Curious Case of Brass Case in C93 Rifle

[Duckford]

Bought my C93 a few years ago from my local gun dealer through another gun shop in a local city. The Century rebuilt H&K would not feed brass from the day I received it, and likely it was the reason why the original owner gave it back to the other gun shop where it was bought. Century still honored the warranty, and even after a gunsmith handled it, would not feed even 5.56 NATO brass. I like delayed roller, and cheap ammunition, so I've simply fed steel through it hard for the last few years, noting the bolt gap was tighter than H&K mil spec.

So I revisited the rifle using brass a few weeks ago out of curiosity. The first round would stick as per usual, but after the first round the rest of the magazine would cycle correctly! Progress! The problem was it would cool down and not cycle the first round. Shot it for 4th of July, 10 rounds loaded for off hand pop bottle shooting at 80 yards, every time I went through the process it was the same, first round stuck hard and the other nine would fire correctly. Funny.

The strangest thing was, tonight I checked the bolt gap to see what it was for this post, now there is no bolt gap! Its so tight that no feeler gauge will fit. I would have thought that the bolt gap would have grown with the wear of several thousand steel cased rounds, and that's why it was functioning with brass. Now it really is a head shaker.

Anyone have similar experiences with a C93, or any explanation from an H&K guy as to what is going on? Thanks in advance as always.

 

[BearBio]

You aren't REALLY shooting pop bottles, are you?

 

[4T5GUY]

No bolt gap = no good. Ideal bolt gap should be @ .016. The bolt head/bolt gap was probably just in spec, for CAI, when they put it together and now it’s not. Some of the Malaysian contract 93 bolt heads were softer than maybe they should have been.

+2 rollers = .002, +4 = .008. They do make bigger ones but much larger you should get your barrel repressed. Rollers are readily available and easy to change out.

Another option would be to get a new bolt head. Again they are available NOS. I’ll bet that’ll open up that gap. Depending on the parent weapon, (origin,) your bolt head might not have been hard enough to begin with or very worn.

Yet another option would be to send it to Jeff @ Parabellum Combat Systems and have him make that C93 perfect. His work is flawless, reasonably priced and a fast turnaround. Heck, have him make it into a Dragon.

Jim

 

[Duckford]

You aren't REALLY shooting pop bottles, are you?

I do shoot a few every Fourth of July, maybe another warm summer evening in the year. I shoot paper and steel for serious practice, but its fun to blow up a few jugs here and there for entertainment sake. If you can't have a little fun on your own property once every blue moon, you might be a fuddy duddy. And I'm a boring guy as it is.

Thank you, Mr. 4T5GUY, interesting information on the bolt head, never heard of that being an issue before. I know how to change rollers, so its the matter of making the order and actually doing it. Might look into other parts, as you mentioned. Still, I'm curious as to why the gun refused to cycle brass when the gun's bolt gap was 0.07, but will finally cycle it at 0.

 

[4T5GUY]

Something else to consider is that 223 commercial, (brass,) is loaded less powerful than 556 NATO.

As you have noticed, the steel cased 556 NATO works great. Since I bought so much of it that's all I've shooting in my 93. The last time I did have brass to shoot it worked fine though.

Jim

 

[Fishinfool]

Can't say for sure what the issue is with your rifle (maybe something in the chamber flutes that does not play well with brass, causing it to stick?) Bolt gap may be an issue, as it is important for headspacing.

I owned a HK 93 back in the day, and it always fed any brass ammo I used. Never tried steel in it. Those delayed roller lock actions are pretty simple, and are usually very reliable.

Larry