boolit selection for k-31

[mike in co]

ok...my latest k-31 is 0.296 x 0.307.........
with the short throats of the k-31 and the narrow dia....what to i select and what do i size to ?? 309 ok or all the way down to 308???

thanks
mike

[C1PNR]

Good question!

Do you have any Lyman U moulds? It might be a place to start.

[versifier]

.309 should be fine, but it wouldn't hurt to try a few at .308 and compare groups. It's really up to the rifle - it may prefer .310, or it might like them all and not be picky. Nobody but your rifle itself can answer that question.

[BudRow]

What is the significance of the "U" mould? Sorry for my ignorance.

[Ricochet]

I'll tell you why I've recently bought a .308" sizer: My K-31 has a throat that goes directly from a loose fit around the case neck (just large enough to fit a .311" boolit in) to .308", about 1/16" in front of the case mouth. It's a square shoulder, no taper. Anything above .308" gets shaved. The rifling origin's just a little farther into that .308" section. If the boolit is any bigger than .308", it has to stop against the chamber shoulder, not the origin of the lands.

Yours may differ.

[Ricochet]

And "U" is Lyman's designation for a mould that casts bullets undersized for the nominal diameter of the mould design.

[mag_01]

------- For the K-31 I use a 200gr. boolit sized .309--gas checked and I see no problem with fit ---leading----loading----Sure is a great shooting rifle----Mag

[texas tenring]

The K-31 has a very short and tight throat! I think we need a group buy that fits the Swiss rifle.

My K-31 slugs .306 I have'nt done a chamber cast but I know enough from loading those full length gas check projectiles that the throat is short and tight.

If we were talking something else, I would be in Heaven. (Forget that!)

I'm really disapointed!!! Since I started casting my own boolits I found out that size dose really matter!!!!!!!!!

[JerryW]

I've had good shooting out of a Saeco 315 in my K31. JerryW

[B747]

The two boolits that have worked very well for me in the K-31 's are the RCBS 165-SIL and the Lyman 311672 (about 162 gn with the GC).

I have sized them at .309, .310, and .311 and found some accuracy fall off at .311.
I now size at .310.

Great accuracy from loads down in the 1300 fps range (10.0 gn Unique) up to 1700 to 1800 fps with powders in the AA5744 burn rate.

The long 200gn boolits will also work, but you will have to either taper size the nose diam down to fit into the bore or seat well below the neck/shoulder.

Wally

[Bob S]

For my K31's I use the Lee C312-155-2R (the 7.62 x 39 bullet from Lee), or the Lyman 311672. Sizing depends on the rifle. I have one rifle, 1962 overhaul date with a .3092" groove diameter. I size the Lee bullet to .310 for this one, but with most others, .309. With 16 grains of 2400, it regularly wins or places in "as-issued" matches. The five shot groups fired from prone with the issue sights are pretty consistent at 1-1/2-1-3/4" at 100 yards; if I put the clamp-on scope on it, under 1-1/2".

I have one rifle that has about 5000 rounds of jacketed ammo through it (NRA High Power XC) so it has a "throat" of sorts. Groove diameter is .307+, and it will take a Lyman 311299 sized to .309 with the GC at the base of the neck. I do strive to keep the GC in the neck as grouping in my experience is more reliable that way.

Speaking of K31's, I got some new "ballast" for my hat, a 2" K31, from Frank Binendijk :



Resp'y,
Bob S.

[mike in co]

bob do you shoot with the east coast navy shooting team...seems i know someone out there...from the old shooters.com.....steve....i think

[Bob S]

Mike:

I was a shooter, coach and sometimes team captain/OIC of The Navy Rifle Team from 1986 to 1993, when I retired. When I retired, I really pulled the plug and have not really kept up with who's who. I still get the message anouncements for the LantFLT/ PacFLT and All-Navy matches, and some times I get the match bulletins, too, but I don't recognize most of the names. Some of those guys/gals were probably still in diapers when I was with the team. If you're talking about an "old timer", we may be acquainted.

Resp'y,
Bob S.

[Ricochet]

That little K-31 pin is too cool!

[bravokilo]

Barrel dimensions:

http://castboolits.gunloads.com/show...&highlight=K31

http://castboolits.gunloads.com/show...&highlight=K31

http://castboolits.gunloads.com/show...&highlight=K31




Bullets:

http://castboolits.gunloads.com/show...&highlight=K31

http://castboolits.gunloads.com/show...&highlight=K31

A little bit of checking would have shown that your barrel dimensions are pretty much standard for a K 31. I did not include all of the links I found on recommended bullets as some seemed to repeat the same information. Of course I didn't even check any Swiss rifle forums, they probably wouldn't have any worthwhile info anyway, right?

http://pub18.ezboard.com/btheswissri...ommessageboard

http://www.gunboards.com/forums/forum.asp?FORUM_ID=37

Any more legwork that you need done?

BK

[mike in co]

bk, a supporter of joe, has assigned himself the job of 'HELPING" me with this task.

similar to joe, he cannot digest what he reads.

his first reference...the poster has no size listed for his bore, so useless, and only has one mold...so no reccomendation,the later poster does list a bore size, but does not reccomend a bullet.

i will not go look at the rest

i do not need this kind of 'HELP"

thanks
mike

[bravokilo]

for expecting you to read past the first post.

Barrel:

Link 1

My K31 sized out at .295 x .307, so I'll start at .309 diameter. Starting at .311, without knowing your bore diameter, seems just a little on the large size. Especially considering that the K31's seem to come in a little on the smaller side.

However you go, I'll be very interested in your results.

Link 2

ok right off the bat....i shot sierra 174 311's. i slugged the muzzle and my k31 is 310 x 302. this was a major disappointment, but it was a cheap gun from big 5. this was the same load i use in my 91/30 with hornady 174 hpbt. just a few to put the scope on paper. i used weaver rings which gave a nice rezero. spent some time centering the mount mostly up and down with a minor left right adjustment. put the scope on, fired a round....adjusted the mount a bit left to right...and then again. put a target at 100yds, fired a two rounds getting a better zero...then put three rounds in the x ring( an sr-21 target.....less than an inch.

best i can tell the mount did not move and these were some stout loads...flat primers....

Link 3

FWIW, I have one that slugged .295 x .307. Should be a good candidate for the moulds that throw a little undersize.
__________________

The grooves on my 1942 vintage K31 run just over .306"

Have slugged 3 different K31's. .306+ on 2 of them and 307 on the other one.

My K-31s slugged .306, .307 and .307.

jh45gun, just for the heck of it I slugged my K31 .295x307. The metal is really nice and so's the bore but the stock looks like someone rode it hard and put it away wet.
Going to get another when I get the bucks. Frank


Bullets:

Link 1

Harder to find a cast load that doesn't shoot well then a good one in my three K 31's. Favorite boolits are Seaco #315 & Lee 155gr sized .309. Lots of powders work, but being as fugal as I am my favorite load at this point in time is the #315 in front of 19gr WC 820. My 820 is AA 9 burn rate. On the days my eyes are working right that load will shoot 1 1/2 inch groups on a calm day at 100yds off a bench with issue sights set on the lowest setting. Those K 31's get shot more often then any of my other rifles. I just can't tell you how addictive they are. Have fun.

Pb head

I've used Saeco 254 -- a 115 grain bevel based plinker -- with 15 grains of WC820 (aa9) for a good 50 yard load. Sized to 309. Shoots to the right but very fun and cheap.

1Mau., The 19gr. WC 820 + Saeco #315 recipe is right on the money! All you have to do is to remove all Cu fouling from the bbl., size your CB's (more to follow) to .309", FL size your brass and you're in business. Btw, 21-22gr. AA 5744 or H/IMR 4198 will also work very well. As for CB designs, the K-31's seem to shoot most of them (Ly. #s 311291, 311041, 311466; Lee C-309-180R, Lee 113gr. "wadcutter," etc.) exceptionally well, but you'll have to seat them deeply into the case, given the abrupt throats on the carbines. Btw, if you have a Lyman pistol powder measure, rotor #11 will give you ~19gr. WC 820. Slow-burning milsurp powders will also work, but you'll use substantially more of them (and mag. primers as well): 47-48gr. IMR 5010 + .7cc Grex; 47-48gr. WC 860, NO filler.

Link 2

If memory serves, some who shoot the K-31 have posted good results with the Lee C312-155-2R and the RCBS 308-165-SIL. The Lee boolit is a single cavity in standard form; unless you can find one of the 6 cavity group buy examples that Leftoverdj recently honcho'd for a custom run.

I have had good luck with most of the Lee 30 cal bullets in this gun. The noses on most are undersized anyway and this works well with the K31's tighter bore. I use the Lee soupcan with 4.5 of Red Dot for plinking. The Lyman 31141 seated so the front band just engraves is a good load also.

Wayne, What KCSO and S. Wheeler said! The K-31's short throat doesn't preclude the use of CB's at all. As KCSO mentioned, many of the bore riding designs, e.g., the Lee C309-180R, Ly. #311291, Ly. #311284, do have noses that are small for .30cal. (.308") but not 7.5mm (.307"). Also, seating CB's below the [case] neck-shoulder junction doesn't detract from accuracy in the least. Further, you'll be happy to know that K-31's shoot many different CB weights and designs very well: They handle the 113gr. Lee "soupcan" and the 200gr. Lee that S. Wheeler used shot very well. Indeed, I've had better results in my K-31 with the Lee C309-180R and Ly. #311291 than in my .30-06. Even the .30HBC shoots OK in the K-31.


For a mould , I like the RCBS 308-165-SIL, sized .310.




Like I already said, if you had looked at the barrel links you would have found that your dimensions are pretty much standard. I found only one that varied to any great degree. I wonder who has that one?

If you HAD looked at the bullet links you have found pretty much the same recommendations that you have found here. I think it would be pretty safe to expect most the recommendations would work in the AVERAGE K 31. I personally vote for the RCBS 308-165-SIL. It works well in ALL of my K 31's.

BK

[mike in co]

for expecting you to read past the first post.


ok right off the bat....i shot sierra 174 311's. i slugged the muzzle and my k31 is 310 x 302. this was a major disappointment, but it was a cheap gun from big 5. this was the same load i use in my 91/30 with hornady 174 hpbt. just a few to put the scope on paper. i used weaver rings which gave a nice rezero. spent some time centering the mount mostly up and down with a minor left right adjustment. put the scope on, fired a round....adjusted the mount a bit left to right...and then again. put a target at 100yds, fired a two rounds getting a better zero...then put three rounds in the x ring( an sr-21 target.....less than an inch.

best i can tell the mount did not move and these were some stout loads...flat primers....

Like I already said, if you had looked at the barrel links you would have found that your dimensions are pretty much standard. I found only one that varied to any great degree. I wonder who has that one?

If you HAD looked at the bullet links you have found pretty much the same recommendations that you have found here. I think it would be pretty safe to expect most the recommendations would work in the AVERAGE K 31. I personally vote for the RCBS 308-165-SIL. I works well in ALL of K 31's.

BK

gee i dont know...but maybe you could tell me what this link has to do with small bore and cast boolits.....

THATS TWO DOWN......

stop..i do not need your version of 'HELP"

mike

[bravokilo]

I included that one to show that was larger than the norm(1out of 11 examples). From that we can infer that most of the reports on bullets that don't list their barrel dimensions have barrels that fall within the average, ergo they would be valid suggestions for your barrel. Or you could look at the threads and see if you could match up posters who listed their barrel specs in the first links and see if they also gave recommendations in the bullet links. Of course you would actually have to READ the complete links first. Anything else?

Somebody help me out here. Is this really that hard to follow?

BK

[mike in co]

only for you....
i asked specific questions looking for specific answers....
silly me
see i did a seasrch and did not find WHAT I WAS ASKING FOR......

so i started a thread...thats how it works here....

i try not to make ASSumtions........instead i ask very pointed questions.

no its not hard at all.....


not about the NORM, nor INFERED

HARD DATA ABOUT SPECIFICS IN MY ORIGINAL POST......

your version of HELP is not needed

mike in co
by the way...the rifle you brought up won a 200yd match with that larger than norm bore.....