Die Squishing Boolets

[BulletFactory]

HELP!
I'm loading for a 9" BCM barrel. The powder is compressed in this load. 18.5 got it to cycle. When I seat the bullet, the base of the bullet hits the powder and bottoms out, beginning to compress it. The bullet seating die hits the top of the bullet to push it into the case, as you know, but it's squishing the bullet causing its diameter to increase. This increase in diameter is causing the throat of the barrel to swage off a "ring" of lead as it chambered. The second round wouldnt seat in the chamber and got the gun stuck. When I got the round out of the barrel, the little lead ring that was sheared off the first round was stuck around the second round like a little necklace

http://i1313.photobucket.com/albums/t557/The_Prodigal_Sun/Bullet%20Squish%20002_zps5n6iscfm.jpg (http://s1313.photobucket.com/user/The_Prodigal_Sun/media/Bullet%20Squish%20002_zps5n6iscfm.jpg.html)

[BulletFactory]

The bullet seater is changing the profile of the round, making it impossible to chamber. What do I do?

[Maven]

The bullet seater is changing the profile of the round, making it impossible to chamber. What do I do?

Have you thought of using epoxy glue and that greased or waxed CB (i.e., wax/ grease on the nose only) in a dummy round in that bullet seater to make it a custom fit?

[BulletFactory]

It was the first thought that crossed my mind, yes. Like bedding a rifle receiver to a stock, right>?

[Yodogsandman]

Maybe not PC the boolit??

[BulletFactory]

Why skip that step?

[Bzcraig]

The epoxy trick works to some degree but how about a powder with less density?

[BulletFactory]

Im not sure waht you meant BZcraig

[Nueces]

I think I'd add one step to solve your problem. Use a powder compression die, as do some black powder cartridge shooters.

Something like an M-die with a flat stem, adjusted to compress your powder just below the base of your seated bullet.

[BulletFactory]

Im not sure what that is, do you have a link?

[243winxb]

Crimping while trying to seat the bullet. Back seat die out/up so crimper doesnt contact case mouth.

[BulletFactory]

You mean, compress the powder, THEN seat the bullet?

[BulletFactory]

Crimping while trying to seat the bullet. Back seat die out/up so crimper doesnt contact case mouth.


I..am..not...seating./.and...crimping...in...the..same..die...Sorry...my ...space...bar...just...quit..so...I...added...the ...periods/...to,...make..this...legible...

[243winxb]

You can not compress ball powders like 296 or h110

[BulletFactory]

...........

[BulletFactory]

this is accurate 1680 oh wow keyboard works

[243winxb]

Most seating dies have a built in crimper. It was just my guess.

[243winxb]

http://www.ilrc.ucf.edu/powders/sample_detail.php?powder_id=18 Flat ball powder.

[Nueces]

You mean, compress the powder, THEN seat the bullet?

Yessir, that is what I meant.

[BulletFactory]

Okeydokey looks like I have a die to set up. Probably will use the body from the extra factory crimp die. Shoulda got a .5.56

[runfiverun]

your fine.
think about this for a second.
what happens if you back the seating stem off about 1/8th turn?
okay now what happens if you back the seater die off 2 turns and set the stem back down?
your squishing the boolit in the process somewhere.
and sometimes it is as simple as the boolit is catching on something inside the die.
but I'm guessing the length between the bottom of your case and the seater stem is too close together.
when you seat everything fully your bumping the nose diameter.

if this were a shot shell you'd buckle in the sides of the case where the crush section of the wad is slightly.

[BulletFactory]

I love this place

[243winxb]

.334" is the maximum neck diameter of a loaded round. Some, converted 223 brass to 300 aac blackout may be to thick in the neck area, without inside neck reaming the brass.

[runfiverun]

good point 243.
but his problem appears [to me] to be further forward.

I was running into what I thought was boolits hitting the throat in my AAC and it turned out to be LC brass and .310 boolits giving me the grief in the neck area.
a swap to thinner brass cured the issue for cast and relegating the LC brass to the ruger or to just jacketed bullets in the AAC worked out for me.

[Yodogsandman]

"Maybe not PC the boolit??"

My thought was that the extra diameter from the PC coating is making the boolit tip oversized for your seating stem cup. That it also causes you to have to seat the boolit deeper to allow for that thickness when chambering.

[GrayTech]

Seems odd to seat a bullet so hard it's deformed. What's the neck tension like? And how soft is your alloy?
Expand one case neck so the boolit is a slip fit, seat a boolit and try chambering it.
Try less powder in one to see if you still get the deformation.
Rule out one thing at a time till you identify the problem.

[BulletFactory]

good point 243.
but his problem appears [to me] to be further forward.

I was running into what I thought was boolits hitting the throat in my AAC and it turned out to be LC brass and .310 boolits giving me the grief in the neck area.
a swap to thinner brass cured the issue for cast and relegating the LC brass to the ruger or to just jacketed bullets in the AAC worked out for me.

I trimmed all the necks with a Forster neck turning tool, because I heard that some like LC do give neck thickness issues.


"Maybe not PC the boolit??"

My thought was that the extra diameter from the PC coating is making the boolit tip oversized for your seating stem cup. That it also causes you to have to seat the boolit deeper to allow for that thickness when chambering.

I had the barrel out of the gun, and the bolt separated from the BCG. I would take a sized empty round with a bullet set in with too great of an OAL. I would try to hand-chamber the round using a rod passed through the cam pin hole in the bolt. This allows you to rotate and lock the thing. I take the bullet to the seating die, and go a little deeper and try to chamber the round by hand. I repeated until I got the thing to lock. Then, I took the bullet in about another .02 to .03" deeper. This was done before attempting to add any powder.

Charts started powder at 18.3, and starts compressing at 18.5. Max is around 19 but I never mess with maximums.


Seems odd to seat a bullet so hard it's deformed. What's the neck tension like? And how soft is your alloy?
Expand one case neck so the boolit is a slip fit, seat a boolit and try chambering it.
Try less powder in one to see if you still get the deformation.
Rule out one thing at a time till you identify the problem.

I had mo deformation with an empty case.

At 18.5gr Accurate 1680, I examined the primer, and found no evidence of brass flow around the firing pin dent. There were the very early signs of primer starting to flatten, but not enough yet to cause for concern.

I am about to go check and see if I can find a different powder that doesn't compress. I kinda hate to mess with that, considering it can be lots of fun truing to get a 9" to cycle.

[runfiverun]

you could try seating in stages.
and turning the round over and shaking the powder up around the boolits sides.

or just using less of a faster powder, 9-10grs of 4227 might give good results without the problem.

[BulletFactory]

From my reading, I found out that A-1680 is at maximum at 18.7 gr when using a SMK 168 gr bullet. I have a cast powder coated 168 gr bullet. Too close for comfort.

I think I will be saving the 1680 for subsonic loads, and Im not developing them until I can get the gun to run wit a supersonic load. Dont even have a can/stamp yet.

Looking for a new powder now

This raises an important question.

When all I can find is data on a jacketed round, is there a formula, or rule of thumb to figure the powder charge for a cast bullet?

Seems like 1680 is the go-to powder for SUBS and H-110 is for Supers. Both have been tested extensively by AAC, the maker of the 300BLK.

I have two bullet molds, so I only have 168 and 220 to choose from with bullet weight.

[Wayne Smith]

You are trying to compress the powder with the boolit. This usually does not work, thus the compression die used by BPCR users. I made one to use loading my 44-40 with BP. Make sure your powder is compressible, be aware of how much you are compressing it, and keep a close eye on your chronograph, or find a different powder.

[BulletFactory]

Its a different powder at this point.. Probably H-110

Should be able to buy a Chrony in Dec or Jan.


I like how Hodgdon stands up for Jesus Christ, so I try to go with them. Hs-6 for the .40 and H-4895 for the M1A

[popper]

Do you use a long drop tube? I had the same problem when loading 168 Amaxs, 4227. You could seat to the right depth but then the air & powder forced the bullet back out before I could crimp. You may need to expand a bit more to reduce neck tension. PC makes a tighter seal than lube. Try seating in steps to let the air escape or cool. Do check loaded rnds for OAL - I got a nasty surprise.
IIRC, 4227, 1680 can go 10% compression (sierra data).

[243winxb]

http://www.300blktalk.com/forum/viewtopic.php?t=82165
I have not shot any of these in my AR yet, but in my Rem 700 AAC BLK 1-7 16" bbl, I get 1" - 2" groups at 100 yrds with a bi-pod and Nikon 3-9 Prostaff....nothing fancy.

11.2 grns A1680
Lee TL309-230-5R sized to .309 w/gas check
Powder coated
CCI 200
COL 2.173

Lots of drop though. The rifle is zeroed at 100 yards with 125 grn SMKHP and to make the 230 cast hit the bull I have to use all the little circles under the cross hairs (sorry, just too lazy to look up the drop right now). and
I use 10.8 gr of 1680 out of an AR with Noveske 10 inch barrel. These are seated to 2.21 and fly 1020-1050 fps. I use Hi tech coating

[runfiverun]

velocity is a good indicator.
say you find a cast load that gives the 1100 fps you want to target or 1300 ish fps [you can lower] it's a good candidate for a straight trade.

as is pressure.
if you can find a good jacketed load with [say] 32,000 psi in your 308 it would be a good candidate to work over for cast loads.

[Wayne Smith]

Rule of thumb for using condom data. Cast boolits are softer and slipperier than condom bullets so, as long as the length and weight of the bullets are comparable you are safe using condom data.

[popper]

168 & 110/296 are fine grain powders so you can get more in the case than 4227 or Rl7. SMKs are BT so you have more space with a FB/GC. 19 of 1680 worked fine under a 155 Amax, 14 worked under a 185 cast. I don't run 100% fill loads as I don't trust temp varations vs pressure. Get a drop tube, it does increase packing powder density.

[OS OK]

Have you tried a flat seater? Just push on the nose?
Depending on the powder you are using and whether or not there is space in the cases...you can hold your finger over the mouth of the case and gently tap the powder charged case to settle the powder some. I've even touched them to my vibratory case cleaner to vibrate them a bit and settle coarse powder.

[MT Chambers]

I would use a droptube but no way would I try to compress smokeless powders with a compression die.

[JWT]

I have touched the charged case to my vibratory cleaner to settle the powder. Works good when using 4064 in an 8mm.

[runfiverun]

1680 is a super fine grained ball powder.
it's slower than H-110 so needs a bit more to reach pressure.

if your using a bolt gun you have tons of other options.
a couple of us are running 3.5-4.0 grs of stuff like bulls-eye, 700-x, and red-dot to poof the LEE 230 out to 50-100yds.
if you wanna go a bit faster AA#-9 or 2400 both are easy to get velocity from.

[popper]

My 170gr boolit looks like yours, base isn't below the neck. BO throat is long so you can seat way out, if it will feed. I seat my 185 gr. Base about where your is , IIRC 16 gr. 1680, not compressed. Looks like your crimp is way hard also. Who says it is a compressed load?

[BulletFactory]

Lyman 50, and in several other places. You can look at it, and see that the powder is higher in the case than the rounds base will be when seated.

[popper]

My point was (I probably didn't state it correctly) OAL is spec. for that gun load test. You should be able to seat longer for a non-compressed load (safe) until the boolit doesn't jam the lands or it is too long to fit mag or feed properly. I've loaded 19gr. 1680 under a 155 Amax, which is a BT (less space for powder) and not a compressed load. Load some dummys & find what chambers and feeds properly, then try 100% fill if you need them that hot. Crimping into the groove is not required, my moulds don't even have a crimp groove.

[KenH]

Your accurate 1680 should be fully cycling with only 15 grains and a 168 cast bullet. With a 9" barrel in 300BO 15 grains should be giving somewhere around 1200 fps, but more important right at 10,000 psi at the 4.5" point for your gas port which should cycle the action just fine. These numbers are all per QL program, but have proven to be pretty close.

What about using Litl-Gun as a powder? it tends to give a bit more pressure at the gas port for same fps than some other powders.

I've had your problem with my 300BO also, the point portion of the bullet is too large and jams with the rifling preventing a full chamber. I've had to seat bullets deeper than desired to get them to chamber. I'd like to have a bullet with about .300" diameter front portion back to seating point.

Ken H>

[BulletFactory]

http://phase5wsi.com/ar-15-m16-pistol-pigtail-gas-tube.html

could this be my issue? I was thinking it might be a problem but it looks amazing with the BCM fluted barrel. I'll go to a straight gas tube if I have to. :/

[KenH]

You've got a pistol gas tube which has the gas port at 4.5" - with full power loads you're getting a good bit more gas power to the BCG, but that's usually indicated by "slamming" the bolt back. Does your 9" barrel cycle good with lighter loads? Subs?

The gas tube you linked to will allow the pistol gas port to act more like a carbine or rifle gas port by causing the gas to take longer to operate the BCG. If your system works good with lighter loads, but not heavy loads, it just might work.

Do you have a light BCG or light buffer to improve function with subs? If so, this just might be the answer. I've got a 16" barrel with a pistol gas port (4.5") same as you have. I've also got the standard mil-spec buffer and BCG and have not had any issue with full power loads. I've shot perhaps 40 or so rounds of factory full power loads, but mostly subs (240 grain) and mid range loads in the 1300 to 1500 fps range. You mentioned 18.5 grains of 1680 (?) to get it to cycle..... were you getting a fail to feed? No LBO? It should not take anywhere near a full power load to get a pistol gas system to fully cycle with LBO.

Ken H>

[BulletFactory]

I have a F/A BCM BCG. I haven't gotten the rifle to cycle, only to eject, or double feed.

[KenH]

OK, since this thread is the first I've seen of your 300BO, does it function correctly with factory full load ammo? eject empty, load new round, lock bolt back on empty mag? Is this round you're trying load the only load giving problems? I also powder coat cast bullets and have to be careful the bullet nose doesn't get too large to fully chamber. That doesn't sound like your problem.

I've used Harbor Freight red for PC, but MUCH prefer Smoke's clear. Just covers so much better.

Ken H>

[BulletFactory]

I powder, then size so diameter remains consistent. I'll try a better powder. HF powders are, meh.

I haven't had any factory ammo. I'm going to pick up a box of subs and supers pretty soon. I also put a straight gas tube on the gun, but haven't tried to fire it yet.

I seated the bullets too long so that I could see the mark in the powder coat from the throat. Then, I would try with another round, set deeper, until I had no contact marks, then I went just a little deeper. At first, I wqas setting them too deep, and it would fail to feed every time.

[KenH]

Awwww shucks, when I read your post about the curly gas tube, I read too quick and thought you were thinking of using that tube. Naw, you've got that tube now. That would make subs hard to cycle for sure.

What was the OAL of your loaded rounds that are working?

Ken H>

[BulletFactory]

2.135" oal

[KenH]

I load a 170 grain cast bullet to 1.94" OAL because the nose bumps the rifling. With j-bullets seems like I'm out to 2.1" or so. I've loaded so few of them I don't really remember. I'm using IMR4227 or Litl'Gun powder so don't need so much in the case.

Good luck - I don't have a clue why you're having so much trouble with full loads cycling.

Ken H>

[BulletFactory]

Thank you :) I'm pretty sue its the gas tube. I will let you guys know.

[KenH]

Looking forward to your future reports on your setup.

Ken H>

[BulletFactory]

I'm buying a chronograph in early December, and at that point I should be able to begin load development.

[KenH]

You will LOVE the chrono! They're fun and take some of the guessing out of the loads.