Hornady lnl bushing fail?

[mac86951]

Well, I have an unusual problem:

Ok, sizing 223 bulk on my Hornady LnL AP. I notice a small metal flake drop out of the press when I remove the die from the bushing in the press when changing dies to the next caliber.

Lots of investigation later and I find that the LnL quick change inserts in my AP press and subsequently the separate one I bought for my Rockchucker conversion all exhibit stress cracking / failures.

Images show the "locking" lugs are shearing under compressive force. Last image shows what they are supposed to look like, but has this bushing also has stress cracks on two lugs.

I researched and found that Hornady had a bad heat-treat batch and lots got out. They're sending me a set of replacements; but since I saw same failure on a conversion bushing for rcbs at different time, I'm still hesitant in that the system can hold up.

Hornady made good; one call and voila some COVID-19 Mail delays and here are my new bushings! I'll try them out and see if I run into the problem again.

I've converted the RCBS back with the original bushing. I realize that while the LnL quick-change may be a good idea for swapping dies; sizing 7.62 machine gun brass, or long cases like 338L that the quick change bushing may not be strong enough for RCBS Cam-over loads; but strange to find so many bushings fail.

Thanks for the replacements Hornady, I'll put them to use right away,

-Mac

 

[Twicepop]

I thought this was a bad idea when they first brought it out. The threaded die system spreads the load over the entire length of the thread, not at the much smaller pressure points of the LnL system. Any bushing not subjected to the proper heat treat procedures are bound to fail as you found out the hard way.

 

[mac86951]

Well, I set up an experiment tonight to check the LnL bushings. I have several sizing dies in 6.5 Grendel and I'm checking case sizing in a Wilson case gauge. Originally, my father handed me down a Redding die and a troublesome AR barrel. I found that in order to get brass that fit the case gauge; the die was ~ 1/2 turn past contact using Lee shellholders and RCBS press. From what I read on this forum, 1/2 turn past seems excessive, but not out an extreme amount. I know I could Chuck it into a lathe and shave a 1/32" off the die, but never thought it a problem.

Anyway, long story short. My other die (Hornady) sizes cases at a light contact of shell-holder. Switch to bushings and sure enough, light contact on the shell holder, no visible change after 60 cases. Heavy contact; 10 cases, two lugs are cracked and near failure. I know I'm stressing the system, and I'd rather have a weak link that's easy to fix, but die-set up is very particular on the LnL bushings and they don't hold up to those of us who like Cam-over on the single stage press.

I will keep my AP press set up for no-contact to the plate and it should run forever. I'll keep the power sizing to the threaded insert in the RCBS press.

-Mac

 

[drano38]

Thanks for sharing. I have a LNL AP from the first year they came out, and bushings for about 4 calibers.
better inspect them closely soon.
Glad Hornady sent you replacements, and I hope they hold up for the long run.

 

[mac86951]

Thanks for sharing. I have a LNL AP from the first year they came out, and bushings for about 4 calibers.
better inspect them closely soon.
Glad Hornady sent you replacements, and I hope they hold up for the long run.

Two more pics posted to help inspection:

Hair-line crack; lug that is coming unglued - I scratched at the crack with a finger nail; and just to the left of that lug is the crack starting on the next lug.

Ignore the bench in the background; it's organizing time.

-Mac

 

[Dusty Stevens]

I cant see how they last as long as they do

 

[Shooter13]

I tried the LNL in the rockchucker with by BR loading, I can see vertical movement that made me think this is not a good set-up for precision loading so I switched everything back.

 

[10at6]

I tried them and it was easy to see there are a bad idea. Good concept poor materials

 

[Gappmast]

They have been selling them for over 20 years and they seem to work. I would say they are powdered metal or die cast and a few bad parts made it past inspection not a bad design.

 

[rardoin]

^^^^Agree. They do not appear machined but die cast. No heat treatment for the metal used if indeed that is the case. I don’t use them for precision sizing operations (although I haven’t had any issues in cases like .270 Win and smaller) but they are great for changing tooling in a ‘second operations’ press.....like decapping, mandrel sizing, ring die small base sizing and even pointing bullets.

 

[TylerFromMS]

I tried the LNL in the rockchucker with by BR loading, I can see vertical movement that made me think this is not a good set-up for precision loading so I switched everything back.

Same. After a while it’s like the o-rings started failing and I was getting a lot of movement on the die, leading to inconsistent sizing.

 

[dstoenner]

I had similar results with my Hornady press. I bought that press because I really like the idea of the quick change. As my reloading skills improved i was looking at consistency and saw that my case sizing wasn't consistent. Well I tracked it down to the fact that after about 10 case sizings, the LNL bushing had basically unscrewed (unset) itself a few degrees and now as the ram bottomed out on the shell holder you could watch the whole die and bushing lift up a few thousandsth. You can imagine what that was doing to my head spacing I was trying to control.

A note, if you measure the engaging surface of the LNL bushing, it is a ramp. As the ram goes over top dead center, the die is being lifted by the pressure off of the ramp and then it slowly moves down the ramp with more and more slop. I does seem to stop but at that point you are getting the inconsistencies. I tried even not letting the ram touch the shell holder but it would still do it based on the brass compression force alone, just took more cases to do it.

So I bought a threaded sleeve to replace the LNL female bushing and now have to screw the die in. While it takes maybe 1 minute or so extra for setup, it is worth the extra effort to get consistent sizing.

I went to Hornandy about this issue, they sent me another female LNL bushing adapter. Turns out the new ones are made a little different and my old die LNL bushings wouldn't lock in to the female. They sent me out a box and of the 5, only 2 worked. So much for that theory of interchangeable.

Except for this issue, I am very happy with my press. Going on 10 years old and somewhere north of 20K rounds.

David

 

[Fast14riot]

I use a Hornady classic cast press with bushings for all my reloading, including my F/open ammo. I have found that it does not like a heavy cam over and have shaved down a couple shell holders since they're cheaper and easier to replace than dies, but I do get excellent uniformity in my 40° shouldered cases as well as cases like 30-06. I also use Lee lock rings with O-rings and get very concentric ammo.

It's not a system that takes heavy loads well, hard cam over and heavy contact with the shell holder of course will wear it out. The bushings are designed to be the weak link. Set it up to allow things to float and I think you will like the ammo you get as well as things not wearing out so quickly. Anything beyond contact with the shell holder is just causing press flex anyway. It's not like the die is compressing to bump the shoulder more, anyway. Stop stressing your system and use it like it's meant to be.

 

[rogn]

Is there a violation of the K I S S principle here?