First off this is my first time reloading cast bullets for rifle so please correct me if I'm doing something wrong.

I am reloading Missouri Bullets 247gr for my 8in Blackout pistol
Per Missouri Bullets they are loaded at 2.12 overall length
I was subsonic rounds so I loaded five rounds with Accurate 1680 powder, 11.5gr, 11gr, 10.5gr and 10gr
First five 11.5gr were consistently around 1050, but I noticed first cycle didn't  feed, and the edge of the bullet was shaving off
Second five 11gr were around 946 I believe, and first and second cycle didn't feed, again noticed shavings of edge of bullet.

Upon inspection, I noticed that the 11.5gr had a 3.6in group at 50 yards, 11gr had a 2.9in group at 50 yards. That is way to large for my expectation.
I measure the bullets diameter at 0.300 while the box stated 0.309.

Missouri hasn't commented on this yet. Any ideas?

I wanted to also note that I have noticed feeding issues with magazines other than the standard steel magazines. I cycled five rounds through a military magazine and noticed no shaving. I have not shot it using that mag.

You need to buy a good reloading manual and read it.

You always start at your beginning load and work up, starting high and going down is a good way to damage or blow up a gun.


As for not cycling, that could be due to a massive amount of things. Some rifles can't cycle subsonic loads without a can. This may be your problem. Cast bullets can be a little more advanced of a skill, I would suggest you get some jacketed bullets, and start to learn from there.

Usually, with subsonics, you start with a mid-range load and work your way down to get them reliably subsonic while still cycling the gun. With this particular bullet, you might need to play with overall length to get it to cycle well. I generally use steel 20 round magazines without issue. I generally shoot them only with a suppressor, but shooting without can affect cycling. With 1680 and a pistol length gas system, you shouldn't have an issue with pressures - again, if you'pre having issues in this case, it's likely related to the bullet or the magazine. If you look in the 300 BLK master thread, I posted the OAL I use that seems to work.

Thank you for replies. As you have mention subsonic is the opposite order. Working way down so you don't run into pressure issues being to slow but blackout is more forgiving. I'm not worried about cycling as I've narrowed that down to magazine follower. What I am concerned about is the accuracy and bullet diameter. Is it common for cast bullets to be sized at .300 for a .309 caliber?

How sure are you of that measurement? At that diameter, the neck of the case probably wouldn't even hold it. Are you getting any neck tension?

(Mine are .309 last I checked)

Nope.

If I bought 30 cal lead bullets I would expect to measure .309 or .310, certainly not LESS THAN .308
Rule of thumb with lead is at least .001 larger diameter.

Possible mix up, OR are you measuring these in the round, after you crimped them????

I'm doubting they're 0.300.  They'd drop straight through the neck--don't think you could even crimp them. Leakage around them would be bad enough that you're very likely to get one stuck in the bore.




There are a lot more variables than simply messing w/ the powder charge.  Get a different can of powder, try a different primer, change the lube on the bullet (for starters).


 

Lots of good suggestions so I'll be more detailed. These bullets are very long there is plenty in the case. There is a slight crimp they are not going anywhere. I measure bullet right above the case neck. I can take a measurement where it goes in the case in a couple minutes. This is why I am concerned I thought that was small too. These have the hitek coating and are not lubed. I'll take a couple pictures too.

Makes sense.  The bore riding portion should fit exactly in the muzzle (0.300 would be about right).  The driving bands should be .310
 

Okay thankfully I believe I got a little ahead of myself. Was disappointed about shot groups so much I wasn't thinking. I did that've the case of bullets available and didn't think there was much of a taper. .300 right above case but .309 at base. Hopefully the pictures show up but do you think just a slight shaving at tip would grow off shot groups that much at such a short distance?

Doubt it matters, but you can try loading them right into the chamber and see if it makes a diff.

Sorry about the pictures apparently I haven't figured it out to have them embedded. Alright so size of bullet appears to be fine, charge with powder is where I want the velocity, bolt is fussy with what magazine to use for feeding so only thing left is to play with length correct?  Do i go to the opposite extreme by loading some at full length? With a bolt I would put a round without a charge and close the bolt to get a tight fit, but an AR platform is different you want a slight gap correct?

Measure one before you seat, and measure the driving bands, those should be 0.309
On most rifle bullets, in front of the crimping are the bore riding portion and should be about 0.297 to .300

ETA wow am I behind.
Did you slug your bore? Just because that's what it's supposed, doesn't mean it is.
Are you seating approx. 0.020 away from the start of the lands?
This is something you need to be aware of.
Just went through getting mine to shoot good, about 1- 1-1/2 @ 100, and I'm happy.
DBL ETA You need to switch mags(dinged bullets) or your OAL is wrong

I did measure the lands before I seat, and they are correct at 0.309. I acknowledged that I was wrong when I first measured, and I was happy it was me. No I did not slug my barrel, jacketed bullets get me 1MOA so I was happy with that being just a 8 in barrel. Attempting subsonic with cast bullets appears to be a whole different game.

0.020 from the lands thank you for that information I will check on that. I just wasn't happy with 3-4 in groups at 50 yards.

As I mentioned about the dinged bullets, I am switching magazines.

Make sure the front band of bullet doesn't seat past the end of the chamber, will have problems chambering all the way
ETA what kind of mag did you use?

Not sure if I'm picturing what you are saying. I have had bad luck with 20rd pmags with jacketed bullets even, but these shaving were using midwest industries metal 10rd. Military steel 30rd seem to be no problem

At the end of the chamber, there is a ring just before the rifling starts. You don't want the band to engage it.

I'm casting the same bullet with NOE flat base mold and powder coating it.
8" cmmg barrel
H2 buffer

Use usgi mags only loading 12 rounds.
(That's a lot of wait to bounce around on recoil)

My oal is 2.225 light crimp,feeds excellent, very dependable. Suppressed or unsuppressed.

11.2 gr. RL7 = 1075-1100 fps
One ragged hole in the center at target at 25 yards. 20 rounds.

My hardness is 11. Missouri bullet looks like it there's 20. That can affect accuracy.

I'd try extending your overall length to 2.225 first.

Is your rifle locking back on an empty mag after you shoot?

Yes the bolt locks back when empty. I was actually impressed that an educated guess the first charge I tried cycled and was the velocity I wanted. From what I hear blackout is easy compared to others calibers for subsonic though.

I was wondering on the hardness level if that was too hard. I read that when Missouri first started making the bullets they made them softer. I'm not up to making my own bullets yet and haven't seen anyone else selling big bullets like that.

that's my thoughts too... I doubt they would be seated with ANY neck tension (read: drop in) at .300

just read the update....

ok, hand feed one into the chamber, close bolt. extract, does it look like that?

trying to see if the damage is from being stripped from the mags, up the feedramps and into the chamber or after it enters the chamber.

Alright did some more testing and want to see if anyone else has ran into this. This is addressing the cycling.

First, overall length. 2.26 max blackout length compressed to 2.24. I did take the advice from here and ended up using 2.225in. which had two land marks 180 degrees from each other.

Second is feeding, all my round are feeding good on the inside ramp but the round on the follower was either hitting the ramp flat or on the outside off the ramp. This cause the shaving or the bolt to go right over it.
http://i40.photobucket.com/albums/e213/rayyoder/feed%20ramp_zpsjiq8ebqb.jpg
I tried a couple different magazines.

http://i40.photobucket.com/albums/e213/rayyoder/Magazine_zpsltaxjvpq.jpg
Colt worked and has a different design. Left to right colt 30rd, Kay industries 30rd, CAA command arms 30rd, and pmag 30rd.

How has everyone handled flat point bullets cycling? Is it my barrels feed ramps? I have a CMMG barrel.

As long as you are using cast flat point bullets you will get some degree of shaving of the bullet tip.  It has to do with the round moving forward out of the magazine and striking the feed ramp of the barrel extension and rising up to finish entering the chamber.  I use cast bullets in my 7.63x39 and my 300 Blackout. I use this bullet pretty much exclusively to eliminate lead scraping.





I also size them according to whichever barrel I am shooting them out of.

Are you also using the lyman neck expansion die in 30 cal to prep the case prior to loading?  The neck expansion case enlarges the case neck so you are not shaving the side of the cast bullet as it is being seated in the case, thus causing accuracy problems due to the bullet not being concentric in the bore.

Those are interesting bullets. The thing is that I want to use flat nose bullets as they deliver more impact, and are better for hunting at subsonic speeds.

Interesting day that went back and forth though. I'll explain what the conclusion is for anyone interested.

AR pistol - 8.2" CMMG barrel. 1:7 twist 300 blackout using 245gr MIssour Bullet flat nose bullet with hi-tek coating.

Jacketed bullets no problem, and have been getting under 1 MOA accuracy using a 1-5x scope.

I recently made a Form 1 suppressor therefore I wanted to try subsonic ammunition. Factory loads are way too expensive, and jacketed bullets range from 0.33 to 0.45 cents a round. Cast bullets are around half the cost so it peaked my interest.

I am using a multi-stage Dillion loader with RCBS three die set. I seated the bullets at 2.12" per Missour Bullets recommendation. Results were hideous at 2.9 to 3.6 in groups at 50 yards. As noted above I was getting quite a bit of shaving of the tip of the round. This was due mainly to the round that is directly above the follower in the magazine. Depending on what type of magazine I used. It would either go off to the side of the feed ramp, or hit the ramp flat and the bolt would just go over it almost every other round (round above the follower).

I then switched to a Colt magazine that  worked the best, and seated the rounds at 2.26" max length. This was completely too long, and wouldn't work in some of the magazines. I worked my way back, and found 2.222" worked the best for me where it just started in the lands giving me under an inch groups some touching at 30 yards loading one at a time. Cycling was still not good as the bolt was going over the rear of the round causing the round to jam diagonally in the chamber. At this point I figured these flat nose bullets were not going to work.

Conclusion was a small modification in the magazine. Bending the rear tabs on the magazines just a 1/16" upwards allows the bolt to push the round an a little bit more of an upward angle. This allows smooth feeding with no deforming of the bullet.

Obviously this only works with metal magazines, but it works. I now have better groups, and cycling that actually works. I'll have to do a better range report at a farther distance, but wanted to share this with anyone else that might be having these issues as well.

Thanks for the update.
Good to here you got it running.