BRNO Mod 2 accuracy

[Wombat]

"Tension on the Action / Barrel screws is also something I try and keep consistent to maintain accuracy."

I haven't tried that. But I have put some pressure under the barrel near the front of the forend. That helped a fair bit.

I havent tried different screw tensions.

Both screws are meant to be 20-25 inch pounds, do the rear one then the front. Made a big difference with mine.
Oddly enough mine shoots very well with some old PMC zapper I had, just as well as with SK rifle match

[bigrich]

i was thinking of having the stepped front sight on my cz 452 2e supermatch machined off and re-crowned by a gunsmith. harmonics in the barrel from the weight of the front sight on one side of the barrel an all that. it has a 24 inch barrel, reckon it can afford to loose two inches. have read on rimfire forums this has improved accuracy on the posters rifle. any opinions ? the "choked" bore idea is food for thought. the cz 2e is bascally a modern mod 2 brno as far as i can find out

[on_one_wheel]

My mod 2 Bruno has been shortened, threaded and recrowned by a gunsmith.

It shoots exceptionally well just as it did prior to having it done.

[bigrich]

thanks for the feedback OOW i was going to fix up a old krico, has a sloppy trigger, but shoots almost as good as the cz 2e. thinking i would rather tweak the cz as it will shoot amazing groups at 50 with eley ammo. have read the cz are made on the same machines as the brno were made on since ww2. what length did you get your barrel down to OOW ?

[Oldbloke]

"Both screws are meant to be 20-25 inch pounds, do the rear one then the front. Made a big difference with mine.
Oddly enough mine shoots very well with some old PMC zapper I had, just as well as with SK rifle match "

Interesting, I've been doing the forend first.

[on_one_wheel]

thanks for the feedback OOW i was going to fix up a old krico, has a sloppy trigger, but shoots almost as good as the cz 2e. thinking i would rather tweak the cz as it will shoot amazing groups at 50 with eley ammo. have read the cz are made on the same machines as the brno were made on since ww2. what length did you get your barrel down to OOW ?

I haven't actually measured it.
It was shortened just enough to remove the bulky front sight, probably around 2" or 3" would have been removed.

[Oldbloke]

Well i had an opportunity to put a few through the Mod 2
I tried a few diff brands but RWS Club went well. Perhaps the best yet.
Shot at 50 yards. I put 10 through her prior to this group.

RWS Club @ 50.jpg (27.73 KiB) Viewed 8881 times

Free floating?
Any ideas on improving on this group?

[marksman]

so the barrel is free floating

I would be cleaning the bore, then fowling and try
didn't work, touch up the crown, trigger and bedding

by the stringing I would call the action is bending in the stock

[TassieTiger]

That’s what -a 1 inch group at 45m ? I’d think you’d do better. My model 2 has also been cut and shut - it’s the shortest barrel I have in the safe and the lightest fire arm by a long way - kids love it and can hit swinging golf balls at 50.

Interesting - my barrel is floating BUT the stock is off centre some distance. It’s disconcerting but it shoots so I’m not touching it.

Have you tried the regular workers - CCI subs, SK magazine, Eley ?
I again agree with MM - a clean, re foul, try some diff ammo and ensure nothing is touching barrel.

[Oldbloke]

No it isnt free floating. Do u blokes think i should i?
Tried
cci
Win subs
Rws. Club
Win bushman
Win power point

Few others i cant remember.

Any suggestions?

PS. Trigger is ok. No complaints

[Stix]

I floated mine & it created all sorts of problems...

If you float it, try that washer trick at the same time...

I think that group looks weird so marksman is prob right...

Get that action sitting up on a washer so its free from tension...

Look at the rolled pin that houses the action screw--you can easily punch that in & out, so make sure thats not too long or too short.

Might also be worth trying with & without the front screw, & at dirrerent torqe settings.

[Stix]

If you do float it & its worse, you csn just bed it up to that barrel screw to get it back...

[bigfellascott]

No it isnt free floating. Do u blokes think i should i?
Tried
cci
Win subs
Rws. Club
Win bushman
Win power point

Few others i cant remember.

Any suggestions?

PS. Trigger is ok. No complaints

Have you changed the trigger spring to something lighter? It helps.

[Oldbloke]

Ive had it from new (40 yrs) Never shot well. But semi retired now so have some more time to play. Ill try the washer or credit card trick. But got a feeling I tried that yrs ago.

What ammo suggestions do you blokes have?

Do i need to clean between ammo brands or just shoot a few to wax up prior to testing?

[Oldbloke]

Yes mate, changed the trigger spring yrs ago. Mmmm from memory its 2.5 lb.

[peterclark]

The Brno Model 2 has been produced in a number of variants including heavy ‘varmint’ barrels, reduced dimensions for young shooters and even a full-stock version. There is sufficient space in front of the foresight to accept threading but it would be necessary to remove the foresight completely if you wanted to fit a model that sleeved back.

[Oldbloke]

Sooo, decided to slug it in both directions. . Result was obviously very tight in the throat. This would result in the bullet "rattling" down the barrel.
So decided to scrub it out. After about 4 hrs a heap of eds red and a few doses of sweets its much cleaner. Have worn out 2 bronze brushes in the process, but still the last 12mm or so a bit tight still. But much improved.

Will continue to clean today. Free float using the bussiness card trick. Buy more ammo and retry in a few weeks.

P.S. Trigger is 2lb.

[marksman]

its a bad thing for a 22 to be tight at the throat but it is a good thing for a 22 to be tight at the muzzle
good luck with it

[sungazer]

Thats pretty interesting and a good warning for the rest of us that dont do much cleaning of the old 22s. It certainly makes sense when it goes bang even if it not a very big bang there is still going to be carbon blown forward. Not all of that is going to be cleaned out by wax and the next bullet.

There really is nothing like measuring things to be able to then make decisions on. I really had this shown to me when the gunsmith used a set of bore dimension gauges. He used them in the muzzle end to find out how much needed to be taken off the barrel so he could recrown the barrel at the nominal bore dimension.

[Oldbloke]

So, I reckon this is about patch # 40. Still a bit to go. Throat is still tight.

patch 40.jpg (42.32 KiB) Viewed 6372 times

Starting to wonder about never cleaning a 22lr?

[sungazer]

You could think about a Nylon brush on a drill. If you dont have any bore paste type cleaners you can also use Autosol on a patch on top of a Nylon brush. Not my invention a common cleaning technique amongst the old boys.

You may have the black ring or doughnut just in front of the case near the throat common in CF a carbon deposit that can build up to critical levels if not constantly kept on top of it. once you know about it you just clean in that area a bit more each clean and it never gets started.

Just think how she will shoot one it is clean and of course re fouled. That part always does my head in. I clean the barrel as spotless as I can then it needs 2-3 shots to get back to perfect consistency.

[in2anity]

It’s dumb not cleaning a 22. There, I said it.

[Oldbloke]

You could think about a Nylon brush on a drill. If you dont have any bore paste type cleaners you can also use Autosol on a patch on top of a Nylon brush. Not my invention a common cleaning technique amongst the old boys.

You may have the black ring or doughnut just in front of the case near the throat common in CF a carbon deposit that can build up to critical levels if not constantly kept on top of it. once you know about it you just clean in that area a bit more each clean and it never gets started.

Just think how she will shoot one it is clean and of course re fouled. That part always does my head in. I clean the barrel as spotless as I can then it needs 2-3 shots to get back to perfect consistency.

Yes, tight just a few mm into the barrel. But could be lead rather than carbon s**t.
The rest of the barrel feels good now.

Do u mean Autosol metal polish?

[sungazer]

Yes thats the one a you put a patch around a nylon brush with a bit of Hoppes on the patch or whatever your cleaner is and a smear of the Autosol on the patch. You give the chamber end the first 6 inchs about 6 short 6 inch passes and then give the complete barrel about 3-4 full passes back and forward.

Like everything with cleaning you have to adjust the regime to suit what you have in the barrel.

[Oldbloke]

Well I did sungazers trick but used "silvo". As I already had it. Also used bronze brush with a drill at the throat.

Definately improved but still a bit tight at the throat for first 12 mm.

Floated the barrel using the bussiness card trick. Recrowned using 400 grit and oil.

Will hopefully report back in a few weeks with a better result.

[Stix]

Im no expert...obviously...but be careful with a bronze brush spinning around on a drill in the throat...id keep to back & forth directional movements myself...

I once de-leaded my brno & it took months...i even bought that lead removing cloth...but ultimately just back & forth with a stiff brush to rip it off & you'll eventually get there...

[Oldbloke]

Im no expert...obviously...but be careful with a bronze brush spinning around on a drill in the throat...id keep to back & forth directional movements myself...
.

Yeh, thats what i did

[marksman]

autosol is a plant based compound not much different to JB bore clean paste, they will not hurt your bore
but when using it too often understand that the bore if it is too clean the projectile will act like tires on ice and not seal properly for a bit till the shine is covered in fowling
when using it to polish throats you should keep the polishing around the throat area
if you have built up a carbon ring at the throat a paste is IMHO the best way to get rid of it as well as a good soak with carby cleaner

[Oldbloke]

So,,, thought i would follow up with the results of my tests using my 1977 Mod2 Bruno. To cut the mustard i purchased a new Bushnell 3-9×40 limited edition. The Tasco world class 2-7×30 must have been faulty from new as the amount of use it had was little indeed. It had become apparent the scope was probably causing part of the problem.

I tried about 10 types/brands of ammo. And tried floating the barrel using the business card trick.

In the end RWS Club come up trumps. In fact once i decided it was the best and shot a few groups is seemed to gradually improve. This is the last group i shot today with no change to the original bedding.

20191128_180244.jpg (684.47 KiB) Viewed 6257 times

[in2anity]

50m group OB?