K31 shoots right w CB

[nitrohuck]

Hey all,

So I found that my k31 shoots a little to the right (~3") at 50yrds, I have read before that this is somewhat normal for cast boolits and low velocity loads in a k31, is this true?

I know the obvious answer: Move the front sight to the right, well, easier said than done, and I cannot spend $40 on a front sight adjustment tool at the moment, as that is such a ridiculous cost for a perhaps one time use.

Currently loading NOE K31 mold bullets, 16gr of 2400, and CCI Large rifle primers,

cheers fellas and happy holidays!

[HollowPoint]

Mine used to do this very thing as well. I did move the iron sights but the gun would still shoot to the right.

The hotter the barrel got, the more pronounced it got.

After a thorough examination I found that my fore-stock was making contact with the left-upper
side at the muzzle end of my barrel. The first two or three shots weren't as far to the right as
my following shots.

I figured that as my barrel heated up the small amount of pressure being applied by the fore-stock
became enough to move my shots to the right.

A couple of hours of hand-sanding the inside of my fore-stock seemed to have cured the problem. This
is now one of my most accurate rifles.

HollowPoint

[nitrohuck]

hmm, okay, perhaps this is the culprit... no way of knowing at the moment as I am at work, but if the wood is putting pressure on the barrel will it be visibly obvious?

Guess I'll wrap some sandpaper around a 3/4" pipe and have a go at it if this does infact seem to be the issue

[Maven]

hmm, okay, perhaps this is the culprit... no way of knowing at the moment as I am at work, but if the wood is putting pressure on the barrel will it be visibly obvious?

Guess I'll wrap some sandpaper around a 3/4" pipe and have a go at it if this does infact seem to be the issue

I wouldn't do that if I were you unless you're 100% certain that the stock is interfering with the bbl. I owned 2 very accurate K-31's, which also shot ~6" to the right @ 100 yds. Ditto for my friend's K-31's. Once I readjusted the front sight on each, the problem was resolved. As you mentioned in your original post, the problem is the rate of twist (~1:9), which is optimized for military jacketed bullets and loads. Btw, you don't need to spend $40 for a sight adjusting tool, just go to your favorite hardware store and purchase a nut splitting tool, i.e., the kind with a bolt that must be tightened with a wrench. (Mine's a Craftsman.) Use layers of duct tape where necessary, drape it over the front sight and twist it until it breaks the staked front sight loose. That takes a bit of effort, but once done, you can make finer adjustments quite easily. Hope this helps!

[nitrohuck]

when you say "breaks the staked front sight loose", am I actually breaking something? perhaps a stupid question...

Once it is "broken free" will it continue to hold zero? I've clearly tried to get it to move with a rubber mallet and allen keys with rubber covers on them, didn't do jack

[legend]

the nut splitter works well, i ground off the sharp end on mine and it works great.
it will not "break" your sight it just is staked into the metal to hold it to one spot,you are only going to move it from the staked spot,yet it still stays in the dovetail.

[nitrohuck]

A rubber mallet and a rubber cover Allan wrench aren't going to apply enough force. You need a steel hammer and a brass drift or punch. The use of brass is to eliminate damaging the sight.

Roger that... perhaps I will give this nutsplitter an attempt... don't have the tools at hand to file down the sharp end of the splitter, but a bunch of ductape will hopefully do the trick as HollowPoint suggested

For only $10 on Amazon i can't go wrong... does anyone know off the top of their head what size the nutsplitter they use is? I see one that ranges from 5/8-7/8" that seems like it should fit yeah?

[HollowPoint]

hmm, okay, perhaps this is the culprit... no way of knowing at the moment as I am at work, but if the wood is putting pressure on the barrel will it be visibly obvious?

Guess I'll wrap some sandpaper around a 3/4" pipe and have a go at it if this does infact seem to be the issue


On my K31 the wood contacting the barrel wasn't obvious until I started looking closely for anything out of the ordinary.

When I adjusted my sights I just used a brass punch and for the sanding part, I wrapped some sandpaper around a wooden dowel
and went a little at time.

It's now free-floated all the way back to about two and a half inches from the front of the reciever.

I would have to agree with Mavin when he states that sanding your fore-stock isn't necessary unless you're sure there's interference
with the barrel.

HollowPoint

[nitrohuck]

Ahh sorry I realized it was Maven who said that he used the nut splitter to move the front sight


perhaps the dollar bill test will do the trick for checking barrel contact, will give it a shot tonight and see how it goes!

[Maven]

nitrohuck, Also take a look at this article on accurizing the K-31: http://www.swissrifles.com/sr/pierre/accurizing.html It is quite easy to do and requires little gunsmithing or difficult to master skills. In fact, it takes less than 1 hr. to accomplish and can be undone if necessary.

[TreeKiller]

Huck
I sent you all the ones with small air pockets [smilie=1:

[NuJudge]

I have read over on the SwissRifles website about people getting this type of lateral change in POI when shooting very light loads. My cast loads in the 7.5X55 are not light, and I have not seen this.

Can I suggest, if you have not tried it yet, some Swiss GP11 and make sure you actually have that lateral change of POI.

If you are not willing to buy the adjuster or modify a nut splitter, you can adjust with a drift and a hammer. The Swiss heavily staked the front sight to keep it from moving, and you will probably have to use such for the initial movement. Use a vernier caliper to keep track of movement.

[NuJudge]

Some links that talk about lateral change in POI:
http://www.castpics.net/subsite2/ByFireArm/Cast%20in%20the%20K31.pdf
http://theswissriflesdotcommessageboard.yuku.com/reply/67460/Light-loads#reply-67460


The math of K31 front sight adjustment and nut splitter modification:
http://collectorguns35625.yuku.com/topic/3467#.UODIquQ0WSo

[nitrohuck]

Huck
I sent you all the ones with small air pockets [smilie=1:

LOL I knew it!!! :p

Thanks for those CB's btw, only put a few down the barrel, just getting used to them, sized all the 316299 and th c309-180 @ .314 down to .309 in my brand new fancy sizin die (not fancy, lee sizer)... Cleaned a bunch of cases tonight, will try and reload Monday and get some actual data for a range report

BTW thanks again for the almonds and pistachios also! haha, I've got some of our homegrown honey that I'll send your way and you can compare VT honey to your hive's products!


Thanks for the links fellas, I really should probably get some GP-11... I just haven't gotten around to ordering any mostly because a lot of websites are backed up with holidays and "Obama Scare" (yep, see what I did there? lol)

If anyone has some that they want to get rid of let me know, I'd take a anything and will pay the normal asking price, will toss up a WTB ad also.

Cheers for all the help guys, it has been a pleasure learning this info, applying it, and not blowing my fingers off in the process :guntootsmiley:

[TreeKiller]

Huck;
You got bees? Than send my funky old brood wax back. :-D

[nitrohuck]

Huck;
You got bees? Than send my funky old brood wax back. :-D

the stepdad does actually, he's been going nuts lately with his new bee craze haha, we just harvested something like 250lbs of honey, perhaps not a lot for someone who has done it for awhile, but I was blown away as this was his second time really doing it... I hear the unrefined beeswax is great for bullet lube and other uses?

Could probably even use it to lube up my new lee mold, I've yet to prep a mold before, as I've never cast a single bullet in my life, but that will be changing over the next couple of weeks!

ON TOPIC: just tossed up a WTB for some GP-11, from what I have seen around on the internet it definitely seems that they shoot a bit to the right with the lower power rounds like 16gn of 2400 (which is what I'm using)

Also, will be on the lookout for a nut splitter!

[nitrohuck]

Figured I would post an update so far, will have a real range report soon when I can nix out perceived variables:

Took out the rifle and at 50yrds I was having a tough time getting any decent groups together... all were clearly about 5-7" to the right, and large spreads to say the least... my m39 at that distance will hold all five rounds touching at 50yrds, so I know that while I am a novice, I wasn't missing THAT badly, and that the rifle must have not liked the bullet or powder charge.

Well all the sudden I hit pay dirt with 18 grains of 2400 and the Lee C-309-180, at 50yrds four of the rounds went into a 1" space (albeit completely off to the right side of my 8" target lol), with a single flyer about 2.5" out, this is most likely due to the fact that this was the second time I have ever loaded my own rifle rounds, no less cast boolits, so inconsistencies on my end are a major factor as I get settled in with making consistent rounds.

Will be messing around more with charges at around 18 grains and will see if I can get to 20+ grains with any decent accuracy.

I also have about 50 cast NOE K-31 boolits I need to have more practice with but have yet to lube/size/GC them, still waiting on gas checks to arrive in the mail.

I bought some GP-11 ammo from Grafs, so I'll expect to see it arrive in the mail in the next five years or so, :p they're runnin late to say the least