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-   -   Range Report on CZ-455 With New 1:9 Twist Barrel Liner (http://thehunterslife.com/forums//showthread.php?t=19602)

gitano 09-17-2017 07:07 PM

Range Report on CZ-455 With New 1:9 Twist Barrel Liner
 
So as some of you are aware, even though I have a couple of Ruger 10/22s that shoot the Aquila SSS cartridge pretty well, http://www.thehunterslife.com/forums...ad.php?t=19492 I have been trying to 1) get a 1:9 twist barrel for a .22 RF bolt gun, (http://www.thehunterslife.com/forums...ad.php?t=19507), and 2) get a subsonic load for the .22 Hornet. (http://www.thehunterslife.com/forums...ad.php?t=19575) And here is another thread about the purchase of a CZ-455 in pursuit of #1 above. http://www.thehunterslife.com/forums...ad.php?t=19596

As I mentioned in one of those other threads, I found a fellow that makes .22 RF barrel liners with 1:9 twist rifling, and ordered two (his minimum). I installed one in an old milsurp 8mm take-off barrel. (The 5/16ths (0.312") OD of the 27" liner fits 'perfectly' in the 8mm (0.315) bore.) A little epoxy, and voila'!, I have a .22 RF barrel, 23 inches long, with 1:9 twist rifling, that I can machine to fit a CZ-455 receiver!

After doing all of the liner installation and machining the breech for the 455, the initial shots were pretty darned poor. I was certainly disappointed. However, after doing a little detective work, I was able to find the problem and fix it. (It was a burr INSIDE the muzzle. Still not sure HOW that happened, but it ain't there now, I assure you!) The next shots were "OK", but nothing to 'write home about'. There were two possible causes for the mediocre groupings: 1) The liner was just "mediocre" :(, or 2) it just needed to be "shot in". Hoping for the latter, I have been putting some bullets through the barrel for the past two days. Yesterday, I put some "diamond dust" on five rounds and shot them first. (That's how I found the muzzle burr.) After fixing the burr, I shot 50 rounds of some bulk Winchester, copper-washed bullets, with a advertised MV of 1280 f/s. Again, nothing special about those groups. But then I wasn't expecting anything special from that ammo. Although, if you look here: http://www.thehunterslife.com/forums...ad.php?t=18863 you can see that that ammo shot pretty well from all three of those rifles.

So today, I decided to put another 50 rounds through the barrel for some more "sweetening" of the bore as j0e_bl0ggs would say. This 50 would NOT be copper-washed, but rather "lead with wax". I chose to use CCI Subsonics with an advertised MV of 1080 f/s. j0e_bl0ggs also suggested that since my real interest was in the Aguila SSS, I should shoot some SSSs before I shot the CCIs, and then again after I shot the CCIs, and see if there was any improvement. So... I shot 10 SSSs, then 5 Norma subsonic rounds, then 25 CCI subsonics at one point of aim, and 25 at a second PoA. Then 5 more SSSs and 5 more Normas. Here are the targets.
The first 10 SSSs:
https://s5.postimg.org/c6n7z14hz/Run..._Before-sm.jpg
I adjusted the scope after the first 5, and "settled down" a bit too. Notice the "1-in-5" flier! :angry:

The first 5 Normas:
https://s5.postimg.org/gwd5nmvif/Run..._Before-sm.jpg
There are 5 shots there, I assure you.

The first 25 CCIs:
https://s5.postimg.org/ujnt9leyv/Run..._1st_25-sm.jpg

The second 25 CCIs:
https://s5.postimg.org/6h6zepybr/Run..._2nd_25-sm.jpg

The "after" Normas:
https://s5.postimg.org/svonuy13b/Run...S_After-sm.jpg

And the "after" SSSs:
https://s5.postimg.org/689eosljb/Run...S_After-sm.jpg
A nice group, no doubt, BUT... Notice the "1-in-5" flier AGAIN!

It certainly looks like things got better. HOWEVER, I must point out that after I finished shooting all of the CCIs, I was not comfortable with my "hold", and I changed my shooting rest from a 1-point system (support only at the receiver just in front of the magazine), to a two-point system (support at the receiver AND support at the butt). The two-point system was a bit steadier. SO... some of the improvement seen might be due to the better rifle support. However, I don't care. Those groups are GOOD. :D I'll take them from a barrel I "made"! ("Made" = Installed liner and machined breech for CZ-455 receiver.)

I think I have found my bolt action, "long" barreled, fast twist, .22 RF rifle that can shoot the Aguila SSS with a precision I am satisfied with.

Paul

PS - I don't have any SSS MVs to report yet though.

Paul

gitano 09-25-2017 09:43 PM

Re: Range Report on CZ-455 With New 1:9 Twist Barrel Liner
 
After seeing the groups in this thread http://thehunterslife.com/forums/sho...044#post149044, it's a little embarrassing (but... the truth be told, I'm too old to embarrass that easily), to post these pictures, but "it is what it is".

These groups were shot at 25 yds with a new Timney trigger on the CZ-455. The factory trigger wasn't terrible, but it wasn't exactly "match" quality either. The Timney wasn't terrible price - $94 delivered to my door - and it was easy to install. No inletting required on the wood. Very parsimonious "instructions". NO text, only photocopied "diagrams". But it was not too difficult to get it installed and adjusted. (NO instructions on how to adjust the pull and travel. :mad:)

ONE of the SSS fliers (the high one) MIGHT actually have been operator error. The rest are "good" aims and 'releases'. All in all, I guess this ia about as good as it's going to get with this re-lined barrel. Maybe it will 'season' a bit more. To date, it's had about 175 rounds through it I think. I will reinstall the factory barrel and shoot some more of the lighter weight subsonic stuff - Norma, Remington, and CCI. Don't have to worry about their gyroscopic stability.

Well... "postimage" has been "down for maintenance" for several hours. When they come back up, I'll post pictures of the targets.

Paul

Pictures from photobucket:

http://i122.photobucket.com/albums/o...pst6ucgins.jpg
This one is from the Norma ammo. Nothing to write home about, that's for sure.

http://i122.photobucket.com/albums/o...psngotqxsw.jpg
These are the SSS groups of 5 shots. The first 5 had a low aiming point because the FIRST shot on the sight-in targets below, was to see where the gun was hitting since I had been working on it. I THOUGHT it was hitting high. Clearly it wasn't. Also, not a very good group. BUT.. the other two groups of 5 aren't TOO "bad". That third groups has the two outliers, one of which (the upper one) MIGHT be operator error. The lower flier is not OE.

http://i122.photobucket.com/albums/o...psjf6vtvuo.jpg
The top shot is, as I mentioned above, the first shot out of the barrel after installing the new trigger. The barrel was removed and reinstalled in that process, so I thought it was worth "sighting in". Based on that shot, I adjusted my point of aim (not the scope) accordingly for that first group of 5 for the SSS.

The LAST three in this picture are the last shots taken. All the SSSs and Normas had already been fired and I had 3 SSSs left in the box and decided to shoot them at three of the four remaining sight-in targets. Those three would have made a very respectable 3-shot group.

I think the 'bottom line' is that this barrel won't get any better unless it "seasons" with continued shooting. I don't think there is anything that I can do - recrown the muzzle or rechamber - that will actually make it shoot straighter. C'est la vie.

Paul

recoil junky 09-25-2017 09:57 PM

Re: Range Report on CZ-455 With New 1:9 Twist Barrel Liner
 
Timneys adjust just like the old Remington triggers. Or so I've been told.

RJ

gitano 09-25-2017 10:08 PM

Re: Range Report on CZ-455 With New 1:9 Twist Barrel Liner
 
It was "figure outable", but there were NO instructions about adjustment. That seems "not right" when one purchases an aftermarket "match" trigger.

Paul

PS - After looking back at the first post, I think maybe this barrel needs some more ammo through it to "settle it in" (not "season") after having been taken out of the receiver. It might take a "little bit" of shooting to "settle" it in the receiver. OR, I might take the stock off, and torque the grub screws that hold the barrel in the receiver down a little more.

Paul

recoil junky 09-25-2017 10:13 PM

Re: Range Report on CZ-455 With New 1:9 Twist Barrel Liner
 
Then there's that :undecided:

RJ

j0e_bl0ggs 09-26-2017 01:50 AM

Re: Range Report on CZ-455 With New 1:9 Twist Barrel Liner
 
It apparently is quite normal for a rimfire to need 'seasoning' after a clean etc. Bit like a cast iron pan!

gitano 09-26-2017 12:05 PM

Re: Range Report on CZ-455 With New 1:9 Twist Barrel Liner
 
Didn't "clean" the barrel. Just took it off and replaced it.

Paul


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