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Old May 21, 2012, 07:12 PM   #1
dyl
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Truncated Cone experience?

Hey all,

Bottom line questions:

1) What OAL cycled the best for you - Generally shorter or longer?

2) If the Lee bullet seater die makes contact on the Ogive rather than the top of the bullet (so I've heard) - should I simply leave it at the original setting even if I switch bullet designs? Case volume would change but distance to rifling wouldn't.

Background below:
I just loaded a box of 155 Grain hard cast Truncated Cone in .40 S&W. (the blunt crayon design). My previous reloading experience is all with FMJ. Going cheap.

- Consulting the manual: I did and the manual has a 150 grain linotype recommended OAL about 1.10My leftover settings from my FMJ bullets (in FMJ produced 1.127") produced an OAL of 1.135. So I dialed it down to head towards the recommended length. I stopped at 1.120" and decided to hand cycle them to test.

The 1.120" produced frequent Failures to Feed - even just using the slide release to load the first round. My original settings of 1.135 seemed to chamber more easily. About 1/3 of the hand-cycled rounds have a dent in the side of the casing - especially if it was a round that failed to feed.

My inclination is to head towards a longer OAL although my Lyman manual would seem to point me towards shorter. Gun in question is S&W M&P40c.

Good thing I only bought 500 of them. I could make them a good bit longer, there is plenty of forward space in the magazine.
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Old May 22, 2012, 12:10 AM   #2
dyl
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Fixed it.

Okay. I found what I believe to be the solution. At this point, this is for anyone who does a future search for:

155 grain truncated cone hard cast bullet in 40 S&W failure to feed.

This particular bullet has a sharp shoulder. I believe a wider bullet head or longer bullet would contact the inside of the chamber sooner to aid in feeding by creating a less steep angle during feeding.

The solution:

Increase the OAL as much as possible while still
1) chamber properly still head-spacing on the case mouth, bullet does not touch rifling. Tested in 2 ways - one rudimentary way is dropping finished round and listening for crisp "clunk" of impact against brass case mouth, not of a softer sound of lead against rifling. Second way is by inserting bullet into chamber until stops, then measuring remaining space with caliper from the back of said bullet to the back end of barrel hood extensions. Adding the two numbers gives your maximum chamber length but does not take into account the next requirement below...

2) be short enough to fill up magazine without binding / slowing down feeding.

My OAL is now 1.170. They feed well by hand cycling. The brass is no longer dented after cycling but there is a shiny spot from impact against the bottom edge of the feed ramp.

I don't think I'll be buying any Truncated Cone with a sharp shoulder anymore. I'll look for something rounded.
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Old May 22, 2012, 12:48 AM   #3
BDS-THR
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I use TCFP and SWC 40S&W bullets from Missouri Bullet Company and they feed/chamber reliably even in tighter chambers of Lone Wolf barrels in Glock 22/27. I use the following OALs with .421"-.422" taper crimp (bullets are sized .401"). With W231/HP-38, I get accurate and no leading loads - http://www.thehighroad.org/attachmen...1&d=1329800605

Yes, with any new bullet, you should always conduct the barrel drop test to determine the Max OAL and feed/chamber from the magazine manually to determine the Ideal OAL that will reliably work from the magazine.



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File Type: jpg MBC40.jpg (34.8 KB, 132 views)
File Type: jpg MBC40load.jpg (84.3 KB, 131 views)
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Old May 22, 2012, 07:49 AM   #4
wncchester
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"....Generally shorter or longer?"

Yes.

I've been reloading for all things that go BANG since '65. I've never even looked to see what a book OAL might be, but I'm of a wholly different era. Fact is, few data sources in those days even suggested an OAL nor did we care. Without dial calipers, we experimented with seating until we found what worked and developed our charge; we lived and our ammo was good.

Last edited by wncchester; May 23, 2012 at 10:55 AM.
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Old May 22, 2012, 08:28 AM   #5
Don P
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I will seat the bullet as long as possible so it chambers good and fits the magazine. You may have to load a few rounds with varying OAL to find a happy medium. My round nose are OAL of 1.138. My new bullets are TCSW. I have not yet loaded any of the new bullet shape
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Old May 22, 2012, 08:52 AM   #6
dyl
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ah HA

BDS, That picture was a good one.

What i have is actually Semi-Wadcutter. Looks like I have IDP #9. Sorry for the confusion.

I would think truncated cone would feed better having smoother edges. That will be my next purchase after I'm through with these.

Wnnchester, Don P
- All this talk about chamber pressures with short OAL and incomplete powder burn / squibs with too long of an OAL really pointed me to following the manual to a T. But if I did that, I'd have 400 useless bullets on my hands now. My (most recent edition) Lyman manual stated that they do NOT "play it safe" with their load data yet in comparison to other manuals their powder charges tend to be a bit milder. I will follow the manual as much as possible but not if it doesn't work (as long as I can stay safe). Lawsuits these days.

Thanks
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Old May 22, 2012, 09:50 AM   #7
BDS-THR
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Quote:
Originally Posted by dyl
What i have is actually Semi-Wadcutter. Looks like I have IDP #9. Sorry for the confusion.

I would think truncated cone would feed better having smoother edges.
Using the OAL listed in the published load data will not ensure the finished rounds will reliably feed/chamber in your pistol as typically universal barrel fixtures (and not actual pistols) are used to measure average maximum chamber pressures.

SWC bullet reliably feeding would depend on several factors (the profile of the bullet nose, ramp angle/length of the barrel, magazine lips/spring tension, etc.). 45ACP 200 gr SWC bullets often follow the same nose profile/ogive of the RN to bump the same part of the bullet nose on the feed ramp to feed reliably.

As the SWC bullet is pushed forward in the magazine by the slide rib, the nose of the bullet "bumps" on the ramp. The reason why SWC bullet don't hang on the ramp edge is because as the base of the round clears the magazine feed lips, the spring tension of the magazine pushes the base of the round up along the breach wall/extractor to align the round with the chamber to be pushed in by the slide/recoil spring. The nose/shoulder of the SWC bullet don't actually "slide" on the feed ramp but "bump" against it.

Ensure you use sufficient taper crimp and Max OAL for the finished round to fall into the chamber freely with a "plonk" and not hit the start of rifling when you spin it. If the Ideal OAL that will feed/chamber reliably from the magazine when you manually release the slide, you should be able to do your powder work up to determine the charge that will reliably cycle the slide and extract/eject the spent case reliably.
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Old May 23, 2012, 01:12 AM   #8
DaleA
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bds-thr - nice pictures to illustrate your point,

(let's see, picture=1000 words, two pictures...)

and you saved yourself a couple thousand words to boot!
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Old May 23, 2012, 06:13 AM   #9
Gahunter12
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Quote:
I would think truncated cone would feed better having smoother edges. That will be my next purchase after I'm through with these.
They may feed well, but I have been battling the same thing. I load all my 180gr TCFP FMJ or plated bullets to 1.130". I have 1000 Friendswood 180gr TCFP cast bullets on my bench as I type this. I have tried everything from 1.165" down to 1.100". I have settled on 1.105" which passes plunk test, mag test and cycle test. I dropped my start charge by 15% with W231 which worked well, but not what I was wanting. My next order will be SWC. My main reason for TCFP was for IDPA practice. I use Berry's RSFP for comp, but wanted to reduce cost of practice. My goal was to load using WST since I load WST for comp. Once I use up these I may just go back to plated.
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Old May 23, 2012, 07:15 AM   #10
Don P
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Quote:
Wnnchester, Don P
- All this talk about chamber pressures with short OAL and incomplete powder burn / squibs with too long of an OAL really pointed me to following the manual to a T. But if I did that, I'd have 400 useless bullets on my hands now. My (most recent edition) Lyman manual stated that they do NOT "play it safe" with their load data yet in comparison to other manuals their powder charges tend to be a bit milder. I will follow the manual as much as possible but not if it doesn't work (as long as I can stay safe). Lawsuits these days.
Well, a few years ago I called Hodgdon to get load data for my 155 grain rn lead bullets for my 40S&W.
Customer service rep at Hodgdon told me they had NO DATA and that NOBODY LOADED LEAD IN 40S&W
I went with a charge weight of 4.8 grains of Titegroup and have had no problems so far.

Now my question was to the CS rep did I have some rare bullet never made before? He did not even give me a starting point or any suggestion other than NOBODY LOADS LEAD IN 40S&W
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Old May 23, 2012, 09:38 AM   #11
BDS-THR
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Quote:
Originally Posted by Don P
Customer service rep at Hodgdon told me they had NO DATA and that NOBODY LOADED LEAD IN 40S&W
Really? Here lead load data for 40S&W from 1999 Winchester load data.

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File Type: jpg 1999 40.jpg (41.6 KB, 52 views)
File Type: jpg 2004-40.jpg (38.8 KB, 2 views)
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Old May 23, 2012, 10:58 AM   #12
wncchester
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"Customer service rep at Hodgdon told me they had NO DATA and that NOBODY LOADED LEAD IN 40S&W "

That good ol' boy may have answered the CS phone but he's no 'expert.'
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