.223 OAL variance, a different twist on the old topic

[gregj]

At least I hope it's a little different of a twist.

Loading .223 with 69gr SMK on Hornady LNL, with Hornady dies. These are not plinking rounds, I'm trying to load fairly accurate rounds for punching bug holes in paper. I'm also priming on the same press but as a seperate process. When loading rounds, the seating die is in station one, in the hopes this position will eliminating most of the flex in the press. Rounds are loaded basically one at a time.

I've noticed I can get fairly significant variances in OAL simply by how hard I can bump the handle at the end of the stroke.

I am fully aware of the variances in bullet manufacturing, and the issues with measuring OAL from the tip rather than with a comparator.

So I have two questions:
- Would flex within the press be causing the OAL variations, and would I be better served loading on a SS press? Along with different/better seating die?
- I have a Hornady bullet comparator. So far I've not figured out the best way to use it during the seating process to ensure I'm at the desired OAL, regardless of bullet tip inconsistency. IOW, should I measure a number of bullets to get a quantiy that are the same length, load those to desired OAL, then take OAL with comparator for future reference?

TIA

 

[243winxb]

Precision Bullet Seating

Single stage is .005" Progressive is .010" maximum COL variation, from what has been said here on THR. If you want better, a custom press would be needed. Benchrest Central would be the place to look. As far as bullets, there are tools for them also. One to check the lenght of bearing surface. Another to trim the nose/meplat. Yes, dies can make a difference. I like my Redding Type -S FL bushing die. Standard RCBS seater. Here is a press. http://www.benchrest.com/hoodpress/hood_press.html

 

[IMtheNRA]

Why do you bump the handle?

 

[243winxb]

Bullet Seating- COL Variances -RCBS Press & Dies.

Sloppy linkage & press spring can cause variation in the COL length. To remove this, a steel washer .061" thick & 1" in diameter is placed over the case onto the shell holder. On seating the bullet, this RCBS press will "cam over" removing any slop or spring coming from the press. No Crimping. This is a new idea of mine. More testing is needed, as i have not loaded using this method. If you think .005" variance is to much? I do not think this press has any spring at all, but maybe sloppy linkage?

 

[gregj]

243, interesting idea, I may try this. Thanks
EDIT: Thinking about this a little more, possibly the linkage stops may be a little worn. Will have to investigate further.

IMtheNRA, maybe bump is not the best way to phrase it. At the end of the ram stroke, the handle "bottoms out" on the available range of motion. If I hit the end of the range of motion harder, or "bump" it harder, I can affect the OAL. Hope this helps clarify.

 

[cfullgraf]

243winxb that ought to help.

If you bottom the shell holder against the die, it should fix the distance from the base of the case to the bullet.

Since the seater die does not normally contact the shell holder, the washer would take up the difference. You would want the press handle to cam over to make sure all looseness in the press system is taken up.

Assuming the seater plug seats against the bullet ogive and not the tip, the over all length variation should be reduced.

 

[RainDodger]

Just as a point of reference... I use a Dillon SDB (a progressive press) for reloading pistol cartridges. I use only 3 of the 4 stations (I don't size or prime on the Dillon).

I've found that when I'm not using ALL the stations, my OAL will vary more than when I use all 4 stations. Things are flexing more when not evenly loaded, including the shell plate and likely the press itself, albeit a tiny little bit if at all. It all adds up, however.

Just something to think about with a progressive.

(For all my rifle loading, I use single stage presses, which allows me to inspect everything at each stage. Yes, it's slow, but I like it. Reloading is more than half the hobby of shooting for me and I'm not in a hurry. That may be why I haven't had a bad cartridge ever... in 45 years of reloading.... )

 

[Blue68f100]

I'm I missing something here. The seating die does not contacts the shell plate.

There is no reason to have the die body contacting the shell holder. Doing so will induce flex, but this will eliminate slop if your press has a lot of excessive wear. I have never found that seating bullets cause hardly any load.

Now with the LNL-AP, I have loaded 308 Win in mine. If the stations are full you will only have about 0.005" variation. Running only the seating die in #4 position will yield ~0.003" variation.

 

[243winxb]

I have never found that seating bullets cause hardly any load.

Not sure how much pressure is needed to expand the brass .002" on seating a bullet. Would be interesting to know. Bullet pull for 5.56 mm is 45 lbs.- Minimum individual 35 lbs. Would pull & push require the same weight?? Flex in the press would be a non issue, if shell holder & die are in full contact, i think?