What’s all the fuss about seating with an arbor press?

[Bc'z]

LA doesnt fit

284?

 

[Dusty Stevens]

284?

Maybe with a 120

 

[fatelvis]

Good stuff. I notice you guys say that the arbor seating yields better CBTO measurements of loaded cartridges. Why is that? Don't the two seating methods use the same basic method of pushing the bullet into the mouth (seating stem that fits over bullet point)? Thanks again!

 

[Bc'z]

Good stuff. I notice you guys say that the arbor seating yields better CBTO measurements of loaded cartridges. Why is that? Don't the two seating methods use the same basic method of pushing the bullet into the mouth (seating stem that fits over bullet point)? Thanks again!

Sort a box of bullets by length only then look at your CBTO and tell me what you see.
I'm seeing. 001-.0015 CBTO variation with the little bit of loading I've done since I started investigating this.
For run out I'm seating half way lowering ram rotating round 180° and finish seating.

 

[Dusty Stevens]

Good stuff. I notice you guys say that the arbor seating yields better CBTO measurements of loaded cartridges. Why is that? Don't the two seating methods use the same basic method of pushing the bullet into the mouth (seating stem that fits over bullet point)? Thanks again!

A good seating die is the point whether its threaded or arbor press type. Most short range br shooters use threaded dies for seating, custom reamed with a micrometer top

 

[CT10ring]

W arbor press...the feel of seating a bullet + case to case variance (or not) - is very clear.
When you have annealed your brass - the difference is noticeable.
Consistent tension is felt...
I'd like to think this method aids accuracy or shows problems or variances in different brass.
That said, I have threaded dies ( 6mm AR ) that load crazy accurate ammo. Give it a try

 

[searcher]

We all read about the woes of runout on presses, whether the die hole in the press is bored "square" to the shell holder. Then there is whether the shell holder is "flat" and so on. The hand press and hand dies take several potential items that are known to cause problems out of the equation. For that reason alone - they are worth a look. doesn't mean you will get more accurate stuff than you are using now - but in the law of averages when taking those problems out of the equation - one would - on average. I use a number of Harrell's dies, Redding "S" dies and a number of Wilson Micro seaters with a hand press. Bruno die, etc.. If I were competing, I'd use the hand dies - but that's just because there are fewer things to continuously monitor - like whether there is any powder under the shell-holder, position of my die in the press (I don't lock them down tight), whether there is any residue on the side of the shell-holder (I remove the retaining clip so they slide around). etc.

 

[jackieschmidt]

Ask Dusty what my presses look like.

I have my own ideas about presses and dies,

 

[wedgy]

I agree with a previous poster saying that brass prep, or lack of, contributes to seating force variances but if you are meticulous about it and anneal with an AMP and still have to cull brass what do you attribute the variance to and is it just "bad" brass ? Just treat it as you would sorting bullets ? Would that piece act the same after firing and annealing again or is it for fouling only ? Ultrasonic cleaning gave me the most variance in seating so I quit doing that.
I can't shoot the difference on anything under .003" runout so that is my limit and I don't stress too much to hit that.

 

[Dusty Stevens]

Ask Dusty what my presses look like.

I have my own ideas about presses and dies,

I learned many years ago, a press thats loose is better than tight. Dies do the work and can only get worse from a press influencing the movement. Your presses are what started my experimentation way back

 

[FNSafari]

I’ve been loading for over 35 years, and have always used my press/dies to seat a bullet, even when loading for precision (F-class) and have been satisfied with my accuracy. Since joining this site (best on the net), I repeatedly see guys suggesting seating with an arbor press. Does it make a noticeable difference from seating with a press and quality die? If so, I will be tempted to go that route also, and try to gain a little extra precision.

No particular advantage with the arbor press, its the dies you use, wilson, Jones or a custom fit to your chamber seating die. BR shooters are running neck tension from maybe .002 to maybe as much as .005. If you have more than that an arbor press may be difficult to use. Other good option if you want to use a std. press is Redding or Forster competition seating dies. IMO, the best press for using these dies with something in the .308 or smaller class is the RCBS Partner press. You are looking for minimum or no bullet runout.

 

[paulT]

I shoot 6 & 7 mm not 308 but of all the inside chamfer tools I have used the K&M has absolutely worked the best. I use a K&M arbor press with a force pack and I haven't had concentricity problems. One thing I do is seat slowly and watch the gauge when I feel the bullet move into the case I note the reading and stop with the bullet about half way in. I then turn the die 180 deg. and finish seating. According to an article I read on the daily bulletin this is supposed to improve concentricity. I can't prove it but like I say I have never had concentricity problems. Try checking the seater stem on your Wilson die. I normally take one bullet of the type I am using and lap the cone on the seater stem using lapping compound on the bullet.
I also have Redding competition seaters that I use in my rockchucker but I have generally gotten more consistent seating depths using the Wilson micrometer die.

Thank you for sharing this info will try that out.

 

[rkittine]

I find an arbor press or my Foster Coaxial seat the straightest. No slop in a cartridge holder etc.

 

[K9TXS]

I have just switched over to an arbor press for range only seating.

When I go to the range for my testing, my brass is primed and ready for powder. My powder is in glass vials and measured to different powder weights.

After I start getting fairly good groups with the powder charge, I concentrate then on the bullet seating depth.

Sometimes I may have to go to another powder charge, but not very often.

After I get it tuned in to where I want, I do all my mass reloading with a Redding seating on a press at home.

This saves me time, bullets, powder and primers in the long run. I can't tell you how many times I've loaded up rounds and later had to pull them or shoot them and not worry about it.

Now I'm loading for prairie dogs and and other critters so I'm looking for accuracy, but I don't need the type of accuracy a competition shooter is looking for.

 

[Ray123]

I’ve been loading for over 35 years, and have always used my press/dies to seat a bullet, even when loading for precision (F-class) and have been satisfied with my accuracy. Since joining this site (best on the net), I repeatedly see guys suggesting seating with an arbor press. Does it make a noticeable difference from seating with a press and quality die? If so, I will be tempted to go that route also, and try to gain a little extra precision.

I don't like arbor presses...I use one from time to time..even modified a way for the forester coaxial press to seat with Wilson inline dies..anything to get away from the arbor press..Had trouble with the Forester micrometer seating die, until I reworked the flimsy thin walled seating stem...also use a Wilson mandrel die, so seating pressure is more consistent, and little to almost no runout. I have actually used a Dillon progressive for many thousands of rounds of 1000 yard shooting 20 years ago... All the fuss on super precision when a tiny change in wind moves your bullet a foot or two, easily.

 

[mgunderson]

I always enjoy reading reloading advice and people sharing ideas. Please remember there isn't just one way to reload great ammo. Spend time talking with great shooters and you will get a better feel for the extremes. There is no road map to great ammo or great shooting.

Put thought into what is holding you back from shooting your best...... and try to fix it. Most of the time multiple solutions exist. A different press or dies might be what you need right now.... or it might be what you need to do to eliminate that possibility.

It is a great journey of exploration and learning. Enjoy it!

 

[Nick Caprinolo]

To my way of thinking, if you want accuracy, your preparation has to be consistent.

Neck thickness is a very important step in forming your brass. After fireforming, I turn a batch of brass so that the necks are all the same thickness. I use bushing dies which assure that the neck is formed exactly every time as long as they are the same neck thickness. This also assures consistency in neck tension.

I use both an arbor press and an RCBS Rockrchucker Supreme that I recently purchased. Being new, there is no slop in its movements and seems to be more constant over my very old and worn Rockchucker.

I usually seat with the arbor press but recently I bought a set of Redding competition dies with the micrometer seating die. Using it in my RCBS press, I have found it as accurate as my Wilson seating die in my arbor press. After a lot of testing I am confident there is very little difference. I went to the range to make some tests, and found that there was no noticeable difference between the two, even when mixing them in the same five shot groups.

The nice thing about the arbor press is twofold. You can really feel and see the seating pressure and they are great for testing at the range. Set all bullets to jam and then reset them after firing groups to set the proper depth for accuracy.

So for me, it depends on what I am trying it achieve and the dies I am using. The press alone, guarantees nothing. it's the preparation and a panicia of other components working in unisine. It's up to you to test and see what works best.

Remember, the target will tell you what to do. This is simply my opinion and what works for me.

 

[Charliephoo]

I don't like arbor presses...I use one from time to time..even modified a way for the forester coaxial press to seat with Wilson inline dies..anything to get away from the arbor press..Had trouble with the Forester micrometer seating die, until I reworked the flimsy thin walled seating stem...also use a Wilson mandrel die, so seating pressure is more consistent, and little to almost no runout. I have actually used a Dillon progressive for many thousands of rounds of 1000 yard shooting 20 years ago... All the fuss on super precision when a tiny change in wind moves your bullet a foot or two, easily.

How do you mind to share how you fixed the flimsy thin walled seating stem on Forster Micrometer seating die?

 

[PracticalTactical]

Thank you for all the responses guys, I appreciate your input. So the force required to seat the projectile is much more evident with the arbor press. Got it. But does that “feeling” or sensitivity translate into better groups in the end? Do you sort them according to “light, medium and heavy” feeling resistance?

I get that an arbor press has a nice feel, but you can set the die in your press in a way that de-leverages the system. This works for both seating bullets as well as primers.

If you think about how the press force levels increase toward the end of the stroke, you can set the die low so the ram bottoms out against your seating die early in the stroke. This can drastically improve your sense of feel.

If you really want to create consistent seating force, measuring it when seating the bullet is already too late. The problem is created earlier in your loading process specifically concerning the quality of the inside neck chamfer and secondarily the inside diameter of the neck.

For chamfering the inside of the necks I have found nothing better than a 1/4 shank cone shaped carbide burr. I like the angle and the impeccable quality of the cut without rolling the edge.

As for the inside neck diameter, nobody talks about this... You can anneal if you want but don't ever assume annealing creates consistency. There will always be a certain amount of case to case hardness variation... Admitting to this is the first step toward the cure...

If you neck turn and run a tight neck chamber, you will have far greater control over someone whos necks are well cleared and does not neck turn.

Ok, here's my point... You need to listen to that little voice coming from every case you size. It will try to tell you how it needs to be sized if you listen closely enough.... No I'm not nuts... Let me explain...

Let's exaggerate the point for clarity... Consider two cases, one that has been annealed and one that has been fired several times but never annealed. Other than this difference, these cases are identical.... Each case will require a different neck sizing bushing because the different hardness levels will have different spring back. The annealed case will establish suitable neck tension with a larger bushing because it will have less spring back.

Ok sure you probably already know that... But what about case to case hardness variation within your lot of 100 cases? Annealed or not, there is still variation...

Suppose your fired 308 case has a neck diameter of 0.344, but with a 0.012 wall thickness the loaded round is .308+.012+.012=.332". We might just grab a .330 bushing and size away right? If you do, you are not listening. You need to let the case talk to you.

Start with a .333 bushing instead, and see if any of the cases will hold a bullet... You might find a few... Put them aside, after all the cases have gone through the .333, change to a .332 bushing.

Size any cases that would hold a bullet with the .332 bushing and they are ready to load.

Now size the rest and do the same... separate any cases that will hold a bullet with the .332 bushing.

Repeat this process until every piece of brass has been sized to one bushing smaller than what was required for it to hold a bullet.

This process effectively sorts brass according to neck thickness and neck hardness variations.

Yes it requires patience, but it is more precise than taking a short cut and running them through the 0.330 and an expander mandrel... If you like using an expander mandrel you can still do that after the above.

I guarantee this process will result in more consistent neck tension because each case told you what it needed, and you listened. If you use this process there will be no need to sort by seating pressure, because they were each sized the same amount, but you can if you just like doing it.

 

[Ray123]

How do you mind to share how you fixed the flimsy thin walled seating stem on Forster Micrometer seating die?

The seating stem flared so drastically as to be paper thin on the edges...and was swaged out by bullet seating. Retired machinist, I have a machine shop in my garage, so make a new one or rework this one first. Decided to reworked the orginal in the lathe collet by trimming off the thin metal to where there would be some structural strength. Then redo the bullet seating area with a center drill followed by a tiny modified carbide boring bar, then use carbide lapping compound on the 108 Berger to form an exact fit to that bullet nose...clean reassemble and try...worked great no marks on the bullet even on a fairly compressed charge.