Josh, thanks for taking the time to do all of this work to show how headspace affects accuracy. I appreciate it. Blessings

Now you give me Heartburn of a different sort....way past age 70 thinking I knew it all "YOU ": come along and start teaching me things I never knew. Keep it up , I and my Saturday morning Breakfast Pals love discussing the new things we learned this week...Thanks from Central Texas

Great channel, interesting results

Very interesting test, thanks Josh!

Very nice glad you secured the target board.

Hi Josh, Great video. I just put a new barrel on my Walther KK 500. To me it seems like you had to dance with 3 numbers for the install. 1. Head space 2. Shoulder depth and 3. Bolt face to barrel face clearance. I spent the time to understand what those numbers were before i removed the old barrel. This proved to be very helpful. Thanks my friend for your videos.

Thanks for the upload. I didn't even know you could change the headspace in a 22.

Impressive, very impressive! The shims do improve, i would like to see my New CZ 457 when i get it! Thanks Josh!

You are becoming my favorite quick. I like my CZs but we only have sporter style gun matches where I’m at.

Good test! Thanks!

Fiy. I used a 18 inch lothar barrel on mine didn't have the shim option but it shoots incredibly good. Great video. Impressed by your content.

I got my Lilja barrel in. Thank you for this video and the instalation video, helped out a lot. Edited 😆

Awesome content man, im in. Subbed. Love my CZ 457 LRP.

Like all your casts . Keep it up

Good video! I checked my Lilja shank length after rechecking calibration on depth gauge. I was 1.198” two thousands off the listed 1.200”. That being the case I went with the new number and did the math. I set up for .041. It worked well with Tenex and did a .244 5shot 4 group average at 50

Good insightful video, as always. Never a waste of time checking in here and looking over your shoulder. I'm jealous of all the trigger time you get to squeeze in. Going to have to try harder to do the same. LOL

Great content. I watch all your videos, two thumbs up.

Loving this content. Keep it up!! 👍🏻👍🏻

Thank You for telling me about them just ordered 1

Good shooting , much fun !

Awesome video. I do have a question. Do you think the groups opened up on the top targets because of a cold bore? I love the way you play with settings living up to your channel name.

It seems like maybe the second five in the mag shot better than the first five? I’d love to see this excellent trial repeated using five shot magazines. Thanks for doing this experiment. Regards Robert ( just bought a CZ 575 😊)

thanx for the info. i would go with the .44 consistency is important, might add a tuner tough

Josh what tool are you using to measure your receiver/bolt depth? Thanks Dave

Thanks for the great videos. I have a question but don’t know if a better place to ask it. Do you ever have issues extracting fired rounds out of your Lilja? I have a Lilja fitted up on my 455 and it occasionally has issues extracting fired rounds. Thanks.

Thank you. I wish you had the crono on so we could watch sd and es numbers for a more detailed study.

From what I was told with the local 22 target shooters. Shim's are not a good idea to use for any headspace. I do not have expirence yet with the 22 barrels, though I have seen shims used causing accuracy issues. Barrel torque will play more affect on accuracy with a tight headspaced barrel. Talking with Manson reamers, the 22 Bentz chamber was designed to give just enough engraving on a Lapua Center X or Midas + Ammo, yet allow extraction still. Headspaced at minimum. Barrel torqued to 70-80#. Im nearly done with my RimX build to give this a shot

Strictly speaking the first two groups shot with the 0.045 heads pace was at an advantage to the others in that you fired a group to warm the barrel then immediately proceeded with those two groups. When you changed the headspace the barrel cooled but it appeared you went straight into the groups without warming the barrel again. I would also do this testing from some sort of jig / clamp to take human error out of the equation. Another aspect to try would be to measure the headspace on the rounds and sort them into different groups and then shoot groups with the same measured headspace. From my experience even Tenex has varying headspace measurements. Thoroughly enjoy your video's. Keep up the great content.

It’s amazing what that little amount does with accuracy. Love my mtr there lights out straight out the box

Thanks for the test, very interesting. How tight of a hold do you use with this rifle? Just wondering, I have to grip mine pretty tight to get consistent groups.

Headspace affects ALL calibers accuracy. Ive got a headspace comparator i use for 4 different calibers and matching headspace makes a WORLD of difference.

Great Video Josh ? where can I get that cheek riser

Josh in between changing the shims the barrel cooled down? Notice on the top first five they opened up and on the bottom they tightened up. So would it be wise to give it a little foreplay and shoot a few first to warm it up? Also I notice there was a little constant breeze as you did mention.

Josh, it's been a while since this video. It seemed like there was a lot going on in it. Wind, barrel cool down while changing headspace, target moving some... Just wondering if you ever concluded on an optimum headspace? I just ordered a Lilja for my CZ. I tend to prefer SK ammo. Did you find a headspace that worked best for SK to be different than Eley? What headspace did you settle on?

Great video. Thank you. What torque were you using on the stock to receiver each time. To keep everything consistent ?

I'm trying to relate this to sorting ammo by rim thickness and am drawing a blank. My issue is essentially the reverse, a fixed headspace in the gun with varying headspace due to rim thickness. Especially in 10/22's, this has a marked impact on accuracy, less so in the 457 as it seems to "crunch" the cartridge into a set space and equalizes the variations in ammunition to a great extent.

Very informational, thanks. What are your thoughts on shimming the bolt? Do you have any data that could compare shimming the bolt vs. shimming the barrel?

I too live in NC and have a CZ 457MTR and just getting to the point of modification. Did you bed the action or just keep it resting on the pillars?

One thing I've noticed that's often missing from these grouping videos is any consideration for shooter and target consistency. You're not going to get accurate representative group size measurements without either a very accurate shooter on the trigger or a super stable one-piece rest. You also need to make sure your target isn't bobbing around in the wind like it was in this video. Most folks are going to dial in their headspace through trial and error without taking actual measurements, so they'll need to remove as many of the other variables as possible to get accurate test results.

For accuracy, I would think you would like the head-space as tight as possible. The problem being that if the head-space is too tight, the primer may ignite when the action is closed. So, the head-space should be closed up until there is a slight closing resistance. But since rim thickness will vary, you could still get a primer ignition when the action is closed. Therefore, one should increase the head-space by one thousands. It would be safer to increase the head-space by two thousands - etc. Successful ignition of the primer is based on the hammer and anvil concept. When you have excessive head space, the rim of the cartridge may not be against the anvil when struck by the firing pin which, on occasion, may result in an imperfect ignition of the primer. So, you do not want excessive head-space. All and all, the standard .043 inch head-space usually recommended is probably best in most cases. I like that you ran this experiment, but when the wind started blowing your target back and forth, you were just wasting ammunition.

Is Eley Match and Tennex more prone to light strikes? At.043 head space and most but not a brands of ammo now eject. Now experience failure to fire. While firing pin imprint is substantial, occasionally I get a dud and won't eject. If fires on rechamber then ejection. Over 4000 rounds on bolt. Never removed firing pin.

my question is': seen and considered that as soon as he starts firing there is always the first distant shot, but the barrel is heated? Then do you shoot the same type of cartridges consecutively? (in jargon waxing) ...

Do you know what headspace is on the factory barrel?

There is a relationship between head space and rim thickness. The spec for 22lr rim thickness is .043 -.007. My CCI sv thickness varies between .040 to .043 If i sort and choose. 042 only . What headspace do i choose.

Where did you find that cheek weld piece on the 457? Looking for something to replace my scuba suit special cut neoprene DIY

Have you tried headspace shims on the B14r yet? The topic came up on the fakebook B14r page today, so I was looking for more shimming info.

How do you change the head space?

great content…..as an cz457 varmint mtr owner, i’m really liking your cheek rest….which one is it?

Good video. I know this isn't apples to apples comparison but my Savage 6.5CM shot better and better with smaller chamber headspace and did so consistently. So much to the point of me leaving it small and cycling my reloads through the rifle. My bolt won't close on some factory rounds and I am just fine with that. My loads are all I want in it anyway...

Which ammo has been your best so far through the lilja barrel. Was it eley match?

Good vid Josh. Wonder if sorting by rim thickness and playing with headspace would show any more improvement

Great content. What kind of chamber is cut in the Lilja barrel?

What is the cheek rest you have on the stock. I have a 457 MTR and I would like to look into getting a cheek rest like yours.

Are the shims put in the bolt ?

Josh, What was the rim thickness of the ammo?

Great video! What was your shim combination on .045 & .044 headspace? I also have a lilja barrel on my 457 trainer and have mine set up at .040 headspace also. Im using a .004" & .002" shim combination

Atta boy!

You mentioned you would drop a link to your video on how you did your Lilja head spacing, i did a search and could not find it . Could you please tell me what is the name of that video?

I just received my new Lilja barrel and man was it tight going into the receiver. I'm worried I'll have a hard time getting it out to change shims, what was the best way you found to remove the barrel? Thanks 👍

A problem I run into with every Lilja Barreled 457 action is this: The barrel hits the front of the bolt guide when there aren't enough shims in place. Just something I have ran into with three Lilja barreled 457's, especially when I set headspace at 0.039 or 0.038 for Tenex or ELEY Match. You can't fit a 0.001 feeler gauge and there are rub marks on both guide and breech. Does this effect accuracy? idk. Is this interference's viber-rayshuns repeatable? Probably not. Did the thought of knowing my bolt guide rubbing the barrel breech pop up in my mind every single time my groups were over 0.6" @ 100yd? ABSOLUTELY. And now it's not and that's all that matters to ME. I can now live with an moa group at 100 because I can blame it on the wind or ammo or something besides that interference.

Help me understand. I thought the headspace for a .22 rimfire was based on the rim of the cartridge. So wouldn't it apply the the recess in the bolt. Atleast that is what I thought on my 1022 ruger.

Hey Josh! Have you done any action torque testing on that rifle? What are you setting the action torque to on that CZ?

Hey man. I, just getting into reloading .22. Ive been reloading for about 20 years,,,,,, but how do you measure headspace on a straight wall .22 lr bullet?

Can't find any link in the description to find out the process of changing head space size?

I know you did this video earlier in the year, but I'm just watching it now. I have some minor criticisms if you don't mind. First, this is the kind of test that would be best done indoors at 50 yards, if you have access to such a range. It was clear that the wind was changing on you. Also, what is the rim thickness of the ammunition you're using? Average, extreme spread, standard deviation. From what I can tell, 22LR head spaces on the rim. So the ideal situation is when the bolt closes, the gap between the breach face and barrel face equal the rim thickness. Tighter would compress the rim (I know that is obvious) and looser would allow a tiny bit of slop. This leaves me with more questions than I can ask in this format. Either way, your shooting was excellent.

Ever do the rim thickness thingy, or bullet total weight?

For comparison, What is the headspace, as it comes from the factory, with the MTR Match barrel?

Started at .042, shot 28 different brands & lots with no issues. Repeated at .041 Match ammo (Lapua, Eley and even Federal) shot fine, but less expensive 22lr like CCI would not extract. Would you suggest going back to .042? Bolt closes fine.

How did you get the bolt action so smooth

Josh do you have your shim installation video available ? Thanks Dave

I just have a few 10/22's IV built...but great video ..if I ever have money for a REAL .22 ..LOL

What do you think about shimming the bolt vs the barrel?

Do you have the yodave bolt spring installed?

The differences between the groups are too small to be sure which head space is the best. The test would be much better if it was done at a 50 yard indoor range to eliminate errors due to the wind. The real world is not a good place to do this test.

Would you take the bolt out and measure the depth of the recess to the bolt face firing pin hole. Then explain how you can reduce the headspace below that dimension. What your video actually shows is you have probably reached the minimum head space at about 42 thou. After than all you have achieved is forcing the bolt to lock harder against the chamber face. That gap / recess in the bolt hasn’t got any smaller. So it’s still 42 - 43 thou even thou you think you’ve shimmed it at 39. Just not possible. There’s another variable and that’s the under rim to base of cartridge measurement. Note you cannot just micrometer the rim without taking into account the radius from the case cylinder. Head space does make a difference so what you need to do is remove metal from the mating bolt edge to reduce that recess. Then you could use the shims to adjust the space. However you need some headspace gauges to measure and be very careful you don’t get crush fires.

And the birds keep on singing despite all the noise.

Hey just curious. Do you notice a significant difference between head space on a CZ MTR barrel and a standard CZ 457 barrel

My MTR bolt is very tight when closing and it has been ever since I got it. I assumed it was because of a match chamber. I see you working the bolt with ease and I don't have that at all. There's no way of keeping in the glass when working this bolt and I'm sure that's not right...

I don’t mean this as an insult but I saw what someone said it could have been the wind… there was one where you opened up and the target was moving a lot. I think it was the third. Honestly from your video i would say there was no difference. I think either the top groups are off because the changes needed a few shots after each time similar to what you did at the beginning or something. I also wanted to mention that the savage b22 has adjustable headspace as well. I know you hate that rifle but just throwing it out there. I watched where you had extractor issues and I watched this a couple days later, you said some ammo gave you extraction issues on this rifle unless it was a certain headspace. Maybe that savage had the headspace off from the factory.

What happened to your CZ/lilja how to headspace video?

I would say this was more a factor of wind then headspace. Even just having the backboard more rigid would have made a difference. Frankly, I thought tighter headspace would have been more accurate to a point. Love the premise, not so much the execution. All your videos are interesting and entertaining, thank you.

Can you see a difference in accuracy between cz mtr barrel and lilja barrel?

Josh, as you were shooting, the target was actually moving die to the wind. Even if the shot was almost spot on the previous shot, the moving target essentially nullified the the ability to measure the precision.

I think the Massive movement of the target negates any information you get from changing the shims!

Seems to me that "all" you are doing is adjusting for the rim thickness from the manufacturer, so perhaps, before you fit shims, you should select, from the ammo that shoots best, identical rim thicknesses THEN add the shim ? Just asking, in no way am I picking for a fight :)

You are getting at least a half inch increase in your group size from the wind blowing your target around.

Your target flapping in the breeze will open up your groups far more than a headspace change.

AFFECT is the correct word.

If you accurately check the rim thickness on Lapua Center X, You will discover a .039 headspace is not possible with Center X.

GOOD SHOOTING, where we came from shooting like that was called “ Being vulgar “. SHOOT SAFE!!!!!!!

As soon as you said you were going to do the spacing off camera I turned your video completely off. That's half the right reason why we watch these videos is for eyes/hands-on experience and for people to teach us things

The moving target keeps distracting me. can't be accurate.

AFFECT.....not EFFECT.

Yawn!. Too boring. Speed it all up and show us the results. Thanks

Worthless test in the wind!