Would you mind seeing if i'm making the right changes in my reloading.

[want2learn]

Working up 6.5x47 Lapua load….would you be kind enough to see if i’m on the right track please.

I spent some time working up best Varget load weight first always using the same projectile (123 Scenar), primer (BR-4), case (Lapua).

My best groups seem to be with 35.5gn Varget which has yielded 3 different groups each ranging from between 0.22 to 0.24 MOA, and while those values sound ok they don't measure up to the amazing groupings i've seen posted here....all the shots in one hole but i'm working hard on technique


The problem i'm noting is that with my reloads in this new barrel, despite the ok groups…. it’s pretty hard to close the bolt on my reloads.

I purchased the Hornady COAL gauge and the Forster Datum Dial and did a bunch of measurements which were repeated several times. Here’s what i found:

My Optimal Rifle Chamber Headspace based on measuring fire formed brass shot in my rifle from Datum to base is: 1.4715 inch

When i prepare a case that was full length sized and cleaned and ready to prime the base to datum is: 1.4627 inch


So to make my sized case fit perfectly in my chamber i would have to bump back the shoulder by the difference 1.4715 - 1.4627 = 0.0088 inch Should i afford a little more room in the chamber and subtract a bit more to accommodate for carbon/dust etc?


Now regarding bullet jump:

The projectile i’m using is a 123 Lapua Scenar which measures 0.745 from base to ogive.

The measured Factory Lapua load COAL (base to ogive… which closes easier when i chamber the round) is: 2.144 inch

The measured COAL of my reloads (the rounds that yielded the aforementioned groups that were hard to close the bolt on) is: 2.186 inch

To mimic Factory Lapua COAL i would need to reduce the COAL of my reloads 2.186 - 2.144 = 0.042 inch …but from a practical perspective perhaps the important number would be a measurement from base of case to the lands.

Base to lands measurement of my chamber using the Hornady COAL gauge (from base of cartridge to when the bullet just touches the lands my chamber) measures 2.580 inch

I’ve read it’s best to try 0.010 inch off the lands…..so my new improved reloads should be made to measure 2.57 inch as measured from base to ogive

Does that all seem ok? thanks

 

[TheOfficeT-Rex]

Woah. Something is way off here, with respect to it being tough to close the bolt on your reloads.

First I notice, you're measuring out to 4 decimals. That's a very precise measuring tool, you likely will not be able to make die adjustments with much more granularity than .001".

Next, Most people will bump the shoulder (headspace measurement) back 2 to 4 thousandths. You're bumping almost 9 thou. It should chamber with absolutely zero issue with that much bump - something else is up, either you're not sizing the base enough or you're jamming the bullet into the lands.

Last, you seem to be mixing COAL and ogive measurements. COAL is from base to meplat. CBTO is base to ogive, and is what the datum comparator will give you. Use CBTO for most measurements, including jump measurements, it will be more consistent because it ignores any uneven bullet tips. COAL is really only in play when trying to magazine feed.

 

[Supersubes]

You’ve been sucked in to pictures of single groups. .24 moa is excellent. Don’t give any more thought to shrinking your current sizes. Since you didn’t say, im assuming you’re talking about a tactical rifle, and not a BR rifle.


No way you should be bumping shoulders 9 thousandths. Something else is going on. Measurement error possibly. While full length sizing, you should be bumping zero thousandths to one or two thousandths on the big end. You need to isolate what’s causing the hard close of the bolt. Seems like it may be a jammed bullet.


There is no best jump. Do a test. See what your gun likes with the current charge weight.

 

[want2learn]

I spent a long time on these measurements but i will recheck
i understand...I will refer and compare to CBTO
it feels like my sizing technique should be proper, i use a Forster Co-Ax and their dies. I let the die touch the base and then gave it an extra 1/8 turn further as the directions mentioned.

so frustrating...but i appreciate all the help.

 

[Supersubes]

That is not a proper way to set a FL sizing die. That may end up being correct, but you’d never start there. There are too many variables to allow that.

 

[Backcountryguy]

When you measure your base to datum line on a Fire-Formed case...make sure you pop the primer out WITHOUT resizing your case to take that measurement, if you are not doing so already.

 

[TheOfficeT-Rex]

I spent a long time on these measurements but i will recheck
i understand...I will refer and compare to CBTO
it feels like my sizing technique should be proper, i use a Forster Co-Ax and their dies. I let the die touch the base and then gave it an extra 1/8 turn further as the directions mentioned.

so frustrating...but i appreciate all the help.

Recheck your CBTO for jam with the bullet your loading, then check it against your loaded rounds. I think that's your culprit.

That is not a proper way to set a FL sizing die. That may end up being correct, but you’d never start there. There are too many variables to allow that.

He's right. Use your comparator to measure a fired case (with the primer popped out, as someone mentioned above). Then, screw your die in until it touches, and then out a 1/32 of a turn or so. Size a case, and measure the set back. It should be about .002". If it didnt change, screw the die in 1/32 or so, resize a different case and remeasure. Repeat until you have the proper bump.

Doing it this way means the brass is not sized as much, and doesnt stretch as much on firing, so you get more reloads and less case separations.

 

[Ranger188]

I'm guessing you're fairly new to reloading and shooting.
A .25 Moa group is excellent. Their are so many variables, you got a lot of
great advise above. You will learn a lot more as you keep reloading, some bad
mostly good. The bad will make you a better reloader knowing what not to do in the future.
Not knowing what barrel, action, trigger, scope and such, we don't know what you or your setup is capable of.
If you see a .25 or less, it's from years of reloading and lots of shooting with great equipment and
it doesn't happen everyday.
Sounds like you have the right tools and load, just need to learn the fine points of reloading.
It will happen. We've all been there.

 

[918v]

What is your body diameter at the base and at the shoulder and the diameter of your neck before and after sizing? What is your loaded neck diameter?

 

[Lunchbox27]

1/4” groups?!

Call it done, drinks some beers, carve a pumpkin.

 

[918v]

U missed the part where he is having a hard time closing the bolt on a loaded round.

 

[want2learn]

to answer some of the questions....i'm very new to this more critical reloading.

Interestingly as a kid i was taught to reload a .222 Remington by an old and i believe experienced friend of the family...but probably i didn't recall all he taught me...... I didn't really do any specific tailoring of the load.....all i did was deprime, clean, used some lee dies, chamfered if it was a touch long and seated a bullet making sure the COAL was correct per the manual and that was it. That old Savage 112V always shot well, rounds fit well and i never played with it or did anything special....i guess i didn't know you could or should.

Now here i am trying to learn this at a later stage in life and i love it but i've got a lot to learn. I've read a book on it , saw a bunch of videos and am following many posts here.

I must have done something very fundamentally wrong and so am starting all over, slowly, carefully, logically i hope with everyone's help.

My gut feeling as i go through all this again and read the above responses is that i didn't set up the die correctly at the outset. It's pretty disappointing as the groups were looking better and better however the effort on bolt closing was significant. Interestingly i never observed any pressure changes in the cases after firing, and i did look for this. I was rather conservative on loads which worked to my benefit/safety.

I don't have any more unmodified fire formed cases to measure....i'll have to get back to the range and try again.

really appreciate everyone's help. I mean that sincerely and am reviewing every comment carefully.

 

[want2learn]

just a little more info:
this morning i completely reset my sizing die and seating die per the instruction manual and per a video i saw.

The Base of the cartridge to Datum of a Fireformed case w/o primer, measures 1.469 inch.

The Base of the cartridge to Datum of a 3x used case, deprimed, cleaned and newly sized measures 1.460 inch


I took out the firing pin on my bolt (it still has the ejector in it...Sako plunger type, there are no more parts to be had for this rifle anymore so i'm a bit reluctant to go much further), I then tried one of the newly sized cases in the chamber......after doing so the Base of the cartridge to Datum of measures 1.461 inch.
I will check, i believe that i used a Lee decapping die as such, i don't think it resizes the cases but i will confirm with another fire formed case.

 

[Steel head]

I spent a long time on these measurements but i will recheck
i understand...I will refer and compare to CBTO
it feels like my sizing technique should be proper, i use a Forster Co-Ax and their dies. I let the die touch the base and then gave it an extra 1/8 turn further as the directions mentioned.

so frustrating...but i appreciate all the help.

that’s the cave man directions not proper technique for accurate reloading.

 

[want2learn]

ok,
So i took a one time factory Lapua shot / fire formed case with spent primer in place and measured the base to datum of the case which yielded a measurement of 1.469 inch

I then ...used the Lee depriming die which shouldn't resize the case.... and then measured the base to datum of the case (with the newly deprimed and fireformed case....which yielded a measurement of 1.467 inch

I then took the resizing die which i totally reset per the manual and per some videos i watched both of which i believe confirmed my technique and again it dropped my base to datum of the case to a measurement of 1.460 inch. So as noted in the aforementioned cases I used that as a starting point and slowly adjusted the die until it finally yielded a base to datum of the case of 1.465 inch.

I think that should be good....that should be a .002 inch shoulder push back.

I then backed the die out a hair more and established a .001 inch push back on the shoulder

Ultimately i'd like to try loading some conservative rounds and see how it works out. i hope the previous loads are still good...we'll see.

Thank you so much again for everyone's help and especially Gregg with the PMs..

 

[918v]

Do these cases chamber ok or does the bolt still close hard?

 

[want2learn]

918v.....what a great question. like a fool i thought i had it so i went and loaded a bunch of ammo meticulously following my folly without ever taking the five minutes to see if a round chambered.

so as you can imagine, i went to the safe, took out my rifle, put on ear and eye protection, pointed in a very safe direction, kept my finger off the trigger and tried to chamber a round......impossible to chamber and of course on extracting the cartridge the projectile had separated from the case.

this afforded me yet another opportunity to do a bunch of measurements. Here's what i found:

I first measured a Factory Lapua loaded round with the same projectile, the 123 Scenar. It measured 2.694 COAL and 2.140 COTB (thank you T Rex)

Then i measured yet another of my new finely and meticulously created reloaded rounds. It measured 2.74 inch COAL, 2.184 inch CBTO and 1.469 inch Base to Datum.

I'd like to say that i know the true headspace on my rifle's chamber as i've measured it many many times...but for the life of me I can never seem to secure a reproducible value despite slowly and carefully using the Hornady tool with the custom base, rereading the instructions, watching 2 videos etc.

My first inclination after looking at the measurements was to seat the projectile deeper into the case to match the factory COAL since i knew that the new case sizing seemed to chamber pretty easily (I did check to see that my "bumped case" did chamber ok using my bolt without the firing pin.).

That said, i wouldn't imagine that it would take a lot of effort for the bolt to merely push the bullet down deeper into the case on closure if that were the rate limiting step...so probably that's not the way to go.

So now what to do?

I don't have a new, never fired factory brass to measure the base to datum value, but on accurate shooter there is a diagram and it looks like that value would be 1.85 inch...if that's correct then my base to datum creation is way off having measured that to be 1.469 inch for a difference of 0.381 inch.

quite an educational experience...but i want to be safe, i want to learn, and i want to excel at this sport.

appreciate any other thoughts/help. thank you

 

[Backcountryguy]

Definitely sounds as though you’re having a hard time closing your bolt because you have the bullet seated too far Out

You’re doing what is called “Jamming” the bullet, and yes, you’d be surprised how much force it feels like it takes when doing this with your bolt compared to seating a bullet on your press

 

[want2learn]

Wow, ok....good to know

I just rechecked the base to datum length on the fire formed case and it's 1.47....same as what i'm getting on my failed to chamber sized reloads.

Is it reasonable then to slowly carefully further seat the projectile in the loaded cases with the bullet seating die?

 

[Supersubes]

Wasn’t it established pretty early on that you were jamming bullets? Surprised you didn’t try and chamber a sized(unloaded) case. The 1.467 sized case ought to be fine. The ammo you loaded can simply be seated deeper(provided the headspace is correct). Getting the bullets out of the lands is going to lower pressures, so no issue there.

 

[Snuby642]

Maybe I should try jamming a few rounds by 3/8 of an inch.

1/4 moa nice.

Pictures?

 

[Supersubes]

Wow, ok....good to know

I just rechecked the base to datum length on the fire formed case and it's 1.47....same as what i'm getting on my failed to chamber sized reloads.

Is it reasonable then to slowly carefully further seat the projectile in the loaded cases with the bullet seating die?

Of course. Why would you think seating them deeper would be an issue?

You should invest in a seating depth tool of some sort. I prefer the Sinclair tool, but many use the hornady.

 

[Snuby642]

So a factory die set up per included instructions yields a. 007 thousands bump, yes par for the course. Also probably close to factory ammo shoulder for 223 , 308 ect

No where have I seen any discussion of trimming the brass?

That can cause a problem.

 

[Supersubes]

So a factory die set up per included instructions yields a. 007 thousands bump, yes par for the course. Also probably close to factory ammo shoulder for 223 , 308 ect

No where have I seen any discussion of trimming the brass?

That can cause a problem.

Since he just yanked the bullet out of a loaded round while extracting, I think we know where his problem is.

 

[Eostech]

on accurate shooter there is a diagram and it looks like that value would be 1.85 inch...if that's correct then my base to datum creation is way off having measured that to be 1.469 inch for a difference of 0.381 inch.

No it is not, 1.85 inch = 47mm, that's not base to datum it is total length.

 

[want2learn]

Eostech....i can't seem to find a base to datum value.

Tomorrow i'll try to seat the projectiles lower...at factory length.

Here's the photo of the .238 group and the .335 group. The other target is in the shed but i can't access it tonight.

 

[Eostech]

i can't seem to find a base to datum value.

The same diagram has got 1.47 it seems, the picture is pretty low quality. You should be gtg, just seat the bullets deeper.

 

[want2learn]

thank you....it really helps.

learning a lot here, great forum, great people.

 

[918v]

The round that pulled apart, can you see if the empty case chambers?

 

[want2learn]

i'm not sure if i resized it or if i mixed it in with others to reprocess, i just can't recall...i'll have to check in the morning

 

[Supersubes]

i'm not sure if i resized it or if i mixed it in with others to reprocess, i just can't recall...i'll have to check in the morning

If it was a loaded round, why would it not have been resized?

 

[want2learn]

it was the round that i had trouble closing the bolt on and when i was able to eject it it took a lot of force on the bolt and the bullet had separated....i just didn't trust it.

 

[Backcountryguy]

it was the round that i had trouble closing the bolt on and when i was able to eject it it took a lot of force on the bolt and the bullet had separated....i just didn't trust it.

If you were able to seat a bullet in the brass, and the bullet didn’t just drop into the brass case...you resized that piece of brass

A piece of brass, after having been fired, will not hold a bullet (proper diameter bullet, for the smartasses) in the case neck unless the case neck has been “shrunken” down by resizing to hold the bullet in place.

 

[Dai Bando]

 

[NamibHunter]

Lots of good advice here.

Buy a reloading manual and read the general instructions, and just follow it. Keep it simple to start with, and simply replicate a good factory match round that shoots well in your rifle. Same brass, trim to minimum (trim) length if needed (already exceeding max case length), then full length size and adjust the die for 0.002” to 0.003” of headspace, use the same bullet, seated to the same depth to achieve the same COAL, etc. That will inevitably mean you are seating for a long jump, which is safe (but not yet optimized - do that later) as long as the powder charge is moderate (but above min book spec).

Once you get that right, then start optimizing powder charge via a ladder test or similar, after that optimize seating depth.

If you have access to a crony, you will find it easier.

 

[want2learn]

i understand
also thank you for the videos

it makes a lot of sense to remove everything from the bolt face, i have removed the firing pin from my bolt without much difficulty but i have to figure out how to remove the plunger type ejector.

unfortunately there aren't any more parts available for this rifle and so i'm a bit scarred of buggering it up. it's a sig ssg3000 and sig no longer supports the rifle. i called a bunch of places to see if they had extra parts like numrich, topgun, eBay, gun broker to no avail

 

[Precision Underground]

Definitely sounds like you were jamming the bullet into the lands.

On another note I’d say read up on the actual process of finding the load you want to shoot. Your 35.5gr made a small 3 shot group, but the charge above it that was only 0.5% different had a poi much higher than 35.5. So one day you will likely run into conditions that push 35.5 right where 35.7 landed. Finding a good load is more about finding a range of charges that shoot consistently well rather than a single charge that produces a small group. You want you load to shoot good every day, not just when conditions are perfect for it to shoot good.

 

[want2learn]

fascinating....i guess i never really considered this.

tomorrow will work on all of this especially bullet seating....need to read and learn more

 

[918v]

i understand
also thank you for the videos

it makes a lot of sense to remove everything from the bolt face, i have removed the firing pin from my bolt without much difficulty but i have to figure out how to remove the plunger type ejector.

unfortunately there aren't any more parts available for this rifle and so i'm a bit scarred of buggering it up. it's a sig ssg3000 and sig no longer supports the rifle. i called a bunch of places to see if they had extra parts like numrich, topgun, eBay, gun broker to no avail

No need to disassemble the bolt.

 

[918v]

FL size a fired case and bump the shoulder .002”

Cut a slit lengthwise down the neck into the shoulder. Deburr the slit.

Insert a bullet into the neck. It will slide in and out with moderate resistance.

Chamber the round, push the case all the way into the chamber until the shoulder bottoms out. The rifling will seat the bullet.

Push the round out of the chamber with a cleaning rod carefully.

Measure the OAL.

 

[spife7980]

FL size a fired case and bump the shoulder .002”

Cut a slit lengthwise down the neck into the shoulder. Deburr the slit.

Insert a bullet into the neck. It will slide in and out with moderate resistance.

Chamber the round, push the case all the way into the chamber until the shoulder bottoms out. The rifling will seat the bullet.

Push the round out of the chamber with a cleaning rod carefully.

Measure the OAL.

For illustrative purposes

 

[spife7980]

unfortunately there aren't any more parts available for this rifle and so i'm a bit scarred of buggering it up. it's a sig ssg3000 and sig no longer supports the rifle. i called a bunch of places to see if they had extra parts like numrich, topgun, eBay, gun broker to no avail

Its a cross pin, just punch it out, the ejector is spring loaded, when you pull that punch back out dont let it spring off into the abyss and youll be fine. I hold it in with a case, some people do it pointing into a zip loc etc. Just dont let it spring away and youll be fine.

 

[want2learn]

thanks ...will try both

 

[Doom]

I've been watching this thread with interest, but there are some things I'm confused about. Has the OP chambered new factory ammo in this "new" barrel? If so did it come out easily after firing? Has the brass in question been fired in any other barrel?

 

[918v]

For illustrative purposes
View attachment 7163799

Two slits is one too many. Not enough tension on the bullet. Need only one slit.

 

[want2learn]

i have only shot factory lapua 123 gn scenar
and my reloads are also using lapua brass and the same projectile as the factory load

the factory rounds ejected fine

i tried to mimic the factory load as close as i could, resizing all the ammo...hopefully in the coming weekend i'll get a chance to try them out.

 

[Doom]

Are your reloads in new brass or was this brass fired in another rifle or barrel? Are you resizing the new Lapua brass?

 

[want2learn]

Doom, i shot factory Lapua ammunition.... and then as i only have full length sizing dies i used that set from Forster to deprime, size and seat the projectiles.

I wanted to take a break from all of this for half a day because i wanted to be really careful and precise. I went through everything again, all the measurements...i even took out the barrel from the receiver, cleaned the heck out of everything to make sure i wasn't missing anything there as well.

I then spent another long time trying to use the full length sizing die to bump the shoulder to that of the the factory load....all to no avail,
As measured from base of the case to datum on a deprimed case the closest i could come was within .01 inch of the measurement i get from factory loaded ammunition.... not the oft quoted .001 - .002. I hesitate stating that here because for the factory loaded ammo i obtain this measurement with a bullet in place (my Forster measuring kit provides for this).....while the deprimed and sized case is of course measured without a projectile in place. Maybe i should seat a bullet and check this?

I think it's time i buy some new dies.....not sure which are most preferred. I really want to shoot and enjoy this new barrel and caliber and yet i do have to remain fiscally responsive. Not sure i trust Forster enough anymore to purchase their neck sizing set....and i would still need a full sizing die periodically. I never ran into this with the .308 Forster dies.

Maybe it's best i get some new fire formed made from factory loaded ammo and send the cases off to Forster to hone out the sizing die...and also purchase a different brand of neck sizing dies.

would sure appreciate your thoughts and recommendations.

 

[Backcountryguy]

I’m not familiar with your particular rifle...so I may be off base here, if I am, hopefully someone corrects me.....but pulling your barrel off the receiver was a mistake unless you have the Go, No-Go headspace gauges to properly mount it again. You also likely just created a new measurement on base to datum line for fire formed cases as well since you pulled your barrel

Again, I’m not familiar with your rifle, so maybe I am wrong here.

 

[want2learn]

no problem and thanks for helping. this rifle is made such that one can replace barrels...there's a barrel extension that is fitted onto the barrel so that you can easily change barrels without having to use go / no go gauges. pretty cool design.