Brno 601 what now

Ive been playing arround with a brno 601 243 i got on the cheap a week or so ago its got the typical last few inches near the muzzle of pitting that you see in old hunting rifles but looks pretty good in the 1st 20 inches of the 23.5 inch barrel
I have played with a few Different bullets and the groups are inconsistent
A load exactly the same will shoot just under an inch about 0.8 or so @100
But the very next group will be 1.5-2 inch
I noticed a bad crack in the stock Attachment 123173
which I thought might be flexing and Causing bedding issues
So I took it round to a mates that’s a wood guy and fixed it
Now solid as I went to the range and re tested
No change in group sizes

So im wondering what to try next I grabbed a mint or very close to mint stainless barrel off a browning
I have pet Machinists that are capable if fitting that if needed but im trying to avoid a rebarrel

Im wondering about trimming it to 20 inches
This will get rid of the pitting in the barrel leaving behind a pretty nice tube
Which would probably improve the accuracy??

Any other ideas??

Attachment 123174

4 groups same load
As you can see each group has pretty clear flyer some worse than others
Typically 2 shots land pretty close then a flyer opens up the group

I have Several pages of targets with Different projectiles
All are the same one good group followed by shit then another gooden

Ive seen barrels far worse than this shoot much better

recrown and try again . . . R

Leave it alone and just go hunting.
It's accurate enough for 99% of hunting situations.
Chop the barrel and recrown if you want.

Quote:

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Originally Posted by norsk

Leave it alone and just go hunting.
It's accurate enough for 99% of hunting situations.
Chop the barrel and recrown if you want.

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Plus 1

Our expectations of accuracy have gone up significantly over time. Our grandparents great grandparents depending your age would have been happy with 4 moa or less in a hunting rifle. Now we moan about anything over 1 shot off a bench under ideal circumstances.
Crowning will likely give a significant improvement it did on a 7x57 sporterised Spanish mauser I used to own that had a decidedly below par barrel.

https://www.nzhuntingandshooting.co....ing-job-54291/

I would take the bull by the horns and trim it to 20" to get rid of the pitting, and you would get a recrown at the same time in any event. 2 birds with one stone.

The .243 in 20" performs pretty damned well.

The pursuit of accuracy is often more satisfying than leaving it as a "good enough for hunting" rifle. In your situation I can fully understand that.

Cigar's idea of a re-bed sounds useful too - and it would be a bit of fun and a new adventure.

Another thing to check on an older rifle is the mainspring (firing pin spring) as old springs can get soft and cause inconsistent ignition which will give fliers. Happens occasionally on a new rifle too when the spring "binds" on the firing pin or inside of the bolt body . . . . I had one just recently where clipping one coil off the mainspring has reduced fliers to nil, the spring had a bulge and was touching inside.

I would give it a good clean, make sure the action and bottom metal are correctly mated and check for wear spots where metal on metal and address anything too proud or bed anything

also it may have historic copper deposits in its barrel. I plugged and left mine to soak while cleaning with JBs bore paste

you can counterbore your barrel the four inches that has excessive wear or pitting to maintain the look and foresite (I did this first in my days before suppressors) then shortened it a few years later

check the twist rate too, if you are on the edge of stabilising a too heavy proj Iv seen the inconsistency you are talking about
A flat base 80gr soft point would be my pick

Im on my second 18inch 243 and its my main rifle so dont be shy to trim the barrel, velocity loss is minor (100fps) and a shortened brno 601 is as good a bush gun as they come

look for spots in the stock where it has warped and may be either touching the barrel or twisting on the action. If its getting wet/dry and things are changing give them a little bit of clearance and some boiled linseed oil

dont rule out anything basic like loose rings or a scope in the process of failing too or a creepy trigger

Quote:

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Originally Posted by Tentman

Another thing to check on an older rifle is the mainspring (firing pin spring) as old springs can get soft and cause inconsistent ignition which will give fliers. Happens occasionally on a new rifle too when the spring "binds" on the firing pin or inside of the bolt body . . . . I had one just recently where clipping one coil off the mainspring has reduced fliers to nil, the spring had a bulge and was touching inside.

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this happened to my brno too
the firieing pin had gunk in it and had mushroomed off too much and wasnt setting off harder primers

My 601 243 had a pressure pad at the front of the foreend, but the stock must also have warped over the years as it was pressing in the side of the barrel too. Sanding off the side contact helped. Bedding then floating the barrel made a significant improvement.

Wow so meny great suggestions this is why I love this forum
I could leave it as is it certainly shoots good enough but it nags me when I know it should or can do better if it was stuffed id be quite happy but it’s not and it should shoot better than it does currently
Which is why ive decided to go Further

I think there’s a big Argument for cutting the barrel to get rid of the pitting and will have the added advantage of a new crown and suppressor thread so I will do that

Ill glass bed the rifle aswell ive done a couple before and I get compond for free so it’s worth doing

Then ill see about doing the trigger as it’s pretty shit tbh

Quote:

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Originally Posted by rambo-6mmrem

Wow so meny great suggestions this is why I love this forum
I could leave it as is it certainly shoots good enough but it nags me when I know it should or can do better if it was stuffed id be quite happy but it’s not and it should shoot better than it does currently
Which is why ive decided to go Further

I think there’s a big Argument for cutting the barrel to get rid of the pitting and will have the added advantage of a new crown and suppressor thread so I will do that

Ill glass bed the rifle aswell ive done a couple before and I get compond for free so it’s worth doing

Then ill see about doing the trigger as it’s pretty shit tbh

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The trigger is adjustable for pull, do you have the standard or set trigger?

@Cigar standard I think
I read your reply to my pm btw
Id already taken the bull by the horns and took it apart ready for the bedding job hahaha
Don’t think it will be to bad to put back together
Put all the bits in bagies labled where they go
And took plenty of photos
I’ll grab some compound tomorrow and get it done

Standard trigger is curved, set trigger is straight. Both can be used like a standard trigger and are adjustable for pull weight, and the lightness of the set trigger when used as a set trigger can also be adjusted.
I can send you a scanned copy of the manual if you like - assuming you get it all back together of course! :D

I will not shoot 10 shot groups 5 yes 10 no
I have never seen a “hunting rifle” with a sporter waight barrel
That’s capable of shooting a good 10 shot group the barrel just gets to hot
I shoot 3 shot groups from a cold bore or as close to as possible with a hunting rifle simply because what it does after that is of no interest to me as i will never need that meny when hunting as the deer or goat will be long gone after the 3rd anyway

I do ocw testing in 0.3gn steps 3 shot groups
The groups you see are 41.5gn of 2209 with @95gn targex loaded 0.020 of the lans for a coal of 2.722 which was the best group from my ocw testing
I will shoot some 5 shot groups once i the rifle shooting well
But if it can’t shoot 3 well it won’t shoot 5 well so its a waste of components at the moment

whats the twist on it

be 1:10 i reckon not that im a expert

id try 85gr pill both the 243s ive had shot like that with with pills over 85 the heavier i went the worse they shot

Quote:

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Originally Posted by quadhunter260

be 1:10 i reckon not that im a expert

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Yep, should be 1:10 for the 243.

Mine likes the 85, 87 and 90gr projectiles, and also shoots the Sierra Prohunter 100gr well.
It hated the 103gr ELD-X, likes the 90 though.

my dads 601 of similar age did well with 87gn hp hornadys or 100gn corelokts years ago

@mimms - you obviously don't read much . . . . if you can't be bothered looking it out for yourself I'm not going to spoon feed you.


Try hanging out (and "listening") to the guys on Rimfire Central, or Accurate Shooter forums for a while . . .

Quote:

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Originally Posted by mimms2

If you overlay all of your "groups" you will have an approximation of the accuracy, which looks about 6moa. Anyone can fluke 1MOA when the planets align.
10 shots doesn't need to be rapid fire. take a minute with open bolt and clear chamber between shots.

And keeping track of them will hopefully show up something. First shot left, second right, third left, fourth right, ie, you'll be looking at mounts/screws.
First left, second lefter, third lefter, fourth lefter... shows that you track that way with heat.
First "flier", the rest a group - shows cold bore.
If you're shooting your 3, the first will be cold, the second two will have a bit of time in a warm chamber so may get increase in velo. Shooting more will confirm/deny.
Disregarding your fliers will lead to an exercise in frustration.

This is about testing the rifle, which does not need to mimic hunting conditions.
If you really want to mimic hunting conditions, fire your 10 shots from dead-cold over 10 days at random times, then see how your group is.

I haven't done OCW so not familiar, but from what I read, the recipes it gives are pretty close to those obtained by ladder. If you've got confidence in them then check that off the list as a potential variable.

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I have to say I don’t know where you got that from
If you line up the Center of all the groups you would have a group as big as the biggest group as all the other shots would fall within that 2.1” or whatever it was

Who gives a shit about point of aim..... the scope can be zeroed at a later date
You’re going for groups not bull if you’re
The rifle is not zeroed for those rounds
And i was changeing my poa between groups to try and get a nicer sight picture which is why you see slight point of impact shifts

Once i have a good load that i am happy with i will zero the rifle for said ammo

Hahaha will do mate I’ll listen if it’s worth listening but I think you’re info is so far off it’s not funny
We will agree to disagree

Well I finished the bedding today shes a little rough at
And missing a bit on the front right
I can touch that up easily though
@Cigar the trigger for your information is not that bad
Went back together in 10min
Attachment 123352

Holds the barreled action tight as

Yeah, my unscrewed action went from rocking side to side to being rock solid after my bedding job.
Rifle shot a group of about half an inch at 200m today, the average is well above that but it seems to throw a quarter MOA three shot group every trip to the range.

@Cigar same here mate
Massive Difference

Not sure about baby shit yellow though
Was the only epoxy tint I had handy
You can’t see it when it’s Assembled so who cares but I didn’t want transparet

So I have bedded the rifle
Shortened and recrowned the barrel and put a thread on so i can use my dpt on it
And got the gunsmith to tickle up the trigger as much as possible

I have some 95gn targex in the mail (what the groups in the op were shot with)
So we will remain consistent during testing

Interested to see the improvement, Im picking the ol girl will shoot now with the rebed and shorten.

So I picked it up from the gunsmith yesterday
Barrel ended up 20.5” 90% of the pitting is gone and the bore looks quite good now
It has a nice new crown and my dpt screws right on the end

A brought some nice warne rings but unfortunately my bolt won’t fit past the eye peice on the scope
So i will need to get higher ones��

Looked the business aswell bugger it
Attachment 124062

Youve got a fast gunsmith :)

A week he never takes longer than that

Fixed the ring hight issue scope is now mounted in a set of Sportsmatch uk’s
Attachment 124099

Results Same load as the target on the op
Shot 3 groups today shot 6 groups all i inch or less a bit more load developing and she will be mint Attachment 124487Attachment 124488Attachment 124489