SPS Blems

[truck driver]

I have been using SPS Blems for all the load development in my 35 AI. During this time Scotty has me using a Hornady Bullet comparator to get my COAL which was all new to me and was use to measuring off the bullet tip. The 35 AI has been a new learning curve for me in more ways then one.
I was having trouble with bullet seating consistency and had to adjust the seating stem with each bullet to maintain the same bullet seating depth with each load. The loads are lightly compressed with the boat tail just getting into the powder column in the case.
I decided to check the bullet length with the comparator and found that the bullets weren't consistent and there was as much as .003" difference between bullets causing different COAL length. This was with the 200gr AB Blems. When I measured 10 premium bullets they were very consistent and were with in .0005"s of each other.
I was just wonder how this will effect the accuracy of my final load work up and if I should be using the 200gr first bullets for load work up and the Blems for practice?

 

[Charlie-NY]

You should do a direct comparison (by test firing) in your rifle to determine if it makes much of a difference. I doubt it.

FWIW - compressed loads frequently cause this problem. Surprised that first run bullets don't display the same variance. Varied case neck tension due to number of firings or cleanliness of brass will also cause this to happen.

Did you use the same brass with the same number of firings on the reloads with the first run and blem bullets?

 

[truck driver]

I've just been shooting the blems and holding the first for hunting when it counts. All loads have been with the same Nosler brass. I was hoping to draw on other's experience so I wouldn't use up my first with testing. I know I will have to shoot some to confirm my findings but wanted to keep it at a minimum.

 

[Thebear_78]

I regularly have to adjust OAL when using a comparator. There is often a difference even between premium target bullets. For all my target loads I seat in a two step process. I have been using micro adjust seating stems, either retrofitting hornady dies or the expensive competition seaters.

I get the first one seated to desired length to ogive, then I back the seater off 10 thousandth seat the second, measure and seat again. It goes pretty quick once you get used to it and your ammo is exactly same jump to the lands.

You'd be amazed at how much difference there can be, my Sierra matching loads are all over the place measured to ogive unless seared this way, and they shoot tiny little groups!


Sent from my iPhone using Tapatalk

 

[jimbires]

TD , are you using a drop tube funnel ?

 

[kraky1]

My bullet comperator makes it pretty easy to check the bullets before they're loaded. Years ago Midway sold a bunch of close out Partition gold at really good prices and I found them pretty funky checking them before I loaded them. I sorted them into two groups and they shot really well but I have a funny feeling I probably didn't even need to do that.

 

[SJB358]

I seat off the ogive. The tiny bit of variance hasn't caused me any concern so far. Noslers seem to have more variance than others but still shoot pretty decent groups most of the time.

 

[truck driver]

TD , are you using a drop tube funnel ?

Yes I do and get a case fill to the base of the neck. I just decided to measure some of the bullets and found they varied in measurements for the blems. The first seem to be consistent and that perked my curiosity.