Base to shoulder measurements virgin to 1x fired

[KeithStone]

So just wanted to throw this out there for peace of mind. 26in criterion R700 remage setup 223 with virgin Lapua brass Varget and 77smk.
Threw a load together in a hurry the other night just chamfered/deburred then mandrel and in the tumbler over night, primed and started loading. Seating depth was 20thou off the lands and just wanted to run till I seen pressure.
23.5
24
24.5
25
25.5
Still no heavy bolt lift, primers looked good and no ejector swipe. 25.5 was crunching powder and it shot about .5 so called it good and ran out and shot this weekend. The issue I have is when I started to resize yesterday the brass base to shoulder went from 1.446 to 1.464 so I bumped it back to 1.462 and called it good but I’ve never had brass grow this much on first firing. I threw my no go gauge back in to make sure something didn’t come loose and I couldn’t turn the handle over so I don’t think I’m long on headspace. And yes I know this is a hot load I’m gonna run with it just to see how many firings I get out of the brass then once it’s trashed I’ll start over and calm it down a bit.

 

[Steel head]

Have you measured your no go gauge to ensure it’s in spec?

 

[KeithStone]

Actually never crossed my mind... Will do that as soon as I get home. So I’d need base to shoulder measurement then call NSS or Forester to verify? I can’t remember the chamber dimensions other than it’s the “match” chamber with a little longer fb than the Wylde.

 

[spife7980]

Mine measure 1.455 with my tooling and rem700 pva remage barrel nut using lapua brass.

Id put the go gauge in, make sure that closes on that and then add new layers of successive layers of scotch tape and measure each trial to see just how far out it gets before it becomes too long.

But ultimately if thats what you get as your fired brass dimensions then it is what it is. I would redo the little test to make sure things didnt go haywire with the brass growth myself but I doubt its tooooo different. BUt if youre gonna stick with the hottest youve tested so far Id want a little more confidence first.

 

[ReaperDriver]

If you're worried about how hot the load is and if it's overpressue, I recently was told by a long time, very knowledgeable reloader that measuring the case head dimension (the solid part just above the extractor groove) and comparing it to the virgin. If pressure is excessive, then that solid head will expand beyond a certain limit (0.001 or less) and causes primer pockets to become loose prematurely.

 

[XLR308]

If you're worried about how hot the load is and if it's overpressue, I recently was told by a long time, very knowledgeable reloader that measuring the case head dimension (the solid part just above the extractor groove) and comparing it to the virgin. If pressure is excessive, then that solid head will expand beyond a certain limit (0.001 or less) and causes primer pockets to become loose prematurely.

This^ but you will need a good blade micrometer and a base designed so that the case sits the same and correct depth to the mic every time.
Unless you had a typo in your OP .018" of innitial growth sounds like case head separration range to me in the little 223rem case.

https://gunsmithtalk.files.wordpress.com/2015/07/556print.jpg

 

[Snuby642]

Thousands of range brass measured and 1.4635 to 1.4640 is the average.
I have never seen any fired brass close to that short.

Is it possible your tooling slipped in some way?

I have seen factory unfired rounds in the 1.455 range but none that were 18 thousands short.

 

[FLIGHT762]

Recheck your virgin brass numbers. I've never seen factory 223 brass that short. What gauge / comparator are you using to get your numbers?

Brass that short should have given you case head separations.

 

[KeithStone]

Alright got some pics for y’all fired brass is the stuff from above been deprimed and resized with shoulder bumped back 2thou. Virgin brass pics is same lot been chamfered/deburred ran a mandrel through it and threw it in the tumbler.
Base to shoulder fired

Virgin

No go guage

Case head virgin

Case head fired

 

[ReaperDriver]

Based on your case head expansion of .002, I would say it’s definitely over pressure. “Why” it’s over pressure still needs investigation. The headspace between virgin to fired seems pretty normal, so I don’t think that’s the issue.

EDIT to add: Check your fired necks to see if they're good to go by just slipping a bullet in and see if the case mouth is too tight. It's a simple test to at least eliminate a potential area. Until about 10 days ago, I would have never believed that neck thickness even from virgin brass could cause those kinds of swipe and pressure signs.

 

[ReaperDriver]

One thing just occurred to me..... is your chamber a .223, a Wylde or a 5.56 chamber? If it's a .223 only chamber and you're shooting factory 5.56 spec rounds or loading to 5.56 pressures - this could also be the root cause of your problems.

MultiBrief: The dangers of mixing up 5.56x45mm NATO and .223 Remington rounds

Even though many people treat the .223 Remington and 5.56x45mm NATO cartridges as interchangeable rounds, this can be a dangerous practice under the wrong circumstances.

exclusive.multibriefs.com

 

[XLR308]

I just checked 5 new winchester cases all five were 1.457" and ten new Nosler cases that ranged from 1.4615- 1.462" and five new Lake City SS109 that ranged from 1.4595- 1.4605".
Your brass seems a bit short to as in out of spec short.
It looks like you are using a quality set of calipers, mine are Mititoyo 12" and a fair bit more rigid than the smaller ones.

 

[spife7980]

You’re using a sinclair #23 insert right?

I wouldn’t worry about the base expansion. I’d worry if your die can’t take it down below chamber diameter and you get clickers. Until then don’t bother with it.

 

[XLR308]

One thing just occurred to me..... is your chamber a .223, a Wylde or a 5.56 chamber? If it's a .223 only chamber and you're shooting factory 5.56 spec rounds or loading to 5.56 pressures - this could also be the root cause of your problems.

MultiBrief: The dangers of mixing up 5.56x45mm NATO and .223 Remington rounds

Even though many people treat the .223 Remington and 5.56x45mm NATO cartridges as interchangeable rounds, this can be a dangerous practice under the wrong circumstances.

exclusive.multibriefs.com

Isnt the headspace dimesnions the same on all three ( 223rem, 223wylde, 5.56x45) the variables being freebore and lead are different.

 

[KeithStone]

iver As stated these are my loads no question any over pressure is due to 25.5 gr of Varget under a 77smk powder is up to the neck shoulder junction. Also it is a 223 match chamber. The question is the brass stretching that much. Being my first barrel nut rig made me think I screwed up the headspace.

@spife7980 yes it is a #23 insert I’ll go ahead and load my once fired again before I screw up another box of virgin brass starting at 23 and see if I can run it back up to 25.5 without issues.

if that works I guess just got me room to fit a few more gr of Varget cheers

 

[XLR308]

Something just isnt adding up, your fired brass is measuring .014" over your no go gauge.
Are you measuring them with the spent primer removed ?

 

[FLIGHT762]

Interesting. My measurements from my #23 Sinclair insert are : 1.428" on a 1.464" 223 Rem. GO Gauge. Virgin factory loaded cartridges measure from 1.426"-1.427" on 5 different commercial and Military loaded rounds.

Fired cases from a Sig 516 5.56 NATO measure 1.434"- 1.437".

My #23 insert is from a very early mfg. Sinclair insert. Although my numbers are different, they are consistent for a comparator.

My Varget loads with a 77 Sierra top out from 24.0 grs. to 24.3 grs., depending on brass. If I go any higher, I stretch primer pockets. These are gas gun loads in a Wilde chamber.

 

[KeithStone]

Something just isnt adding up, your fired brass is measuring .014" over your no go gauge.
Are you measuring them with the spent primer removed ?

Yes sir no primer and I agree I do not fully understand what’s going on here but the second firings should give some more intel primer pockets gone, case head separation or something but should have some loaded up and shot by the weekend

 

[XLR308]

Interesting. My measurements from my #23 Sinclair insert are : 1.428" on a 1.464" 223 Rem. GO Gauge. Virgin factory loaded cartridges measure from 1.426"-1.427" on 5 different commercial and Military loaded rounds.

Fired cases from a Sig 516 5.56 NATO measure 1.434"- 1.437".

My #23 insert is from a very early mfg. Sinclair insert. Although my numbers are different, they are consistent for a comparator.

My Varget loads with a 77 Sierra top out from 24.0 grs. to 24.3 grs., depending on brass. If I go any higher, I stretch primer pockets. These are gas gun loads in a Wilde chamber.

That was my point as well, my measurements are consistent although longer but there will be variance based on the precise drill used to bore out and the chamfer on the insert.
But he is showing .014" longer than the measurement on his No-Go guage with the same insert,

 

[918v]

Based on your case head expansion of .002, I would say it’s definitely over pressure. “Why” it’s over pressure still needs investigation. The headspace between virgin to fired seems pretty normal, so I don’t think that’s the issue.

That is not how you measure case head expansion for the purpose of determining pressure.

What he did is measured case expansion and .002” is normal as the chambers are typically bigger than virgin brass.

 

[XLR308]

Yes sir no primer and I agree I do not fully understand what’s going on here but the second firings should give some more intel primer pockets gone, case head separation or something but should have some loaded up and shot by the weekend

That is not how you measure case head expansion for the purpose of determining pressure.

What he did is measured case expansion and .002” is normal as the chambers are typically bigger than virgin brass.

It has to be measured precisely at the web and very depth dependent for an accurate measurement with a blade mic.
There are more variables in this than i am qualified to try and explain so have never bothered with it.
I just go off of primer feel, when they feel loose to me i discard the brass.

 

[ReaperDriver]

Isnt the headspace dimesnions the same on all three ( 223rem, 223wylde, 5.56x45) the variables being freebore and lead are different.

Want talking about headspace. The free bore ans lead are the differences IF the OP is shooting 5.56 pressure stuff in a .223 cut chamber per the attached article.

 

[ReaperDriver]

Yes sir no primer and I agree I do not fully understand what’s going on here but the second firings should give some more intel primer pockets gone, case head separation or something but should have some loaded up and shot by the weekend

You just answered your own question re what’s going on. You’re shooting 5.56++ loads in a .223 tight match chamber. There’s your problem. I would ask any shooters on the line to step back when you”re going hot for their safety.

 

[XLR308]

Want talking about headspace. The free bore ans lead are the differences IF the OP is shooting 5.56 pressure stuff in a .223 cut chamber per the attached article.

Totally understand that brother but he stated he worked up loads based off of powder charge while observing pressure signs.
While we are still obviously concerned about the discrepancies regarding his measurements in regards to his No-Go Guage compared to his fired brass measurements i am am concerned .
I dont want a member being injured by confusion or discrepancy regardless.

 

[XLR308]

L

Want talking about headspace. The free bore ans lead are the differences IF the OP is shooting 5.56 pressure stuff in a .223 cut chamber per the attached article.

I figured that was what you were reffering to but someone that works up a load should know how to read pressure and read between the lines.
Been wrong before and not bashing or accusing anyone but no one is perfect.
My main discepency is with the dimensional data since im not standing beside the OP to verify data and not trying to be an asshole just dont want anyone to tear any gear or flesh up due to poor comms or info.

 

[KeithStone]

You just answered your own question re what’s going on. You’re shooting 5.56++ loads in a .223 tight match chamber. There’s your problem. I would ask any shooters on the line to step back when you”re going hot for their safety.

Chill out Karen no innocent bystanders in danger around here. Gonna check primer feel and do another round of load dev on the once fired and we’ll go from there.

@XLR308 what data would you like to verify? If there’s a measurement you think I’m getting wrong I can recheck it.

 

[XLR308]

Chill out Karen no innocent bystanders in danger around here. Gonna check primer feel and do another round of load dev on the once fired and we’ll go from there.

@XLR308 what data would you like to verify? If there’s a measurement you think I’m getting wrong I can recheck it.

The main thing that has me perplexed but not neccesarily woriied is your fired brass being .014" over the size of your no go guage.
Its not like your trying to run max 408 Cheytac loads on a Savage small shank but something just doesnt add up.
I think worst your going to experience in 223rem is some trashed cases and a torched bolt face but just am genuinely curious were the discrepency is.

 

[KeithStone]

Just got my reamer print and looks like brass grew exactly where it should’ve not sure why the Lapua was so far undersized or if it’s an issue with my comparator not touching at the correct spot. I’ll do some more testing with this thanks for the input.