Why can't i reload exact cartridges?

[XSIVSPD]

I dunno, properly designed I don't think there'd be a ton of difference in speed of measurement. I mocked up a set in cad and will be printing it off tomorrow to test. Will report back once I know something, probably Monday.

Anyone (preferably in ak) want to test a set?

 

[LRHMARYSVILLE]

One thing you might also look at is the amount of pressure you are putting to the loading press. I was having an issue much like yours and found the pressure I was applying was not a constant. One I paid attention to this, the consistency increased. Best of luck.

 

[Knightvision]

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.

Taking your seating die apart, cleaning and lubing the seat with moly using a Q-tip and polishing until new Q-tips are clean. Seating the bullet a small amount, backing off the pressure, seating a little more and finishing the seat with the same motion and pressure has made a positive difference for me. Takes an extra 2 seconds to seat a bullet. Good Luck.

​

 

[wonderman4]

Awhile back I was messing around and thought I would do some comparisons. I got out some bullets from the stash and thought I would measure them, base to ogive.

150 gr 0.308" Accubonds, 100 each

Average: 0.5733"
SD: 0.000662" (calculated with excel)
ES: 0.0030"

I was expecting a higher ES.

 

[CNC Apps Guy]

I'm curious to know what defines "exact".

Exact in my world is less than 1Ångstron (0.1 nanometer).

 

[misterc01]

For that reason, I am going to Sinclair Stainless Comparator insert to see if it is more exact for my purposes. My experience so far, Having said that. my measurements are all TO ME pretty much "close enough" so I am not worried about "exact." Like shooting, if my goal is to hit in the black, then ANYPLACE in the back is accurate enough. The comparator gets me to my seating depth. Then I measure COAL for both magazine clearance if needed, and the actual shapes of the bullet. I use both tangent and secant ogives, and so the ogive is my important measurement. So, all of being human, will get variances someplace, the issue is how much they stack to affect accuracy.

 

[Locknload]

I have read part of this post and did not find an entry that addressed the cartridge case so if it came after I stopped reading, excuse the possible duplication.

CH makes an interesting case trimmer, it uses individual chambers to hold cases, the cutters are square and a bolt with a lock nut holds the case to length. I won one in a steel match. Anyway, studied it, then I started squaring my cartridge bases by flipping the chamber over, then just cutting the base until I have a 100% bright cut face. Uniform primer pockets. Then I fire the case in a square, square, square action with 100% lug contact. Then I trim in an RCBS pro trim. Start at the bottom and work up, US cases are pretty much crap and require a good bit of work to be match worthy.

If you load in competition dies using competition bullets you should get pretty good results for competition. Standard bullets are pretty inconsistent in shape and length. Like bulk 22 LR ammo. Oh, you can measure every bullet by the ojive, before you load the round.

I also sort by capacity, my match brass, 100 rounds, has exactly the same capacity, but that is another subject.
Ed

PS, The 85 Sierra HP, 120 SMK and 140 Hornady Interlock work well in the 6.5 Swede, 260, 6.5 Grendel, 6.5-06, 6.5 TCU.... I own several, and have another 260 AR 10 barrel on order. Like 6.5 potato chips.....

 

[coop2564]

I think the universal errors that are out of our control have more effect than this. Perfection is too elusive. Hakuna Matata

 

[JW74]

One thing that can effect OAL measurement is primer seating. Is the primer flush with the bottom of the case or protruding ever so slightly etc?

 

[Bigaldepr]

One thing that can effect OAL measurement is primer seating. Is the primer flush with the bottom of the case or protruding ever so slightly etc?

If the primer is above flush your problem is not the COAL, you need to find out why and fix it. The primer always needs to be slightly below flush.

 

[JW74]

If the primer is above flush your problem is not the COAL, you need to find out why and fix it. The primer always needs to be slightly below flush.

Correct, but if the caliper base is resting on a slightly protruding primer will that not give a longer "false" COAL? This is not my issue just something I have seen before.

 

[redleg1013]

Use a micrometer seater. Seat them all a little long, like .01" seat, measure, then dial in the difference to your desired length. Is it nominal? No, but if you're looking to eliminate the thou or two difference you're getting, this is your way out.

 

[Howland]

Use a micrometer seater. Seat them all a little long, like .01" seat, measure, then dial in the difference to your desired length. Is it nominal? No, but if you're looking to eliminate the thou or two difference you're getting, this is your way out.

I do exactly this. And 0.010" long is a good place to start. I've found when you try to seat only 3-4 thousanths more, there can be enough tension that the bullet doesn't move. You keep turning the spindle down 1 thou at a time and still nothing happens until 1 more thou and all of a sudden you're 5 or 8 short.

 

[sapper299]

If you don't want to spend on a custom seater plug, make your own. Lapping paste on a bullet and lap the plug to better fit the ogive. I did that to eliminate the ring on my VLD/ELD style bullets and got much better results in maintaining acceptable variance in COAL. Purchase a new plug for your other non critical bullets.