Inconsistent bullet seating 40 S&W OAL

[fella5]

I'm reloading Rainier 180gr FP using Redding Competition Dies and a Hornady LNL Press. When trying to seat the bullet at 1.125, I get a variance of 1.124 - 1.138 OAL. I have tried to load one at a time and multiple rounds at a time with no difference. Do you guys get consistent OAL no matter what? I'm wondering if it is the bullet shape and that its because the Redding bullet seating is seating off the ogive of the bullet and not the top. I have also tried not using the taper crimp to see if that was the issue, but it is not.

[Jim243]

I am not going to be of much help, but is your shell plate tight and not wobling Try one case at a time and see if you have the same problem.


Jim

[fella5]

Yup the shell holder is tight and not wobbly. I have tried one at a time and multiples with the same issue. I'm guessing it has to be the bullet since the redding die seats the bullet from the ogive and not the top.

[PA-Joe]

Are you using the correct steating plugger? They make one for Round Nose and another for Flat Points. If you look at the bullets this difference is normal. If you measure the ogive they will have a closer tolerance.

[Don P]

Is the cup in the seating die dirty? A few thousand is OK but .013 seems odd. All I will add is clean the die and see if it helps

[243winxb]

Measure off the ogive. Take the seater plug out of the bullet seating die, place it on top of the cartridge and measure from the base of the case to the top of the seater plug.
Progressive press can add as much as .010" variation to the COL. From Lee's FAQ website

Seating depth variation

There are a number of possible causes for overall length variation. One is the way it is measured. If you measure overall length from the tip of the bullet to the base of the case, remember to subtract the variation due to bullet length tolerance. The bullets will vary in length due to manufacturing tolerances (bullets with exposed lead noses are the worst in this regard) and this will add to the overall cartridge length variation. Remember that the bullet seater plug does not (or shouldn't) contact the tip of the bullet when seating, but contacts farther down the ogive. For a more accurate seating depth measurement, take the seater plug out of the bullet seating die, place it on top of the cartridge and measure from the base of the case to the top of the seater plug.

Another possible cause for bullet seating depth variation is seating and crimping at the same time when trying to apply a firm crimp to untrimmed cases. Variation in case length also causes variation in the amount of crimp applied. Long cases get a heavier crimp than short ones. When seating and crimping at the same time, the crimp is formed as the bullet is seated into the case. The crimp will form sooner on a long case, and therefore the bullet will not be seated as deeply. The solution is to seat and crimp in a separate step (the Lee Factory Crimp die is good for this) and/or trim cases to a uniform length.

The amount of force required to cycle a progressive press varies with the number of cases in the shell plate. When the shell plate is full, it is harder to lower the lever than when there are one or two cases present. This can lead to variation in cartridge overall length because there are different loads placed on the working parts of the press. When the shell plate is full, seating depth will be slightly long, because the load is higher and all of the clearances are taken up. With the shell plate nearly empty, the load is not great enough to squeeze out these clearances, and the seating depth is short.

[fella5]

Thanks for the feed back... This is a new die set and I cleaned off all th shipping oil that was put on these dies by redding. 1st time using it. They told me that they don't make a flat point or semi wad cutter seater plug for the Competition die bullet seater. Redding also mentioned that it is recommended to go off the ogive (which I do for rifle) than the tip of the bullet for consistent jump.

The cripming is done on a different satation and I too eliminated that part from my seating. So I'm guessing its just these Rainier 180gr FP nose bullets.

[wingman]

I had same problem with Rainer bullets on 9x18 cal. went with a different
brand.

[fella5]

What brand did you with?

[PA-Joe]

Is this a LNL Classic single stage press or the AP progressive. If the AP when you set up the dies you have to have a case in each position. This stabilizes the plate and keeps all of the positions at a uniform height.

[fella5]

I have the LNL progressive. And I did make sure to have cases in each station except for the last couple of course. I checked the bullet pal and base to ogive and it varies also with bullets that have the same base to ogive measurements.

[Rangefinder]

I'm going to go out on a limb and ask... Have you checked your primer seating depth? OAL length is going to appear to be off if you're primers aren't all seating flush with the base and you measure across the center--could be they aren't seating fully or you have a few shallow pockets. Just a thought.

[fella5]

I thought of that too so I made sure I measured the ones where the primers were seated well. I used a Hornady bullet and neck comparator on both ends of my micrometer which also allows for the primer to not be part of the measurement since the primer would be placed where you check the bullet ogive. I'm going to purchase Bayou 180gr TC bullets and hopefully that seats better.

[Artsville]

i have the same problem with Extremz plated bullets....I load on a 650 and i am happy if i can keep oal at -/+ .004. I think it is the bullets. If you ever look/measure every bullet there is a lot of variation. I can even see the flat point isn't really flat so the bullet uniformity is not too great.

One day i will have to get some quality jacketed bullets and see what happens, but i can get plated really cheap so i keep buying them.

art

[fella5]

I was planning on picking up some Hornady XPT just to see how well those seat. I'm starting to shoot a lot and like shooting the plated because they are cheap.

[wingman]

What brand did you with?
__________________
Scott

I switched to Berry Plated for 40cal and I've tried Zero jacket bullets without
OAL problems.

[fella5]

Thanks! I might pick up a box of Berry's at Cabelas and give those a shot.