you look at the performance of the best of our "defective" actions, perhaps it can be seen that this problem is not to big, in the overall scheme of things....not the weakest link in the chain.
 
Heck, a coil spring bearing between front of lugs and rear of barrel (pin/glue/chewing gum attachment to bolt?). Would have to extend past bolt nose and might screw with ejection. Maybe glue or somehow attach a metal ring/sleeve/washer at rear of barrel to extend over bolt nose and engage a shorter spring. Not much room for a spring though. Back to o-ring, polyethelene pipe or other compressible plastic? For me in my case, I think Mr. Allen has it pegged: a fine custom rifle with all potential faults remedied still wouldn't read conditions and break the shot for me. If it did, what fun would that be anyway? Of course, I'd still love to upgrade....maybe after kids grown.....
 
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I think you blokes cant see the forest for the trees, your case holds the lugs against the abutments as long as you dont over resize.
 
Maybe glue or somehow attach a metal ring/sleeve/washer at rear of barrel to extend over bolt nose and engage a shorter spring. Not much room for a spring though. Back to o-ring, polyethelene pipe or other compressible plastic? astro turf
 
Some of you'se guys need to read 'Rifle Accuracy Facts' by Harold Vaughn, and do a search for "Borden Bumps."

YES the problem exists, and yes there have been some fixes but my opinion is firmly with Mike A

al
 
The Borden Bumps are a great idea, to keep the bolt in true alignment with the center of the action... as "mike B" in Oz and "Al in Washington stated", The snug case keeps the lugs tight to the receiver face.

My thoughts are that a groove or relive cut in the rear of the threaded area of the bolt shroud would allow for the insertion of an "O-Ring", this O ring could tighten up the bolt shroud fit, while keeping it all centered. I'll look one over later today for clearance issues...

Paul
 
Nope... You got to have the slot for firing pin cocking piece. The best way might be to turn it down in a groove build a pair of half moon sleeves, epoxy them on then turn them down to a snug fit like the "O-ring" would be, then re-cut the cocking piece slot.

Paul
 
Paul,
A good while back there was a fellow that posted with an accuracy problem for one of two rifles that he had that were the same action. The point of mentioning the second rifle is that they both started out shooting fine, one continued that way, and the other's accuracy degraded, for no apparent reason. I suggested that he try the teflon tape on the shroud threads trick (the shrouds were of the Remington style.) and it fixed the problem..really. Later, he went back and checked the fit of both shrouds, and the one that had the problem was quite a bit looser than the one that had continued to shoot well. My point is that perhaps at a certain level of fit, there isn't a problem, and when wear or original tolerance combined with wear cause the fit to go beyond some amount of clearance, then the problem shows up on the target. It seems to me that another way to approach the problem would be to make a threaded plug that could be used to cast a tighter fit in the bolt. If the plug was sized properly, it seems to me that a good fit with a replacement shroud would be possible.
Boyd
 
Boyd, Bolt shrouds are not difficult to make, actually very easy. You can fit them as close as desired. What is important
is that the bore for the firing pin is true with the bolt, not the shroud. The reason is that most bolts have the 1/3-13 thread
out of allignment to some degree. Simply tightening up the thread fit often causes drag on the Firing pin.
 
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