A couple weeks ago I noticed some cracks in the McMillan stock on my 600 Overkill. Sent it back to them and they said there is no way they can build a stock to handle that kind of recoil. I'm getting a full refund which is nice, but now I need to find a replacement stock. Anyone have any recommendations on a good lightweight stock for the CZ550?

Do you have a pic of the barrel channel. ? Did the stock start breaking around the under barrel recoil lug??
Seems like you will have to have a stock made from titanium or a good high strength aluminum alloy then skin it with epoxy or fiberglass .

How many shots did it take to destroy the stock?

Sadly I didn't take a picture of the barrel channel. It wasn't cracked there, but they did mention that the steel insert in the stock was bent.

Round count was between 75 and 100. Haven't done an exact count.

Maybe a stock with an aluminum bedding plate? Accurate Inovations may be able to hep, but not sure about "lightweight".

Good news. I got a call from the general manager at McMillan and he wants to try building a new stock for me with some extra reinforcing. Says it will take a couple months to make, but hopefully it will stand up to the recoil.

No offense but I am totally unsurprised that stock cracked as shown. That it took 75 to 100 rnds is in fact impressive. This is the classic log splitter effect of a action moving in the stock under recoil. I would have crossbolted it through the web behind the mag box and behind the action recoil lug on even a Mcmillan fiberglass stock. Looks like your bolt handle is hitting the stock bolt recess on recoil too. No Pillars ? Ive even added a third lug behind the rear action screw. Steel Bed it thorougly too.Do you have a proper barrel mounted recoil lug or did you try and salvage the CZ mech? Ive heard some of what Mcmillan recommends and frankly am
Not in agreement. My two AHR built walnut stocks have shown no evidenve of cracking after over 1000 rnds or more. Once you get your new stock i suggest you send it to AHR and have them set it up right. Best of luck- Rob

What about the stock that AHR makes?

quote:

Originally posted by Robgunbuilder:
No offense but I am totally unsurprised that stock cracked as shown. That it took 75 to 100 rnds is in fact impressive. This is the classic log splitter effect of a action moving in the stock under recoil. I would have crossbolted it through the web behind the mag box and behind the action recoil lug on even a Mcmillan fiberglass stock. Looks like your bolt handle is hitting the stock bolt recess on recoil too. No Pillars ? Ive even added a third lug behind the rear action screw. Steel Bed it thorougly too.Do you have a proper barrel mounted recoil lug or did you try and salvage the CZ mech? Ive heard some of what Mcmillan recommends and frankly am
Not in agreement. My two AHR built walnut stocks have shown no evidenve of cracking after over 1000 rnds or more. Once you get your new stock i suggest you send it to AHR and have them set it up right. Best of luck- Rob

I think they are planning on doing just about everything you mentioned. He even talked about steel bedding, so I'm hoping it will be good to go when it's all done. The bolt handle only started hitting on the last few rounds. I'm pretty sure it only started hitting after something else let go. It's also just got the stock CZ recoil lug. I'm not going to change anything else right now. McMillan has a lifetime guarantee on their stocks, so they will either fix it or refund my money. I'm just going to do everything they say so I don't have to worry about the warranty.

By the way, where do you get pillars for the 550, or do you just make your own? And for that matter where can I get a new front trigger guard screw, mine is bent a little.

Just did a bullet count. The rifle has 89 rounds through it.

! am in complete agreement with Rob.
Did you have any bedding at all in that stock?

I have used McMillan stocks on 500 A2 and .500 "Tornado" rifles.
I always get the magnum fill and then use hidden crossbolts as Rob described (allthread steel) and pillars, stainless steel or aluminum,
and fully glass bed everywhere from tang to secondary recoil lug on barrel with proper relief of tang.

The B&C-made CZ Kevlar stock with full aluminum bedding block "endoskeleton" from butt to forend tip is probably stronger than you can make any McMillan.
Strongest of all, bar none.
For the CZ 550 Magnum it weighs 2.5 pounds.
Only thing is, can your barrel fit in the channel?
Probably could be made to do so.

McMillan stocks are not drop-ins.
The CZ Kelar can be used as a drop-in, as long as the barrel channel fits.
Of course bedding the CZ Kevlar at primary and secondary recoil lugs is better for accuracy, even if not needed for strength.
The rifle will bed itself in the aluminum bedding block.

Your tougher than me. If you bent the front action screw on a CZ action in 89 rounds. And you STILL WANT to shoot the rifle. . My hats off to you.

JESUS! How many ft lbs of recoil energy we talking about here??? About like my unbraked .300 Win Mag ultralight?

-John

Pillars are easy to make and definitely help. I would not use the CZ recoil lug but install a rectangular one with a 1/2 X1/2 inch rear bearing surface 3/4 of an inch long. Contoured to the barrel and screwed and soldered in place. I inlet the stock to fit it and steel bed it in place Before doing any other bedding or you'll never get the barrel out of the stock. Then you bed the action paying attention to the tang. If it can't move it can't split! I can assure you no fiberglass or wood stock not set up as I've described will fail in time. Depending on the config this gun will generate well over 200 ft-lbs of recoil. Do it right and no problems.Mcmillan is a great company but this is rarified atmosphere to them. They know me so feel free to have them call if they would like to discuss the details.-Rob

quote:

Originally posted by RIP:
Did you have any bedding at all in that stock?

Nope. I never took the rifle out of the stock once I got it from the gunsmith. Figured he would do whatever was necessary, but obviously not.

quote:

Originally posted by John Galt:
JESUS! How many ft lbs of recoil energy we talking about here??? About like my unbraked .300 Win Mag ultralight?

-John

lol Not even close. It's unbraked and generates over 230 ft lbs of recoil. For some fun check out some of my YouTube videos. The last one below is me.

quote:

Originally posted by Robgunbuilder:
Pillars are easy to make and definitely help. I would not use the CZ recoil lug but install a rectangular one with a 1/2 X1/2 inch rear bearing surface 3/4 of an inch long. Contoured to the barrel and screwed and soldered in place. I inlet the stock to fit it and steel bed it in place Before doing any other bedding or you'll never get the barrel out of the stock. Then you bed the action paying attention to the tang. If it can't move it can't split! I can assure you no fiberglass or wood stock not set up as I've described will fail in time. Depending on the config this gun will generate well over 200 ft-lbs of recoil. Do it right and no problems.Mcmillan is a great company but this is rarified atmosphere to them. They know me so feel free to have them call if they would like to discuss the details.-Rob

Thanks. I will definitely make some pillars for it. And talk to McMillan about everything else.

The point of such things is beyond me.

Your gunsmith really should have known better. Had those cheesy CZ action screws fractured or failed, you could have been speared or struck in the head by the barreled action. That's borderline stupid or criminal! He should have known better or at least asked the right questions. Sorry but I have freely shared the recipe for building this gun for about 15 years now and other than some bruises no one has really gotten hurt that I'm aware of and there are hundreds of .600 oks around. I'd like to keep it that way.

The shooters in the videos were all making the same mistake -standing up straight , vertical.

There was a thread on AR about stocks and the agreement was that 375 H&H or better should have two cross bolts . This was in response to early CZ stocks breaking.

Full bedding the receiver distributes those recoil stresses well. Best choice of resin [epoxy etc ] ? Best choice of fiber [glass, graphite ] ?

Go ahead ,shoot , I'll watch !!

On the big guns, I usually make my pillars out of steel rather than aluminum. Generally out of whatever steel scap is laying around. Trim to fit on the Lathe.Drill the screw holes 0.001 over the screw diameter. I then rough up the outside surface to better hold the bedding and often contour them to seat on the action as close as possible too. I open up the screw holes in the stock and make sure lots of bedding epoxy gets into the pillar channel. Every little bit helps.-Rob

The gunsmith who did not bed that McMillan stock for a 600OK was incompetent or criminally negligent.
McMillan always says their stocks must be bedded.
I am surprised they would warranty such an abortion.

Some of my rifles have pillars made from threaded steel tubing like used in light fixtures and lamps.
Threaded on the outside and smooth on the inside where the insulated electric cords run.
They stay put like solid steel allthread used for hidden crossbolts, bedded in epoxy.
Look in an electrical supply or hardware store and you will find some nice pillars.