Is this a crimp groove or just an inflection point?

[brewer12345]

I cast up a bunch of these today for my 350 Legend: http://www.accuratemolds.com/bullet_detail.php?bullet=36-180L

I tend to be oriented on crimp grooves, but I am not sure this boolit has one. What I am wondering is whether I want to be crimping at the first spot just below the truncated cone before the cylindrical part flares out. I will be powder coating, so no worries on the lube grooves. Should I just seat to the OAL I want? Something else? I won't be anywhere near max charges since this is meant as a downloaded plain base load based on whatever shoots best out of trail boss, unique, or 2400.

[RickinTN]

It does not have a crimp groove. Seat to where the bullet gently contacts the throat, wherever that is. I really like the Lee FCD but will caution to not overdo it.
Good Luck,
Rick

[greenjoytj]

Nice looking Boolet.
I would use the tapered area between .385” to .415” to roll in my crimp if the firearms action and chamber length allowed for the resultant C.O.L.

[brewer12345]

Nice looking Boolet.
I would use the tapered area between .385” to .415” to roll in my crimp if the firearms action and chamber length allowed for the resultant C.O.L.

That is where I was thinking. I need to coat these, age them, slug the bore, and figure out what to size them to first. Then the fun starts.

As an aside, I cast a bunch of Lee 452-230-TC with a new mold first then used my Accurate mold for the first time. The Lee is competent enough for mass production of pitol bullets, but the Accurate mold is obviously of way, way higher quality. I was really impressed.

[Dusty Bannister]

It appears to me that this bullet is cut to have the nose at bore diameter. The remaining driving bands appear to be cut for groove diameter. Once you apply powder coating, all those tolerances will change and may not even chamber past the ogive. You might find it not practical to powder coat this bullet. I think you would be wise to try the bullet as cast to check for fit before you waste time and effort powder coating and making the bullet that much larger at all points along the axis.

[tankgunner59]

I agree with RickinTN, I use the Lee FCD in all of my calibers. But you have to experiment to decide how heavy to make your crimp, too light and you could have a problem with boolit set back and too tight and you could have serious pressure problems.

[brewer12345]

It appears to me that this bullet is cut to have the nose at bore diameter. The remaining driving bands appear to be cut for groove diameter. Once you apply powder coating, all those tolerances will change and may not even chamber past the ogive. You might find it not practical to powder coat this bullet. I think you would be wise to try the bullet as cast to check for fit before you waste time and effort powder coating and making the bullet that much larger at all points along the axis.

Will keep this in mind as I experiment. The rub is that the bullets cast right at 360 and I have read that the bores on these rifles can be anywhere between 355 and 358. 358 and as-cast should be fine. 355 and as-cast may be an issue.

[mehavey]

I need to coat these....Do not uniformly PC those bullets.
The forward band the you refer to as the inflection point, is really designed to fit the short freebore/throat of the LEGEND chamber.

https://i.postimg.cc/BvmysqqS/350-Legend-ACC36-180-LG-Norma-200-sm.jpg

PC-ing will build up that critical diameter -- which is unsizable -- and jam thing up.
(Instead, learn to love a thin coat f ALOX again. It's magic stuff.)

[mehavey]

BREAK BREAK... I looked back in my emails to Tom Ellis at Accurate when I remembered that I was the one who had him cut the first plain-base 36-180L by filling in the gas check shank of the LG.

In my earlier correspondence to him of 07/25/2020...

BTW: On a bet, I shot my standard 36-180LG powder-coated/#2 and without the gas check on the base yesterday.
It shot ridiculously well (.1.25 MOA @ 100) out of my 16" AR Legend.
Clean it it up to a true plain-base and no telling.... <grin>

So try the PC... maybe your chamber will like it.

[brewer12345]

Confusing, eh? I am leaving the rifle alone for another week or so until a permit runs out that I have been using it for. After that, I need to slug it and contrast that to the forward section measurement and decide if I want to powder coat, tumble lube, or whatever. Will also need to size based on the slugging results.

Based on weight I have a little over 400 keepers from my casting session, so I should have enough to experiment with if I want to try powder coating vs. tumble lubing, different sizes, etc.

[brewer12345]

Oh yeah, I should mention this is not going to be a high pressure exercise. I am after a low pressure, low speed, low blast accurate load for 50 yard shots and under.

[high standard 40]

My thoughts on the bullet referenced in the OP. While that bullet does not have a crimp groove as such, the shoulder just below the ogive is intended to be used as such. The nose section just above that crimping shoulder is reduced in diameter to .350" which should be about bore diameter on most 35s. Thompson Center hand guns, Encore and Contender, are famous for loose chamber throats. For this reason, I wouldn't personally consider this particular bullet for an Encore. That bullet would likely not make a smooth transition from case to bore and may not yield the best accuracy. That bullet was likely designed for a chamber with little or no leade. The RCBS 200 is a hard bullet to beat in most 35s and Accurate offers a design that is a near clone of the RCBS 200.

[mehavey]

The bullet was deliberately designed for the 350 Legend SAAMI chamber.
So no crimp ever intended.

The short section(s) above the case in Post#8 (http://castboolits.gunloads.com/showthread.php?421022-Is-this-a-crimp-groove-or-just-an-inflection-point&p=5139995&viewfull=1#post5139995) fit both freebore leade, and then bore itself.

[mehavey]

-- Delete --

[BK7saum]

The 350 legend is designed to utilize a taper crimp as the case headspaces on the case mouth. A roll crimp or too heavy a crimp will cause misfires or high pressure upon firing due to locking the bullet into the case as the case itself is forced into the leade.

[brewer12345]

Thanks for all the pointers, guys. I am going to start with tumble lubing about 50 boolits to play with. I have one more potential hunt with this rifle as-is in the next week or so and then I will clean it, slug it, and start to figure out what to do.

MEHavey, do you know what your bore slugs to? Looks like you sized to 357?

[mehavey]

I generally don't slug the newer AR actions (223/5.56, 6.5G, 350L, 500Beo, etc) as they're "generally" built to spec
(and the flash suppressors/brakes make life miserable) :roll:

That said on the Legends (this one a CMMG upper): I've run the Speer 180FP sized .356/.357 to superb effect;
and cast from .357/.358 (ditto)

Empirically... it acts as a SAAMI .355/6

[brewer12345]

Great, thanks. Will see what my barrel is like, but I tumble lubed 50 and unless I see radical differences I will probably start by sizing to 358. This thing shoots factory FMJ and Hornady interlocks quite accurately.

[mehavey]

If those are factory-loaded Legend, you might measure/find they're .355/.356

[brewer12345]

If those are factory-loaded Legend, you might measure/find they're .355/.356

Been shooting Win FMJ with a 145 grain bullet. Guessing it is a 355/356 bullet as well. Which means a 357 or 358 sizing is probably indicated for my cast. I may play around with some 147 grain 9MM JHP loads as well, but I really want to make cast work.

[cainttype]

Follow Rick’s advice in the second post, seating maybe just short of your bullet encountering resistance from being too long (contacting throat or rifles origin).

The SAAMI standard for the chamber was .357”, so larger than .3565” in the throat will likely not work at all.
I had to open mine up to take a larger diameter.

Tom’s bullet has short a .350” diameter section above the top driving band, so it looks intentional (and smart) so PCing there doesn’t create a problem with oversized projectiles.
I think you’ll likely see a .356” or .3565” sizer die handy here, fitting any driving band area outside the case mouth.

You should try no more than removing the bell of the case mouth after seating... You’re not dealing with much recoil (or bullet set-back from it), and you don’t need heavy tug to burn slow powders when you’re using lighter loads using faster powders.
As long as you have enough tension when the projectile is seated, worrying over a crimp probably isn’t necessary... It also headspaces the way it should.

[brewer12345]

I have 356, 357 and 358 sizers. You would try the 357 first?

[cainttype]

With .357-358” you will only be sizing the driving bands, but if you seat out enough for the driving bands to be beyond the case mouths, I “think” you’ll like run into resistance pretty quick in a proper chamber.
Seated at the top of the first drive band may be OK.

I’d likely try .356” first, and would maybe be able to get a little more COAL.
It should slip-fit the throat. If it shoots well you can always experiment with others later for fit, function, performance.

[brewer12345]

Thanks, CT. Now I just wonder if I can get away with sizing down 4 thousandths.

[cainttype]

You usually can, but if needed you have the option to go .358”, then .356” if wanted.

[cainttype]

Using alloys that don’t have a lot of antimony will help.. and sizing ASAP after cooling casts.

[mehavey]

Size down 4 thousandths? (Goodness... what are you starting with ?)

Note that Tom's 36-180LG (which is just the 'L' w/ a gas check)
chambers fine sized to .357 in the CMMG as shown in Post#8.
(It also chambers at .358, but I come down another thou on general principles);-)

Note also just how much the (shank) forward driving band is left outside
the case mouth -- and accommodates the chamber leade perfectly.

[cainttype]

It should “chamber” fine at .357” as long as the top of the front driving band is basically flush with the case mouth, the nose (or lack of thereof) is 0.350” and isn’t getting sized or contacting the throat walls..... 0.357” is a little too large for a SAAMI throat.... A little fire-lapping can remedy that, though.

[brewer12345]

These cast right at .360.

[cainttype]

https://saami.org/technical-information/new-cartridge-chamber-drawings/

If you see the short throat (ball seat) in the chamber you will notice the spec at is 0.357”, so (if correct) anything to clear that needs to be about 0.3565” max.... Inside the case mouth you might get away with slightly larger diameter because it does not REACH the throat, but it’s in the mouth area that expands on firing to “release” the projectile.
Getting “too thick” there can/will increase pressures, so it’s important to have some clearance there, too.... more to keep track of.

I’d rather work easy first. It might yield “Good enough” and allow you lots of enjoyable shooting while you have time to explore other options at leisure.
The groove being .355”-.3555” might play well with .356” that fit the short throat.... Just be sure that anything larger in the throat doesn’t pull an unfired bullet on extraction to dump powder in your rifle.

[mehavey]

1. Size to .357
2. Load dummy round to OAL where distance from case base to leading edge of front driving band is 1.8" (Post#8 (http://castboolits.gunloads.com/showthread.php?421022-Is-this-a-crimp-groove-or-just-an-inflection-point&p=5139995&viewfull=1#post5139995) again)
3. Load into magazine; Insert magazine in rifle; Slingshot charging handle to load round with full force.
4. Eject round.
5. If ejection sticky, decrease OAL a few thou until clean ejection.
6. Walk away.

(Don't overthink this) :drinks:

[mehavey]

postscript: Go find some Norma-200 if possible.
;-)

[cainttype]

“Simple” is what has been carefully described here.
IF your chamber is cut to SAAMI specs 0.357” will not clear the throat, it will cause stickiness.
If this particular design is used, sizing 0.357” should chamber freely if the front of the top driving band is seated flush with the case mouth... Simple.
That said, why bother with “seating out” when you know the driving band should stick?
IF “easy” works well, seating out to near rifling engagement, at 0.356”-0.3565” diameter it is certainly something that doesn’t need over-thinking.

[brewer12345]

1. Size to .357
2. Load dummy round to OAL where distance from case base to leading edge of front driving band is 1.8" (Post#8 (http://castboolits.gunloads.com/showthread.php?421022-Is-this-a-crimp-groove-or-just-an-inflection-point&p=5139995&viewfull=1#post5139995) again)
3. Load into magazine; Insert magazine in rifle; Slingshot charging handle to load round with full force.
4. Eject round.
5. If ejection sticky, decrease OAL a few thou until clean ejection.
6. Walk away.

(Don't overthink this) :drinks:

I think this is what I will try. If it doesn't work, can always size down again to 356 and try again.

The notion of trying to get hold of a powder I do not already have is daunting. Something I have should work, just a matter of trying.

[mehavey]

Try these powders, in roughly this order, if you have:
Norma 200
Ramshot X-Terminator
Alliant Reloder- 7
Hodgdon H335
Hodgdon H4227
Accurate 1680
Accurate 5744
Accurate 2200
IMR 4227
Vihtavuori N110
Hodgdon H4198

[brewer12345]

Try these powders, in roughly this order, if you have:
Norma 200
Ramshot X-Terminator
Alliant Reloder- 7
Hodgdon H335
Hodgdon H4227
Accurate 1680
Accurate 5744
Accurate 2200
IMR 4227
Vihtavuori N110
Hodgdon H4198

Remember, I am not looking for a full power load. I am hoping for subsonic, but definitely below 1500FPS. SO I am going to be fooling with Unique, Trail Boss, and maybe 2400. Unique and 2400 have worked well for me in low powered loads in 30-06, so hopefully I can do the same with the 350L. Also have Tite Group, but have not used it in the past.

[mehavey]

OK... just plan for it not to necessarily cycle.
You'll need a much heavier bullet to stay slow and still generate cycling pressures.

See http://castboolits.gunloads.com/showthread.php?387647-350-Legend-and-Cast-Boolits&p=4765780&viewfull=1#post4765780

[brewer12345]

I am shooting a bolt action, so any deficiency in cycling is due to the nut behind the trigger.

[mehavey]

Go for it.... :2_high5:
(What barrel length?)

[brewer12345]

Ruger American Ranch, so 16". This has become my dedicated beaver and muskrat gun.

[mehavey]

I'm not a big fan of Trailboss -- but in this case -- Quickload tells
me that a 90% case fill (of space under the bullet) works really
well for 1,200fps out of a 16" barrel with Tom's bullet

[brewer12345]

I'm not a big fan of Trailboss -- but in this case -- Quickload tells
me that a 90% case fill (of space under the bullet) works really
well for 1,200fps out of a 16" barrel with Tom's bullet

Yeah, I am hoping I can get a fast powder to work because it should all burn up in the barrel. In low light conditions, blast and flash are a real minus.

[mehavey]

In that case, TrailBoss is the best of all the powders you said you had -- by far.
Few people who tout it for BP originals appreciate just how fast it is.
El Spiko Grande

[brewer12345]

I have bullseye and hp38 as well.

[mehavey]

In terms of "fast powder burn to completion

350 LEGEND
ACCURATE 36-180L
16" barrel
1,200fps load

Bullet travel by time burn completed:

Bullseye: 3.7"
HP-38: 1.7"
TightGrp: 1.0"
TrailBoss: 0.8"
Clays: 0.4"

[brewer12345]

Yee haw. Knew Trail Boss was fast, but wow. Any of them will work, then. I'd like to get TB to work simply because of case fill, but we will see if I can get suitable accuracy. My yardstick is small groups at 50 yards, so hopefully that isn't too challenging. Unfortunately, the impending blizzard in my area will probably fill the canyon I shoot in with 3 feet of snow, so it may be a while before I can test loads.