ar15 loading issue

[jproaster]

New re-loader here. Reloading for 1 in 7 twist with 14.5" barrel, 223 cal.
Cleaned up mixed brass.
Loaded 77 smk to 2.240 oal.

Using a pmag 30 to cycle through several rounds for chambering. I can't seem to get past 3 or 4 before a jam of one sort or another. Learned about "mortaring" today due to the bolt jamming almost totally closed.

Did the same test with some cheap 55 grain ammo (pretty sure reloads from?)...cycled fine. Upon comparison between my reloads and the other ammo. It appears that the cases on my reloads are longer. Wondering if this is an issue. Speer Reloading manuals shows case length at 1.760. Mine are at 1.770 after resizing.

Oh. and the bullets are scratched on my reloads too.

Thanks for any help.

[greentick]

Your resized cases are over-length. Max case length is 1.760.

Trim-to is 1.750. You will probably get some stretch with resizing.

[mikejonestkd]

Greentick is spot on, trim your brass.
Also, the 77 gr SMK is a long bullet, and may not feed out of a pmag @ 2.240"

[jproaster]

Thanks fellas. Always good to find the culprit.

Now to get the right tool.

John

*Bought all this reloading equipment 5+ years back. Barely touched the stuff for different reasons. Glad TFL is here to get started again.

[HiBC]

Make sure you are not collapsing the shoulders by inadvertantly over crimping with your seater die. Use "Search" for more info.

[jproaster]

Will do.

The only reason I thought to ask about the case length was visual inspection alongside good ammo with a serious magnifying glass- could see the difference.

[HiBC]

Measure for any diameter increase at the shoulder. Right at the corner.
Compare it to the diameter just behind the shoulder.
If you set the seater die to contact the shellholder,I'd expect you have discovered this problem.
Realize that even if you carefully set a light crimp,if your case length grew,its a heavier crimp.

As the press applies that force to the case mouth and bullet,the shoulder will collapse a bit. As it does,the shoulder slope will cause the shoulder to cantilever outward. It makes a little bulge.

Driven into the tapered chamber,it can get quite stuck.

You mentioned "mortaring"

[Ifishsum]

Cases weren't sized quite enough? Overall case length can be an issue but in my experience stuck rounds on chambering are more often from slightly oversized or deformed brass. Does the shellholder touch the die at the top of it's stroke while an actual case is being resized? And if you are trying to crimp the SMK at all it will bulge the shoulders (sometimes not enough to really notice) because the SMK typically has no cannelure to crimp into. If you feel you must crimp it (I don't) you'd need to use a Factory Crimp die to avoid a slight shoulder buckle. Be sure your bullet seating die body is backed out enough that it does not contact the top of the brass.

[HiBC]

Crimping is subject to debate. I don't crimp
Some do. Sometimes its intentional,sometimes its just because screwing the die to the shellholder seemed like a good idea (Read instructions??? Surely I jest!)

I'll agree that partial sizing can extrude the shoulder forward,and what would be "head clearamce" becomes "head interference"

[jproaster]

Thanks again all. I will be looking over these issues quite closely this week. Thankfully I have a gun perfectionist friend to call on. I should've just waited for Tom.

Again. Thanks.

[burrhead]

I don't crimp any bottle neck ammo. Load those 77s to 2.255 or longer if they'll fit in your mag.

[lordmorgul]

Recommend buying a case gauge. I’ve taken to checking every single reload for rifle or pistol in the correct gauge. It’s overkill, but it ensures a quality product, and at my rather low volume it’s not that hard to check each as it is going into the loaded ammo boxes.

You would have immediately seen your case mouths protruding from the case gauge, before or after loading them.


Andrew - Lancaster, CA
NRA Life Member, CRPA member, Calguns.net contributor, CGF / SAF / FPC / CCRKBA / GOA / NAGR / NRA-ILA contributor, USCCA member - Support your defenders!

[Twinsig]

Ditto.
Started loading this recently after years of straight walk pistol, one of the primary purchases was Wilson 223 case Guage. Already had trimmer tools.

[44 AMP]

Learned about "mortaring" today due to the bolt jamming almost totally closed.

I'm not a fan of banging the rifle on the ground if it jams. I can understand doing it under emergency conditions (like when people are shooting at you) but otherwise, not so much.

One of the big drawbacks to the AR design is the charging handle, being both small and only working one way. Not an issue when things work right, but not much help when they don't.

As to case length, it does matter. The part of the rifle chamber where the neck fits is large enough to allow the brass to expand and release the bullet. The part in front of the chamber is not. Too long a case can allow the case mouth to enter that smaller diameter portion of the barrel and that's not a good thing.

Also others have stated, crimping where there is no crimp groove can bulge the shoulder of the case, which prevents it from fully chambering. Even if you don't try to force it shut with the forward assist, it can still jam up tight.

Get a case trimmer and trim your brass. Don't crimp bullets that don't have crimp groove. Don't crimp anywhere but in the crimp groove. Full length resize your brass, and then test your ammo. If you're still having problems, chambering, you may need to use small base sizing dies.

[jetinteriorguy]

You said your new to bottleneck rifle reloading and it hasn’t been mentioned but always resize before trimming. Resize, check for proper length with the case gage, trim as needed and deburr and chamfer. I also recommend a slight chamfer on cases that don’t need trimming to help start the bullets seat a little easier.

[Irish Lad]

"Recommend buying a case gauge. I’ve taken to checking every single reload for rifle or pistol in the correct gauge. It’s overkill, but it ensures a quality product, and at my rather low volume it’s not that hard to check each as it is going into the loaded ammo boxes.

You would have immediately seen your case mouths protruding from the case gauge, before or after loading them."

+1


Gives me peace of mind.

[gwpercle]

Using a case gauge doesn't guarantee your loaded round will fit your rifles chamber .
Don't load up a quantity of ammo without first checking the fit in your rifles chamber .

Back in the day ...we were instructed to use our rifles chamber as the correct gauge ...
that must the reason I own no "case gauges" ...you don't really need them .
Gary

[Bart B.]

Nobody shooting best results in centerfire rifle matches crimps case mouths into bullets.

The USA military match and sniper ammo doesn't have crimped in bullets.

The reason any rifle ammo's bullets are crimped in is to keep bullets in place in rough environments so it will reliably chamber and fire when needed. It was never intended to improve accuracy. What commercial match ammo has crimped in bullets?

[44 AMP]

IF you have, and know how to use calipers, you don't need a case gauge. Nice to have but not a necessity.

[jetinteriorguy]

I like using case gauges to check length for trimming. Fast and easy to pick out the ones that need trimming. Otherwise not good for much.

[stagpanther]

I make an inert cartridge for just about every load I develop--especially for AR's. Just because a cartridge properly conforms to the case gage doesn't mean it's going to feed reliably.

[HiBC]

It helps to know what the gauge is designed to check ,what you are checking and why.
No offense intended,but many of the folks who dismiss a case guage don't know what they are doing with it. They mis apply the tool and then think it does not work.
I assume we are talking about what may be called a "bushing cartridge headspace gauge" I'm not directing these comments to another type guage.

What is this guage designed to do? As a bonus,it will check if cases are over trim length. So will a calipers,or a case length gauge.

I would not buy a bushing gauge to check trim length.

What I greatly value the bushing gauge for is measuring or checking the case head to shoulder datum measurement as it applies to chamber headspace.
IMO,a bushing gauge is my preferred tool for setting my sizing die to give me a repeatable head clearance.

IMO,for that purpose,it excels.

Simply using the step on the case head end,you can assure you are sizing to SAAMI spec for head clearance purposes. To be clear,I do not ask this gauge to check anything else. It does not,and cannot,check any diameters. Its not a plunk or chamber gauge. If that is your expectation,you don't understand gauging.
Thats not a problem with the gauge.

I take the use of my bushing gauge one step farther. Yes,I can simple use the step to assure my cases are within SAAMI high/Low limit.

But suppose I want .002 head clearance for my rifle.

No problem.Assuming the neck is trimmed so it does not protrude from the gauge

I can drop the case in the gauge and measure over the length of the case and gauge as an assembly. I measure from the neck end of the gauge to the case head. Assume its an unsized case and I want to shorten it .002.

I have couple of possibilities. The gauge provides me with the SAAMI hi/lo step. I can mic or caliper it. Maybe I know I want .003 over the SAAMI minimum step. Easy. Set the die so you can measure with calipers over the case assembled into the die. Its a lot like the Hornady clamp on the calipers Lock and Load setup.its just all there in the bushing.

And,like the Hornady Lock-and Load or the RCBS Precision mic,you can take a before and after comparative measurement to see how much the length changed during sizing.

If you write your numbers down,you can easily set you sizing die at .002 head clearance,or .004 or whatever you want. If you are fortunate enough that your fireformed brass is zero head clearance (and it may not be) you can simply size it so you get the desired change. Once you know that number,three years later you can repeat it with the gauge. Your gauge will be the repeatable standard.
Your calipers will do.

As a machinists,I take it to the next level. I have a comparator stand. It an 8 in square piece of very flat granite that has a 12 in tall post sticking up out of it. The post is to hold a dial indicator. I can zero the dial indicator on the high/low limit step of the gauge, Then I can drop cases in the gauge and slide the case heads under the indicator,

I just don't understand the perception that a bushing gauge is not useful.

A bushing guage physically cannot perform as a chamber plunk gauge. To measure the length,there must be clearance on the diameters.

If it can measure diameters,it cannot be free to measure length. They conflict.

If you have been trying to use your bushing gauge as a plunk chamber gauge,yes! You have been disappointed.

If I try to use a vise for a drill,I'll be diappointed. I might think my vise is useless.

Whose fault is that?

----------------------------------------------------------------------------------

Bonus tip!:

As I have the comparator stand and indicator

And I also have Vee-Blocks

I can stand a vee-block up on end,and put a bolt,an AR bolt,for example in the vee block with the rear,bearing face of the locking lugs resting on the upper surface of the vee block The vee block simulates the locking surfaces inside the receiver. Suppose I want to compare 4 AR bolts for headspacing purposes. Maybe I need .001 or maybe I want to match or verify another bolt. This setup can do it.I just set the indicator on the breech face.

[jproaster]

Thanks all for sharing more "know how" information. I've got quite a bit to learn to be a safe reloader.

As to the trimmer, I thought I'd try a Giraud Tri trimmer. They're apparently closed til Aug 10 if I remember the company's recorded message correctly. Hope I can get one sooner than later.

John

[Metal god]

What trimmer did you use to trim the cases you loaded ?

[jproaster]

To be honest, I didn't realize I needed to trim. The person who helped me get started has reloaded for years and has loaded thousands of 223; he never brought it up. The fault is my own though; should've read the materials closer.

As to trimmers, I'm hoping to obtain the Giraud TriTrimmer asap.