more blackout advice needed super sonic this time.

[Lloyd Smale]

Trying to get a full power cast bullet load in the 120-130 grain bullet weight class. Ive got a 130 Seaco round nose mold and a 130 lachmiller spitzer mold. I cant seem to get either to run in my gun. Im casting them hard and powder coating. Ive tried seating at the recommended length for jacketed 120-130 grain bullets (that run fine) and have seated them out to the point the neck has problmes holding them. they all want to stove pipe. they start coming up out of the mag and hit the feed ramps and the bolt rides over the case. Now I have had good luck with the 155 lee. What the heck am I doing wrong? Is there a 120-130 cast bullet that runs a 100 percent in your gun at full power? Is pc coating drag causing me problems? Ive even bought p mags and bravo company mags that are specifically for the 300 bo. Any help be it molds seating dept ect would have welcome. What Id like is a cast bullet that shoots to about the same point of aim as 130 bts and 130 ssts. Gun is a 16 inch psa with a pistol length gas system. I runs jacketed perfectly.

[popper]

Try loading deeper. Bolt should be pushing the base, sometimes it doesn't go back far enough and forward friction with the bolt bottom pushes it forward.

[Lloyd Smale]

Ive been making sure there all the way back in the mag and have been seating them at the same dept as recommended for jacketed. I even tried varying that. I wondered about what you suggested that the bolt isn't coming back far enough. I see they sell 300 bo specific buffer springs that are much lighter but for the most part they claim there only nessisary for carbine and rifle length gas systems and for sub sonic. What I did yesterday was to grind a bit on the feed ramps to knock the edges off and polished them and I pulled my buffer apart and took one of he weights out of it. Some day soon I will give it a try like that. One other thing I noticed is I was test firing in the yard so I slapped a suppressor on it so it wouldn't bother then neighbors as much. It put a lot of gunk in the action in a short amount of time. It possibly could have been slowing down the bolt too. Toward the end of my testing I was getting failure to lock back on an empty mag so your bolt not going back far enough might be my problem. The added weight of the 155 might have been what made it run so much better. Thanks for the suggestions. I went through all the hoops getting my 9mm ar pistol to work a 100 percent but didn't really research the 300 bo enough to know that they can be finiky too.
Try loading deeper. Bolt should be pushing the base, sometimes it doesn't go back far enough and forward friction with the bolt bottom pushes it forward.

[popper]

2 possible problems. Bolt doesn't go far enough back and carrier tries to chamber the rnd - doesn't work most of my stove pipes are from this (short cycling). Other is cycling too fast (BCG over-run). rnd doesn't get enough time to pop into proper position in mag to get picked up by bolt. Heavier buffer helps to slow down the BCG from overgassed situation. You have a long barrel, can, pistol gas so probably way overgassed. AGB is probably the solution. You didn't state the load, my guess is light starts faster then the heavier, over-run situation.

[Gtek]

Have you pulled a chambered round and looked at nose, maybe jamming in ramps? Right angle of attack, right size nose, sticking. Checked upper to extension transition for smoothness?

[Lloyd Smale]

ya the noses show marks from hitting but then any of the problems causing stove piping would result in the noses being hit. Ones that don't jam don't show any contact though. I did do a bit of smoothening the ramps though and haven't tried it since.

[Lloyd Smale]

2 possible problems. Bolt doesn't go far enough back and carrier tries to chamber the rnd - doesn't work most of my stove pipes are from this (short cycling). Other is cycling too fast (BCG over-run). rnd doesn't get enough time to pop into proper position in mag to get picked up by bolt. Heavier buffer helps to slow down the BCG from overgassed situation. You have a long barrel, can, pistol gas so probably way overgassed. AGB is probably the solution. You didn't state the load, my guess is light starts faster then the heavier, over-run situation.

your making sense there. When I had all the problems I was shooting full power loads with a can on it. I think maybe it is either being over gassed or possibly just the crud that built up real fast from shooting full power through a can. Gun was filthy after just 30 rounds. My first thought was a lighter buffer or spring and pulled a weight out of one of my 3 oz buffers but then got thinking and maybe im just compounding the problem running the bolt to fast. Guess it will have to wait till some of this snow goes to really find out. Another odd thing is It runs like butter if you run it by hand. It never stove pipes doing that. But then every time ive tried function like that the gun has been clean and oiled. I ran into the same filthy gun malfunctions running a can on my 9mm ar15 too. I guess for the most part im not that conserned about using a can on this 16 inch gun. It will be more of a hunting gun then anything else. I am building a 300 bo pistol though and will want to run a can on that one.

[Baltimoreed]

My rifle, a Seekins upper/lower and a Wilson ss bbl, liked my v-max loads but not my pc loads [pc made the noses too fat]. Gave up on it for a while and am working on other projects but am learning through others. I will get back to it later this year.

[jmort]

There is a discussion going on for a dedicated 300 BO mold.
See Group Buy Discussion sub-forum.

[mattw]

I have had great success in the 150 grain cast range with the NOE 311-152-SP. But, like you wanted to go a little lighter. This weekend I cast and test fired the Lyman 311359 at 117 grains. I have a very short throat and fairly tight chamber in my barrel, it is a 16" with pistol gas system. I love the gas system, have not had any issues with any bullet weights. I have had issues with nose diameter, if the bullet is larger than about .305 ahead of the driving bands, it will not work. So, the 311359 was seated basically within a couple thousands of the the front of the front driving band with a healthy charge of 4227 and fed well at about 2000FPS.

My rifle has an H1 buffer and stock spring. The H1 was added to slow down the bolt just a little, this was done early on when shooting 110 grain jacketed bullets and the ejection was out of sight at about 2 o'clock and 20 feet! The H1 has brought all of my ejections to between 3 and 4 o'clock and about 12 feet. I have not started to work on the feed ramps on the barrel yet, but I think I will because from time to time the bullets get slightly deformed with the 117 being the most obvious. I have been using P-mags as D&H(?) have real feeding problems with the 150's. So far, I have only had 1 FTF after initial load workups. 4227 really seems to be an ideal powder in my platform, H110 seems to pressure spike to soon and I have not been able to locally source 1680.

236483

[Lloyd Smale]

im looking for a full power plinker. Don't care to much about a HP and would really want a gas check and a crimp grove.
There is a discussion going on for a dedicated 300 BO mold.
See Group Buy Discussion sub-forum.

[popper]

I use the 31-142C, PB FN & no crimp groove in my pistol & carbine, no problems. I've pushed it to 2100. I've used the hornady 110 half jacket with pistol powder in the pistol, still won't cycle and they are super. With a long barrel and can, pistol port pressure is high and lasts for a long time so bolt unlocks early, case pushed back and action gets real dirty. Heavier boolit will allow better case burn, reduce soot and although pressure spike will be higher, it won't last as long. Heavier buffer slows bolt speed and unlock time.
I modified the 31-165 design, selected the weight for max energy (1k '-#) and fps (trajectory), FN for hunting & reasonable BC. PC so no LG. Funky base so culling for bad bases is much easier (and it seats like a charm). Actually it started as a 'plinker' 31-145C) for SIL's 308MX. At 50 yds & 1875 fps it was as accurate as a max load 31-165A 308MX (2400 fps). It worked so well I modified it for BO.
I'd stick with the 150 that works, not much cost for the extra alloy or powder.
edit: actually as I sold the 165A and MX moulds, thinking of redoing my 401-165 FB mould with the same mods for PC.

[Lloyd Smale]

how many oz buffer do you recommend? can I just pull apart my 3 oz buffer and add another weight? ive got a collection of buffers I can pull apart.
I use the 31-142C, PB FN & no crimp groove in my pistol & carbine, no problems. I've pushed it to 2100. I've used the hornady 110 half jacket with pistol powder in the pistol, still won't cycle and they are super. With a long barrel and can, pistol port pressure is high and lasts for a long time so bolt unlocks early, case pushed back and action gets real dirty. Heavier boolit will allow better case burn, reduce soot and although pressure spike will be higher, it won't last as long. Heavier buffer slows bolt speed and unlock time.
I modified the 31-165 design, selected the weight for max energy (1k '-#) and fps (trajectory), FN for hunting & reasonable BC. PC so no LG. Funky base so culling for bad bases is much easier (and it seats like a charm). Actually it started as a 'plinker' 31-145C) for SIL's 308MX. At 50 yds & 1875 fps it was as accurate as a max load 31-165A 308MX (2400 fps). It worked so well I modified it for BO.
I'd stick with the 150 that works, not much cost for the extra alloy or powder.
edit: actually as I sold the 165A and MX moulds, thinking of redoing my 401-165 FB mould with the same mods for PC.

[popper]

Yes, the number represents the tungsten weights. There is a mfg. that just sell weights alone but for the same money you can get the entire buffer.

[Lloyd Smale]

I pulled a carbine buffer and rifle buffer apart. took the rubber spaces out of the carbine buffer and found a full length weight wouldn't fit. I ground down till it would just fit and it only raised my weight from 3 oz to 3.35 so it was hardly worth all the effort. Ended up just ordering a 4 oz carbine buffer to try. It was only 20 bucks. Wonder If a guy couldn't cast some out of hard lead like monotype or just pour a bit into the buffer to replace one of the weights or even use a 50 cal cast bullet.

[popper]

3.0 oz, 3.8 oz (H), 4.6 oz (H2), 5.4 oz (H3) & 6.5 oz (HSS). I've heard of lead shot and poured for weight but not commercial.

[Lloyd Smale]

shots a good ideal. Ive got a bag of #9 shot that I haven't found a use for other then snake loads in handguns.
3.0 oz, 3.8 oz (H), 4.6 oz (H2), 5.4 oz (H3) & 6.5 oz (HSS). I've heard of lead shot and poured for weight but not commercial.

[Texas by God]

Maybe lighter or heavier than you want but the Lee C309113F and the C309150F ran perfectly in my .300 seated with the ogive in the .223 shoulder length. My problem was lack of accuracy. My 16" .300 BO is carbine gas and buffer.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[skeet1]

Lloyd,
You didn't say what powder you were using? I wonder if changing to some other powder that may change the amount of gas supplied to the action might be called for. I was wanting to use WC 820n for my rife because I have a lot of it. It wasn't kicking the action back far enough even with loads that seemed to be high pressure. This powder is on the very edge of being too fast. I changed to slower burning powder, H110, Shooters World Blackout and Little Gun and the problems went away. Just a thought.


Ken

[Lloyd Smale]

so far ive been playing with wc297. its a bit slower then 110 and a bit faster then 1680. closer to 110 though. Is your gas system pistol length?

[skeet1]

Lloyd,
No, mine is a carbine. WC 297 should be just fine so that should not be a problem.

Ken

[Lloyd Smale]

im not a powder expert. I wondered if the fact 297 has a flash suppressant in it was doing something. But then so does power pistol and its never caused problems in any semi auto handgun.
Lloyd,
No, mine is a carbine. WC 297 should be just fine so that should not be a problem.

Ken

[Stuckcase]

Heavy buffers. Com
Heavier mass more often makes feeding problems disappear. Heavier buffers can lead to bolt bounce however. This issue can be problematic. Easier solution may be an adjustable gas block.