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Bolt lift force

clowdis

After reading a few posts about how hard 3 and 4 lug bolts are to lift and cock I decided to take my trigger pull gauge and test a few different actions. This was by no means a scientific test, just a few observations.
Panda (2 lug) 6#
Barnard (3 lug) 7#
Remington 700 and an old 78 (2 lug) 8# ea.
Defiance with PTG bolt and 32# firing pin spring (2 lug) 11+ #
RPA Quadlite (4 lug) 10.5#
Looking at this I don't see that multiple lugs will guarantee a lighter bolt lift. In fact the Barnard is almost as smooth and easy as the Panda. Even at 10.5# I don't find the RPA hard to cycle in prone position because of the short stroke. Very smooth! I can see bolt lift being a factor in benchrest and across the course but I don't see the big deal in other disciplines.
 
Nice! Thanks for sharing. This gives some basic idea of differences in bolt lift and at least may spur some experimenting.
 
I found this to be an interesting post for a variety of reasons. I wondered where you placed the gauge on the bolt (before the knob, on the knob, etc.)
If you secured it or just guided it with your fingers? I tried it of course, all out of merely interest. I could see where the amount of bearing surface would maybe count. The smoothness of the finish on the lugs also. And maybe the number of lugs in conjunction with the aforementioned two.
I merely kept the gauge on the bolt knob and kept it from slipping with my fingers. My findings are not scientific. My trigger gauge has never been calibrated for anything. I just tried to keep it the same on each rifle. Three Savages lifted at 7-9 lbs. Remington 700 at 9lbs. And a Weatherby Mark V (which has 9 lugs) lifted at 4 lbs. I tried a Blaser but could not get a good reading as I was unable to secure the gauge. For what it's worth the Blaser feels quite light.
The above was done by me for my own knowledge and I am not suggesting anything with this except my own un-scientific findings. It has nothing to do with any discipline of shooting.
 
The easiest way to do this I have found is to make a loop of electrical tape around the bolt knob. Leave enough slack to put the trigger gauge in and pull up in an arc staying at 90 degrees to the bolt handle position. It's generally repeatable to a few ounces on my Lyman gauge. I'll post mine tonight.
 
I have seen factory Savages with 28-32 LBS bolt lifts. With a little modification, timing, and a bolt lift kit one should get the bolt lift on cocking down to 8-10 LBS.
Nat Lambeth
 
Rustystud said:
I have seen factory Savages with 28-32 LBS bolt lifts. With a little modification, timing, and a bolt lift kit one should get the bolt lift on cocking down to 8-10 LBS.
Nat Lambeth
Click to expand...

I should have mentioned my 3 Savages are not stock. They have exactly the work done to them you describe. The Weatherby and Blaser are as they were from the manufacturer.
I see that Dakota Mike, quote:" The easiest way to do this I have found is to make a loop of electrical tape around the bolt knob. Leave enough slack to put the trigger gauge in and pull up in an arc staying at 90 degrees to the bolt handle position. It's generally repeatable to a few ounces on my Lyman gauge. I'll post mine tonight.has a good suggestion on how to set up for a reading." Good idea.

The Blaser with the 'fingers' instead of lugs and say a Heym with balls may be hard to beat in the easy to lift bolt test.
 
an action with a "steeper cocking cam angle to eliminate cock on close" with a full 24lb. spring.

Not all actions/bolts need to be re cut/TIMED as per a Borden!
 
M-61 said:
I found this to be an interesting post for a variety of reasons. I wondered where you placed the gauge on the bolt (before the knob, on the knob, etc.)
Click to expand...

I tried to keep the gauge in front of the bolt handle knob to keep it from slipping off.
 
Alex Wheeler said:
If you do not mind cock on close your correct. Personally I hate it.
Click to expand...

Nothing farther from the truth!
Monkey see,monkey do by copying Jim Borden's engineering is not applicable to any & all actions/bolts/trigger groups.

30+ yrs experience tells a different story without a you tube video's required on my part
 
Dans40X said:
Nothing farther from the truth!
Monkey see,monkey do by copying Jim Borden's engineering is not applicable to any & all actions/bolts/trigger groups.

30+ yrs experience tells a different story without a you tube video's required on my part
Click to expand...
I was timing actions before I ever seen a Borden. Far from copying Borden. Its not necessary to copy such a simple concept, pretty straight forward. Not sure what your trying to get at here, but 30 years of experience doing something doesnt mean anything to me. Glad you watched my video, and hope you learned something :)
 
Keep producing video's & trying to baffle most with BS.

Yes,after a half dozen inquiry's from those less fortunate of letting someone experiment on their equipment,about a minute to a minute and a half into your video was enough BS for me.

If memory serves me correctly, a yr or so ago, zfastmalibu was eager to learn the correct process of timing an action & fire control.
 
Dans40X said:
Keep producing video's & trying to baffle most with BS.

Yes,after a half dozen inquiry's from those less fortunate of letting someone experiment on their equipment,about a minute to a minute and a half into your video was enough BS for me.

If memory serves me correctly, a yr or so ago, zfastmalibu was eager to learn the correct process of timing an action & fire control.
Click to expand...
Most gunsmiths don't know about timing and a lot don't know it can change accuracy. In the benchrest game it was proven. I only know of two or three gunsmiths in the country that do this work. If you look at the shortrange BR, a lot of actions were reworked, even custom ones and they were all done by one or two gunsmiths. Matt
 
Dans40X said:
Keep producing video's & trying to baffle most with BS.

Yes,after a half dozen inquiry's from those less fortunate of letting someone experiment on their equipment,about a minute to a minute and a half into your video was enough BS for me.
Click to expand...

Dan -
Make a video showing your ways of bolt timing and trigger timing.
Would enjoy seeing it and learning your correct ways !.!.!
Donovan
 
I didn't measure the difference but I went to a 28# spring in my Definace Rebel this week and it is noticeably heavier than the stock spring (I think the stock spring in a 700 style action runs about #24)
 
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