Seating length question please.

[jimmy milnes]

So my 6.5x47 with 123 sst has a real sweet shooting spot at 2122 col. But I got some bullets the last week and loaded some last night,
Thing is some are seat around 4 to 6 thou. deeper than my required length "obviously haven't moved the die" I'm guessing it's variation on a poor batch an will end up checking the length of them all "ogive to base" next time coronation street is on, however my main question is would you alter the die to seat at the correct depth or not? I'm aware that I'll then have a larger space between bullet base an powder as I'm not compressed on the load an wondering if anyone in the know, knows what effect doing this will have on accuracy.
Hopefully I've explained what I mean without babbling too much.
Cheers Jimmy

 

[big ears]

But a comparator and measure off the ogive it’s much more reliable than from tip. small tip deformities can occur in the box of bullets during transit

 

[jimmy milnes]

But a comparator and measure off the ogive it’s much more reliable than from tip. small tip deformities can occur in the box of bullets during transit

Yes that what I do sorry if I wasn't clear enough on that matey

 

[Cottis]

4 thou? Are you shooting gnats off the back leg of a dog at 1000yds? If you are, then maybe tinker. If not, seat em and shoot em. It's gonna be fine.

 

[jimmy milnes]

4 thou? Are you shooting gnats off the back leg of a dog at 1000yds? If you are, then maybe tinker. If not, seat em and shoot em. It's gonna be fine.

I do get your point and was it only a deer rifle I'd agree, but it can mean the difference between a carrion being missed or being dead at 2 or 3 hundred yards.

 

[samdk]

I find that differences in seating depth in my loads are usually down to varying neck tension. I now use a LE Wilson expander mandrel and run that through all my case necks, now they are all spot on!

Sam

 

[DeLaRue1953]

I had a batch of .308 155g Lapua Scenars that varied up to 10-12 thou from base to ogive recently, if you need consistency then the only way is to measure & batch then seat accordingly, altering the die without doing so is just chasing your tail otherwise imo.

 

[jimmy milnes]

I had a batch of .308 155g Lapua Scenars that varied up to 10-12 thou from base to ogive recently, if you need consistency then the only way is to measure & batch then seat accordingly, altering the die without doing so is just chasing your tail otherwise imo.

Did you find that the difference in gap behind the bullet effected pressure an so accuracy node ?

 

[Cottis]

I do get your point and was it only a deer rifle I'd agree, but it can mean the difference between a carrion being missed or being dead at 2 or 3 hundred yards.

Still don't worry. I use a .222rem to shoot corvids out to 300yds+ and whilst the load is spot on and put together with care, I don't stress about a coupla thou. Your 6.5 Lap is going to be even more forgiving. Brass prep, neck tension and charge weight consistency are bigger concerns.

I would also advocate FL sizing without expander ball and then sizing up necks with an expander mandrel die. Dead easy and you can fell the difference/consistency when seating bullets.

 

[samdk]

Still don't worry. I use a .222rem to shoot corvids out to 300yds+ and whilst the load is spot on and put together with care, I don't stress about a coupla thou. Your 6.5 Lap is going to be even more forgiving. Brass prep, neck tension and charge weight consistency are bigger concerns.

I would also advocate FL sizing without expander ball and then sizing up necks with an expander mandrel die. Dead easy and you can fell the difference/consistency when seating bullets.

Sound advice that, de-cap, FL size and then expand the necks with a mandrel.

Sam

 

[DeLaRue1953]

Did you find that the difference in gap behind the bullet effected pressure an so accuracy node ?

Hi, Luckily I check the seating every 5 rounds so I noticed the difference more or less straight away. I pulled them all & then batched them. I have a Redding micrometer competition die so I just dialled in the difference between the batches & seated them, no noticeable difference then at all of course. Good luck!

 

[User00044]

As has already been pointed out, inconsistency in seating depths may be result of inconsistent neck tension . You don't n't mention how many firings the cases have . If you've started to see a witness ring from the seating process it's a possibility that it's time to anneal . I suffered similarly , believing it to be the seating stem , before realising the necks had hardened .

 

[Muir]

I do get your point and was it only a deer rifle I'd agree, but it can mean the difference between a carrion being missed or being dead at 2 or 3 hundred yards.

I don't think so. I will spend the summer shooting prairiedogs -think a 16 ounce beer bottle- out to 400 yards. A few thousands of an inch won't matter. Most commercial press and die combinations will give you that due to the compounding of tolerances in the load chain. Varmint bullets are seldom consistent enough to reliably measure off the ogive to an exactitude anyhow.

If the load is so sensitive that .003" in seating depth matters, the OP should go back to the drawing board. As mentioned. Case condition and technique can account for this 'error' as well.~Muir

 

[foxinmad]

What Muir said Jimmy, just load the 47 and crack on matey. I thought the same as you when I had a few different measurements when loading my 47, the crows and maggies never knew that they were out a baw-hair

 

[foxinmad]

 

[jcampbellsmith]

So my 6.5x47 with 123 sst has a real sweet shooting spot at 2122 col. But I got some bullets the last week and loaded some last night,
Thing is some are seat around 4 to 6 thou. deeper than my required length "obviously haven't moved the die" I'm guessing it's variation on a poor batch an will end up checking the length of them all "ogive to base" next time coronation street is on, however my main question is would you alter the die to seat at the correct depth or not? I'm aware that I'll then have a larger space between bullet base an powder as I'm not compressed on the load an wondering if anyone in the know, knows what effect doing this will have on accuracy.
Hopefully I've explained what I mean without babbling too much.
Cheers Jimmy

You're lucky the seating has only changed 4-6 thou. I've had Hornady bullets change seating by 20 thou in a similar scenario. Hornady bullets can vary substantially lot to lot. If you are really concerned test the rounds as you have seated them and redevelop if you are not happy.
Regards
JCS

 

[jimmy milnes]

OK guys first thing is I'd like to thank you all for the replies,

As the football was on last night I got a chance to run the remainder of the box of sst with the verynear calipers an an ogive tool, all were within 1.5 tho.. Brass is brand new unfired an yesterday I stripped and ultrasonic bathed my seating die. Go figure same thing/variation.. Can't for the life of me work it out.. So just going to shoot the dam thing before I get a doubt issue creep in prior to trigger squeeze
Edit.. The one thing I did notice on stripping the die "forster mic type" is that it doesn't push to seat on the ogive, it pushes further towards the tip of the bullet that's could maybe explain things

 

[samdk]

OK guys first thing is I'd like to thank you all for the replies,

As the football was on last night I got a chance to run the remainder of the box of sst with the verynear calipers an an ogive tool, all were within 1.5 tho.. Brass is brand new unfired an yesterday I stripped and ultrasonic bathed my seating die. Go figure same thing/variation.. Can't for the life of me work it out.. So just going to shoot the dam thing before I get a doubt issue creep in prior to trigger squeeze
Edit.. The one thing I did notice on stripping the die "forster mic type" is that it doesn't push to seat on the ogive, it pushes further towards the tip of the bullet that's could maybe explain things

Hi Jimmy
What prep do you do on your new brass before loading?

Sam

 

[jimmy milnes]

Hi Jimmy
What prep do you do on your new brass before loading?

Sam

Run the FL die an that's it Sam.

 

[samdk]

Run the FL die an that's it Sam.

Ok, it might be worth checking the length as I have found all my new Lapua brass to vary in length +- 4 thou! (and Norma does too) I now give them all a trim as I found the extra length, which was all in the neck, was causing inconsistency in neck tension and seating depth.
Sam