My first attempts at working up loads with IMR XBR and Hornady 75gr match have not yielded good results.

So far Ive had much better luck with 52gr SMKs and Tac, RE15.

Barrel is a 1:8 twist faxon 11.5.

Should I be crimping the 75's?

I wouldn't if you are looking for accuracy. I've never seen where a crimp helped group size shrink.   What is your load?

22.5 xbr @ 2.25 oal.

Im trying to work up a defensive load using hornady 75.

Im thinking of pushing it to 23.0 and trying that.

Nosler 77 Grain Custom Competition





In 2003, Nosler introduced their .224" 77 grain Custom Competition HPBT bullet as an obvious competitor to the 77 grain Sierra MatchKing.  The shape and ballistic coefficient of the Nosler bullet is very similar to that of the Sierra MatchKing.  The Nosler bullet does have one major difference from the Sierra MatchKing; it is constructed using the thinner J4 copper jacket.

The Nosler 77 grain Custom Competion bullet is typically sold without a cannelure, however Nosler occasionally releases the bullet with a shallow cannelure similar to the one found on the 77 grain SMK loaded in MK262.  The cannelured version of the 77 grain Nosler will be the focus of this report.



















For the first phase of testing, I hand-loaded the cannelured version of the 77 grain Nosler BTHP to a typical SAAMI velocity (approximately 2600 fps from a 20” Colt barrel) to establish an accuracy baseline.  No case mouth crimp was applied at this phase.  As per my usual protocol, accuracy testing was conducted from a concrete benchrest at a distance of 100 yards.  The forend of my Krieger barreled AR-15 rested in a Sinclair Windage Benchrest, while the stock of the rifle rode in a Protektor bunny-ear rear bag.  A Leupold Competition Scope was used for sighting.  Wind conditions were monitored using a Wind Probe.  









Three 10-shot groups were obtained which had extreme spreads of:

0.797”
0.827”
0.812”

for a 10-shot group average of 0.812”.  The three groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group.  The composite group had a mean radius of 0.26”.  This test shows that the Nosler bullet itself is capable of consistent sub-MOA accuracy at 100 yards when fired from a semi-automatic AR-15.














For the second phase of testing, I safely worked up a load for the 77 grain Nosler BTHP to a nominal muzzle velocity of 2800 fps from a 20” barrel using a non-canister grade military powder. (In previous testing, I found that the average muzzle velocity from seven different lots of Hornady 5.56 TAP was 2808 fps from a 20” barrel.)  No case mouth crimp was used in this phase of testing either.

Since my Krieger barreled AR-15 has a 5.56mm Match chamber that is “a little too tight” for mil-spec pressure loads, I used my AR-15 with a 20” Noveske DCM barrel for this phase of testing.  This Noveske barrel has the “Noveske Match Mod 0 chamber which is designed to offer 100% reliability while retaining maximum possible accuracy. The chamber body is slightly larger than the 5.56mm NATO minimum, but within the 5.56 NATO tolerance. The throat is redesigned for proper bullet alignment with the axis of the bore. This chamber was developed to fire MK262 Mod 1 on AUTO in hot environments."



















Accuracy testing using the Noveske barreled AR-15 and Nosler 77 grain BTHP at a muzzle velocity of 2800 fps was conducted in the same manner as described above in the first phase of testing.  Three 10-shot groups were obtained from 100 yards.  Those groups had extreme spreads of:

0.880”
0.857”
0.845”

for a 10-shot group average of 0.860”.  These groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group which had a mean radius of 0.29”.










For the final phase of testing I added a taper crimp to the case mouth of the previously described load used in phase two. A 10-shot string of this load fired over the Oehler 35-P chronograph from my 20” Novekse barrel had a muzzle velocity of 2801 fps with a standard deviation of 12 fps.

Three 10-shot groups fired from 100 yards from the 20” Noveske DCM barrel had extreme spreads of:

1.033”
0.914”
1.241”

for a 10-shot group average of 1.063”.  As before, the three groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group.  The mean radius for the composite group was 0.31”.

I appreciate the work you do, but damn brother, you could have just said with your testing you didn't find a crimp to help accuracy.

You should appreciate the work he puts into compiling data for others. The OP may find some other bits in there to help with his loads as well.  With that said it would still have taken more effort to type "your testing you didn't find a crimp to help accuracy" rather than copy/paste.

Judgement based on facts is important. Without hard data it's just someone's opinion.

 

NO crimp... Some will argue, but keys with these are (assuming brass is treated consistent) are 1) a good bullet seater (Redding or Forster) to handle runout and 2) consistent neck tension (anneal brass every time, just alike).

But then he'd be just another poster offering an unsubstantiated opinion.

I had trouble finding a good load with Hornady 75's too.. I first tried them during the 2013 powder shortage. Tried 6 powders.... H335 was best out of them (I forget the list I tried but it even included 3031 because it was all I could find at the time).. But then I repeated the H335 results and things got erratic.

I gave up on them. When I recently ran out of Nosler 77's (which run fantastic in my Shilen), I went and tried CFE223. I was impressed enough to load 2k of them (without a crimp).

I have not tried the XBR in 223... But it runs nice in Grendel and 308... Maybe try a different powder.

IMO, crimp won't help you IF you have consistent neck tension. First, check that. Then.. try a different load.

Good luck!

Excellent post Molon, keep them coming. I' like to see a thread with just your posts for reference.

If there is a cannelure, I give it a slight FCD crimp.

Pictures and his research backs up what he is saying. Proof is in the pudding. Thx Molon, you're doing the stuff I wish I had time to do.

You can't read, can you? And no, it would still take more time to first find his post then copy+paste than to type a simple sentence.

Do you people not go into other sections of this forum?

There's a thread in the ammo thread just to fondle Molon's balls.

Knock it off.  Only warning here.  AeroE

Go to the ammo thread.

Again, if all one does is read GD, they MAY not know Molon. His work is referenced by research papers.

What kind of crimp are you talking about using?

I have never found crimping with the seating die (taper) to help anything especially accuracy.

The Lee Factory Crimp die has improved accuracy in all my semi-auto handloads.

The only real answer to your question is to try it for yourself.

If crimping helps, then do it, if it does not then don't.

I do, but with the LFCD.  Others have found increased accuracy with this die as well.

Here is one test where accuracy was improved.

http://www.accuratereloading.com/crimping.html

I crimp my 55gr FMJ bulk loads with a FCD very lightly.  They still shoot right around 1", which for ammo that I load 1000 at a crack, is good for me.

I do not crimp anything that I am looking for accuracy out of.

And yes, Molon's testing is some of the best Ive seen.  I wish I had the time to put that kind of effort into my reloads.

I crimp anything in a semi auto
When I say crimp I dont mean buckle the bullet, just a light crimp is fine.

the majority of shooters will not be able to tell much of a difference crimp or no crimp as far as accuracy goes, unless you are shooting some extreme distances.
even then you probably wont notice it unless you are dead nuts accurate on your ability to call the wind.


just food for thought

If it's going in a semi-auto or machine gun, it gets a bit of a crimp with LFCD regardless of other variables.  This is my method.  YMMV.  

If I'm trying to duplicate a known load (MK262 Mod 1, M118LR, etc.) I use the LFCD even if I'm going to shoot the ammo through a bolt gun.  I have yet to find any adverse affects from crimping these 'generic' or 'clone' loads.  I set the LFCD to not completely close - so that I can still see a gap in the collet.

I do not crimp custom match loads for precision rifles.

I've only loaded several tens of thousands 5.56.

I never crimp.

If your neck tension is right, crimping is superfluous, as any impact that would setback a non-crimped bullet will also set back a crimped bullet.

If your neck tension is good.

Not according to Sierra.

http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm

How's your reading skills bro?

From YOUR LINK:

"crimping is still, at best, an occasionally necessary evil. Avoid it if at all possible.

The other—and in our opinion, better—option is increased neck tension."

You are talking BR or F-class precision loading. These guys are just shooters.





I use case mouth lube so the seating pressure is consistent, load all ammo immediately after neck sizing on a press with a pressure gauge and anneal the brass only every 3rd loading.
 

The OP stated 52 grain SMK's shot better than the 75's. They always have for me as well. Without knowing the groups size of either load we're still in the dark as to whether he's good to go.

My Winchester M70 HVV in .223 (1/9) twist simply loves Hornady 75 grain hpbt match bullets with 23.5 grains of VihtaVouri N540. Velocity is 2720 fps and allowed my to place first in the slow prone stage of every tournament held the year I shot a bolt gun. Every rifle has it's preferences, that rifle loves the 75's, but probably shoots 52's even better. 1/9 twist barrels aren't always reliable for shooting heavy bullets, but this one was. The 26" barrel no doubt helped.

52/53 grain match bullets hammer out of every rifle I've tried them in, especially at 100 yards. They always shoot tighter groups once I find a load that works.

As far as self-defense is concerned any bullet will do in .223. You already have 3.5 times the muzzle energy of a 230 grain fmj fired from a .45acp point blank. Even light weight varmint bullets are devastating for self-defense.

I load for accuracy in NRA high power tournaments, the same ammo can be used for whatever else needs shooting. BTW - I never crimp military calibers, not even .30-06.

Worse than that -   Maybe I was ahving a bad day but my 52 SMK shot wonderfully


I am going to try 22.0 - another batch of 22.5, and a bacth of 23.0.

Disregard, I see it's been addressed.

Yup, a necessary evil.

Also, bullets creep forward more than they set-back.

Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. Some years ago, we decided to examine this phenomenon more closely. During tests here at Sierra’s range, we chambered a variety of factory Match ammunition in an AR-15 rifle. This ammunition was from one of the most popular brands in use today, loaded with Sierra’s 69 grain MatchKing bullet. To conduct the test, we chambered individual rounds by inserting them into the magazines and manually releasing the bolt. We then repeated the tests by loading two rounds into the magazine, chambering and firing the first, and then extracting and measuring the second round. This eliminated any potential variation caused by the difference between a bolt that had been released from an open position (first round in the magazine) and those subsequent rounds that were chambered by the normal semi-automatic operation of the rifle. Measuring the rounds before chambering and then re-measuring after they were carefully extracted resulted in an average increase of three thousandths (0.003") of forward bullet movement. Some individual rounds showed up to seven thousandths (0.007") movement. Please bear in mind that these results were with factory ammunition, normally having a higher bullet pull than handloaded ammunition.

To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension. The first option, crimping, brings up some other issues that can be troublesome. In general, crimping degrades accuracy. Most match bullets are not cannelured (which also seriously damages accuracy potential), a requirement for correct application of most crimps. Still, there are taper crimp dies available from most of the major manufacturers. Lee offers their “Factory Crimp” die as an alternative, which seems to be one of the better options for those bullets without a cannelure. That having been said, crimping is still, at best, an occasionally necessary evil. Avoid it if at all possible.

According to Sierra, even factory ammo with more neck tension than handloaded ammunition, neck tension alone could not secure the bullet.

"Let it go"???  You allow someone to post "fondle Molon's balls" in a technical thread and you don't remove that post from the thread?? And then when SaturationTech objects to that post, you tell him to "let it go"???

I'm willing to bet that if someone had posted "fondle dryflash3's balls" in this forum you wouldn't just be telling people to "let it go."


...

Thanks Molon. Won't make the mistake of speaking up again.

Tag, this thread it relative to my interests....

If the 5.56 bullet is jumping the case neck on loading, that's easy enough to check.

Same applies to setback.

In the countless 5.56 rounds I've loaded without a crimp, I have not experienced a problem during ordinary cycling.

Good neck tension is the key.

If you are crimping to (try to) overcome inadequate neck tension, you should re-examine your brass-prep methods.

I dont know if its the crimp, powder combo, bullet, etc.

I loaded up 25 each this AM of

22.0
22.5
23.0

Will see how they do. This is my first time loading heavies for this barrel. Maybe , as said before, it doesnt like hornadys. Which would be sad, becasue Honrady 75s are half the price of SMKs.

Tag for interest as I have the same components ready to go but haven't pulled the trigger yet.

I did discover completely on accident that my Dillon trim/resizing die produced neck tension as such that crimping is un necessary.  Good bullets group right at an inch if I do everything else right.

Dillon's trim/resize die constricts the neck way too much, requiring that it be addressed in a second operation IMO. Either a K&M Expandiron or Sinclair International neck expander needs to be employed to open it up some more. Another option is to run the brass through a neck sizing die with the proper sized expander ball in place to achieve no more than .003" of neck tension.

Trimmed brass as it comes out of Dillon's trim/sizing die also needs to be de-burred and chamfered. I ended up giving the Dillon trimmer away to a friend with five (5) trim dies for only $100.00 and was glad it's gone. There is no excuse for the neck diameter their dies create and they know it's an issue and have done zero about it. A .244" neck is plenty to gain sufficient neck tension, theirs creates something closer to .239".

If I still owned that trim/resizing system I would send the dies out for modification if I intended to keep it.

With the Dillon Trim/Resizing die, there is no expander ball. You have to resize the neck one way or another, most people run a Lyman "M" die to open it up after trimming. If You loading without expanding the neck, you may be able to gain a lot of accuracy by setting proper neck tension.