Key-holing powdah-coatwd cast 170s in 6.5x55 Swede

[Lefty223]

Just picked up a MINT Swede M38 bent-bolt Mauser short rifle, looking like it was just issued from the armory; only 1 tiny ding on it that should ‘iron’ or steam out.

Slugged the bore @ 0.267”, but only had some “cruise missile” clone powdah-coated 170-grain cast from Gardners Cache, also @ 267. The 170s are over anything in weight I can find in books, so I tried the ubiquitous ‘The Load’ of 16-grains of Alliant 2400, but they tumbled @ 50-yards & shot a 3’ group or bigger …

Now I hear that 6.5s can be TOUCHY to load for cast loads, and the Swede has a fast 1-in-9” twist … but heavier bullets like fast twists. My fear is I didn’t push them fast enough … but w/no published load data to go by … well, I’m out of ideas. Thoughts?

[Dutchman]

Swedish Mausers are not touchy to load with cast bullets. Military Swedish Mausers twist rate is 200mm.

First suggestion is stop trying to shoot 170 gr in the 6.5x55. Get some Lyman 140 gr 266469 or 150 gr 266673 @ .266" or .268". Keep velocity around 1,500 fps.

Carl Gustaf m/38. Shooting the same identical 170 gr cruise missile from Gardner's Cache as you have. Load was 13.8 grs 2400 at 50 yds. There is yaw in this bullet but was fairly accurate at this range.

[Lefty223]

Thanks Dutch! I have someone 140s on the way from M&M Bullets out of VT.

But from the looks of that target … in the meantime I should try the 170 cruise missiles that I have on hand with a lighter charge of 2400.

[Larry Gibson]

I did extensive testing of the 170 gr CM at velocities from 1200 to 2400 fps in my 6.5x55s. never could get the bullets not to yaw and sometimes above 1500 fps accuracy was very, very poor. All my testing was at 100 yards with some at 200 yards. Dutchman's load is down in velocity where the CM can be made to shoot reasonably well, at least at 50 yards. I also concur with getting a lighter weight bullet. I prefer the Lyamn or NOE 264455, a 130 gr Lovern design.

[Dutchman]

1915 Carl Gustaf m/38 with the original barrel. The scope is Tasco 6-18x44. This is what I test ammo with. I can watch a knat walk across the X at 50 yards. If a particular load doesn't shoot accurately its not the rifle or the shooter.

Many m/38 conversions made in the later years of use have Husqvarna m/38 barrels because the Gustaf factory was no longer making barrels for the m/96. The HVA barrels had the tangent rear sight already installed. The Gustaf rear sight is stepped. That's how you can tell if your rifle has a Husqvarna or Gustaf m/38 barrel. Neither is better than the other.

I have a hard time accepting .267" groove diameter on a rifle you say is "mint". Swedish military ammo uses .264" jacketed projectiles. A barrel so large as you say would not pass muster with inspectors and certainly wouldn't be very accurate. The Swedish use land diameter to gauge barrel wear. They use pin gauges at the muzzle and throat but we've never been able to ascertain the markings on the brass disc having been taken at the muzzle or throat. One of the enduring mysteries.



13.2 grs 2400 with Lyman 266673 @ 50 yds. Five shots into one hole. Velocity about 1,500 fps.



Tell me exactly the method you use to slug the bore. Do you oil the bore beforehand? Soft lead slug? Completely through the barrel? Do you have access to pin gauges?

How do you open the neck to seat bullets? Lyman M die or similar?

You ever hear: the devil is in the details...

Swedes are not difficult to shoot cast bullets. But like all things they have their own peculiarities. Think of them as a woman. No two are alike. Some shoot extremely accurate like my 1915 Gustaf and some don't. You have to learn those peculiarities of your rifle. I have half a dozen m/96 and one m/38 and I've been shooting 6.5x55 for 55 years. But I haven't been shooting cast bullets in 6.5x55 for that long so I'm still learning.

I recently snagged an older Ideal 266469 that drops bullets at .269/270". I had one of our members make me a custom .268" size die for my Lyman 4500 size-lube press. Modern Lyman molds of that number drop .266". Its not always about bullet diameter as evidenced the Lyman 266673 is .266" and shoots five shots into one hole at 50 yds. At some point you have to stop listening to bullet casting gossip and start shooting and find out first hand what works and what doesn't in YOUR rifle.

Dutch

[Lefty223]

SLUG - Barrel oil, soft pure lead round balls, mics to 0.0001”. Interesting comments about the stock disk, I don’t have enough it in front of me to double check the values stamped.

And no, I do not have access to pin gauges, that size anyway.

BARREL - Action marked 1942 Husqvarna. Has the Metallverken Vasteras micrometer adjustable rear sight installed.

JACKETED - It shoots ~1 MOA @ 100-yards w/ 129-grn Spitzers.

CAST LOADS - I should have the 140s in next week and will play around with them, also the ‘M’ die has been ordered.

Where as I already have them on hand … I have nothing to lose by trying that light load with the 170-grn cruise missiles.

I do thank you BOTH for your input! And the only ‘gossip’ I had heard, when looking for a 6.5 cast boolits that were “in stock”, was that they were hard to get to shoot well.

But I will refrain from such internet gossip and will listen to you gentlemen. Many thanks again! I will update this post later with updates …

((Nice target there by the way! FYI, after I do load development at the bench, all my shooting is offhand … )(

[Adam Helmer]

Lefty,

In my experience, keyholing bullets are caused by too much velocity, or too little velocity, or a bad muzzle crown. I hope this helps.

Adam

[Lefty223]

KEY HOLING - Thanks Adam, I think in this case it is too much velocity, but I’ll confirm on SAT.

STOCK DISK - Bore condition is 1, Land measurement marked as 0.649”, Torped shows 0 strecks. The stock also has the little placard for sight adjustments out to 600-meters on it.

SIZING - FWIW I’ve had ‘undersize’ cast boolits shoot great in some rifles before, like my 1870 Vetterli-Vitali 10.4x47R of 0.429” bore that I need to size boolits to 0.426” to get them to chamber, due to the original ‘heeled bullet’ design. In competition last year I shot a 10-shot 3” group with them - offhand @ 100-yards - to take 1st place in a weekly milsurp shooting event.

[Larry Gibson]

Several .264 jacketed bullets shoot moa in my Swedes. Mostly the flat based softer cup/core bullets of 120 - 140 gr. However, all three of my 6.5x55 Swedes lug out at .266 groove diameter. They pin gauge .255 at the muzzle. Chamber casts reveal they all have a tapered throat measuring .268 at the chamber mouth and tapering to .266 at about 2/3 the throat length to the lead. I prefer the Lovern designed 266455 (129 gr) and the 266469 (140 gr). I size them at .266 and seated out to the leade (rifling) the then "fit" perfectly in the throats. I suppose one could have a tapered bullet made to fit the throat, but I doubt any accuracy improvement would be obtained given the sublety of that change.

[mac1911]

I think the biggest problem we face with the swede is your reaching some high rpms with the 1/7.8 twist at lower velocities.
I can just sneak down to low 2 moa in the 1300-1400 fps range then right at that 1550 range it just falls apart.

[garrisonjoe]

My Swede 96 will keyhole and tip cast slugs starting at about 1700 FPS and faster.

So, I load cast at 1600-1650 FPS. Several molds will hold 1.5 MOA and the Lyman 266673 (150 grain) cast at about 16 BNH and sized to 0.266", pushed by 17 grains of 5744, will get down to 1 MOA. The NOE 270-163 mold is also capable of 2 MOA with several powders.

good luck, garrisonjoe