Variations of 'same projectile' Hornady 150gr SP Interlock

So, while casually reloading, I do check everything, from powder throw on scales to final seating depth check with comparitor and verniers - hello, whay am I seeing 2 variations in seating depth when the microometer seating die is set...?

Measure a few projectiles using the comparitor ( worth their weigh in gold I feel )..

Must have a mixed batch of projectiles in the box - can even see the difference side by side - crazy for same bullet type and weight!! 30 thou difference so these have differing ogive shape - thats got to have an effect surely....
Sad times when you try an keep everything within a spec....

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they are known to shift the cannalure ring between batches too....thats not on in the same box....wasnt bought 2nd hand perchance????
we had member get caught earlier in year with mixed projectiles in box resulting in blown up rifle.

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Originally Posted by Micky Duck

they are known to shift the cannalure ring between batches too....thats not on in the same box....wasnt bought 2nd hand perchance????
we had member get caught earlier in year with mixed projectiles in box resulting in blown up rifle.

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I must admit, this was an old box bought when I bought my 308 eons ago, and rather than keep proj separately, Ive thrown 'same' Interlocks in the same box - foolishly believing there would be no change in batches - so I take some responsilibility - didnt think they'd vary that much though, wow... almost need to load test the same bullet twice given the variations.. Shocker really!! Least I know now the micro seating die nor verniers wernt moving...!

Are you sure they are the same weight?

hornady have always made more than one type of 150grn flat based sp.... wouldnt be hard over time to buy two different types.

Greetings,
I have found the same thing with other Hornady projectiles. The ones with the sharper, more noticeable ogive are later. There does seem to have been a deliberate change over time. Same projectile number but different shape needing different seating depth.
GPM.

I recently pulled some factory hornady whitetail 150gr rounds and comparing to a box of 150gr interlock projectiles i found that exact differences you have in the photo. Makes me wonder if the factory rounds are slightly different compared to a box of projectiles we get on the shelf...

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Originally Posted by 7mmwsm

Are you sure they are the same weight?

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Yes, instantly checked that!! were a few grains off 150, though 150gr they were...

Referring back the photos, the early version measured the 0.508 inch to ogive, whereas the later and current proj measured the 0.47 inch ogive to base... offering less bearing surface ... must be a good reason for the changes...

Iv come across this just yesterday with 180eldm one old box and one nex box though I didnt check when i opened the new box and went to shoot them and felt the jam so stopped came home and measured 20thou difference

Same with 175 ELDX in 7mm, older ones the ogive is further back, bullets the same length but will jam at shorter length on the new ones. Always pays to check between batches, same as powder lots.

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Originally Posted by Nasty Factory Trigger

Yes, instantly checked that!! were a few grains off 150, though 150gr they were...

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How many grains off?
I weigh everything and have never had a variation of a few grains. If the box says 150, they are always within .2 or .3 of a grain.

Probably wore the tooling out and changed the design at the time for whatever reason when the new dies were made up. Highlights why it can sometimes be such a pain in the arse trying to duplicate a factory load, as the factory pills that shoot so well might be made at the same factory that loads the factory rounds where as what is available for reloading comes from a different plant with different tooling altogether. Also another good example for checking every time you can a new lot of components in, as even stuff from the same shipment can have several lot numbers in it and they can all have slight differences.