Question about cooking and bolt lift on elite precision 338LM

[Robinhood]

Now sand the firing pin spring down .010"(starting point) on the O.D., Polish the ends of the spring inside and out. Use some Kretex in your Dremel to polish the cocking ramp and edges maybe do a single point lift kit. Keep the inside of the bolt body clean and polished. Keep the detent ball in the rear baffle clean and lubricated. It will run like .....happy time.

[Andrew863]

Cocking ramp has already been re worked, and the spring has been polished. I'm looking into a lift kit or making some. The one thing I don't understand, on the firing pin spring. What are u trying to accomplish by knocking down the O.D. of the firing pin .010? To make sure there is no drag on the ID of the bolt body?

[Dave Hoback]

Cocking ramp has already been re worked, and the spring has been polished. I'm looking into a lift kit or making some. The one thing I don't understand, on the firing pin spring. What are u trying to accomplish by knocking down the O.D. of the firing pin .010? To make sure there is no drag on the ID of the bolt body?

Exactly! This is to eliminate any chance of the spring from rubbing anywhere inside the Bolt Sleeve. Also lightens it just a smidge. Although cutting just a couple coils and heating/flattening the cut end as I do, works better for lowering the spring rate. The factory unit is just so vastly over-sprung!

[Andrew863]

How much do u cut off. I'm going to try and work over a spring and have a stock one. Then try and shoot them both to make sure it doesn't influence SD's

[Dave Hoback]

How much do u cut off. I'm going to try and work over a spring and have a stock one. Then try and shoot them both to make sure it doesn't influence SD's

Roughly like the picture. I left it a coil longer because as I said, I finished the spring cut end back like factory. Heated and flattened the end, then ground it flat.

https://i.ibb.co/NCzR0XC/DF02-E47-F-1228-487-F-960-D-9432755-E91-F7.webp (https://ibb.co/qjw6Hzj)

[Robinhood]

Andrew, When you reduce the diameter of the spring by removing material you reduce the spring rate. It is like using a smaller diameter wire. The object, at least in my mind, is to keep at least .200" to .230" firing pin travel and reduce the bolt lift/cocking effort. Shortening the BAS or adding a shim behind the head to install the lift kit is smart. I have noticed on some bolt/firing pin assemblies, that polishing the ends and the ID about a half inch in often seems to help also. I am thinking that in general smooth, polished coil springs in firing pin assemblies is a good thing.

I guess it could be a placebo effect but it works in my feeble mind.

Also, I would think twice about trimming length and heating it up for any reason. It is a hit or miss at best. Savage Firing Pin springs may be tempered.

[Dave Hoback]

I agree with Robin. Polishing metal parts that move against one another IS in fact a very good thing! And he does bring up a good point with the springs. Yes, they absolutely are tempered. Sorry, I should have mentioned this before. What I did was isolate only that last cut coil. Wet paper towel was stuffed on the inside & wrapped around all the other spring coils so only the cut coil was affected. Now, I’m not telling you to DO anything I do. I’m simply answering questions and explaining what I did. But in any of this, only do that which you completely understand. Everything I’ve ever done I researched and did after I knew & understood. I didn’t have to ask because I knew. So never just DO a project on someone’s word. Always research what you want to do completely, first. I’m not saying asking questions is wrong. I’m just saying don’t take anyones word on things immediately.

[charlie b]

When I am messing around with stuff like this I have a rule. If I am not positively sure of what I am doing I have a spare part handy, in case I screw up the one I am working on.

[Robinhood]

Thanks for clarifying that Dave, and Charlie, I was thinking the same.