Bought a box of Sierra 85gr HPBT for my .243 rifle and loading them up tonight found crazy length differences. The whole lot is floating back and forth by as much as .007 most are off by .003-.005. Anybody ever come across this with Sierra? I have had really good luck with their stuff in the past. BTW I'm measuring from the ojive not the tip. This also has me thinking that when I measured my seating depth to the lands did I get a long bullet or a short bullet from the box to measure with???
Sierra .243 bullets #1530 really inconsistant length?
- Thread starter Lefty Trigger
- Start date
Should have said that I'm getting my measurements while seating. My depth to the lands is 2.253 measured with my comparator. So I was looking for a "loaded length" of 2.233 for a .020 jump. I'm getting crazy lengths like 2.228, 2.235, 2.238 stuff like that. almost having to measure and adjust the die on every one.
Sierra in their data sheet lists the COAL of 2.650 for this bullet and the Lyman book lists the COAL at 2.615. Seating a bullet to 2.615 COAL and then measuring that round to the ojive gives me a length of 2.255 which in my gun is a .002 jam. There is no way I could ever load to the COAL length of 2.650!
RetiredArmy
Gold $$ Contributor
Could it be a primer pocket issue? Primers are seating at different depths. Try seating a bullet in an unprimed case. See where that takes you.
Thanks Bill
Thanks Bill
akajiggs
Gold $$ Contributor
The 1530's are some of the best shooting game bullets that there are.Try measuring some Hornady and Bergers and see how they measure up.I think you will find that they will all be a little inconsistent .
That being said,all are good bullets and do a good job.I have killed a lot of deer with all of them but for my money,the 1530's are #1 for deer.
If you want match grade,try some Barts or Vapor Trails.They are very accurate and very consistent.
If I were you,I would not worry about .002-.005.I would shoot them and let the hair fly.
JMO
Jim
I'm using a RCBS Competition seating die that has a micrometer. I do not crimp and this die does not even have that option. Using a Lee classic cast single stage press. Also I have found that most bullets I have loaded will vary to some degree but the point being I have never see a box out this much. I have loaded these before and they were not this bad. My Hornady 87gr V-max's vary by no more than .002 and that seldom happens.
butchlambert
Site $$ Sponsor
Are you for sure that your seater stem is working on the body of the bullet and not the tip? The amount that you are speaking of is less than the thickness of a hair, unless of course, you are a true blonde.
In addition, seating pressure gives you different seating depths. It's not all that sierra has a horrible problem.
Years ago i had a box of 1530 bullets that produced 3" groups @ 100 yards out of my Rem 40X when the norm was 3/4" or smaller.
I now give every component a lot number and record it. When accuracy goes bad, i have a place to start.
Sierra sells seconds, maybe you got a box? https://www.sierrabullets.com/about-us/factory-outlet/
dcali
Bullet Maker
That sounds like a seating problem, not a bullet problem. Is your seater hitting the tip of the bullet for some reason (maybe clean it?), or is it contact around the ogive like it's supposed to.
I don't know how people are getting 5-10 thous of variance on cartridge base to ogive. If things are working as they should it should be closer to .001 variance.
I don't know how people are getting 5-10 thous of variance on cartridge base to ogive. If things are working as they should it should be closer to .001 variance.
If you've ever compared bullet ogive shapes on a 50X + optical comparator, you'll see the slight shape differences across a given lot of bullets that easily make that happen. Especially when the seater contact diameter is many thousandths forward of the ogive diameter CBTO is referenced.
Some have observed 3 or 4 different pointing dies were used making a single batch of bullets used in a given cartridge lot as that many distinct shapes were revealed. Any 7.62mm or 30 caliber Match ammo lot are 2 examples. Lapua used to do that several years ago.
Any ogive diameter reference other than a few thousandths less than barrel groove diameter is a waste. Use the diameter the lands first touch the bullet. What diameter does the seater touch the bullet?
Last edited:
dcali
Bullet Maker
I understand, but when I measure my bullets post-seating with a hornady comparator tool, they're all the same. Practically speaking, the ring contacted by the seater is as consistent as the ring contacted by the comparator. The same would not be the same if something were causing the seater to contact the tip.
Is that comparator contact diameter a few thousandths smaller than bullet diameter?
Are all loaded cases headspace equal to chamber headspace?
Last edited:
GAnderson
Gold $$ Contributor
Use your comparator and measure just some of the bullets...this should tell you real quick if the bullets are the problem or seating them is the problem. Neck tension variation &/or seater stem issue(as stated above) could be causing the Cartridge Overall Length measurement variation more so than the bullet itself.
Can the bottom of the seat die be set to make contact with the shell holder and still get the OAL you want? The contact would act as a stop.
Redding has this and more ,as a tech tip on there website. http://www.redding-reloading.com/tech-line-a-tips-faqs/143-seating-depth-variation
Lee makes a dead stop seating die that works the same way.
All are said to remove slop from the press.
Last edited:
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.