I placed this question on the gunsmith forum as well.

For you CZ 550 owners; Is the floor plate on the CZ 550 secure under the recoil of a 458 Lott or would it be wise to have it welded shut?

EZ

I shoot a CZ .416 Rigby, .404 Jeffery, and a .500 Jeffery and have never had any issues with the floor plate. Why would you consider welding your floor plate shut?

Some guns do not have a very secure mechanism to keep them shut under heavy recoil and they will pop open leaving the contents of your magazine on the ground.
Welding them shut eliminates that scenario.
But if they work, No sense in messing with them!

If the shells don't pop out of my .500 Jdffery, they probably won't pop out of your Lott. Do they pop out at the range? If not, don't worry about it.

Dave,

I appreciate your insight. I am having some misc. work done on this rifle at the gunsmith and thought I would ask the question so to have it addressed while it was there if need be.
Looks like I have less to be concerned about Thanks!

EZ

eezridr
I had the same concern about the floor plate. After inspecting it I decided to stay with the factory situation. (but I also changed many other things). For practicing and to make sure that there is no problem with this and some other things on a new CZs you should shoot about 100 rounds on the range with the load that will be used on game, if you are planning to do so.
Until today I shot 40 factory rounds in my cz Lott and I see no problems with my floor plate. After finding the best handload for mine I will make some more tests and change everything neccessary before using it in the field.
A friend had serious troubles with the floor plat on his new cz550 in .416 Rigby. He showed it to me and we found out that his was different from mine.(?) CZ seems to produce many good rifles- but some have strange malfuntions that must be eliminated.

I have CZ's in 375, 416 Rigby, and the 450 Dakota I took to Zim last month. None have ever given me any concerns.

Rich
Buff Killer

I was made aware of an issue on some CZ 550's that the barrel was not threaded square into the receiver and when a scope was added they either shot to low or too high.
I do not plan on adding a scope to this rifle so it is a moot point to me but curious if anyone else heard of this problem?

CZ,s are right up there with Rugers for unbelievably tough and if I,m an example , pretty idiot pruf ...... In a thousand or more rounds shot thru CZ 550 . 9.3x62 ,300 win mag. 416 Rem and 458 Lott . I have not had any malfunctions once I got them feeding correctly ...... . The floor plate latch is very secure ..... I am really [ not] into blind magazines on rifles .....

The only rifles I have seen open their floor plate on firing are those with multipeice bottom metal like the Ruger M77 and the Winchester M70. Adjustment of that middle screw can be tricky.

If you want a perfect rifle,send it directly to a gunsmith who has had plenty of experience with them.You will have a quality rifle.Maybe not the best,but you will have something that functions well enough.It will cost you an arm and a leg and a long wait.As I've been told by a gunsmith,most gunsmiths are behind on their work.I am sure that dealing with anyone,will raise your blood pressure.The only time when these guys don't get to you is when you get the whole thing off your mind and couldn't care less of your rifle etc...

My Floor plate on my CZ 550 458 Lott does not come loose when shooting. Maybe there is something wrong with yours. Get it checked out
by a gunsmith.

Being a mechanical engineer I have always felt compelled to mess with everything! The CZ 550 out of the box is a platform from which i begin. I believe you do not need a 25" barrel on a DG rifle.
The front sight is sort of junk and I plan to use this rifle with open sights only; The magazine spring is sloppy soft;
All that being said, it is a good platform. Mine has two crossbolts and of coarse a recoil lug on the barrel but I plan the glass in the whole works. I think I could stuff 5 rounds in the magazine.
I am addressing the issues I felt wanting along with a new 3 position safety.
This is probably the heaviest recoiling rifle I own and the initial question was posed so if required I could have it addressed while in the shop. Most of you know gunsmiths are pretty methodical with their work so I would just as soon try and get what needed to be done while it was in their the first time.
It would appear from the responses that it is fine.

EZ

I have 2 CZ 458 lotts and a rifle built on a Sako in 458 Lott and have never had the floor plate come open.
Bill