mysteries of 22lr--part 3

[stagpanther]

While looking through my spare barrels rack I came across a Lilja 9 twist 22lr match chambered barrel I ordered years ago when I had embarked on a fantasy of loading my own high BC solid bullets and shooting long range.



That fantasy went down in flames as an abject failure; whenever I got into higher pressure territories the cases would often blow out--mostly because the firing pin was impacting right next to the relief slot cut out for the extractor, and the match chamber's tighter dimensions allowed pressure peaks to easily exceed what otherwise would be OK in a conventional chamber. Even when doing lower pressure loads, the results were hardly competitive with patterns I get from my 12 gauge shotgun.

The barrel was not cheap, and I decided to give it one last attempt before mounting it on my wall of shame (which has lots of trophies on it). I decided to load up CU's smallest 32 grain solids which they say should work well in conventional 16 and 14 twist (I previously had tried all of the projectile weights) and not get greedy, just try an average load.

Same result, a very wide pattern (shooting at 153 yds). Some of the dispersion was due to shooting in windy conditions as it was blowing 15 mph in a crossing tailwind, but I'm talking like dispersion of 12."

That was it, it was time to yank the barrel and scuttle it once and for all.

I just so happened to have a spare box of Tenex in my range bag and decided to see how badly it shot compared to the solids. I shot two 5 shot groups side-by-side though I couldn't see where the shots were landing through the scope. When I walked to the target I couldn't believe what I saw--the first group was under MOA and the second was right at MOA.

What the heck? how is it possible this stuff shoots so much better than the solids--which is what the barrel is for at faster twist? And shouldn't the faster twist result in reduced performance of conventional close-to subsonic lead bullets? My other CZ jaguar is extremely accurate (by my standards, anyway) but only when I shoot in near-calm conditions, I would never waste premium ammo long-distance shooting in any kind of winds over 7 mph or so.

Is it possible the faster twist actually helps improve performance and maybe even wind-bucking a bit of conventional lead 22lr ammo? I did a bit of googling for net wisdom and I'm not the only one who has encountered this counter-intuitive phenomenon.

I found this on Sniper's Hide and it might give a second lease on life for my barrel--or at least a new fantasy for me to indulge in.

here's Mike Bush of Vudoo Gun Works on fast twist and barrel length (Post #27):

"It wasn't long ago that no one really cared about the BC of the 40 grain projectile used by Lapua, Eley, etc., but now, Lapua publishes their BC (not sure if Eley does). This is because the community started stretching the legs of the 22LR and Lapua was the first to respond by teaming up with us prior to intro'ing the V-22 to market. They developed two custom drag curves and made it available in the Lapua and Applied Ballistics apps so we could calculate firing solutions the same way we do for centerfire. Looking at the BC and doing the math to determine how much of it we're using by way of the twist rate, it became clear that out of the available .172, only .120-ish was being used with a 16 twist barrel. Working the math backwards, the solution for using all the available BC in the 40 grain bullet was considerably faster, I was astounded and questioned whether I did it correctly....so, I did it again and came up with the same answer. So, we made a few barrels. Two barrels were fit to two different actions but not at the same time. The first barrel was 18" and ultimately, it shot like crap, which was discouraging. Digging a little deeper and creating a few models to look at angular velocity vs muzzle velocity, etc., the conclusion was the barrel needed to be longer at this particular twist rate. I chambered up a barrel finished at 22" and tested initially at 50 yards. The improvement over the 18" barrel was vast....I remember looking at the first five shot group and saying out loud, "son-of-a-bitch!" After a few more groups, I handed the rifle off to Bob (whom is a sponsored shooter and does the testing based on our specific protocol) to shoot the strings of 500 round tests. The first 500 rounds is broken down into 100, five shot groups at 50 yards. Just over 90% of the groups were beautifully round and measured just over the diameter of the bullet. Amazing....but it got better. The groups at 100 were easily half the size of average groups from a 16 twist barrel (16 twist barrel was 18"). I continued to shoot this rifle for over a year and performed a silent test in September at the NRA World Championships (teamed with Lapua for the third consecutive year). We had numerous targets, all steel plates at varying distances. I took numerous prototype rifles for the masses to shoot so I could observe third party testing without the shooters knowing what was new/different and I called wind on every target for three days in a row. The groups from the fast twist barrel at distance were amazingly small and I had to call wind differently compared to the slower twist barrels. A week later, I handed the rifle off to Daniel Horner for a longer term test, but I had enough data to make more barrels ranging from my single digit favorite up to 15 twist. Bottom line is, the fast twist barrel is an absolute superstar at 22"."

I had the Lilja barrel re-crowned (I dinged the muzzle) and it measures about 21.5".

[tangolima]

Elegant rifle! 1moa at 100yd? That's very good. The best I could do, with barrel tuning and all, is 1.2-1.5moa. Hey, if it works, it works, fast twist or not.

-TL

Sent from my SM-N960U using Tapatalk

[stagpanther]

New problem--the production lead bullet ammo--because it's generally lathered with goo of some sort--often leaves the case stuck in the match chamber after firing--especially Lapua's. Bummer, I thought I finally had discovered the barrel's true calling. The least likely to get stuck is Eley's.

[tangolima]

Try putting some lube on the casing. 22lr came in grease / wax in the old days.

Perhaps the extractor can use some refitting. My marlin used to do that. I refitted the extractor for better engagement angle and sping-out.

-TL

Sent from my SM-N960U using Tapatalk

[FrankenMauser]

Interesting results.


My son's new Kidd barrel won't extract unfired Eley or Wolf.
Must be fire or manually extracted. (If you shoot much .22 LR, as those of us responding so far do, you need this tool: https://aandjsporting.com/the-extractor/)
Was a bit of a burden in our last national level match, where *any* shot fired off the clock was an ND and match DQ. The classic was not allowed, "I've got a live one chambered, I'm gonna send it."
Had to ask permission on every stage where he timed out with a live round chambered - or, when we were unable to ask for whatever reason(s), use the above linked tool (which is great).

My Marlin 880SS has a rough chamber. Once the machine marks get filled in with wax, it doesn't like to extract anything. I've optimized the extractor as much as I can, but the roughness of the chamber trumps it. I need to fix that.

The barrel was not cheap, and I decided to give it one last attempt before mounting it on my wall of shame (which has lots of trophies on it).

I have a "barrel of shame." There are a few complete rifles and shotguns in there.

[stagpanther]

It seems to be a problem more likely to happen with tight match chambers; what I think is going on is with successive cycling and firing more lubricant gets deposited on the chamber walls increasing the likelihood of the case jamming. I think case rim design might have something to do with it as well since the Eley ammo I used did not leave cases in the chamber and the others did; especially Lapua's, which is a huge disappointment since I just started using Lapua's better stuff. Thanks for the tool reference--I was thinking of making something like that myself since I don't like inserting a ramrod down the barrel a la muzzle loader to get the case out. I don't know about other rimfires--but the CZ bolt's and chamber face topology on the CZ has the slot for the extractor right next to where the firing pin impacts--which I consider a bad design feature since that creates a spot of weakness for higher pressures and also deforms the rim upon firing pin impact. This generally is not an issue with CZ's own larger dimension chambers, but with the tighter chamber on my Lilja it is.

[Spats McGee]

I haven't been around here much lately, and I missed what kind of rifle that is. I'd love to know (hint, hint). I, too, am exploring the mysteries of .22LR. I'm just not as far down that road as you.

[stagpanther]

I have two CZ 457 actions--one which I retained the CZ barrel--my Jaguar--and this one which I put a Lilja barrel match-chamber fast twist barrel on. Although it shoots well--it has its quirks which make for annoying stop-and-go shooting to clear cases with some ammo. I put both actions into KRG Bravo chassis and did yo-Dave spring jobs on them--I find that it is essential to get the triggerpull under 1 lb for long range precision work. You can easily sink as much money into a precision 22lr rig--if not more--than in a conventional larger caliber bolt rifle. To me the CZ is a reasonable start point in keeping costs down compared to a real custom rifle; sorta like the Savage actions of the rimfire world to me. But increasingly manufacturers like Kidd and Vudoo are offering complete custom builds that are very cost-competitive to a "do-it-yourself" build--and in the 22lr world the pressure for real performance is extreme--great for the shooters. Me personally 22lr shooting is an essential skill-building base for all other types of shooting that I do (not saying that I have necessarily gotten any better at any type of shooting, LOL).

[Spats McGee]

Originally Posted by stagpanther

I have two CZ 457 actions--one which I retained the CZ barrel--my Jaguar--and this one which I put a Lilja barrel match-chamber fast twist barrel on. Although it shoots well--it has its quirks which make for annoying stop-and-go shooting to clear cases with some ammo. I put both actions into KRG Bravo chassis and did yo-Dave spring jobs on them--I find that it is essential to get the triggerpull under 1 lb for long range precision work. You can easily sink as much money into a precision 22lr rig--if not more--than in a conventional larger caliber bolt rifle. To me the CZ is a reasonable start point in keeping costs down compared to a real custom rifle; sorta like the Savage actions of the rimfire world to me. But increasingly manufacturers like Kidd and Vudoo are offering complete custom builds that are very cost-competitive to a "do-it-yourself" build--and in the 22lr world the pressure for real performance is extreme--great for the shooters. Me personally 22lr shooting is an essential skill-building base for all other types of shooting that I do (not saying that I have necessarily gotten any better at any type of shooting, LOL).

Thanks. I'm just starting down that road, but from what I can tell, you're absolutely right about CZs being a good starting point. Lotsa gun for the money.

[stagpanther]

Got really deep in the weeds this morning after shooting some fairly wide groups in the 2 MOA or so range at 153 yds and discovered some revealing things about this particular barrel and ammo used in it.

Taking a bore scope look I discovered there tended to be a heavy lead abrasion deposit at the head of the throat after shooting--much more so than I see in my regular non-Bentz chambered barrels. This morning I decided to see what difference it would make single hand-feeding, Tenex was the easiest but still was a tight fit--I had to get the cartridge as straight aligned as I could prior to closing the bolt. Lapua exact and RWS 100--which are outstanding performers in my other barrels were so tight I'm guessing lead is possibly being shaved off the bullet as it enters the chamber. Neither of those two got accuracy results approaching that of Tenex. I don't think it's because Tenex is better ammo than the other two--it likely is that it simply has a slightly better fit to the chamber. It also is the only one of three ammos that doesn't leave the case in the chamber when extracting the brass after the shot. Because the magazine presents the bullets at an angle, I also think it is quite likely the bullets are being deformed at the chamber face when going into battery from the magazine. Tenex clearly bested the other ammos repeatedly, turning in one especially nice group of the 3 groups I shot.

[stagpanther]

Winds dropped to near calm this evening and I grabbed the 22lr--I also was able to get a rare chance to shoot longer distance. I ended up at 239 yds. I didn't clean the bore from yesterday's shooting--maybe should have since only the first 5 shot group was pretty tight--the next two groups opened way up to to between 4 and 5 inches. The bolt got noticeably harder to close so I figure I fouled out.