Question on bullet seating.

[Alaskaman11]

Question guys.
Does bullet seating effect std dev?
The issue I’m getting, with my dasher and 308, I get a std dev in the single digits, my 223 bolt gun is getting around 25 to 30 std Div. My process is the same on all, but the difference is I use LW Wilson seating die for the dasher and the 308 and a standard rcbs for the 223. It’s the only difference I can find. Thoughts?

 

[918v]

No

 

[Alaskaman11]

What would cause such a spread?

 

[Aftermath]

Lots of threads and at least as many opinions...

First will be the faux statisticians...how many rounds are you evaluating and that is not enough unless you shoot 6000 rounds...not 100% incorrect but missing much.

I support the theory that the smaller the case volume, the more influence vary small variations contribute to things such as velocity...and, by extension, SD of that velocity.

 

[Alaskaman11]

I was running 5 shot load development groups. The STD DeV variance was that spread across the 5 control groups.

 

[Ex E6]

Question guys.
Does bullet seating effect std dev?
The issue I’m getting, with my dasher and 308, I get a std dev in the single digits, my 223 bolt gun is getting around 25 to 30 std Div. My process is the same on all, but the difference is I use LW Wilson seating die for the dasher and the 308 and a standard rcbs for the 223. It’s the only difference I can find. Thoughts?

OK : Take #5 closest matched cases in .223 ,that have been fired from YOUR weapon . Clean and prep identically . Then reload as near as accurately and identical as you can including OAL . Take those #5 test group to the Range ,with a CLEAN bore fire #2-3 any old rounds for fouling .
Now fire the #5 test group for accuracy as well as Measurement within 1 minute . Post YOUR results .

This is from Ballistics POV :

Statisticians have determined that values no greater than plus or minus 2 SD represent measurements that are are closer to the true value than those that fall in the area greater than ± 2SD. Thus, most QC programs require that corrective action be initiated for data points routinely outside of the ±2SD range.

I've been pulling the handle closer to 60 years now and I've NEVER gotten 2 SD !.

I have on #3 occasions placed two 7.62X51mm and four 5.56X45mm into the same hole at 100 yd. and 200 yd.
I'm NOT talking about a ragged hole group but the exact .308" and .224" hole diameter . Had there been No backer change ,I'd not have been credited with the hits .

Fyi : One of MY personal best groupings of #15 shots averaged 87 SD and a Dime covered the entire group with change at 200 yd. . So go figure and that Rifle is MY 1990's 20" ES2 A2 AR 15 Bushmaster bone stock ,with MY handloads

 

[Steel Blue Valiant Panther]

Yep, bullet seating can affect SD. Your Wilson die must be getting you more consistent depth.

 

[Alaskaman11]

OK : Take #5 closest matched cases in .223 ,that have been fired from YOUR weapon . Clean and prep identically . Then reload as near as accurately and identical as you can including OAL . Take those #5 test group to the Range ,with a CLEAN bore fire #2-3 any old rounds for fouling .
Now fire the #5 test group for accuracy as well as Measurement within 1 minute . Post YOUR results .

This is from Ballistics POV :

Statisticians have determined that values no greater than plus or minus 2 SD represent measurements that are are closer to the true value than those that fall in the area greater than ± 2SD. Thus, most QC programs require that corrective action be initiated for data points routinely outside of the ±2SD range.

I've been pulling the handle closer to 60 years now and I've NEVER gotten 2 SD !.

I have on #3 occasions placed two 7.62X51mm and four 5.56X45mm into the same hole at 100 yd. and 200 yd.
I'm NOT talking about a ragged hole group but the exact .308" and .224" hole diameter . Had there been No backer change ,I'd not have been credited with the hits .

Fyi : One of MY personal best groupings of #15 shots averaged 87 SD and a Dime covered the entire group with change at 200 yd. . So go figure

I’ll do this. As for your last point on the FYI, all 5 groups were a ragged hole. Maybe I should just stop worrying about it

 

[918v]

What would cause such a spread?

Wrong powder charge, seating depth, neck hardness, seating pressure.

 

[Ex E6]

I’ll do this. As for your last point on the FYI, all 5 groups were a ragged hole. Maybe I should just stop worrying about it

I did this off the dirt NO mat at a LEO BBQ/Picnic Accuracy demonstration one afternoon ,so as to demonstrate the benefit of loading your own . With BLC-2 Bulk bullets with cannelure no less and 1990 LC cases . Note the classic Paper BBQ plate target
Back then MY Bushmaster wore a Simmon AETEC 2.8X10 44mm scope ,not exactly a precision piece of glass but did well enough on 6 power at 200 yd. .

 

[Alaskaman11]

Wrong powder charge, seating depth, neck hardness, seating pressure.

That’s why I was wondering with the LE Wilson being a more precise seat. Is that why it would have the differences between say the 6 Dasher and the 223

 

[Ex E6]

Neck tension can cause irregular pressure ,thus effecting velocity .

There are SET variables which NONE of us can account for or compensate . Powder same lot same canister can vary 3 +% ,Primers 2 +%

Those two factors alone make 2% SD ; IMPOSSIBLE .

 

[918v]

That’s why I was wondering with the LE Wilson being a more precise seat. Is that why it would have the differences between say the 6 Dasher and the 223

It’s not a more precise seat. It’s more convenient as in easier to set the seating depth. Unless you have an issue with the bullet nose and seater stem fit.

 

[straightshooter1]

OK : Take #5 closest matched cases in .223 ,that have been fired from YOUR weapon . Clean and prep identically . Then reload as near as accurately and identical as you can including OAL . Take those #5 test group to the Range ,with a CLEAN bore fire #2-3 any old rounds for fouling .
Now fire the #5 test group for accuracy as well as Measurement within 1 minute . Post YOUR results .

This is from Ballistics POV :

Statisticians have determined that values no greater than plus or minus 2 SD represent measurements that are are closer to the true value than those that fall in the area greater than ± 2SD. Thus, most QC programs require that corrective action be initiated for data points routinely outside of the ±2SD range.

I've been pulling the handle closer to 60 years now and I've NEVER gotten 2 SD !.

I have on #3 occasions placed two 7.62X51mm and four 5.56X45mm into the same hole at 100 yd. and 200 yd.
I'm NOT talking about a ragged hole group but the exact .308" and .224" hole diameter . Had there been No backer change ,I'd not have been credited with the hits .

Fyi : One of MY personal best groupings of #15 shots averaged 87 SD and a Dime covered the entire group with change at 200 yd. . So go figure and that Rifle is MY 1990's 20" ES2 A2 AR 15 Bushmaster bone stock ,with MY handloads

Hmmm??? "NEVER gotten 2 SD" in that time
Having been precision reloading for ~ 9 years now, my .308 has given me several SD's of 2 or less (all 5 shots or less). One 3 shot with an SD of 1.0 . And only once I got a 1.7 SD with 5 shots out of my 6.5 PRC. LOL, yeah . . . I know, that statistical thing, and that 1.0 SD group I got wasn't particularly good and didn't go with that load because of the poor mean radius number. In fact, I've had a 5 shot SD of 2.0 and the group size was over 1 MOA. But, most of my low SD's I've recorded have had very good groupings. For sure, a low SD just does not guarantee a small group.

I’ll do this. As for your last point on the FYI, all 5 groups were a ragged hole. Maybe I should just stop worrying about it

Low single digit SD's are a good thing to strive for, but what count's is what you get on target. I simply look at SD's as measure of how well I'm putting together my cartridges. . . . consistency with all the elements matters!

 

[Alaskaman11]

It’s not a more precise seat. It’s more convenient as in easier to set the seating depth. Unless you have an issue with the bullet nose and seater stem fit.

Maybe I should of used consistent

 

[straightshooter1]

Question guys.
Does bullet seating effect std dev?
The issue I’m getting, with my dasher and 308, I get a std dev in the single digits, my 223 bolt gun is getting around 25 to 30 std Div. My process is the same on all, but the difference is I use LW Wilson seating die for the dasher and the 308 and a standard rcbs for the 223. It’s the only difference I can find. Thoughts?

To answer you're question, IMHO, yes. . .but to the extent of how much variation there is in the seating. You need substantial variation to see it in the SD's. Probably the biggest factor here is, the difference in cartridge selection, which often is THE major factor. For example, a Dasher is one of the cartridges that's much easier to get good performance on paper and in terms of consistency. A 223 is much tougher to get the kind of performance one can get out of a Dasher or a .308.

Don't know if you saw this in another thread, but the graph produced by Little Crow Gunworks should give you some idea as to the relationship of things that effect things like SD's and precision the most:

 

[spife7980]

Are you using 223 components that are of equivalent quality as the dasher brass?
The answer will 95% be “no.”

Crap components, that much of 223 is, won’t ever shoot well. Get lapua brass, anneal it, mandrel it, develop a good load and you should be able to get it below 10. An sd below 10 on a 223 is pretty dang good.

“Bullet seating” alone won’t affect crap. You need to get more specific with your queries to get good answers.

 

[918v]

Maybe I should of used consistent

Again, a standard seater die does not seat less consistently than a Wilson or other match grade die unless you have fit issues between the bullet nose and the seater stem such as the bullet tip bottoming out inside the seater stem.

 

[Ex E6]

Hmmm??? "NEVER gotten 2 SD" in that time
Having been precision reloading for ~ 9 years now, my .308 has given me several SD's of 2 or less (all 5 shots or less). One 3 shot with an SD of 1.0 . And only once I got a 1.7 SD with 5 shots out of my 6.5 PRC. LOL, yeah . . . I know, that statistical thing, and that 1.0 SD group I got wasn't particularly good and didn't go with that load because of the poor mean radius number. In fact, I've had a 5 shot SD of 2.0 and the group size was over 1 MOA. But, most of my low SD's I've recorded have had very good groupings. For sure, a low SD just does not guarantee a small group.

Low single digit SD's are a good thing to strive for, but what count's is what you get on target. I simply look at SD's as measure of how well I'm putting together my cartridges. . . . consistency with all the elements matters!

Not that I was aware of . ANY SD in single digits is what I'd consider a WIN . Loads that are in single digit SD's will in theory group together better ,as obviously velocity dictates POI . Lessen the charge and impact becomes lower ,increase it climbs .

ALL depending upon bullet aerodynamics and distance to impact . Loads for LR shooting at 100 yd.-300 yd. makes little difference but at a K yd. is where it really shows up .

 

[straightshooter1]

Not that I was aware of . ANY SD in single digits is what I'd consider a WIN . Loads that are in single digit SD's will in theory group together better ,as obviously velocity dictates POI . Lessen the charge and impact becomes lower ,increase it climbs .

ALL depending upon bullet aerodynamics and distance to impact . Loads for LR shooting at 100 yd.-300 yd. makes little difference but at a K yd. is where it really shows up .

Just before I started precision reloading I read that it was difficult to get .308 cartridges into single digit SD's, especially compared to the likes of 6ppc's or Dasher's. But, I was determined to see just how low I could get them, especially using a factory gun like an RPR (I think maybe the Krieger barrel helps a little ). My hope then was to just get an SD of 9. . . even for just 5 shots. I've come a long ways and typically get in the low 6's for a large series of shots (like 40 and 50 shots recorded). Last year I procured a box of Alpha brass and a fire forming session of 80 rounds, the SD was 6.5 and the 5 shot groups were good, but not great.

Now, if I don't get single digit SD's I know there's something not working, like I tried out some Remington 9.5's and 45 shots gave me an SD of 20.4 and groups were over 1 MOA. It wasn't one of my best loads I was playing with, but it should have been much lower than that. Tried another 10 rounds with one of my better loads that typically works well and still didn't get a good results with those primers (SD of 14.4).

And yes, you're right on. . . SD's can really show up in vertical dispersion on target at distance.

 

[BuildingConceptsllc]

I've always had a much harder time getting consistent low SD with 223 vs anything else. with 6cm, 6.5cm, and .308 I always have lower SD than 223, even with great components, but the components matter a lot.

 

[Ex E6]

Just before I started precision reloading I read that it was difficult to get .308 cartridges into single digit SD's, especially compared to the likes of 6ppc's or Dasher's. But, I was determined to see just how low I could get them, especially using a factory gun like an RPR (I think maybe the Krieger barrel helps a little ). My hope then was to just get an SD of 9. . . even for just 5 shots. I've come a long ways and typically get in the low 6's for a large series of shots (like 40 and 50 shots recorded). Last year I procured a box of Alpha brass and a fire forming session of 80 rounds, the SD was 6.5 and the 5 shot groups were good, but not great.

Now, if I don't get single digit SD's I know there's something not working, like I tried out some Remington 9.5's and 45 shots gave me an SD of 20.4 and groups were over 1 MOA. It wasn't one of my best loads I was playing with, but it should have been much lower than that. Tried another 10 rounds with one of my better loads that typically works well and still didn't get a good results with those primers (SD of 14.4).

And yes, you're right on. . . SD's can really show up in vertical dispersion on target at distance.

To make good ammunition component selection is crucial ,to make Fantastic Ammo requires the Key component ; The Correct Powder , bullet weight and sound cases regardless of brand name ( partial annealed necks definitely help ) .

Now will run of the mill Military expended cases make the best ammo ?. Probably not and it most certainly makes a difference WHERE those cases came from !. A well worn M60 or a 249 SAW ISN'T gonna be a great starter base cartridge decision .

I've had some of the best groups I've produced with lousy SD #'s but compensated with KEY components including decent cases .

Norma , FN , LC , PPU even S&B ( Yeah go figure ) . Yes I've got and also use Lapua . What I've found out over the years is , a PPU can be just as accurate as a Lapua case . Having been in a few Ammunition factories ,including Lapua and Norma , I've found things very similar and both had stringent QC . Sellior & Bellot ( Pronounced correctly is Sell-er Bel -lot ) accent on the B & L not on the t . When a Czech says it in English , it's nearly identical to Sailor Below . Just to clarify that .
Point is Seller & Bellot produces some of the BEST factory made ammunition in the World ,Bar None . NO company allowed behind the scenes analytical analysis of their components ,including Brass and it's % trace elements .

MY personal opinion , as I said having been to a few factories , Brass rolls looked nearly identical in the Nordic Factories ,so ??.
One is not permitted to view puck to cartridge draw process but all other operations were open to view . With any and all questions answered cheerfully . A Very Close Long time Friend ,was in charge of Norma up until about 4 years ago ,when He retired .
Just in case anyone wondered How I was able to visit those facilities .

I also batched Industrial explosives as well as Smokeless powder ,way way way back for Hercules Powder . So less than a handful of related industry people are left ,around various manufacturing facilities which I still remain in touch with .

Some of the very best 7.62X51mm cases I still retain are , FN and groups from when I fired factory Military rounds proved it and reloads are super accurate . MY Favorite Powder these days is VV for MANY of My reloading choices . IMO ; VV is holding some of the strictest tolerances that I've access too .

 

[straightshooter1]

To make good ammunition component selection is crucial ,to make Fantastic Ammo requires the Key component ; The Correct Powder , bullet weight and sound cases regardless of brand name ( partial annealed necks definitely help ) .

Now will run of the mill Military expended cases make the best ammo ?. Probably not and it most certainly makes a difference WHERE those cases came from !. A well worn M60 or a 249 SAW ISN'T gonna be a great starter base cartridge decision .

I've had some of the best groups I've produced with lousy SD #'s but compensated with KEY components including decent cases .

Norma , FN , LC , PPU even S&B ( Yeah go figure ) . Yes I've got and also use Lapua . What I've found out over the years is , a PPU can be just as accurate as a Lapua case . Having been in a few Ammunition factories ,including Lapua and Norma , I've found things very similar and both had stringent QC . Sellior & Bellot ( Pronounced correctly is Sell-er Bel -lot ) accent on the B & L not on the t . When a Czech says it in English , it's nearly identical to Sailor Below . Just to clarify that .
Point is Seller & Bellot produces some of the BEST factory made ammunition in the World ,Bar None . NO company allowed behind the scenes analytical analysis of their components ,including Brass and it's % trace elements .

MY personal opinion , as I said having been to a few factories , Brass rolls looked nearly identical in the Nordic Factories ,so ??.
One is not permitted to view puck to cartridge draw process but all other operations were open to view . With any and all questions answered cheerfully . A Very Close Long time Friend ,was in charge of Norma up until about 4 years ago ,when He retired .
Just in case anyone wondered How I was able to visit those facilities .

I also batched Industrial explosives as well as Smokeless powder ,way way way back for Hercules Powder . So less than a handful of related industry people are left ,around various manufacturing facilities which I still remain in touch with .

Some of the very best 7.62X51mm cases I still retain are , FN and groups from when I fired factory Military rounds proved it and reloads are super accurate . MY Favorite Powder these days is VV for MANY of My reloading choices . IMO ; VV is holding some of the strictest tolerances that I've access too .

Likewise, I've found PPU cases to produce quite well, even as a mix of lots. What I have of them is a collection from range brass that I picked up as I collected various brands of cases to compare when I first started precision reloading. I also collected a LOT of FC brass that also performed quite well and have fired a lot of them as I developed my reloading procedure. These days, Lapua is my main choice. The Alpha brass, a rather recent purchase, performed great initially, but haven't shot them a lot yet as I'm still waiting for my Lapua brass to give up the ghost before I do.

I really like the VV powders that I've used for my 6.5 PRC. I just wonder how affordable they might be in the near future given current political environment.

 

[DownhillFromHere]

I support the theory that the smaller the case volume, the more influence vary small variations contribute to things such as velocity...and, by extension, SD of that velocity.

^^^ I agree with this.

Over hundreds - thousands - of rounds of 6.5CM, 6BR, and .223 loaded over the last several years in Starline, Peterson, and Alpha brass with top-shelf bullets and powders, I've come to expect my .223 SDs to be over double that of the larger calibers. One of my more "persnickety" buddies used to grump about how high his .223 SDs were; he loaded nothing but Lapua brass and his ES/SD values for larger calibers was and remains in single digits.
----
Edited to add: all handloading for my precision rifles is done in same-lot, bought-new brass... I would expect SD values to go kinda nuts with mixed-brand range brass. No bleeping way I'm going to trust unknown range brass. Even blaster ammo for my and my son's ARs is from known sources.

 

[Alaskaman11]

Thanks, thats good to know. THe rifle really like the Varget and SMK combo and it groups amazingly. guess i wont worry to much about it.

 

[Ex E6]

Likewise, I've found PPU cases to produce quite well, even as a mix of lots. What I have of them is a collection from range brass that I picked up as I collected various brands of cases to compare when I first started precision reloading. I also collected a LOT of FC brass that also performed quite well and have fired a lot of them as I developed my reloading procedure. These days, Lapua is my main choice. The Alpha brass, a rather recent purchase, performed great initially, but haven't shot them a lot yet as I'm still waiting for my Lapua brass to give up the ghost before I do.

I really like the VV powders that I've used for my 6.5 PRC. I just wonder how affordable they might be in the near future given current political environment.

Truthfully VV powders are a bargain , compared to what those thieves are peddling older US powers produced by " Foreigners " .

What we need as a Country is #4-8 MAJOR munitions producing plants IN THE USA !. Eventually outsourcing comes back to bite one in the ass !.
Range brass pickups are a mixed bag ,sometimes one gets brand new once fired and sometimes one gets headaches from #35 firings in someone Else's chamber . I've not compared a lot of different manufacturers brass , however I've shot and reloaded a crap load of LC & SL 1942-44 .30 Cal M2 once fired in My Garands and was blown away at how many reliable reloads I achieved . #50 I stopped ,cut two cases for real thickness measurement . Easily would go another 10 reloads . I did partial anneal necks after every 3 Rd. firing ,so as not to lose necks from splitting . I also use 1953-68 Mixed 7.62X51mm LC and Match brass ,mainly for M14 and two 7.62X51 Gas guns ,haven't lost a single rim and those extractors are notoriously hard on cases . I used a batch of W cases commercial and after #2 firings scrapped them ,as they looked like a Grizzly bear mauled them and pieces of rims were torn away . So I NEVER us that brand of case in anything ,I reload or shoot .

Laupua is excellent brass but it's also COSTLY now days ,so I tend to avoid it ( unless someone discards it ) ,yet we both know Reloaders DON'T discard Laupa unless it's time has expired . Those days of Lapua Range brass are distant memories .

Swiss make decent brass cases ,as did RWS at one time . IF only FN was still making cases

 

[straightshooter1]

Truthfully VV powders are a bargain , compared to what those thieves are peddling older US powers produced by " Foreigners " .

What we need as a Country is #4-8 MAJOR munitions producing plants IN THE USA !. Eventually outsourcing comes back to bite one in the ass !.
Range brass pickups are a mixed bag ,sometimes one gets brand new once fired and sometimes one gets headaches from #35 firings in someone Else's chamber . I've not compared a lot of different manufacturers brass , however I've shot and reloaded a crap load of LC & SL 1942-44 .30 Cal M2 once fired in My Garands and was blown away at how many reliable reloads I achieved . #50 I stopped ,cut two cases for real thickness measurement . Easily would go another 10 reloads . I did partial anneal necks after every 3 Rd. firing ,so as not to lose necks from splitting . I also use 1953-68 Mixed 7.62X51mm LC and Match brass ,mainly for M14 and two 7.62X51 Gas guns ,haven't lost a single rim and those extractors are notoriously hard on cases . I used a batch of W cases commercial and after #2 firings scrapped them ,as they looked like a Grizzly bear mauled them and pieces of rims were torn away . So I NEVER us that brand of case in anything ,I reload or shoot .

Laupua is excellent brass but it's also COSTLY now days ,so I tend to avoid it ( unless someone discards it ) ,yet we both know Reloaders DON'T discard Laupa unless it's time has expired . Those days of Lapua Range brass are distant memories .

Swiss make decent brass cases ,as did RWS at one time . IF only FN was still making cases

Last year, to my surprise, I happened to see some discarded 6.5 cm Lapua brass that appeared to be just once fired (having what looked like factory sealant around the primer as an indicator), so I picked the 40 rounds laying there for a shooting buddy who reloads that round (I don't shoot the Creedmoor). The different range brass I've collected are from shooters at the range shooting from factory boxes of cartridges while I was there. I've always been careful about picking up range brass, not wanting to have any of those "headaches" from previous reloaded cases; who knows how many times or how they were processed. I've not fired all the different one's in my gun, being I was more interested in the more specific differences (like consistency in weight, primer pocket depths, centering of flash holes, etc.).

Initially, I did focus on Federal brass and wanted to see if they'd perform as well as my Lapua brass. And for the most part they have for my .308, but it takes more effort to get cases to the consistency I find in Lapua brass (like culling out outliers). Because their neck thickness and case capacity being close to Lapua and having got them performing close to Lapua brass, I often use them as test cases before I move on to my Lapua brass when trying something new.

Except for last fall when I bought some Lapua Palma brass, I haven't had to buy any of it since I've stocked up pretty well before Covid. LOL. . . I think I've got enough to last the rest of my life I'm no youngster! I've got a few boxes I picked up as a bargain only paying $79 each for them.

 

[Ex E6]

Our Range either has a bunch of tightwads or super experienced reloaders ,as I never seem to stumble on any decent Rifle brass . I don't see much steel case either . Makes Me
think most shooters around these parts are Hunters and visit the range prior to hunting season . With MY Shooting multiple calibers ,one would think I'd luck out once in a while and find some rifle brass . Pistol Brass ,yeah I've gotten New once fired Good range discards ,especially .45 ACP . What I never see is .44 special , Magnum or .38 Special . Seems they're rather scarce these days as everyone has gone 9mm or .40 cal. .