Tricky chambering the 2nd round in a .308

stratts

Well-Known Member
Hi chaps,
I picked up a 1987 ZKK601 .308 last week and finally got out to try it on Tuesday. Only issue I have is if I load 3 rounds, the 1st is quite tight to chamber, the 2nd takes a bit of effort and sometimes jams at an angle when pushing forward if I'm not forceful enough, and the third chambers perfectly.

If I single load then it chambers spot on every time. If I put 2 rounds in the one on the left looking down struggles to chamber ok.

I compared it to my mates newer Howa .204 and his has to slots either side of the raceways that seem to help the rounds clear each other when loading. The Brno doesn't have one on the left side looking down which is where the round gets a bit 'stuck'!

Also it seems like the spring that pushes the rounds upwards is quite taught. If it's exerting too much pressure from below could this be the reason the 1st of the 3 rounds is difficult to load. This should be an easy tweak but I don't want to weaken it if it unlikely to make a difference.

Here's some pics, although they are not as clear as I thought!

Brno 308 with the straight raceway on the left



Howa .204 with the cut out



Any ideas please?

Cheers
 
a) wrong spring
or
b) too much spring tension
or
c) mag designed for a different case?

start at B!
depending on spring design you can take some of the pressure off by crimping the last bend of the spring with some pliers
little at a time trial and error

you want it to have enough to lift 3 rounds but be slack enough that they are not forced so hard that chambering is an issue
comparing different actions won't help, they all have little design features that won't be relevant on others

to be honest though if this was a shop sale get them to fix it

​or shoot like you only have one round!
 
ZKK 601 is heavily Mauser derived so firstly make sure that the feed lips are smooth and not rough of have been dinged up somehow.

I seem to recall this rifle has had little use. Mine was a bit rougher feeling as it came out of the box but a bit of use and a touch with a fine stone to make sure it was bur free solved it. Then remember it's a 98 Mauser derived action and use it not baby it. It's got no placky bits like some rifles so there is no need to treat it with kid gloves.
 
+ 1 with Brit's comments, they are designed to be safe and work in a hurry. Also drop out the spring and follower and clean the inside of the magazine and the sides of the follower. If there is some dirt holding things up it may not rise cleanly and the second round is not presented cleanly.

David.
 
Hi chaps,
I picked up a 1987 ZKK601 .308 last week and finally got out to try it on Tuesday. Only issue I have is if I load 3 rounds, the 1st is quite tight to chamber, the 2nd takes a bit of effort and sometimes jams at an angle when pushing forward if I'm not forceful enough, and the third chambers perfectly.

If I single load then it chambers spot on every time. If I put 2 rounds in the one on the left looking down struggles to chamber ok.

I compared it to my mates newer Howa .204 and his has to slots either side of the raceways that seem to help the rounds clear each other when loading. The Brno doesn't have one on the left side looking down which is where the round gets a bit 'stuck'!

Also it seems like the spring that pushes the rounds upwards is quite taught. If it's exerting too much pressure from below could this be the reason the 1st of the 3 rounds is difficult to load. This should be an easy tweak but I don't want to weaken it if it unlikely to make a difference.

Here's some pics, although they are not as clear as I thought!

Brno 308 with the straight raceway on the left ....... Howa .204 with the cut out

Any ideas please?

Cheers


Obviously it's never had a lesson. You're comparing a controlled-feed action with a push-feed action, and each works in a different way.

I think the tautness isn't down to a fierce Z-spring but to the follower 'binding'. The RHS cartridge is feeding, but the LHS is not. The follower should have lateral play, and also oscillate around the end of the spring within the well - the floor should 'pitch' in all directions beneath the cartridge. I think that's what you're saying by wider 'slots' on the Howa action.

The BRNO 601 has a staggered box magazine so the walls are of pressed steel - maybe there's a buckled section which is blocking free side-to-side movement & impeding the upthrust of the floorplate/follower..... or the walls are crusted up as Kalahari says?
 
Thanks chaps gives me something to go with for starters!!

Massive lesson learnt though with this rifle is I will NEVER buy anything again from far away without the chance to collect it in person and check it out!!
 
Some of my best rifles were purchases with quirky 'habits' that I fixed. If you can get them, order a magazine and follower. The wrong follower in place can really gun up feeding.~Muir
 
Thanks chaps gives me something to go with for starters!!

Massive lesson learnt though with this rifle is I will NEVER buy anything again from far away without the chance to collect it in person and check it out!!

Stratts it may be something simple. Just remember that alot of different things out in the big bad arent perfect either new or used. Why? Because a human made it and lets face it we aint perfect although we all perhaps like to think it. Ive only ever bought a handlefull of rifles face to face. Even they were "looks in good nick" and alot of trust in the seller. Now out of the distant buys Ive had 1 which gave me a prob (browning) But it was a manufacturing flaw a quick diy job and sorted. A bit different from yours mine wouldnt cycle at all from the mag. All that was needed was a little bend at the top to present the round at a better angle.


Keep your chin up mate

nutty
 
Don't worry mate I know anything can be sorted and I quite like things like this as it means I learn all about the rifles while I'm at it. I'm a bit of a tinkerer at heart and love to get things into bits as long as they go back together!

I'm also dead chuffed because the rifle also likes the Prvi rounds and I put a 5 shot group within 30mm at 100yds again 1st time I shot it!! :D

I noticed the bolt is not as smooth running along the raceways and generally it looks like it's all not very worn, so maybe it just needs using. Would it hurt lapping the raceways with some 600 grit?
 
Don't worry mate I know anything can be sorted and I quite like things like this as it means I learn all about the rifles while I'm at it. I'm a bit of a tinkerer at heart and love to get things into bits as long as they go back together!

I'm also dead chuffed because the rifle also likes the Prvi rounds and I put a 5 shot group within 30mm at 100yds again 1st time I shot it!! :D

I noticed the bolt is not as smooth running along the raceways and generally it looks like it's all not very worn, so maybe it just needs using. Would it hurt lapping the raceways with some 600 grit?

I wouldn't. Let wear in. My CZ Hornet was a bit 'gritty' when I bought it, after 500 rounds it was gone.~Muir
 
I wouldn't put abrasive near it. Clean it all very carefully and let it bed in. I don't know if it is possible with the 601 but many moons ago I saw a magazine spring put in the wrong way round so the highest pressure was at the wrong end of the round. That really b*ggered up the feed. Need to check with someone who knows what they are talking about though. This isn't gospel, just something I have seen once.

David.
 
Thanks chaps gives me something to go with for starters!!

Massive lesson learnt though with this rifle is I will NEVER buy anything again from far away without the chance to collect it in person and check it out!!
Just add ' and try it out' and you will have a good call. I think buying a used rifle is at least as risky as buying a used motor vehicle.
 
I have similar issues with my Parker Hale rifles if i pussy around with the bolt closing! If i do it like i mean it i don't have a problem! Like has been said it is a master action, use it like their coming over the trenches!
 
Don't worry mate I know anything can be sorted and I quite like things like this as it means I learn all about the rifles while I'm at it. I'm a bit of a tinkerer at heart and love to get things into bits as long as they go back together!

I'm also dead chuffed because the rifle also likes the Prvi rounds and I put a 5 shot group within 30mm at 100yds again 1st time I shot it!! :D

I noticed the bolt is not as smooth running along the raceways and generally it looks like it's all not very worn, so maybe it just needs using. Would it hurt lapping the raceways with some 600 grit?

Don't try lapping it.

Make up a magazine full of dummy rounds, i.e. resized case, no primer, drill a hole sideways through the case so its obviously inert and you can feel it, even paint the base (head ?) red, seat ideally an FMJ bullet with a drop of superglue to hold it in place. (FMJ will survive knocking about better than other types).

Then get in the habit of loading the mag with dummies and cycling them through whenever you can. Do it whilst watching the telly. Slow, fast, short stroke, aggressive slamming etc.

Keep the bolt lugs and their sockets in the receiver clean and greased on the thrust face with a dab of lithium moly CV joint grease (a lifetimes supply in a big tub from your car parts supplier). Old toothbrush and brake cleaner ideal for cleaning, cotton bud for greasing.

This will smooth up the action without abrasives, and teach you muscle memory of what works, and maybe what hangs up.

Sorry that you are having problems with another .30, but it seems this one promises some accuracy potential and hopefully no wear/headspace issues this time. Stick with it.
 
Thanks chaps.

I checked it over last night and the spring was under a lot of tension so with a tweak or two it seems better. My 243 is defo looser but you can tell the 308 hasn't seen much work!!

There's also some very very light surface rust from storage which needed polishing off and a bit of elbow grease has smoothed off the raceways so the bolt runs nice. She just needs to see some action now and for me to be a bit more manly I think,

Cheers
 
it is a master action, use it like their coming over the trenches!

that is true
only time i have ever had an issue with my 270 chambering was when I was fannying around trying to do it very quietly and slowly!


Thanks chaps.

I checked it over last night and the spring was under a lot of tension so with a tweak or two it seems better.

I also leave my mags full or ammo for a while settles the spring down a bit
 
Stratts
Don't lap it -- run it in --- If there are no burrs you could try some dry lube --- Don't use anything wet, oily or greasey where it may get on the bullet case or attract dust / grit to stick in the action.
Some bolts feel sticky in the action if they are too dry / clean - my old M55 Tikka is a bit like that.
I did some tests a couple of years back on the "Microlon Gun Juice" product - that is very good for this kind of problem. (It's a great bore treatment as well - it can reduce group size significantly as my tests proved to me)

​Ian
 
Thanks chaps plenty of good advice again.

Yorric did you have to get that stuff imported or is there a UK supplier? Do you reckon it's something that could be brought over from the USA in a suitcase without my 73 year old aunt being arrested, lol!!
 
hi feller see that gear at the game fair, i use teflon spray or ptfe spray dry lube or even brake free, i'v got lots of brakefree from a pal for AR 15 service'g good stuff smells like pear drops and is slick as water if you wish one foc drop me a pm it will last for ever as not a lot is needed :tiphat:
if you had turned up yesterday am ,i could have given you some before i left:doh:
 
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