CZ 527 .223 conversion to .300 whisper

[blackwinch]

I was recently introduced to the 300 Whiper and am interested in converting my CZ 527. Does anyone have any good advice for me?
I've contacted SSK I was just looking for more feedback, help selecting a suppressor, barrel length etc.

[Artful]

I was recently introduced to the 300 Whiper and am interested in converting my CZ 527. Does anyone have any good advice for me?
I've contacted SSK I was just looking for more feedback, help selecting a suppressor, barrel length etc.

Places to start your research
http://www.sskindustries.com/ home of 300 whisper creator barrels & cans
http://www.silencertests.com/ suppressor reviews
http://www.atf.gov/ - your gov't reg's
http://www.srtarms.com/ - Doug has done custom barrel's w/ suppressors
http://www.ar15barrels.com/prod/300-221.shtml - Randell's custom barrels
http://www.corbon.com/ - 300 whisper factory ammo

Free Advice ! Need some answers from you first !
Decide upon how you want to use the gun, is weight important?, Do you see a need to shoot without the suppressor? Do you want the suppressor to appear as add-on to end of the barrel or be part of the gun and just look like a heavy barreled rifle? are terminal ballestic's important (ie hunting loads) or just punching paper and steel? you going to shoot close range only (out to 150-200 yards) or try for targets way out there (200+ yds)? going to do the SBR paperwork and $200 tax or have 16" or longer barrel? - keep orginial stock or go with a different one?

:confused: ;)

[blackwinch]

Sorry I haven't had the chance to reply but, thanks for all the links for potential info.
I never really gave much thought to the SBR, but nice one none the less...
My line of thinking is to have SSK re-barrel the little rifle with a 16" Shilen 1/8, and thread it.
I was thinking along the line of a Gemtech or an AAC but he, JDJ, mentioned that he too can provide me with a suppressor. As this is my first venture down this road I'm a bit confused how to go. I'm not too familiar with JDJ's silencers but, knowing of his reputation the product must be good and the other products stand on their own.
I don't see this rifle as being used only for paper punching, and I do know the limitations of this cartridge but, shots out to 200/250 are in the realm of possibility.
The rifle I shot that got my interest was a Thompson Contender G2 since then I started searching for a small bolt gun that I thought would work well for the project. When I found this hardly shot, in box CZ. So the purchase was made and the project planning began.
I want this to remain a compact piece, the original wood is nothing special but, does have some nice figure to it. I would consider a new compact stock but, the choices are limited. I know HS precision makes a synthetic varmint stock, and Boyd's makes a nice looking laminated stock. Beyond that the choices are limited.

[d-mon]

Hello Blacksmith,
Converting the little CZ is one of the most common transformation being done in france.
Take a look at the following link to see what can be done:
http://www.stopsontfm.com/ look for micro-anthis

Usualy, the CZ action needs to have its face trued up so that the shoulder of the barrel can rest on it (the factory usual mount is " a la Mauser" with the back of the barrel resting on an internal shoulder behind the threads, which is not the best for perfect alignement and concentricity).

Good luck with your project.

ND

[blackwinch]

I kind of wish you didn't tell me they were doing it in France. Australia, New Zealand, Italy but, France. It sure looks cute though. I'm leaning toward having JDJ/ SSK do the whole job and.

[blackwinch]

I did see that link in my research. I think I'm going to stick with JDJ/SSK to have the work done.

[d-mon]

That is the wisest decision, as exporting firearms (legaly of course) out of usa becomes a nightmare. Sometimes, some peoples forget that France and UK are part of NATO as well.
Good luck with your project.

ND

[Scoop]

Take a look at the one I just had done. I sent the barreled action off to PacNor for a rebarrel in .300 Whisper. I went with their 1:6.5 twist SS Supermatch barrel. To say I'm pleased would be an understatement. Haven't really put much time in on load development either, but the 220gr SMK on top of 10.6 grains of Reloader7 is giving me 1020fps and sub MOA groups. Hard to argue with that. I'm gonna play with some H4227 next week. I had SSK build my first Whisper (a TC Contender) and it was a good shooter, but I'm happier with this one from PacNor. The second picture is of the modification that must be done to the mag to allow those fat .30 cal bullets to fit in a .22 cal space (the bullets pictured are 220 gr Sierra Pro-Hunters). I had my local machinist modify the mags. Very simple to do. He just chucked it up in the end-mill and milled out the dimple. I had him only machine down so far so that the relief-cut doesn't show below the line of the weapon when the mag is in place. That dropped the mag capacity to four instead of five. No big deal.
http://www.hunt101.com/img/368063.JPG
http://www.hunt101.com/img/357840.JPG

[d-mon]

Very pretty.
But a twist of 1 in 6.5" seems very fast for these bullet. I thought the norm was 1 in 8"?
ND

[Scoop]

My 8-twist SSK Contender barrel did a pretty good job with the 220 SMK's. I never tried the 240 SMk's in it. It just seems to me that you can't over-stabilize a subsonic projectile, so I went with the 6.5 twist. Also decided not to deal with JD again, so I gave PacNor a shot (they've done an excellent job on other rifles for me) at the whisper. I am certaily pleased with the outcome. By the way, this 6.5 twist barrel also shoots 125 grain Sierra ProHunters (at ~2000 fps) into itty-bitty little groups.

[d-mon]

If you have the chance,
could you please show us one or two groups of the sierras 220or 240s, at 200yards (launched at subsonic speed of course).
That would be interesting. 5 shot groups should be enough.

Many thanks.

Nicolas

[Scoop]

If you have the chance,
could you please show us one or two groups of the sierras 220or 240s, at 200yards (launched at subsonic speed of course).
That would be interesting. 5 shot groups should be enough.

Many thanks.

Nicolas

Can do Nicolas. I'll be heading to the range on Friday afternoon. Should be able to post a few pics on Saturday or Sunday.

[blackwinch]

Now that is the kind of thing I've been looking for...
The real live shooting animal. Your logic sounds good after all you'll never shoot the bore out of a rifle shooting subsonic most of it's life. I see you started with a varmint / synthetic stocked 527 the rifle I'm starting with is a
wood stocked carbine. I would like to keep the rifle as a compact rifle.
I saw that SSK made an "Incognito" Mod 70 and was tinkering with having something like that made up.
I love what you've shown me and I'm getting more excited to get underway I have all the paperwork in hand just need to make the final decisions.
P.S.
What kind of can do you have threaded on the end?

[Scoop]

The suppressor is an AAC Cyclone. You can check them out here http://www.advanced-armament.com/default.asp

[Scoop]

Just got back from the range. Here are some pics as promised. These were shot from a sandbag rest at 200 yards. Load was 10.6 gr of RL7 with 205M primer and 220 gr SMK seated to 2.230 C.O.L. Only had 12 rounds of this stuff left, so you'll have to settle for 3-shot groups. Took me 3 rounds to get on paper at 200 yards (ended up with 16 moa elevation dialed in) so I opted for 3 more 3-shot groups. As a point of reference, the orange dots are 3 inches in diameter, the inner circle is 1.5 inches and the diamond in the center is 1/2 inch square. The group in the first picture measured 1.75 inches center-to-center of the farthest holes. Second pic is 2.25 inches C-T-C and last pic is .875 inches C-T-C. That corresponds to (in order of appearance) .875 moa, 1.125 moa and .438 moa for an average of .813 moa. Not too shabby. Ended up playing with some 190 gr SMk's on top of 8.6 gr of H110. Didn't get any pictures, but this load shows great promise. Average of four 3-shot groups at 100 yards was .750 moa.
http://www.hunt101.com/img/367950.JPG
http://www.hunt101.com/img/367949.JPG
http://www.hunt101.com/img/367952.JPG

[Scoop]

Here's some updated pics with the new Optics. Leupold MR/T M1 Illuminated TMR Reticle.
http://www.hunt101.com/img/368065.JPG
http://www.hunt101.com/img/368064.JPG
http://www.hunt101.com/img/368063.JPG

[blackwinch]

My conversion is underway...
Hoping to come up with a real nice piece.
Pics will follow when I get it back.
Of course I'm going with 1/8 twist and all the details of the work done will be disclosed as it comes along.

[Artful]

Very pretty.
But a twist of 1 in 6.5" seems very fast for these bullet. I thought the norm was 1 in 8"?
ND

1:8 is minimum for heavy slow bullets - lots of barrels have more twist that required - usually doesn't cause a problem - only one i KNOW of was a 220 swift shooter and his bullets were coming apart in mid-air after he rebarrel with a faster twist. But hey that varmint bullets going very fast.

[blackwinch]

I'm looking to have a barely stable 220 or 240 gr bullet on impact.

[Wrangler]

I have becoem very interested in this type of project. What can I expect tp spend to get a reliable one together? I have a stag lower to work with.

[blackwinch]

What I'm building is a different animal. My project is a cute little bolt gun but, there are some choices in the AR area to be had...
Try the following:
http://www.model1sales.com/
http://www.olyarms.com/
http://www.pac-nor.com/
http://www.rockcreekbarrels.com/
http://www.ar15barrels.com/
These aren't in any specific order but, I'm sure any of them would love to help you.
I know that Olympic and Model 1 seem to be listed in the forums and have 300 fireball/ whisper/ 300/221 in their ads but, just ask and you might be surprised who else will do the work for you.

[nixer]

any pricing yet on the actual conversion

[blackwinch]

I got some price quotes and to be honest with you I don't remember...
I sent the rifle to Mike Rock at Rock Creek bbls to be re-barreled, fluted, threaded, chambered and have the stainless blackened...I'm actually going to call him today to inquire about his progress...
I'll be sure to keep everyone updated.

[Buckshot]

My advise to you.
16 inch Heavy (posibly fluted) barrel with a quick detach system (like Gem-Tech)
Barrel I use for my SIG SWAT is a Lothar Walther barrel with a twist of 1/8".
Perfect for shooting subsonic ammo.

Currently my gas vaulve is beïng adapted to make the gun cycle with "Sub's"
That is Why I am not having any foto's yet.

I will post them as well when I have them.

But the Lothar Walther barrel I use looks great!!!

Good luck with your setup.

Buckshot


I was recently introduced to the 300 Whiper and am interested in converting my CZ 527. Does anyone have any good advice for me?
I've contacted SSK I was just looking for more feedback, help selecting a suppressor, barrel length etc.

[blackwinch]

I'm wondering if anyone has any ideas of where to get a good stock for my CZ project...:confused: :frown: :wink: