New member hello and question about cocking ramp

[Smokepole]

Now that's an idea right there. A progressive curve. Initially, I would think that curve would be parabolic since the spring is linear. You and I are in the same boat on the hobby business. It's all a learning experience, particularly in the winter when I don't want to be outside! I have received the text mentioned above, and it indeed has oodles of good info. There's plenty of good formulas for energy, lock time, etc., as well as measured values. At any rate, it looks like, qualitatively, anything we do w/o modifying the travel or ramp will probably cost us in lock time and of course energy (both of which the Savage has plenty extra). I'm just trying to find out what mod will affect it the least, and by how much. If the lock time only goes up to that of a competitor's action, I'm willing to sacrifice that much for easier bolt operation. Basically, the only variables to mess w w/o changing the ramp are, spring rate and preload. I'll post back when I figure something out.

[gmidbrod]

Just so you know Smokepole, I am tagging you with being responsible for pulling me out of the lurking mode. Should be able to kill the hole winter on this one.

I have some more thoughts on the issue.

1st - one of the reasons I just took a couple coils of the firing spring to lighten the force on the cocking pin. I feel the small radius is more susceptible to wearing down fast (it did on my MKII 22). Also, this small radius would seem to be partly responsible for the hard bolt lift issue, especially being sticky if the bolt is opened slowly. Thus, for now there will be less wear and tear on the cocking pin with a lighter pressure on it. It surely cost some in lock time. But it seems on par with my Marlin now. Might need to see about gaining the ability to measure it. Does anyone know of any tools/equipment available to do this?

2nd - I am thinking it may be possible to kill 2 birds with one stone on this one. How about a cocking pin with a larger radius. Of course there would have to be other modifications to accommodate it. The larger radius on the cocking pin would allow some machining on the cocking ramp to maintain that same fixed in space position when cocked. Thus, allowing the removal of material at both the top and bottom of the cocking ramp to accomplish a more parabolic curve.

3rd - I replaced the sear torsion spring with a lighter one from McMaster Carr. Also, took a couple coils off the main trigger spring and got that all adjusted. My thinking is this results in less back pressure forces on the firing pins release from the sear return spring. Thus, the firing pin has less force fighting is forward acceleration since the sear falls out easier. It ended up giving me a very nice trigger to boot. Another factor that makes up for a little loss of lock time.

So, on the issue of re profiling the ramp. I would think a person could use an economic milling machine from Grizzlys to machine the bolt, do some manual honing, re harden it, then do some touch up honing. Certainly the profile wouldn't end up having a perfect parabolic curve. However, I would bet one could get it pretty good. Good enough to make for a nice bolt lift, reduced cocking pin wear, and maintain good lock time without changing layout geometry.

[Smokepole]

That's OK, I've been credited w much worse! I've spent the better part of the day looking thru McMaster's extensive list of springs to find a suitable replacement w no luck so far. But, the best I can tell the stock spring is 3" relaxed and has a rate of about 16.5lbs/in measured rather crudely by me. By Otteson's formulas (that I checked), that spring yields an energy level about 12% more than what Otteson states is the norm for the 110. I guess that could be attributed to friction and vibrational losses (which Otteson clearly states as well). But, the task is finding one off the shelf that takes less cocking effort but provides the 75oz-in of energy he states is necessary to pop a LR primer consistently (that was determined by SAAMI and the military I do believe and it does have a fair amount of safety factor in it---temp sensitivities, pin eccentricity, excessive headspace, etc.). I've spent hours today hunting. The nature of the formulas requires one to do the calculation for each spring. There's not a real good way to just 'look' at the spring's parameters and 'know' if it's better or not. But suffice to say, McMaster doesn't offer anything useful. Other actual spring manufacturers do, but the least min order I've found is $25. I guess that's acceptable to try out.

[gmidbrod]

Update on my cocking ramp profiling. I decided to cut down the top of the ramp .020" and blend to the bottom or beginning part of the ramp. Thus, I approximated a parabolic curve and will need to re harden the metal for permanent use. However, it worked great for alleviating the stickiness at the top of the bolt lift which annoyed me highly on mine. I would bet SSS's mod which probably is just a shorter lift with a straight helical cut works even better. I found on mine now the top of the lift is easier than the beginning after my mod. Thus the straight helical cut with a more gentle slope is probably the best way to go now that I have tried the curve idea. I love learning though.

Another simple mod is to just put the bigger bolt handle on it. It helps greatly, I just wanted to try and stick with the small bolt handle.

Lastly, There is no doubt about the value of SSS's service for those who don't have the "must do it myself" disease. This stuff is definitely a bunch of monkeying around (kind of the whole point anyway), but what a learning experience for myself so far, with much thanks to all those contributing here BTW.

[acasto]

Smokepole

You getting any further along on this quest?
I have been watching with interest your posts about this particular mod. If you feel so inclined, I would like to stay in the loop, and maybe share anything that I can come up with. I have done a few things myself to reduce bolt lift.

Thanks
Tony

[Smokepole]

Yes, I swapped to a lighter weight firing pin spring. I won't come out and say the part number because I don't want anybody blaming any ignition problems on me! But they came from MSC and were cheap. Have to buy a pack of several though. And, I highly recommend Otteson's book. It can be had on Ebay for about $18 plus shipping. The formulas in there will lead you in the right direction. It's a little aggravating because the search is iterative. For the short action, the spring I'm using is a little smaller wire and about 30% lighter rate w the same relaxed length and the factory dimensional preloads (due to geometry of assembly). For the long action, Savage uses a longer spring, 4". But, I'm going to use the same aftermarket spring w a 1" spacer to keep the preloads right. That spacer won't move, so the actual firing pin mass in motion is the same.