Super Bolt Update with PICS (you guys are driving me nuts)

[Gunga]

Originally posted by AGD
Guys,

All good sugestions but we are way ahead of you. The stuff is the glass filled wear resistant "super delrin" but I forgot what it's called. If you mill wear rails you have no way to hold the delrin in place. You can't do a sandwitch the stainless gets too thin and a would cost a fortune.

We were thinking about trying an aluminum sleeve, most of the weight savings with none of the wear problems. See, you guys need to think more out of the box

AGD

Welp, if you have milled or extruded rails (stainless or aluminum), why bother with having delrin as part of the bolt at all? The rails would be the only things in contact with the spring and thus would take all of the abuse, so what would having delrin inbetween the rails achieve? Besides adding weight, cost, and manufacturing difficulties that is.

[Puckz]

Cause it will cause blowback. The bolt needs to seal in the barrel as close as possible to minimize blowback. Having a bolt made of just rails will create a very bad seal.

[Zarak]

I HAVE THE PERFECT IDEA!!!

We should put a couple of those elves in the bolt! Those small guys can do miracles!!!

[zads27]

Hey Tom, where the used delrin sleeve has black areas on it, am I correct in assuming that those parts are worn less than the more white parts?
Do you know approx how many shots the bolt actually went through? Or how many shots the bolt goes through before the wear actually begins to cause performance/reliability problems?
By the wear on that bolt, (assuming the white areas are more worn than the black) it seems that two things causing the most wear are when the flat spring is fully compressed, and the part of the bolt that actually goes furthest into the breach.
Perhaps trying to round out the inside of the bolt spring a bit would help with a more even wear pattern, or maybe shortening the delrin sleeve, or giving it a metal rim around the bottom of the bolt to help keep that part from wearing out so much.
As for the top portion, maybe try making a beveled/rounded edge or something?
Small Delrin sleeve on the back "lip" portion of the bolt to reduce weight more, since that is a big chunk of the weight?

Well most of these ideas are probably unpractical or whatnot, but just giving some ideas.

[DarkRipper]

Neener neener! I briefly had one of these before all of you!!


DR

[Gunga]

Originally posted by DarkRipper
Neener neener! I briefly had one of these before all of you!!


DR

Neener neener neener! I got to try one of these out too.

[donggie]

just a thought

it would probably take a lot or retooling but you could probably achieve less weight for the bolt and shorter cycling distance if you shorten the powertube and bolt and extend the portion of the powertube where the bolt hits. Basically changing the stroke or distance it moves before changing directins. Also the shorter bolt would definitely be lighter. Not sure if there would be any problems with regard to wiggling or orientatino of the bolt during the stroke but from the top of my head, and if I had the resources, I'd try it... who says the bolt has to be that long? am I making any sense?

Don

[Webmaster]

Oh Oh - hey hey! I just had a brain storm for this the other night.

is there any way you could THREAD the delrin sleave onto the steel bolt? Just 3-4 threads at the tip or the base should do it. Maybe just a DOT of blue locktite?

Or is there not enough meat to do this?

[Maverick]

Tom,
I know you already stated that you were working on an aluminum sleeve concept. Could you tell me if the inside dimensions of the bolt can change? If it can you could put a bolt together that looks like the design below. The top bolt is the existing automag bolt. The bottom bolt is one made with a stainless back and front but with an aluminum sleeve making up the main section of the bolt (the red area is made of aluminum). As you can see, the inside diameter of the bolt would be larger. This could have the added plus of improved air flow through the bolt. Let me know what you think.

[donggie]

I think it is a good idea but I would think that the stresses at the point of the joint or attachment of the aluminum to the stainless steel portion may become weak. I'm not even considering the difference in materials and any problems that may cause with regard to expansion due to differences in temperature. Guess it may be a more prudent choice to find a stronger way to attach the aluminum portion to the stainless part. Just a thought.

Don

[Maverick]

I had the same thoughts as far as how to attach the aluminum sleeve to the other pieces. First of all the aluminum sleeve would have to be an extruded aluminum tube. It could be dented if the bolt were dropped but under normal use in a mag I can't imagine it wearing out. It would be much less expensive to make (extruded compared to machined aircraft aluminum). It could then be crimped onto the stainless parts (see the new picture attached). Also, for additional weight reduction the nose of the bolt and inner rod could be machined from aircraft grade aluminum (see green area in the picture). Obviously, this would have to be tested for durability but I really think it could work.

[Maverick]

Also, with the nose of the bolt made of machined aluminum, it would be less expensive to machine different air flow holes in the nose of the bolt. So, if there was a compromise made between manufacturing cost and design of the stainless bolt nose, you could now choose the most efficient air flow design without increasing manufacturing costs by much. I also had another idea in terms of air flow through the bolt. If the inner rod of the bolt came to a point or a more aerodynamic shape it would decrease the disruption of air flow that the flat surface that's there now creates (see attached picture). Again, this would make the air flow through the bolt more efficiently. I don't know if this will really make any noticable difference but is could be something to try.

Tom, I hope I'm not driving you too nuts with this, it's just an idea.

[Maverick]

Here's a picture of what I was trying to get across with the air flow improvement through the bolt. I know that this is a greatly simplified representation of the air flow leaving the powertube but I did this to get my point across.

[Muzikman]

That bolt looks VERY dangerous. Think about this. That crimp some how gives away. Now you have the tip of the bolt coming out of the barrel at 300fps Can you say OUCH?

[Maverick]

I hadn't really thought about that until you brought it to my attention. Honestly though, I believe the existing stainless bolt from AGD is just press fit together (correct me if I'm wrong). I don't beleive they use any welds to hold the nose inside the outer structure of the bolt. Now it is stainless to stainless so there would be much less give in the material, but it still could come apart the same way. In my example, the nose piece would need to have a groove for the aluminum tube to be crimped into. I do believe that this would make a good joint and hold the bolt together. Obviously, only actually building it and thorough testing could really prove any of what I'm saying.