Why can't i reload exact cartridges?

[tigerwerkes]

A few things that have helped me:

1. ELD bullets need specific seater stems to keep tips from bottoming out
2. Inconsistent primer protrusion/seating throwing your measurements off
3. Using 3 light strokes on the seating with a twist of the cartridge in between givens me my best cbto consistency and concentricity

 

[gunmunkey]

It may not be your setup. How expensive is your digital caliper. I'm a millwright by trade and when we want to measure to .001" a $25 dollar measuring device won't cut it. It could easily have a variance of +/- .005". Check the literature it came with. I bet if you had a $200 micrometer your consistency would show, and you'd see that your meticulous procedures are paying off.

 

[SMK1000plus]

A few things that have helped me;

3. Using 3 light strokes on the seating with a twist of the cartridge in between gives me my best CBTO consistency and concentricity

I've also had much more consistency in regards to concentricity using this method when seating bullets, and using it when sizing my cases as well.

 

[Songdoger]

I had a similar issue with a tight neck 22 CHeetah shooting 80 gr JLK's. Drilled the stem out and lapped with bullet. Neck tension was an issue. If too tight it would press bullet into stem then slightly pull bullet out of case on return of the press ram. Got in a habit of swiping finger and thumb in imperial size wax every 3-4 rounds and rolling bullet between fingers. That stop the sticking but not the neck tension issue. Annealing cured that. Good luck.

 

[TheLongRanger83702]

If they do not seat by the Ogive. What do they seat by? The tip? If yours does there junk. Rile dies seat off the Ogive. Most pistol dies think 44 mag, 45Colt 480 ruger. They seat of the tip. Unless you are seating round nose or pointed bullets then they to seat off the Ogive.



OP lots of good advice in this thread. Biggest one. Match your seating stem with the bullet. That will help.

It isn't any better than others because of bullet irregularities. Even with "match grade" I checked after reading this post. I found +/- length variances of 0.0030". I was very surprised at this. Possibly this can be reduced by machined solid bullets. But maybe even that is unrealistic.

 

[theosmithjr]

As the Title suggests, I find it almost impossible to load cartridges that are all exact. I understand there are so many variables it is impossible, but something has been bothering me for years. Let me see if I can explain what I'm trying to say here, and it has to do with the measurement of a loaded round, namely, off the Ogive.

A few specifics, this caliber is 6,5 x 55 but applies to any. Bullet is 130gr the Nosler Accubond. My press is a Foerster Co-Ax, and the Die is RCBS Comp Micrometer Bullet Seater. I am using a Stoney Point Comparator (now Hornady LnL), with the 6.5 insert.

Here is what I'm looking for:

Many do measure exactly 2.530, however I always get a few off, mostly under, and I have learned when all adjustments are set, not to touch and play with adjustments, because that seems to make it worse. If one measures simply to the point of the bullet, you will have variances. But how can it vary measuring to the Ogive?

Ok, close enough, or is there some reason I just can't get 100% of my loads to measure exactly the same? I have not touched anything, how can the measurement possibly be different? This has had me stumped for years, as I have no logical explanation how the measurement can be different.

Try a SINCLAIR BULLET COMPARATOR.
Theosmithjr

 

[joseph gallagher]

That's about the variance of one box of match bullets I mentioned earlier!

All match ammo is not the same. Measured 2 almost full boxes of .308 match ammo
1. FGMM GM308M2 lot#Q37M173
On 16 cartridges B-Ogive varied from 2.209" - 2.223" a variance of .014"
With coal 2.280" - 2.283".

2. Black hills gold .308 175gr. TSMK lot# 1626261395. Followed by B-674
On 19 rounds B - Ogive varied from 2.175" - 2.177" did not measure coal cause these are tipped.

So +- .001 is not the variance on a box of match ammo maybe some, maybe....

 

[bigedp51]

I have the Sinclair and Hornady gauges and they are basically both the same type comparator.
And neither gauge will fix a varying OAL problem no matter how you measure the problem.

 

[skipglo]

As the Title suggests, I find it almost impossible to load cartridges that are all exact. I understand there are so many variables it is impossible, but something has been bothering me for years. Let me see if I can explain what I'm trying to say here, and it has to do with the measurement of a loaded round, namely, off the Ogive.

A few specifics, this caliber is 6,5 x 55 but applies to any. Bullet is 130gr the Nosler Accubond. My press is a Foerster Co-Ax, and the Die is RCBS Comp Micrometer Bullet Seater. I am using a Stoney Point Comparator (now Hornady LnL), with the 6.5 insert.

Here is what I'm looking for:

Many do measure exactly 2.530, however I always get a few off, mostly under, and I have learned when all adjustments are set, not to touch and play with adjustments, because that seems to make it worse. If one measures simply to the point of the bullet, you will have variances. But how can it vary measuring to the Ogive?

Ok, close enough, or is there some reason I just can't get 100% of my loads to measure exactly the same? I have not touched anything, how can the measurement possibly be different? This has had me stumped for years, as I have no logical explanation how the measurement can be different.

If you look at your 2 pictures...at least what I see a first glance is the shell is not level in pic 2....you are only dealing with 2000 difference..mark your calipers center...may help, but also bare in mind the the bullets you use are manufactured by the Thousands at a run!

 

[gator378]

Measure just the projectile from its base to the Ogive. You might find that is the culprit. I have found that bullet dimensions vary.

Me too. I would get small variations and when measuring bullet length I found they vary by a small amount. They manufacture bullets by the thousands and the bullet manufactures have tolerances. amazing small but they are there. I gave up trying to be exact.

 

[joseph gallagher]

I use a Redding Instant Indicator with a bushing that is the exact groove diameter of the caliber I am loading for to establish seating depth. I set up the indicator with a inert master case that I have seated to length for the jump to the lands I want in the rifle I'm loading for. The Redding Instant Indicator paired with a Redding T7 Press and a Redding Competition Seating Die allows me to seat with near dead nuts consistency. Usually within +/- .0005" or under. In my opinion most comparators are useless because they are kind of random to what the inside diameter of the inserts are. They are usually never a diameter that is useful for consistency which is groove diameter. I know there are a few machinists out there that can make custom comparators where you can specify the exact diameter of the hole you need. If I was to ever buy a comparator that is the route I would take. When you measure from the base of the cartridge to the point on the ogive where it is the exact diameter of the grooves of the bore... every single bullet you load will have the exact same jump to the lands. I've found when I seat this way and closely manage my charge weights I almost always end up with loads with single digit ES and SD with very little effort in load development.

I use the same setup as you hot tuna but a different press. In my prior post i mistakenly called the redding instant indicator " the redding comparator"

I follow almost the same process for resizing i size and measure. Setting the indicator to zero with the standard redding supplies.

I never seat or size and call it done always measure. With sizing i measure before and after.

However i have not attained +-.0005" good for you on attaining that level of precision and consistancy.

 

[joseph gallagher]

If you look at your 2 pictures...at least what I see a first glance is the shell is not level in pic 2....you are only dealing with 2000 difference..mark your calipers center...may help, but also bare in mind the the bullets you use are manufactured by the Thousands at a run!

Spend 15 bucks and purchase the anvil that goes with the LNL tool the base of the cartridge would rest on that easier more consistant measurments.

 

[skipglo]

Spend 15 bucks and purchase the anvil that goes with the LNL tool the base of the cartridge would rest on that easier more consistant measurments.

Right! Lmao....It would have been easier than what I suggested.... couldn't remember the name of it. Thanks for the reminder!

 

[joseph gallagher]

I've also had much more consistency in regards to concentricity using this method when seating bullets, and using it when sizing my cases as well.

At least 1 180° cartridge twist before final seating.