K31... cast advice?

[MW65]

Picking up a k31 from a member at the local rifle club... was looking at using cast thru it and potentially shooting it at the silhouette match (requires cast loads)

Any thoughts from the peanut gallery about using cast rcbs 30-180-fn? Any peculiarities with the k31s I need to know?

Thanks!!
Andy

 

[462]

I had two that went bye-bye many years ago, one walnut the other beech, but load data memory is long lost. At the time my only .30 caliber mould was an Ideal 308291, powders mostly were 2400, Unique and probably one or two others, their short throats meant deep seating, and accuracy was excellent. I could never get used to the inward turned front sights' protective ears, though.

 

[Ian]

Tight bore. The bullet to use is the MP 30-180 silhouette.

 

[Spindrift]

I have no idea myself, but I’ve noticed NOE have a mould that is supposed to be designed for the K31. PB in stock.

311-195-RF-J1 | NOE Bullet Moulds

noebulletmolds.com

 

[fiver]

if i'm rememberin correctly that NOE is a Bob Kell design.
the rcbs 30-165 silhouette shoots right nice in the K-31 too.
the NOE is a modified [in front of the front drive band] version with the throat taken into account.

 

[Bret4207]

A Ian said, they run tight. Outstanding rifles, but they aren't your run of the mill surplus military job. IIRC standard specs are .300/.308 and they don't vary at all except to get a little tighter, like .299/.307. The RCBS30-180FN is a great design, but a bit long I fear and if it's typical RCBS it will run a little fat for these guns.

 

[Intel6]

They don't have much of a throat so depending on what you use you will need to seat deeper than usual to get the action to lock up. The NOE bullet has a slight step in the bullet to compensate so the bullet can be seated to "full" length. I picked up the NOE mould when Al first made it and I have only used it. It is a good shooting bullet, no complaints. Others can work, just need to try them as I have seen lots of other designs used with good success..

 

[Maven]

What was written above matches my experience with 2 K-31's as well. CB's such as Ly. #311466, #311291, and Lee C309-180R were very accurate in my rifles when sized to .309" and seated into the [very short] throat. Btw, #311291, whose nose was too small for my .30-06, had to be seated deeply into the case, but a nose reducing die allowed a longer OAL for the K-31. (Ditto the Lee CB). Propellants that worked well were all the usual suspects, i.e.. 18 - 21gr. WC 820/AA #9; 18 - 21gr. IMR 4198; 18 - 21gr. 5744. Unique is also a good choice...in small doses (10.5 -12.5gr.), but I've never tried it.

 

[MW65]

Thanks for the insight! I'll go over my gaggle of 30cal moulds and see what's usable and checkout the Rcbs 30-165-sil, Al's 30-195, and mp30-180...

Not seeing much load data in the manuals I have.... thoughts on interpolating 308 data for the 7.5 swiss?

 

[4060MAY]

My K31 had a .297 bore and .307 groove, first tried RCBS and some Lyman molds, all of the ones I tried were too large for the bore, my friend made a nose sizing die for the 30-180-sp and 311299, sized the bore ride section to .297.
ordered a mold from Mountain molds that fit the rifle, using SAECO 301 as a guide for the shape, and it shot well, shot a postal from the other site with the 308329 (I think may have been 359) 180gr long pointed bullet.
bought the NOE mold made for the K31, and this shot consistently 1 1/2MOA, with 78yo eyes at the time, factory sights.
my friend had some Chinese powder BW-36, said 4895 burn rate, not really more like 3031, no flash supressor, used it up went to Benchmark at 32 grains, very good accuracy

I have about 200 bullets sized and lubed .309, if you want to try the bullet, free for the shipping...PM

mountain molds target 100yds, postal was at 50yds

 

[Maven]

MW65, For cast bullets, I'd certainly interpolate/use .308 data. Also, if you have someone make and use a nose reducing die, you'll find a longer OAL gives better accuracy with the same CB. Lastly, if you have or can obtain Lyman's #311644, i.e., the original design, you'll find it to be quite accurate when sized to .309".

 

[Ian]

Accurate can make you a mould, too, but you need a pound cast to see what you have first.

The MP 30-180 silhouette has two tapers to the nose, the first being narrow and going from about .295" at rhe ogive to around .301", then it gets more abrupt and tapers up too the first driving band. This design requires no nose sizing to fit any .30-caliber rifle regardless of how tight or loose the bore is or how short the throat.

 

[fiver]

just like the old red-dot 'the load' worked in everything within reason.
the 7.5X55 is just a 284 win case necked up to 30 cal.
[i actually use 284 cases necked up in one of mine, the rim is slightly different, but for bench use no problem]
this means you have the same case capacity as the 0-6/303/7.7 jap type cases, and all of those will give you good cast bullet data.
BTW i use unique in the boys 98-11, and it's stupid accurate at 50yds.

 

[Bret4207]

I have a SAECO 30 cal RG-4 mould that drops with every spec undersized. I was going to sell it until someone mentioned it was about perfect for my K31. It's like they were designed for all those "skinny" moulds out there.

 

[MW65]

Thanks to a very kind member, (thanks 4060may!!) I'm now a proud owner of a noe k31 mould. Going to try load development and get ready for some fun silhouette or milsurp matches. Thinking 2400 and maybe rel7... any other powders I should look at?

Thanks!
Andy

 

[Maven]

Here are a couple of powder suggestions since I have little experience with either 2400 or Rel-7:

18 - 21gr. WC 820/AA #9; 18 - 21gr. IMR 4198; 18 - 21gr. 5744. Unique is also a good choice...in small doses (10.5 -12.5gr.),

 

[MW65]

Here are a couple of powder suggestions since I have little experience with either 2400 or Rel-7:

18 - 21gr. WC 820/AA #9; 18 - 21gr. IMR 4198; 18 - 21gr. 5744. Unique is also a good choice...in small doses (10.5 -12.5gr.),

Thinking also guard cartridge loads like for 308/30-06.... bullseye with no gc cast... thanks!

 

[MW65]

Sorry... no pictures, but noe k31 mould works really well thru my toy.

Initial load was 2400 powder @16gr. Nice mild load, with some Kentucky windage got me on the 200yd rams consistently. 500yd setting for 200. 300yd setting for 100yds... and 100yd setting for 25.

Thinking about testing 90gr swc to see how much fun it might be...

 

[fiver]

if you don't already have the Mold.
LEE makes a little 113gr. flat nose G/C bullet that'd maybe even feed from the magazine.