6,5x55

[Ian]

See Spindrift, I wasn't crazy by saying sometimes the bullets like a little room (static fit clearance) to do their thing.....but giving them some room can work against you with a two-diameter, parallel-sided bullet not well supported in a conical throat. You can see that your NOE bullet is capable of aligning itself quite well if you set it up to do so by the static fit part.

 

[Spindrift]

Yep. Point taken, just takes a bit of time, sometimes .
Thank you all, for your patience and good advice.

 

[Spindrift]

Tried some different GC- materials today. Hornady copper checks, VS various home- made checks. 0,012in alu, 0,006in alu and 0,004in beercan. The flimsy beercan checks actually crimped on quite well, and passed the «nail test». Making perfectly concentric checks with thin, flimsy materials is not easy. And, as you can see, I have accepted a few less- than-perfect checks. When crimping these thin checks on with a push- through, you need to send the base first, or you get horrible bases. The thicker alu checks got some aluminum extruded into the lube gap, limiting capacity.



A couple of 5- shot groups with each check constitutes no real «test», but it was interesting to see how well the beercan checks worked today. The thin material makes check cutting/forming effortless. And while my in-house production of empty beercans is pretty low, there’s no shortage of people who seem to be trying to plant beer trees by throwing cans around. Nice to be able to make proper use of them

100m, prone position, 5 shots. NOE 266-140, beercan checks, N120- 19grs. Not breathtakingly accurate, but on par with my better groups, with this bullet.

 

[fiver]

I've seen guys double the thin checks up.

that thicker Al. check looks real nice,, if a little long.
I'd probably run with that.

 

[Spindrift]

Yes, the thickest alu check (2. from the right) looks really nice, and works well- but so far, it doesn’t work better than the less attractive ones.... I’ll shot a bit more, and see.

 

[fiver]

at pedestrian speeds if your getting the base square and the edge consistent you can get away with a lot of other stuff.

I have a lot of jacketed bullets that form a little ring right on the base.
I think it is from the press camming over right when the bullet comes to a stop in the die, I can see a perfect impression of the punch in their base so I know everything is pressed square and tight.
I also get just a hair more core pushed out the nose on them. [this is how I sort them]
as long as it is square and even it doesn't seem to bother the bullets as much as I thought it would.

 

[Bret4207]

"...trying to plant beer trees...". I laughed at that one! Fair warning, I'm stealing it. Too funny not to use! Well done!

Fivers dissertation on dynamic fit and Ians follow up on visualizing the whole event are worth creating a sticky for them. There is so much happening in that brief time period between the primer lighting and the bullet leaving the muzzle. I've put myself to sleep many a night thinking it over and visualizing what I imagine is happening. Wouldn't it be wonderful to be able to KNOW exactly whats happening?

 

[popper]

Only time I've seen targets like #89 is due to bad base. Did an experiment with 40swPB, nicked the base purposely. Other was 145gr PB in 300AAC 1:10 @ 2100 fps . I was experimenting with when to cut the sprue - when just 'solid'. Really nice cuts but IMHO the plate lifted just a bit at the end of cut and base was off kilter. Not enough to see but presented a nice circle group @ 100. They were PCd and as it's an AR, ~20-50 off the lands. The base is angled like a lube groove with a very truncated GC shank. Intent is to have a very well defined 'aperature' when the bullet leaves the crown in this case IMHO, the base was crooked enough to create the round group. Holes are nice round ones but a cycloid trajectory. Bullet is shaped like the one you used with slightly larger meplat. My 'normal' groups are typically random, within the 'cone' of fire - usually with a flyer or 2..

 

[Spindrift]

Thanks for the tip, Popper!
The bases were considered «good». But what is good enough? That’s a tough question. I have tried to focus on casting technique this autumn, I think it is the factor where I have the most to gain at the moment. Been casting bullets for 5-6 years now, and still a freshman- you know how it is. Lots to learn, many variables. But it is really helpful to be in the educational and friendly environment of this forum!

 

[Ian]

Popper is sure right about the importance of square bases or base band on a PC unchecked bullet. Another thing that will get you is slightly crooked sizing or slightly out-of-round castings. When the elliptical casting gets sized, the base band is wider (longer in the direction of bullet travel) at the parting line and that base edge of the base band is what the crown sees. If the bullet happens to get sized slightly more on one side than the other, the band base will be irregular and a flyer will result.

 

[Rick]

Here's how I envision the need of perfectly square bullet bases. Imagine a camera with a uber fast shutter speed and you capture a stills photo of the bullet base the very instant it's in free flight. Except . . . The bullet base isn't perfectly square to the bullet and one side of the base is still just slightly in contact with the crown but the opposite side of the bullet is in free flight. There is still pressure behind the bullet at the muzzle, not nearly peak pressure but still pressure and with one edge of the bullet base still in contact with the crown and the opposite side free of the crown the bullet will be tipped. How much tipping of course depends on how far out of square the bullet base is and how much pressure still remains at the muzzle.

 

[CZ93X62]

What Rick said. This makes empirical sense, even to a non-scientific mind like that of Yours Truly.

What a GREAT THREAD.

 

[fiver]

it's only like 500 psi or 2500 psi what could go wrong.

 

[Ian]

More like 10K typically with full-power rifle loads. As low as 6K and sometimes more like 15K with shorter barrels, but that is the typical range I see with Quickload. I look at this stuff because high muzzle pressure stresses suppressors.

 

[Spindrift]

Last range trip, I shot some Arsenal 266-92, in my Rem 700. Two parameters were tested; various gas checks (beer can, 0.006in aluminum, hornady GC) and jam fit vs 0.03in jump. The load was 19grs Viht N120, which is approximately 1900 fps.
Two observations:
1) At this level, I got better accuracy with thicker checks. Not shocking, I suppose
2) The loads with a little jump were equal, or better, than those with a light jam fit with respect to accuracy

I also shot two four- shot groups, where all the bullets in the group had different gas checks. Beer can check, 0.006in alu, 0.012in alu. Hornady copper). Both groups were 2 MOA, at 100m. Not prize- winning accuracy perhaps, but better than I expected.

 

[Rcmaveric]

Not bad. Better results than I get with a 260 Win which is very similar to the 6.5 x 55. I use the NOE 266 140 with Shooters World Buffalo Bore. For about 1450 FPS. One day that riffle is going to get a new barrel with 1 in 10 twist..... it has a 1 in 8.

 

[Spindrift]

It was time to shoot some cast 6,5 bullets again!
Today, I was shooting my Rem 700 custom rifle, with my newly aquired Vortex Viper 4-16x. I’d like to develop some loads capable of harassing steel plates at slightly extended ranges. The obvious choice among my moulds for long-range, is the NOE266-140 («creedmoor»). It has a stated BC of 0,4203, which is very good for a 140grs cast bullet.



I haven’t shot this barrel much so far, so my main objective today, was to establish sizing preference with PC bullets, and maybe find some promising loads. It was a nice day, a little breeze, some snow on the ground and temp just above freezing.



I shot a few loads over the chrony. All powders by Vihtavouri.

N120/20grs: 1840fps
N140/31grs: 2234fps
N140/32grs: 2300fps
N150/33grs: 2300fps
N150/34grs: 2420fps

Homemade GC from beer can material, installed before coating (they work well).

.265 shot consistently better than .266. I’m pretty happy with both the accuracy and velocity so far. The .265/N150 loads gave 1,5MOA 5-shot groups at 100m, while N120/2grs gave groups at about 1,1MOA.

The N150/34grs at 2420 should stay supersonic to about 850 yards. I hope I can tune the accuracy a bit more, this was only the first test, «fishing for loads»

 

[waco]

I’d like to see the long range steel reports!!!

 

[Spindrift]

I'll keep you posted! My range lacks proper long range possibilities, but we have steel plates to about 380 yards. Should keep med busy for a while!

 

[waco]

380 is a good stretch. Someday I’ll see if I can get out past 500.