.223 neck tension; what am I doing soooo wrong? (RESOLVED, READ ORIGINAL POST)

[ThingsThatGoBang]

I am trying to wrap my head around your issue. Are you saying that at 2.260 your bullet just falls into the case or under pressure?

A sierra 77 isn't going to be any different. I shoot both and have never had this issue.

Thank you for supporting me. Yup, basically, at 2.260, meaning the pressure ring near the boat tail has been pushed past the neck and with rather little effort I can push the bullet into the case or if I chamber the round the bullet slides forward from the momentum.
I’m getting ready to buy a box of 77 grain SMK‘s with hope that they fix the problem.
Can you please watch this brief video I uploaded to YouTube and let me know if you have the same issue with your Berger and SMK‘s? Effectively it is showing how the boat tail of the bullet is wider than the Bering surface. I’m rather confident this is what’s causing my problem though mathematically it doesn’t make sense it’s only .001.

 

[Fire4EffectCA]

My next step is to get some 77 gr SMKs and see what happens.

I get good results with my Daniel Defense MK12 and Sierra Matchkings. I have also tried ultrasonic cleaning and have noticed increased unequal resistance seating bullets with the squeaky clean necks. Yesterday I tried shooting reloaded cartridges with case necks dipped in moly and case necks that were not. I was surprised the cases that were not dipped in moly grouped better than the cases that were. The velocity spread was also tighter on the cartridges that were not dipped in moly.

BTW, the necks on these cases were turned to 0.011” with 0.0035” neck tension.

 

[ThingsThatGoBang]

I get good results with my Daniel Defense MK12 and Sierra Matchkings. I have also tried ultrasonic cleaning and have noticed increased unequal resistance seating bullets with the squeaky clean necks. Yesterday I tried shooting reloaded cartridges with case necks dipped in moly and case necks that were not. I was surprised the cases that were not dipped in moly grouped better than the cases that were. The velocity spread was also tighter on the cartridges that were not dipped in moly.

BTW, the necks on these cases were turned to 0.011” with 0.0035” neck tension.

Good stuff. Mine too is a Daniel Defense MK12. I just located some 77 gr Sierra Matchking‘s at a local gun store and will pick them up tomorrow and perhaps that will clean up my problem. I am optimistic it will. Thanks for sharing your reloading recipe in the pictures too.

 

[Fire4EffectCA]

Good stuff. Mine too is a Daniel Defense MK12. I just located some 77 gr Sierra Matchking‘s at a local gun store and will pick them up tomorrow and perhaps that will clean up my problem. I am optimistic it will. Thanks for sharing your reloading recipe in the pictures too.

The velocity was around 2,700 fps out of the 18” barrel. The spread was 15 fps and the standard deviation was 7.1. There were no pressure signs on the cases. I would reduce the load and work you way up to 2.7gr of N540.

 

[M4orturnate]

I didnt read the whole thread so i apologize if this came up. Are you using a bushing die? If so is the bushing in it? Ive seen that before. I shoot 223 with .002 neck tension and i cant push the bullet in at all.

 

[MarshallDodge]

Personally I think you turned the necks to thin. I get very good neck tension at mag length seating I am reloading Remington brass and its not as thick as factory Lapua.

Take a few cases that have been fired, size them and seat a bullet. Don't use any that you have turned necks on your premed any other way.

I'm pretty sure this is the issue. He needs a smaller neck bushing.

 

[Lawnboi]

If you want a reliable means of checking your neck tension, grab a pin guage, they are under 10 bucks, and check. Measuring with a calipers, doing some math trying to guess how much or little spring back your getting only gets you so far.

K&m sells pin guages grab the appropriate size for what your looking to get for tension, if you really want to play with it a size above and below. This makes it easy to dial in bushing size, and helps you understand what’s happening with hour brass over subsequent loading.

 

[ma smith]

Op check the sizing button. In redding is -1.5 thou.

Use that as a poor mans pin gauge.

How many cases have ID > your sizing button [-1.5 thou]???

Forget the calipers and OD measurements...

neck wall variations will cause errors in neck tension estimates, even in lapua brass...

 

[BuildingConceptsllc]

My measurements for my bolt gun 223 is 1.855 with Hornady match. It's shoots really well in mine and is pretty cheap too. I'd give that a shot.

 

[Snuby642]

Op check the sizing button. In redding is -1.5 thou.

Use that as a poor mans pin gauge.

How many cases have ID > your sizing button [-1.5 thou]???

Forget the calipers and OD measurements...

neck wall variations will cause errors in neck tension estimates, even in lapua brass...

You don't seem to get that a before and after neck od measurement gives a known amount of tension?

Repeatable and not a lot of high level math involeved.

It does not matter about wall thickness brand of brass or anything else .

If you use a 0.002 under mandrell your nt is 0.002 every time no measurement necisary ever.

 

[ThingsThatGoBang]

I didnt read the whole thread so i apologize if this came up. Are you using a bushing die? If so is the bushing in it? Ive seen that before. I shoot 223 with .002 neck tension and i cant push the bullet in at all.

I’m not. But I may get the Redding, unless you recommend other. But first, I’m picking up some Matchkings tommorow, and hope they fix the problem.

 

[ma smith]

You don't seem to get that a before and after neck od measurement gives a known amount of tension?

Repeatable and not a lot of high level math involeved.

It does not matter about wall thickness brand of brass or anything else .

If you use a 0.002 under mandrell your nt is 0.002 every time no measurement necisary ever.

no, this is not reliable info.

First, OD is not ID because between them is inconsistent amounts brass, even on Lapua.

Second, mandrels are not ID either because of springback.

Third, you cannot trust any caliper rated +/- .001 telling you .001 is with certainty.

Fourth, case necks have uncertain parallelism and concentricity.

All of these can create 'measurement errors' of various types.

 

[opeagle]

Put the Forester die back together and adjust it properly, I’ve not seen any reason to run bushing dies, especially with an AR.

 

[ma smith]

[eta]

If you cannot freely drop a -1.5 expander into a case neck, its safe to say you have min 1.5 thou tension at .224

Its a simple test and more reliable than many others if all you have is inferior measuring equipment.

The (redding) expander measures -1.5 thou +/- .0001 (or within 0.1 thou) on a micrometer not a caliper.

So its more accurate than a caliper of uncertain calibration, against a case neck of uncertain parallelism, made of brass of uncertain uniformity....etc

 

[Lawnboi]

You don't seem to get that a before and after neck od measurement gives a known amount of tension?

Repeatable and not a lot of high level math involeved.

It does not matter about wall thickness brand of brass or anything else .

If you use a 0.002 under mandrell your nt is 0.002 every time no measurement necisary ever.

This is far from the truth. Every time you size there is spring back to some degree. Dependent on anneal, number of firing, bushing selected, amount the die sizes all contribute to neck tension. Using different size bushings, with the same size mandrel can change things a thou or two.

I thought like you did until I got pin guages. That and fighting with consistent neck tension before I started annealing. There is always spring back.

 

[Tokay444]

Crimp and shoot.
I’m sure after crimping they’ll pass the industry standard wall press test.

 

[Snuby642]

You rocket scientist realize he is feeding an ar, right?

Next your going to have him weight sort brass and bullets.

A prize goes to the first one that sells him a prometheus powder measure.

Why don't you help him choose a medium - heavyweight bullet that will run at mag lenght which is what he needs.

He will be fine with his equipment and brass if he gets bullets that work mag lenght.

Anneal or not but be consistant.
I suggested not annealing a test round to eliminate variables.



Calipers are fine if you are consistant in thier use.

My new venture into reloading .223 isn’t off to a very good start. Help! SOS!

 

[TwistedOneinSeven]

@spife7980 raises a really good point about amount of projectile bearing surface engaged in case neck @ThingsThatGoBang
Bear with me, I haven't used 77gn OTM so I'm using basic maths off .223 cartridge dimensions and Berger website
With the 77 OTM bullet OAL of 1.015 and Nose Length of 0.513, you may be seating bullets into neck even beyond bearing surface reducing bearing/neck contact.

Cartridge Diagrams

6mmBR.com is the best guide for 6mm BR Benchrest precision shooting, complete with 6BR FAQ, Reloading Data, Shooter Message Boards, Reader Polls, and Photo Gallery. Match event calendar and rifle competition accuracy training tips. Equipment reviews (.243 bullets, 30BR cartridge, 6mm Norma...

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22 Caliber 77 Grain OTM Tactical Rifle Bullet

Berger 77 Grain OTM (Open Tip Match) Tactical Bullets are a Boat Tail design often used by Mil/LE professionals and competitve shooters who seek the highest accuracy possible. The 77 Grain OTM Tactical is excellent for AR’s, black gun applications or bolt action rifles with twist rates of 1-7″...

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My .223Rem load is COAL 2.25 using a little 55gn Sierra GameKing so the Berger 77OTM may be a fair bit longer in COAL you'd think than your stated 2.260"

My advice may be for nought if you want to use longer/heavier pills in .233 and AR. We aren't allowed anything that goes bang and is painted black here Down Under : )

As @Tokay444 says, another option is hit them with a crimp die and go shoot.
I messed up resizing die setting on .223 once and reloaded 500 rounds, then realised they had virtually no neck tension......
I hit the suckers with a Lee Factory Crimp Die, set for a solid crimp and they were all good at the range.
https://leeprecision.com/reloading-dies/rifle-dies/factory-crimp-die/

 

[Feniks Technologies]

I must have missed it. But seeing people mention that you turned the necks.

If so, that’s likely the issue. You can turn necks thin enough that they won’t be able to hold a bullet enough that it won’t move with force if your tapping or a bolt carrier slamming forward.

 

[Devildog]

I didn’t read every post so if I’m being redundant forgive me. I had a similar problem I was setting up my Dillon 650 with new 223 dies from Dillon as well. My bullets had little neck tension and you could easily push the bullet into the case. Sent the dies back in, and Dillon said there good to go. Still had the same problem.

i had a set of Hornady dies setting around and I tried them and they worked perfectly. Never figured out the problem but it sure appears to be related to the sizing die. Just FYI.

 

[Mudflap621]

I see the references to turning necks as well but only thing I've found OP to state is that he uses a turning Mandrel to size his neck versus an expander ball.

 

[ThingsThatGoBang]

I didn’t read every post so if I’m being redundant forgive me. I had a similar problem I was setting up my Dillon 650 with new 223 dies from Dillon as well. My bullets had little neck tension and you could easily push the bullet into the case. Sent the dies back in, and Dillon said there good to go. Still had the same problem.

i had a set of Hornady dies setting around and I tried them and they worked perfectly. Never figured out the problem but it sure appears to be related to the sizing die. Just FYI.

The die is what the bullet manufacturer suggests is the trouble. I’m getting Sierra Matchkings today, and will possibly get a bushing die too. Thanks.

 

[Mudflap621]

Whats the measurement on the Sinclair mandrel?

 

[BuildingConceptsllc]

The die is what the bullet manufacturer suggests is the trouble. I’m getting Sierra Matchkings today, and will possibly get a bushing die too. Thanks.

Did you turn this brass?

 

[powdahound76]

Could you just downsize the expander mandrel for this brass to get desired tension on the .223 sized Berger bullets?

I shoot 75 BTHP and 77 SMK, so no experience like you are having.

For precision AR loads, the extra step of a mandrel is worth it to me.

 

[ThingsThatGoBang]

Did you turn this brass?

No neck turning, but did try a turning mandrel on test brass with same results. Picking up some SMK now, will see if different bullets make a difference.

 

[ma smith]

Let us know if sierra is not a perfect .224 diameter.

 

[ICU22250]

I spoke with Berger bullets a second time today just to verify that I am using the correct bullet and I was assured 100% that the bullet box shown early on in my post is indeed meant for AR15 magazine fed applications. It’s a mystery, and yet one more reason on my list of reasons why I drink. .
My next step is to get some 77 gr SMKs and see what happens.

I honestly think just to rule it out, you need to try another sizing die, without doing any extra steps to your brass other than the bare minimum it takes to make a loaded round and see how your seating goes.. Maybe something crazy going on with the case neck portion of your die where its out of spec, giving you one measurement at the case mouth but changing the further down the neck you go. Probably not but it will rule out your die being the issue anyway. JMO

 

[918v]

If hes applying .005“ of neck tension and the bullet is not being retained then another sizing die wont help.

 

[918v]

Thank you for supporting me. Yup, basically, at 2.260, meaning the pressure ring near the boat tail has been pushed past the neck and with rather little effort I can push the bullet into the case or if I chamber the round the bullet slides forward from the momentum.
I’m getting ready to buy a box of 77 grain SMK‘s with hope that they fix the problem.
Can you please watch this brief video I uploaded to YouTube and let me know if you have the same issue with your Berger and SMK‘s? Effectively it is showing how the boat tail of the bullet is wider than the Bering surface. I’m rather confident this is what’s causing my problem though mathematically it doesn’t make sense it’s only .001.

It does make sense if there isnt enough springback on the annealed neck. The pressure ring opens up the neck and once it goes beyond the neck/shoulder junction there isnt enough neck tension to retain the bullet.

 

[EMorr]

I have a theory that involves a little math. I may be right but I may also be very wrong, but that has never stopped me from offering an opinion.

I have never and will never felt the need the need to push a bullet against the wall to check for neck tension and here is why.

I don't have the exact projectile that you are using but I do have a 69 grain SMK on hand so I'll use that as a comparative example. The meplat on that projectile is 0.064" in diameter. That means that the surface area of the meplat is 0.0032169 square inches, now take 1 and divide it be 0.0032169 and you get 310.858. Basically what that means is for every single pound of pressure you apply to the meplat of the projectile you are essentially creating 311 PSI of pressure against the projectile.

An AR-15 is not a 1911, it is not slamming a big fat projectile off of a steeply angled feed ramp. My though would be to not push your completed rounds against the wall but simple take them to the range, chamber them and then eject them and then check the setback. If you can't move the projectile with just your finger and no wall I'm guessing they will be just fine.

 

[ThingsThatGoBang]

Let us know if sierra is not a perfect .224 diameter.

The SMK are a consistent .224 the entire bearing surface. I also purchased a Redding bushing die using the .243 bushing (also got a .244)! giving .242 OD, and .247 seated, so .005 neck tension seated, gust like the very beginning of all this, but now with the SMK SUCCESS! That bullet isn’t moving anywhere unless there’s exploding gun powder behind it. I guess my troubles are related to the Berger profile with that darn pressure ring, though the Forster FL die isn’t impressing me either.
I also tried the same seating approach using the berger bullets with some change for the better as compared to the Forster sizing die, but it’s about 50-50 success (not acceptable) and admittedly at this point for the testing I’m doing I am not using properly cleaned and annealed brass. That will be my next set of tests.
On a positive note, Bruno’s Shooter Supply here in Phoenix had Varget, so it was a double success.
THANK YOU!

 

[Mike_in_FL]

It does make sense if there isnt enough springback on the annealed neck. The pressure ring opens up the neck and once it goes beyond the neck/shoulder junction there isnt enough neck tension to retain the bullet.

IMO, this is the explanation..

I don't have an AMP or any annealer. I do know that you have to sacrifice a piece of brass for that AMP to work properly. Did your friend calibrate it to your brass? Are you using mixed years or lots of LC brass?

I just use caveman RCBS FL dies for .223. These don't keep me from shooting under moa in a bolt or AR.

 

[ThingsThatGoBang]

IMO, this is the explanation..

I don't have an AMP or any annealer. I do know that you have to sacrifice a piece of brass for that AMP to work properly. Did your friend calibrate it to your brass? Are you using mixed years or lots of LC brass?

I just use caveman RCBS FL dies for .223. These don't keep me from shooting under moa in a bolt or AR.

Switching to Sierra 77MK‘s fixed the problem, and also got the Redding bushing small base sizing die with .243 and .244 bushings. Same .005 neck tension as before but now the bullet isn’t slipping. But to answer your question, my friend shoots F class and he’s much more experienced than I am. He annealed the brass, and the analyzer code is 0125 or 0126 depending on the couple Lake City he analyzed. He actually analyzed and annealed nine different manufacturers of brass that I will someday load and Labradar to see how different brass affects consistency. Yes I am using mixed years of Lake City. 13 through 21 is in the collection to pick from.

 

[ThingsThatGoBang]

I have a theory that involves a little math. I may be right but I may also be very wrong, but that has never stopped me from offering an opinion.

I have never and will never felt the need the need to push a bullet against the wall to check for neck tension and here is why.

I don't have the exact projectile that you are using but I do have a 69 grain SMK on hand so I'll use that as a comparative example. The meplat on that projectile is 0.064" in diameter. That means that the surface area of the meplat is 0.0032169 square inches, now take 1 and divide it be 0.0032169 and you get 310.858. Basically what that means is for every single pound of pressure you apply to the meplat of the projectile you are essentially creating 311 PSI of pressure against the projectile.

An AR-15 is not a 1911, it is not slamming a big fat projectile off of a steeply angled feed ramp. My though would be to not push your completed rounds against the wall but simple take them to the range, chamber them and then eject them and then check the setback. If you can't move the projectile with just your finger and no wall I'm guessing they will be just fine.

Thank you. The only reason I felt the need to pressure test the bullet was because the seating was so unfamiliar. Whereas a bullet usually has a fairly consistent feel during the entire stroke of the press, this was resistance followed by the handle slamming freely. With little resistance the moment that the pressure ring, which is at the boat tail, clears the neck, I was concerned.

Went shopping today, the Sierra 77 MKs resolved the issue, I also got a Redding bushing die which seems to be superior to the Forster die I started with, and they had Hodgdon Varget in stock so it all worked out for the best. I still have .005 neck tension just like at the very beginning of all of this but the bullet is not slipping like it did with the Berger 77.

 

[ThingsThatGoBang]

If hes applying .005“ of neck tension and the bullet is not being retained then another sizing die wont help.

So the issue is resolved. I got Sierra 77 Matchking’s. I also got the Redding small base full length sizing die. My neck tension is still .005 but that bullet is not going anywhere except out the end of the barrel. Success!
Using the Redding die with the berger bullets still yields the same problem that once that pressure ring gets past the neck it is slips in the brass.
I will add this to one more thing that I will probably never be able to explain in this lifetime.

 

[ThingsThatGoBang]

I honestly think just to rule it out, you need to try another sizing die, without doing any extra steps to your brass other than the bare minimum it takes to make a loaded round and see how your seating goes.. Maybe something crazy going on with the case neck portion of your die where its out of spec, giving you one measurement at the case mouth but changing the further down the neck you go. Probably not but it will rule out your die being the issue anyway. JMO

Thank you. I did purchase the redding small bass full length sizing day with .244 and .243 bushings. I used the .243 bushing on the Berger bullets with marginal difference, the bullet still slips. The seating is still resistance until the pressure ring clears the neck at which point the handle of the press has very little resistance to it.
I also purchased Sierra 77 MK‘s. Used with the redding die, and I have .005 neck tension just like before but the bullets are not slipping. Success.
Best of all, the gun store had Hodgdon Varget so it all worked out for the better. Thanks again.

 

[ICU22250]

Thank you. I did purchase the redding small bass full length sizing day with .244 and .243 bushings. I used the .243 bushing on the Berger bullets with marginal difference, the bullet still slips. The seating is still resistance until the pressure ring clears the neck at which point the handle of the press has very little resistance to it.
I also purchased Sierra 77 MK‘s. Used with the redding die, and I have .005 neck tension just like before but the bullets are not slipping. Success.
Best of all, the gun store had Hodgdon Varget so it all worked out for the better. Thanks again.

No problem, im just glad you got it sorted out with a good replacement projectile.. It sucks getting stuck in a rut like that, it just destroys the whole mood. Lol

 

[whatsupdoc]

I have both 77 Berger OTM tactical and 77 Sierra match kings and they are almost
exactly the same measurements.


Base to Ogive
77 Berger OTM: .540
77 SMK: .542

Length
77 Berger OTM: 1.013
77 SMK: 1.011

 

[ThingsThatGoBang]

Thanks. I’ve not measured to the ogive, as I have gotten to truly seating for production it as I’ve been working through this slippery bullet issue.
The one 77 Berger OTM bullet length I measured (and have that measurement with me at this very moment) was 1.020. That seems rather close to yours, a difference of .007. Likewise the Sierra measured .975, and that was after my pressure test to see if it would move so maybe it is deformed, .036 is a rather significant difference between your measurement and mine. Interesting. I will need to measure one straight from the box when I get home.

 

[semperfireloading]

I have literally shot thousands of Berger 77 OTM that I use in AR15's. I load them between 2.250 and 2.260. The issue is not with Berger, the issue was the bushing.

I would recommend you ditch the BUSHING. You don't need it. Just buy any standard Die (not small base) for 223, and typically, the expander ball will be either .222 or .223, which will give you between .002 and .003 neck tension, and you will spend the rest of your life not having that issue every again.

Just buy this.

Amazon product ASIN B000N8OE2E
They sell an expander that is .223 for that as accessory, if you want lighter neck tension. That one is probably .222

 

[rustyinbend]

I find the combination of a "smallish" bushing, and then an expander mandrel that's the proper size for the neck tension I'm looking for ... is a great combination for the larger cartridges I use (6.5-CM, 300-WM/PRC, 338-LM). I've always wrestled with the whole expander ball thing and never gotten great results from it. YMMV. That said, I use the die with expander ball for volume reloading of 300-BLK, and it works fine.

 

[Rhed]

You’re using a FL die right? And not a body die? A FL die, depending on brass, should already give .002 +- of neck tension. Use a mandrel afterwards to get consistent neck tension.