Full diameter action mandrels

[Taylor Stratton]

I've turned down a few actions to go in sleeves. The middle of all the action was warped going to the outside. Never to the inside.

@DaveTooley Can you elaborate a little bit about what you mean “warped going to the outside?”

 

[DaveTooley]

@DaveTooley Can you elaborate a little bit about what you mean “warped going to the outside?”

I mount the action on a mandrel and take a clean up cut on the outside so it will fit inside a sleeve. Both the front and rear receiver rings would fit as is but the middle section, adjacent to the loading port, would always be larger in diameter and restrict the action going into the sleeve. The actions weren't round or straight. Does it matter? Not so much for every day use.

 

[Taylor Stratton]

Oh I see what you mean Dave. Ya that makes the most sense to me. I figured that’s the way it would be.

 

[Doug Beach]

I’m interested in a set, as well.

 

[Taylor Stratton]

@Doug Beach, @jkohler, @marazzi59, @tac284, @tobnpr, @RDA72927 I called Sarah at JGS and she’s checking if they will agree to grind them for us and how much they would charge. She will get back to me shortly. I asked for at least 6 sets with 5 bars per set from .701-703 in .0005 increments with .0002 tolerance for straightness and diameter.

 

[Alan Warner]

JGS made mine. Regardless, your paying for tolerances. Spin them in v blocks and mic them when they come in. I can say JGS hit the specs on all of mine as usual. Would be interested to hear what they can do them for. Found the original ad for reference on price. I didnt buy them to make money, I just wanted a set and had to buy enough to get the price down so I sold the rest. Actually had a couple sets sitting around for quite a while.... https://forum.accurateshooter.com/threads/precision-action-truing-mandrels.3910417/

You fellas draw up what you want and I'll quote it. I grind between dead centers every other day.
Alan

 

[Taylor Stratton]

You fellas draw up what you want and I'll quote it. I grind between dead centers every other day.
Alan

Would you be able to hold .0002 or better on diameter and straightness?? If so I’d be down to consider that depending on price. I’ll wait to hear from JGS to see if they would and if so how much they would charge. If you did them for us (assuming 6 sets with 5 bars/set, 30 bars total) what do you guess your time frame would be just out of curiosity?

 

[tac284]

I would have no issues with @Alan Warner doing them if he can meet that spec. He makes great tools and products. Thanks @LRBoltMan for doing the work! If I can help in some way let me know. Will be interesting to see pricing...

 

[Alan Warner]

Would you be able to hold .0002 or better on diameter and straightness?? If so I’d be down to consider that depending on price. I’ll wait to hear from JGS to see if they would and if so how much they would charge. If you did them for us (assuming 6 sets with 5 bars/set, 30 bars total) what do you guess your time frame would be just out of curiosity?

How long are they? Dia? Material, Rc?
I would say, .00005 size end to end, maybe
000075 depending on length. Roundness within. 000025. All@ 68 F.
Job like this needs cryo after double draw.

 

[mikecockcroft]

I was going to buy a set from Alex but procrastination got in the way. I’m in for a set. Have no doubt Warner can get it done to spec or better. Either will work for me.

 

[Taylor Stratton]

How long are they? Dia? Material, Rc?
I would say, .00005 size end to end, maybe
000075 depending on length. Roundness within. 000025. All@ 68 F.
Job like this needs cryo after double draw.

12” rods. That sounds fantastic. I’m up for recommendations from you and others on material and hardness. I was thinking stainless so they won’t rust? Im open to suggestions. We will just be putting the rods in and out of action bores for indicating prior to blueprinting and checking straightness of existing custom actions.

Also only had plan on getting 5 bars. Every .0005 from .701-.703. Does anyone else think we need a broader spectrum? @Alex Wheeler says his .7015 and .702 are his most used.

 

[tac284]

If memory serves me correct, gage pins are made of 52100 bearing quality steel and RC of 58-62. That is basically what we are looking for but in a 12” length. I don’t know pricing on that material so maybe there would be something else that would serve the purpose but a better price point. Maybe Alan can guide us? You can purchase 52100 from McMaster Carr in an annealed state. You would have to start with .750 diameter though...

5 bars from .701 to .703 sounds good to me.

 

[Alex Wheeler]

I'm out of service for the most part I'll look at the rods monday to give an idea on sizing

 

[Alan Warner]

If memory serves me correct, gage pins are made of 52100 bearing quality steel and RC of 58-62. That is basically what we are looking for but in a 12” length. I don’t know pricing on that material so maybe there would be something else that would serve the purpose but a better price point. Maybe Alan can guide us? You can purchase 52100 from McMaster Carr in an annealed state. You would have to start with .750 diameter though...

5 bars from .701 to .703 sounds good to me.

52100 is OK but even at Rc62 it is easily scratched. My first choice would be A-10. Will run to Rc 62/63, grinds well and is more wear resistant. Approx cost for a 5 pc. set with cryo and a min of 6 sets would be in the neighborhood of 775 per set. if you want to add TiC or TiN I can RFQ from my available vendors.

Edit:
BTW, never buy form McMaster unless you absolutely have too-- they are nearly double to mill pricing.

 

[butchlambert]

52100 is OK but even at Rc62 it is easily scratched. My first choice would be A-10. Will run to Rc 62/63, grinds well and is more wear resistant. Approx cost for a 5 pc. set with cryo and a min of 6 sets would be in the neighborhood of 775 per set. if you want to add TiC or TiN I can RFQ from my available vendors.

Edit:
BTW, never buy form McMaster unless you absolutely have too-- they are nearly double to mill pricing.

Alan, did you get my email on die inserts for your die?

 

[Taylor Stratton]

Well guys,I just got a call back from JGS, they will not be grinding any bars or odd jobs for the time being. They are too busy. I don’t know of anyone else at the moment other than @Alan Warner to get them from which is a very good option if we can get enough guys to make it worthwhile for him. Anyone know anyone else to contact that may be interested in getting a set? Currently we are at 7 sets myself included if everyone is still on board.

 

[Alex Wheeler]

Holding tolerances like that is not cheap. You never regret buying the best tools, its an investment in your career. I am sorry, busy day and I forgot to look at the rods. I can say my original rods were a good range. I only found one action that needed a smaller one. So the bottom is good. I want to look at the high side to see if you can eliminate one on that end to save some money.

 

[jackieschmidt]

I’ve recently discovered how to check action straightness in actions I’m blueprinting with the old bushing and .500 mandrel and I’m commonly getting .0025-.005 runout right behind the action when it’s shouldered up on the tenon. I’m a little disappointed as I spend so much time indicating and taking light cuts to try and make them perfect. I’ve checked a few custom actions that were anywhere from .006-013!! I had no idea.

I’d like to try some full diameter mandrels to indicate actions in for blueprinting and to more accurately check the customs I’m working on (im hoping they aren’t really that bad). Where would you guys get these mandrels made? I would imagine you’d want them hardened and ground. What tolerance would you ask to be held on them? Thanks guys! I always appreciate your input and help.

I am a little confused as to just what you are saying in your first paragraph.

 

[Taylor Stratton]

I am a little confused as to just what you are saying in your first paragraph.

See comment #5 from tucker65 for a video example of what I’m measuring. It’s a test to see how straight the threads and face were cut in relation to the bolt bore raceway. The full diameter rods were interested in are a much better way to get this measurement.

 

[Taylor Stratton]

Alright @jackieschmidt, @jdscada, @tstevens09, @DiffEQ, @mikecockcroft, @RDA72927, @tobnpr, @tac284, @marazzi59, @jkohler, @Doug Beach who is on board for purchasing a set? Inform and tag anyone else that you know may be interested in getting a set as part of the group buy. @Alan Warner will grind them for us. 5 bars per set from .701-.703 dia. out of A-10 steel in 12” lengths. We have a tentative price of $775/set but we have to order at least 6 sets. A normal .500 mandrel and bushing set runs around $500+ and this is a far superior method of finding center of the action bore. Well worth the extra money in my mind. Like Alex said, it’s an investment you will never regret. Chime in and tag friends that may be interested. I will buy a set!