The Summit is unique in that it has a extremely slop-free hard fixed lock up more so than a traditional 2-pice bolt action. When it locks up the bolt has near zero slop.The other issue is that rimfire rim thicknesses varies greatly, so if the headspace you have set is not "ideal" for a particular round/rim thickness, you start getting wild flyers until you disassemble and do the time consuming tuning to headspace for that round.
I tested Feddersen barrels which historically delivers "more" consistency across widely varied ammo. Even then I am seeing that inconsistency and extreme preference for one round which is out of character for any Feddersen barrels I have owned. So that logic is some bolt float/slop is needed. This was tested using the same stock, trigger, barrel and torque and repeated the test many times. I did this because the Summit inconsistency from round to round was driving me insane on the same barrel which were 1/8" grouping and then move to the Summit and boom 1/2" groups with the same ammo in the same trigger and stock. Tune it and back to 1/8" groups, but the other ammo that delivered similar groups, boom 1/2" groups... made me nuts. Only explanation was no bolt slop.
I ended up doing some trickery to allow the bolt to have a tiny bit of slop. I drilled out the linkage on my Gen 2 shown in the first pic so that two silicon o-rings sit in between the linkage shown above and the bolt pin. The o-rings provide enough resistance for thin rims and is forgiving enough for thick rim rounds.
I will say half way into the mod I panicked about "what if it didn't work", I've trashed a Summit, but it worked and even smoothed out feeding. The net is that my Summit now has about the same bolt float as the semi now and now also deliver the same consistency. 1/8" barrel shoots as well across is wildly less picky about what it will shoot well and there is no linkage stress from the bolt locking out on an oddly thick rim.
I tested Feddersen barrels which historically delivers "more" consistency across widely varied ammo. Even then I am seeing that inconsistency and extreme preference for one round which is out of character for any Feddersen barrels I have owned. So that logic is some bolt float/slop is needed. This was tested using the same stock, trigger, barrel and torque and repeated the test many times. I did this because the Summit inconsistency from round to round was driving me insane on the same barrel which were 1/8" grouping and then move to the Summit and boom 1/2" groups with the same ammo in the same trigger and stock. Tune it and back to 1/8" groups, but the other ammo that delivered similar groups, boom 1/2" groups... made me nuts. Only explanation was no bolt slop.
I ended up doing some trickery to allow the bolt to have a tiny bit of slop. I drilled out the linkage on my Gen 2 shown in the first pic so that two silicon o-rings sit in between the linkage shown above and the bolt pin. The o-rings provide enough resistance for thin rims and is forgiving enough for thick rim rounds.
I will say half way into the mod I panicked about "what if it didn't work", I've trashed a Summit, but it worked and even smoothed out feeding. The net is that my Summit now has about the same bolt float as the semi now and now also deliver the same consistency. 1/8" barrel shoots as well across is wildly less picky about what it will shoot well and there is no linkage stress from the bolt locking out on an oddly thick rim.