LA101 head space

[Adzy]

Had my LA101 checked for headspace , a 0.02 shim was added and this is the result . Less flyers than I would expect to see at 50 yards 5 rds SK Pistol match green . Extremely happy with the results.

[Larry]

what do you mean a spacer was added? Where and how?

[Adzy]

The LA101 bolt has the three lug locking ring on the bolt handle , the clearance between the bolt face and the rim of the .22 cartridge is adjustable with shims specially sized in a kit ( 0.02 , 0.03, 0.04 ,0.05 ) from triggershims.com .

[Larry]

Yes I am somewhat familiar with the bolt it is a rear locking but where do the spacers go?

[Larry]

Ok went to the website you mentioned and saw the bolt parts diagram. Thats a nice little adjustment certainly has done the job for you.

[Adzy]

I have been reading about this clearance being a potential improvement due to the strike of the firing pin being deeper causing a more consistent firing of the rimfire cartridge. The .22 Precision Rimfire competition leave no stone unturned in the pursuit of accuracy, it pays to do some research on what the top shooters are doing .

[Boundry Rider]

I have been reading about this clearance being a potential improvement due to the strike of the firing pin being deeper causing a more consistent firing of the rimfire cartridge. The .22 Precision Rimfire competition leave no stone unturned in the pursuit of accuracy, it pays to do some research on what the top shooters are doing .

No doubt this will cause a ruffle
Better penetration from modifying the firing pin imprint. Don’t waste energy deforming the rim where there’s no primer paste, and by not deforming the rim the case rim stays true against the barrel.
Before on the left, after on the right. CZ452 22LR, Savage 93 17HMR and CZ455 17HMR.

[allan]

The .22 Precision Rimfire competition leave no stone unturned in the pursuit of accuracy, it pays to do some research on what the top shooters are doing .

True! 22LR head space is but one part of the jig saw when it comes to extracting maximum performance. I use SK/Lapua exclusively and my 22LR builds are head spaced at 042/043 to accommodate that brand rim thickness. Consistent ignition, chamber dimensions, bedding and crown all play their part. The quality of the barrel is the key as not even the big name brands are all created equal!

Bottom line...The 22LR, no matter the build quality, will only shoot as well as the ammo it is fed - Lot testing the expensive stuff is both time consuming and costly

I've got one of those shim kits here for my B14R - It's still in the spare parts box as this particular rifle is shooting so well, the only way I could improve it is to do a full build and I'm happy to use it as received.

Better penetration from modifying the firing pin imprint. Don’t waste energy deforming the rim where there’s no primer paste, and by not deforming the rim the case rim stays true against the barrel..

Definitely worth doing regardless of brand or cost - Good looking FP strikes you have there!

[Adzy]

I understood the rim contains the primer ,and it’s spun into the space during manufacture.

[bladeracer]

I understood the rim contains the primer ,and it’s spun into the space during manufacture.

Yes, that's correct.

[Bills Shed]

You are going to have to explain this to me. I see that they are deeper and smaller . The firing pin indents seem to have moved more to the centre and away from the rim and the firing pin marks are visibly smaller. Did to change the firing pin as well? . As the priming compound is in the rim, why move away from the rim? My 101 shoots beautifully and I am not going to stuff with it.

[Boundry Rider]

Savage was the worst, look at the poor imprint on the case. Many non fire episodes. Was 1MOA> and fliers 1 in 8 shots, now it CAN achieve 1/2 MOA 5 shot groups with infrared and better with glass optic. 455 was similar with the fliers, the 452 was already pretty good but now is excellent. These are hunting rifles not target. These HMR are for me to achieve head shot/ and or ethical cull bunnies all night to 120Y. The .22 is for parrots and lorikeets from 30-90Y in trees on orchards with winsub hollow points. No room for fliers and underperforming firearms.

First; primer paste is contained at brass thickness inside the rim. Primer paste is required to be crushed fast and consistently. So why crush the brass outer edge as well? Shift the impact inside the edge and crush primer paste and not brass edge.
Second; less surface area on firing pin equals more impact pressure. So much so that you can actually lighten your firing pin spring (to reduce your lockup effect) and still have consistent ignition.
Third; look at your fired case after a bladed firing pin has impacted it. You will have an imprint under the rim where the rim sets against the barrel chamfer. So crushing the rim affects the alignment of the brass case inside the chamber prior to powder ignition and seal. Why pay for headspace resetting when your bladed firing pin is drop kicking the case across the chamber prior to ignition? Impact inside the rim and keep the case square in the chamber.

Firing pins are cheap and are metallurgical construction, light stone, diamond file, emery paper etc. Choose your own method if you wish to modify yourself. And for all the naysayers, look at the imprint of a combination single shot (.410/.22LR) on a .22 case. It will be inside the case edge as it is impacted by a center fire firing pin offset so this isn’t new science.

Hope this helps others.

[Boundry Rider]

Also, deleting fliers includes tap tap tapping under your magazine after you’ve been tilting your rifle all over the place so the powder lies at the bottom of the case for every shot.

[JohnV]

I am not very conversant with making rimfires shoot extra well other than a basic bedding and trigger job worked mostly on centerfires but I did notice that my Brno 2E has resistance as I close the bolt more so than other Brno's I have come across . So one day I chambered a round then took it back out and I could see that the bullet was actually engaging the lands slightly . This led me to believe that this may be the main reason my Brno shoots better than some others I have seen .
Not better than a Mod 1 I have seen but pretty close to it .