Headspace your Bolt

[cajungeo]

The out of the box 10/22 has a head space aprox. .055”. The Rim of the 10/22 LR is .042” the extra space causes fliers. The headspace can be adjusted, but should not be attempted unless you have experience in machinist type work, and have worked to precise tolerances. If you do not have the experience stop here, and check out this gunsmith. He can do it for you. DRC (http://www.drccustomgunsights.com/)

If you exceede the .0425" headspace Ramfires are likely. Do not use bolt if you mess up. Better to buy another. If you go too deep and ruin your bolt. You can buy another from Ruger for $25.75.

A mill mach is preferable. I used a stationary disc sander using a carpenter square to check disc set at 90 degrees to table, and to feed the bolt square to the disc. Use a fine sanding disc.

First check the butt end of your calipers (use as a depth gauge) on a hard surface to insure it is calibrated to zero. Note: it may not be the same as the jaws zero! Adjust calipers to make it so.

[cajungeo]

The object is to achieve a headspace of .0425” with face square and polished.

Drive out the firing pin roll pin and firing pin spring. Remove extractor, and spring.

Measure depth of your bolt headspace. Mine measured .055”. Lay bolt on its topside, and slide along the carpenter square as a guide. By feeding, cool in water, checking depth, and face square proceed to .044” This will leave you .0015 to polish disc marks out, and smooth bolt face. I had a coarse disc, and there is still some marks left, but face is smooth, at a depth of .043. I used a dremel polish wheel, and toothpaste as lapping compound.

Now you must check your firing pin so as not to protrude past the new bolt face. It wouldn't hurt to be a couple thousands shorter than the bolt face. This is in the full fwd position. Remove material from rear of pin, and re-check. I did not have to shorten my pin. If you do not shorten your pin you could end up with a a slam fire or face full of hot powder! :eek:

[cajungeo]

While you have your firing pin out, smooth up its surfaces. It comes from Ruger very rough. I smoothed firing pin with 220 grit, then 320 grit sand paper. Also there is a burr in the fwd end of the firing pin slot. This can cause your firing pin to ride up. Remove it with a jewlers file. Ref photo.

The final result. Headspace .0425” - .043” will increase accuracy. :D

[cajungeo]

Results from the Bolt Headspace Mod. Your mileage may vary.

Ok I'm back from testing the head spaced bolt I did on my target rifle. Using my benchmark ammo, the Winchester Dynapoints. I fired 30 groups of 5 @ 25 & @ 50 yds. for a total of 150 rnds Wind gusty 12 mph from 7:00. Here are the results.

(1) Gone are the occasional lite round, the drop in flier. There were none!
(2) Over all groups shrank an average of .1". Worst group was .585" with 1 flier opening it to .748". Best group was .124" with a flier opening it to .342". This average was at 50 yds. At 25 yds., there was mostly 1 raged hole. :D

There were still some fliers using the Dynapoints, but they were mostly the high ones. At this stage the only improvement I would hope to gain from using this ammo would be to sort by measuring rim thickness, and weighing. I have tried this in the past. It is tedious. It is time now to move up to match ammo. :D

Note. When you do this mod, always, always check firing pin protrusion in the full fwd firing position. Do not fire your rifle if pin protrudes past the bolt face or you may get ram fires or a face full of hot powder! :eek: I checked both my bolts. I did not have to remove material from my firing pins. I do get a heavier pin strike on the case rim. I may not worry about installing the anti float pin for the firing pin now. :D