Reloading question.....How to consistently get single digit SD

[raven88]

I am getting a little frustrated….. and wondering how to achieve consistent single digit SD…. I’ve loaded for years….. However, after getting my magnetospeed and seeing double digit SD in teens more frequently than single digit SD……I’m looking for advise on what I need to do to get consistent single digit SD with my rifles.

I haven’t weighed cases….and I use the bullets right out of the box. I use mostly Hornady and Berger bullets for my two 6.5 CM rifles. For my 308 rifles I use Sierra and Hornady bullets. I am using Hornady brass for the 6.5 CM’s, and Win brass for the 308’s

My workflow is:
Knock out primers
Stainless wash brass
Anneal brass (bench source)
Size (Redding FL neck bushing die)
wipe/clean off sizing lube
Trim (Girard)
Prime (forester bench primer)
Powder using chargemaster…..(random verify with gempro 250) but may soon get that "auto trickler" http://www.autotrickler.com
Bullets (Redding micro seater die)

Any guidance is appreciated.

thank you
greg

 

[spife7980]

Test the difference that varying bushings give you and see if one works better than another. Lube your necks with imperial dry media. Try different brass all together that is reported to be more consistent from the get go.

 

[raven88]

will get some lapua brass.......haven't used it yet.......I bought a couple cases of factory Hornady ELD-M and it shoots under .5 from both of my 6.5 rifles..... now that Lapua brass is available for the 6.5CM I haven't got any because it costs more than a factory loaded round. I'll order a box of the lapua brass and try it.

thank you for your input

 

[spife7980]

Before you spend money, if you have the tools, take some measurements and see if you can create a good consistent lot of what you already have. Neck thickness and concentrically. Water or case weights etc. to narrow that down. Or spend the 60 bucks.

Have you noticed the effect of that SD at distance or are you just trying to get them down empirically for good measure?

 

[shoot4fun]

Have you chrono'd any of the Hornady factory ammo?
Curious to know what accuracy you're getting with it and what SD the Magnetospeed shows.
Lowering SD does not always improve accuracy.
I used to use only five round sampling for chrono data but now I use at least 10 shots.
I firmly believe that is a truer sample size.

 

[raven88]

Before you spend money, if you have the tools, take some measurements and see if you can create a good consistent lot of what you already have. Neck thickness and concentrically. Water or case weights etc. to narrow that down. Or spend the 60 bucks.

Have you noticed the effect of that SD at distance or are you just trying to get them down empirically for good measure?

probably empirically for good measure..... but I read on here folks saying they usually get single digit SD........so I'm chasing the same animal. My groups on paper are generally better when I have single digit SD (I've checked at 100 and 200yd) when I don't screw things up. But I have had good groups with SD in low teens that are .5 or under.

 

[raven88]

Have you chrono'd any of the Hornady factory ammo?
Curious to know what accuracy you're getting with it and what SD the Magnetospeed shows.
Lowering SD does not always improve accuracy.
I used to use only five round sampling for chrono data but now I use at least 10 shots.
I firmly believe that is a truer sample size.

yes I have chrono'd factory ammo..... the first case of Hornady ammo was before the last change they made with their ELD-M bullet. That particular case I chrono'd a bunch of groups and the MV avg was 2842 from my 26" LRI barrel. The second case of same ammo was after the change in their bullet and the MV is generally in the 2770 range. SD for the Hornady factory ammo generally is between 10 - 17. Both my RPR with LRI barrel and the Tikka T3X CTR shoot the factory Hornady ammo well. Advantage to the RPR and when I do my part the factory ammo will generally be .5 or under. I have everything from magnetospeed on excel spread sheet. One of the best groups I ever shot was MV 2855 and SD 17.

 

[Horns8491]

You got a good process going there with some really nice gear. Neck turning should help or you should at least get Lapua brass. SS tumbling creates inconsistent neck friction - using the imperial media may help but it's messy and time consuming, and when I was going that route, I tried to be consistent with it I know that there was variation in how much neck lube each case. I have now abandoned SS tumbling (see recent post about getting pins out of brass after SS tumbling). You can upgrade your scale as you mentioned. I run the Sartorius but I think the A&D D Fx 120 is plenty good and half the price. I've seen the autotrickler in action and it looks pretty sweet. I bet that will get you there.

 

[Sig Marine]

Stainless steel pins or ultrasonics clean cases AND the inside of necks very well. Unless you are lubricating the inside of your necks, you are metal to metal when seating bullets and could be creating problems with bullets release because of the unwanted friction. As mentioned by another poster, try some dry lube or an extremely light coating of imperial sizing wax inside the neck before dropping powder and seating. As for powder dropping systems, I've used a Chargemaster and gotten single digit SDs with David Moore's sleeve and insert in every load I've developed. I also know many others who get single digit SDs and consistent loads using the Chargemaster as well. Not saying the Autotrickler isn't nice, just that you can still make good ammunition without it.

 

[Marksman10x]

You can do all the prep work you want and measure to the individual kernel of powder, but if you're load is not right, it doesn't matter.

To me, it sounds like you need to adjust your charge weight. Try going up and down a grain in 0.3 grain increments. See if that helps

Or, you could do a ladder or ocw test. I'm a big proponent of finding the entire node and loading right in the middle. This approach has served me very well for years in sub-freezing to 100+ degree temps.

FWIW, I do a fraction of the brass prep you listed, and have no problems getting 20 shot strings with single digit st dev's, usually around 6-8, I strive for 7 or less.

 

[raven88]

You got a good process going there with some really nice gear. Neck turning should help or you should at least get Lapua brass. SS tumbling creates inconsistent neck friction - using the imperial media may help but it's messy and time consuming, and when I was going that route, I tried to be consistent with it I know that there was variation in how much neck lube each case. I have now abandoned SS tumbling (see recent post about getting pins out of brass after SS tumbling). You can upgrade your scale as you mentioned. I run the Sartorius but I think the A&D D Fx 120 is plenty good and half the price. I've seen the autotrickler in action and it looks pretty sweet. I bet that will get you there.

yes...... after reading the article that Orkan put in his post on the SS media thread, I'm going back to the vibratory tumbler and order some rice to give it a try. I like the way the brass looks after wet tumbling with SS, but inspection is so critical and time consuming, not to mention the neck tension issue.

I think a new scale and auto tricker may smooth out my workflow and help get more accurate and consistent powder charges at a significant reduction in time.

good info all

 

[raven88]

Stainless steel pins or ultrasonics clean cases AND the inside of necks very well. Unless you are lubricating the inside of your necks, you are metal to metal when seating bullets and could be creating problems with bullets release because of the unwanted friction. As mentioned by another poster, try some dry lube or an extremely light coating of imperial sizing wax inside the neck before dropping powder and seating. As for powder dropping systems, I've used a Chargemaster and gotten single digit SDs with David Moore's sleeve and insert in every load I've developed. I also know many others who get single digit SDs and consistent loads using the Chargemaster as well. Not saying the Autotrickler isn't nice, just that you can still make good ammunition without it.

to be honest, I overlooked the inside of neck with regards to the neck tension issue. On top of that, I did not even consider lubing necks. I have Moore's insert for my charge master and I get single digits since installing and using it. I'd just like to get proficient enough to get single SD all of the time. I agree that the autotrickler is not a must, but for those that can afford it would expedite the precise powdering of brass. This forum and the folks that frequent are great wealth of knowledge.

thanks all

 

[BlackFenix]

I am a huge fan of Federal GMM primers. They made a big impact on my SD!

 

[Marksman10x]

You can easily achieve single digit standard deviations with brass that has been SS tumbled and never annealed. I did it this afternoon with 6.5x47 brass on its 21st firing, never annealed, and trimmed only twice in it's life. CCI450's, Varget, and 140 ELD's.
Five shots at 36.4 gave a st dev of 5. And 36.6 had a SD of 3. Even combining all ten shots gave a single digit SD. And accuracy was about half moa for both groups. Also you could overlap the two groups and it would still easily be sub-moa.

These results mirror those of many other load developments performed in the past with many different calibers.

Again, I'd really suggest tweaking your charge weight. Immediately outside the node, sd's were 14 and 18