77 SMK & COAL Variations (RCBS SB Die)

[rlsmith1]

I'm loading 77gr SMKs to mag length (2.6") but I'm getting variations between 2.55" and 2.60". Is there anything I can do make this a more uniform process? Below is my process.

1. Tumble once fired brass (RP in this case)
2. Resize and deprime
3. Trim cases to length (Layman hand trimmer)
4. Prime
5. Powder
6. Seat

I do get some tip deformation as described in this thread but I'm less worried about that. Is there anything I can do to bring this variation back to 2 or 3 thou? Accuracy has been ok for the one 5 shot group I have shot with one flier that was high. I'm 80% sure it was a variation induced by me rather than shooter error. Stringing was horizontal on the other which leads me to believe I've got more seating depth variation than I should be ok with. I did not have the chrono out to verify velocity as this was the first set of loads.

 

[TxWelder35]

I got some 2nds from midway couple months back and had the same issue, ended up going through all them with a comparator and separating them all out by BTO length.

 

[Mudflap621]

You measuring cbto or just using coal?

 

[whatsupdoc]

Take 20 bullets and measure the length. They are not exactly the same.
What you are seeing is bullet length variation and seating depth variation stacked together.

 

[rlsmith1]

I'm just measuring coal... Don't have an ltog tool. I will measure 20 and set my seating die off the middle value. Thanks guys

 

[smoothy8500]

I find that the tips on SMK's are always slightly messed up and measure off the ogive instead of the COAL. Your seating die indexes from the ogive anyways, so tip variations are not so worrysome.

 

[db2000]

Yeah, BTO is the way to go

 

[rlsmith1]

Is there any way to measure BTO without the BTO tool?

 

[spife7980]

Is there any way to measure BTO without the BTO tool?

Its pretty tough to measure something with out the tool to measure it with.

Doesnt have to be fancy, any datum will work if you want to make one but the comparators made for it are pretty easy and convenient.

 

[sinister]

You can try a Whidden tip uniforming and trimming tool. You gain better consistency at the cost of a little drag -- maybe requiring a quarter minute more elevation than non-uniformed bullets.

 

[rlsmith1]

Thanks guys, didn't realize the tool is $7. I just ordered one and a couple extra for the other calibers I plan to reload.

On the modifying these bullets, I think I will be fine inside 600 yds without messing around with the tips. Great info I appreciate it!

 

[spife7980]

Thanks guys, didn't realize the tool is $7. I just ordered one and a couple extra for the other calibers I plan to reload.

On the modifying these bullets, I think I will be fine inside 600 yds without messing around with the tips. Great info I appreciate it!

7 for the little bushing and then like 20 bucks or something for the actual body that holds the insert onto the caliper.

I suppose if you were in a bind you could take the seating die apart and use the actual seating stem itself. BUt I would rather just get the little convenient easy tool to put on the calipers.