Hi
I have recently aquired a second hand Brno 601 which is missing the screw in the forestock that puts pressure on the barrel. Do any of you know the size of this screw and what thread size it would be.
Many thanks

Rod

I don't have a 601 to check, but MOST European rifles made in the last few decades use standard M6x1 (6mm diameter, 1.0mm pitch) for guard screws and the like. You will be able to get a screw or bolt of this size at your local hardware shop (if you don't have one lying around in your garage or tool shed) to at least check if it is the correct thread.

You then might have to go to a specialist engineering or fastener supply house to get one with the head type and finish that you want.

quote:

You will be able to get a screw or bolt of this size at your local hardware shop (if you don't have one lying around in your garage or tool shed) to at least check if it is the correct thread.

I've tried every hardware store in town (US) and can't find one that will work. If you find one at your hardware store, buy me a couple

You'll probably have to call CZ and buy it from them.

New_guy

Have you tried the more common metric sizes? e.g. M6x1, M5x.8, M4x.7 (I gather from reading this forum and others that they are not too common or readily available in the US, but they are in NZ, and most other countries)

If you have already determined that they don't fit the 601, it will save Rod the trouble of rediscovering the same thing.

quote:

Originally posted by redrover:
New_guy

Have you tried the more common metric sizes? e.g. M6x1, M5x.8, M4x.7 (I gather from reading this forum and others that they are not too common or readily available in the US, but they are in NZ, and most other countries)

If you have already determined that they don't fit the 601, it will save Rod the trouble of rediscovering the same thing.

Metric bolts are not easy to come by in the US. Sure, the most common sizes are available, but fine-threaded types for typical gun fasteners are not common. I'm not sure what thread sizes were tried, as i took the recoil lug "nut" to the hardware store to test it first hand.

I called CZ to find out what the threads were, but they wouldn't tell me... they just told me that I wouldn't be able to find one on my own and then send me a replacement.

Head dia.390 [ 10 m/m], stem dia .254 [6.45 m/m] Thread M 6 X .75 metric [Avg dia .230-.231"]. This means the stem is reduced in diameter for the threaded section. Easier to buy one.

Thanks for that Redrover, I'll try at our local machinery place and see what they come up with. Good to see another Kiwi on this site. If tthey are plentiful I'll get some and post over to you guys in the states if you need them.

Cheers
Rod

Rod

After seeing the specs for the screw you are looking for, I’d second Tom Burgess’s suggestion that you try to buy a factory job. If the enlarged diameter shank is an essential requirement of it (and I suppose it is, or the factory probably wouldn’t have made it that way in the first place) then I’d rate your chances of getting a satisfactory replacement over-the-counter at an engineering supply house at exactly nil!

Even standard styles of M6x0.75 (ISO Fine) screws and bolts are pretty thin on the ground, in my experience. I once hunted around quite extensively for medium length bolts or cap screws of this thread, but all that any of the specialist fastener suppliers around Wellington could come up with, or locate anywhere else in the country, were 60mm long, hexagon-headed set screws. They weren’t any use to me. I wanted to make up a pair of guide screws to use in re-bedding a Grunig and Elmiger target rifle, which has M6x0.75 guard screws, so I needed something much longer, and with a fair length of plain shank.

If the BRNO/CZ agents here cannot or will not supply you with a replacement screw, I guess you could, as a last resort, make a passable substitute out of a 1/4in engineers bolt with a plain shank length greater than the full length you require. Cut off the 1/4in thread, get the end portion of the shank turned down in diameter and re-threaded M6x0.75, and get the head machined to the diameter and height you require. Expensive solution, though, unless you can do it yourself, or you have a ‘tame’ gunsmith or machinist you can call on. Good luck.

Try Peter Van Meurs at ProCal Trading in Victoria (0352811380).
I wouldn't mind betting that he will have one lying around somewhere.

quote:

Originally posted by new_guy:

quote:

Originally posted by redrover:
New_guy

Have you tried the more common metric sizes? e.g. M6x1, M5x.8, M4x.7 (I gather from reading this forum and others that they are not too common or readily available in the US, but they are in NZ, and most other countries)

If you have already determined that they don't fit the 601, it will save Rod the trouble of rediscovering the same thing.

Metric bolts are not easy to come by in the US. Sure, the most common sizes are available, but fine-threaded types for typical gun fasteners are not common. I'm not sure what thread sizes were tried, as i took the recoil lug "nut" to the hardware store to test it first hand.

I called CZ to find out what the threads were, but they wouldn't tell me... they just told me that I wouldn't be able to find one on my own and then send me a replacement.

Every Home Depot/Lowes/Osh/Ace and every other hardware store and machine shop supply store I have been in carries metric screws and bolts. Metric useage in the USA has been fairly common for a number of years now.