Extream Spread and SD Problems any Advice??

[TAC77]

Went to the range today to try out some new loads, Every load that I tested had a large ES and SD, I trim all of my brass, FLS every time that I reload and use a Wilson Neck Bushing Die to set, my neck tension, clean all primer pockets every time. But I am still not getting the results that I am looking for. If anyone has any suggestions please let me know.

Thanks

TAC77

 

[Winchester69]

What does your target look like?
.

 

[glo]

Hi TAC,
we need more information. Like, how many times has this brass been fired, did you change bullets, mix lots, change powder, change primers, etc…

My first guess is that your problem comes from full length sizing of your cases. If you are shooting from a semiautomatic platform I understand the FLS. But if this is bolt action rifle, FLS may be your problem, especially if you have reloaded these case several times.

 

[Bob3700]

Low ES and SD comes from careful loading. FL or Neck sizing has little to do with it. I FL resize my 6 BRX brass for each firing and consistently get SDs in the single digits.

If you are confident that your case prep and powder charges are as consistent as they can be, the next big step is neck tension and bullet seating depth.

If you can, work up loads for a bullet seated long into the rifling. Try .020' long to start. Now begin working your neck tension down. My bullets seat with just the weight of the RCBS press handle and I cannot spin a seated bullet in the case with my fingers.

Another approach to consistent neck tension is to uniform your neck ID with a mandrel, like a Lymann 'M' die.

Either of these two techniques will help reduce your ES and SD numbers.

Bob

 

[TAC77]

Guys,

I realize that I wrote this a little fast.

Here is my load

155 Lapua Scenar Moly

Lapua Brass Fired 4x

CCI BR2

Bench Mark Powder 44.2 grns

I use a Redding Small Base Body die to resize the body and bump the shoulders .002

I use a Wilson Bushing Die to size the neck and de-prime

I then check all case necks for burs and nicks, and clean them up if necesary) Clean the primer pocket.

I then seat all of my bullets with a Wilson Seater die.

While I am filling all of my cases with powder I continusly double check powder charges. In most cases they are 100%

Seating depth is +.015 in lands

Thanks for your help

TAC77

 

[glo]

Good morning again TAC,
well it looks like you do very good case preparation. I see you use a small base body die. This again reinforces my first thoughts of the FLS being the culprit. I would still be interested in knowing if you are shooting from an AR platform,semiautomatic). The load sounds like a .308 Winchester, but that’s a wild guess.

If case neck tension is the problem I would anneal the necks every 2 firings or so to keep the spring back tension the same.

 

[TAC77]

glo,

The load is for a bolt action 308, the rifle was chambered using a 95 Palma reamer. The main reason that I FL size every reload is that when I do not FL I always have numerous cases that are a little sticky when I chamber them. This is a single shot rifle that I have set up primarily for F-Class matches.

I got into the practice of FLS my brass every reloading with my last match rifle due to the reason that I mentioned above, but have not tried just neck sizing with this rifle. I will give it a try on the next go around. Thanks for your input, if you have any more advice please let me know.

Thanks again,

TAC

 

[expiper]

I think it is the powder charge....is it at or near max...if it isnt then the velocity,,SD-ES))will bounce all over the place...the powder doesnt burn rite if you are running with the choke pulled....how do the primers look....why are the cases gettin 'stiky'??...do the dies and chamber match...there culd be a lot of things makin the cases too tite....what is the velocity...is it low or high ...sounds like you need more powder...tell us more...and we can tell you more...Roger
PS...there is nothing wrong with FL sizing if the dies match the chamber...

 

[glo]

Okay, now where getting somewhere. I would bet dollars to dimes it’s the FLS with the small base body die. Get your self a set of dies made for a Palma 95 chamber. Then you’ll have a match set. Start a new thread and ask who makes Palma 95 sizing and seating dies. Maybe ask in the Buy/Sell threads of the forum. I wouldn’t be surprised if Forster or Redding made them on special order. Still annealing is a good idea.

Expiper has a good point about being at or just less that max powder charge. My thinking is that you may have stretch out your case just enough,4x FLS) to have a larger internal volume. A grain of added capacity would be enough to throw off your SD. Especially if you were at or near max powder charge on initial loading.

If you have and original, prepped and non-fired case from the lot you are now shooting, check the case capacity against a 5x FLS case. Remember to do all the same case prep that way you’ll be matching apples to apples.