Cetme reliability w/o chamber flutes?

[stretchman25]

I have a Shilen barrel blank that I originally bought to use on a custom 700 Remington build. Instead, I want to use it on a Cetme. It will have a 308 Winchester chamber, not a 7.62 Nato. I am not interested in using military ammunition. All of the loads that I plan on using will be handloads. My main concern is with the chamber not being fluted. Will the lack of flutes creat problems with functioning and reliability? I am not really wanting a pure combat rifle. My real goal is to see what type of accuracy the rifle can produce and still function correctly without it being subject to combat type conditions.

[AliYahu]

The flutes are to equalize gas pressure and help the rifle function, it'd be like an FAL without a gas piston.

Eli

[Holescreek]

This year I've given up on talking people out of bad ideas in favor of getting to read about the problems they'll run into later. Get yourself a sturdy ram rod to use to to pound the shell out of the chamber and a box of broken shell extractors (maybe you will get a discount buying them in quantity). Make sure to take plenty of photos along the way and update your progress regularly.

[andresere]

Originally Posted by Holescreek

This year I've given up on talking people out of bad ideas in favor of getting to read about the problems they'll run into later. Get yourself a sturdy ram rod to use to to pound the shell out of the chamber and a box of broken shell extractors (maybe you will get a discount buying them in quantity). Make sure to take plenty of photos along the way and update your progress regularly.

+ get extra bolts, rollers, and misc parts (pretty much everything that is supposed to move when fired).

[Canuckienns]

Man, that,s a good one!! If your pulling my leg, you got me smiling.
This system only works with a fluted chamber.

[tog]

Originally Posted by Holescreek

This year I've given up on talking people out of bad ideas in favor of getting to read about the problems they'll run into later. Get yourself a sturdy ram rod to use to to pound the shell out of the chamber and a box of broken shell extractors (maybe you will get a discount buying them in quantity). Make sure to take plenty of photos along the way and update your progress regularly.

This!

[Zeusizme]

Without the flutes in the chamber the gun won't work at all. But sure go ahead and install the barrel and take lots of pictures of the gun and the sad expression on your face when it doesn't work.

[Kolat]

I have a motorcycle engine laying around that I was going to put in a motorcycle, but instead I've decided to put it into my lawnmower. Will it work?

T

[Tim Dreas]

On Spanish websites I often see a change from the CETME B to the CETME C listed, is the CETME C has a fluted chamber, as if the CETME B does not. The CETME B is suppose to work with both 7.62 CETME and 7.62 NATO ammunition with a change of bolt parts. The CETME C is suppose to be chambered for 7.62 NATO. Now maybe the rest of the parts have be designed to work with or without a fluted chamber as the G3 really requires a correctly fluted to function properly. The 9 mm MP-5 has a fluted chamber but doesn't need it at all. The G3 will choke without proper chamber flutes, at least with some ammunition. When H&K first started selling the G3 they stated that it had tested with and designed to be used with both brass case and steel case ammunition. The quality of most steel case 7.62 ammunition seems pretty poor though.

[STGThndr]

Originally Posted by stretchman25

I have a Shilen barrel blank that I originally bought to use on a custom 700 Remington build. Instead, I want to use it on a Cetme. It will have a 308 Winchester chamber, not a 7.62 Nato. I am not interested in using military ammunition. All of the loads that I plan on using will be handloads. My main concern is with the chamber not being fluted. Will the lack of flutes creat problems with functioning and reliability? I am not really wanting a pure combat rifle. My real goal is to see what type of accuracy the rifle can produce and still function correctly without it being subject to combat type conditions.

Why? There are better vehicles for that Shilen barrel. The CETME and HKs are made for and expressly designed for rugged field conditions and the barrel is part of a system.... a comabt weapon. Not really designed for handloads either. Not saying that it won't work with reloads (don't know, havent tried it, nor commercial ammo either) but it is set up expressly for 7.62X51.

[Holescreek]

Just because it's a Cetme doesn't limit it to it's original profile. If I had a nice barrel I wouldn't hesitate to chamber flute it and put it on a Cetme platform. I just wouldn't waste my time putting an unfluted barrel on one.

Here's a link to my last Cetme build:
http://www.falfiles.com/forums/showthread.php?t=317022

[STGThndr]

Hole, VERY nice lookin build. A lot of custom work went into that- I was thinking more along the lines of slappin the barrel onto an otherwise standard CETME.
One of the best (or favorite) rifles I ever owned was of all things a Century build CETME clone. Sold it to get an FAL.

[Holescreek]

Stretchman25's question wasn't out of context with regard to rebarreling a cetme, lots of us have made accurate shooters out of them. The biggest drawback to making one shoot accurately is the barrel. There just aren't many choices available due to the chamber flute requirement.

As far as the model B/C and optional flutes, the ufluted chambers required cases with heavy oil or wax type coating to function, and that was for the lower powered cetme round. The flutes became standard for the NATO round.

Lots of people reload for the cetme, contrary to internet opinion, the cases aren't destroyed. They are pretty hard to locate though!

[Tim Dreas]

Originally Posted by Holescreek

Stretchman25's question wasn't out of context with regard to rebarreling a cetme, lots of us have made accurate shooters out of them. The biggest drawback to making one shoot accurately is the barrel. There just aren't many choices available due to the chamber flute requirement.

As far as the model B/C and optional flutes, the ufluted chambers required cases with heavy oil or wax type coating to function, and that was for the lower powered cetme round. The flutes became standard for the NATO round.

Lots of people reload for the cetme, contrary to internet opinion, the cases aren't destroyed. They are pretty hard to locate though!

The CETME Model B rifle did use the same barrel with only changing bolt parts for 7.62 CETME and 7.62 NATO. Spain originally tried loading 7.62 NATO using a bullet designed after the FN SS77 bullet in a 7.62 CETME case in 1961 but had problems with that ammunition. In 1964 the CETME Model C manual has a shooting table based on the FN SS77 bullet but production Spanish ammunition appears to be based on the NATO reference cartridge which is more similar to the US M80 bullet than the FN SS77 bullet. It doesn't look like Spain ever updated the shooting table in the CETME manual to match the ammunition they were using. It is also interesting that Spain changed the bullet design of their 7.62 NATO ammunition. I do not know what year Spain changed the bullet design though. The one in the manual doesn't match the ammunition I've seen, so it may have been fairly early in production.

[Holescreek]

Lots of rare info on the cetme cartridge development here:

http://www.militaryfirearm.com/Forum...ards-7-62-NATO

[Tim Dreas]

I looked in the CETME model C manual and it shows a 9.4 gram bullet. It is based on the 7.62 NATO reference cartridge. Originally when Spain tried to make a full power 7.62 NATO cartridge they used the FN 9.3 gram SS77 bullet in a 7.62 CETME case in 1961. That didn't work out so well for them. The H&K G3 manual shows a 9.5 gram DM41 bullet. The shooting tables are different for the CETME model C and G3. Britain went with a 144 grain bullet based on the FN SS77 bullet but it may be loaded slightly hotter. Australia based their ammunition on the British ammunition. Canada settled on a cartridge based on the NATO reference cartridge and calls for a bullet weight of 144 - 148 grains / 8.4 - 8.6 grams. I usually see the NATO reference cartridge stated as having a 9.45 gram bullet. The Portuguese ammo looks like it's based on the NATO reference. The Dutch ammo may be also. Surprisingly not based on the FN ammo. The Dutch were still buying reference cartridges from the US Frankford Arsenal in 1965. The US switched from M59 steel core ball to lead core M80 ball ammo around 1966. The south African ammo has a 9.27 gram bullet, also called 143 grains but it is closer to 142 grains. It is based on the FN SS77 bullet which is 9.3 grams or 143 grains. It is also rated about 50 fps slower than most. FN updated the SS77 ammo to a version called, "SS77/1" but I don't know how it is different.