Charges and Seating Depth

[JFettig]

I measured my port and it is .083" according to my calipers, I think tp555 driled it to .08 if I remember correctly.

I'll look into AA#9. Not sure if I know anyone who has any. Until I buy or find some, I'll stick with supersonic loads and take your advice against opening it up. The plan was to open it to .090 max.

Thanks,
Jon

[pug]

Each gun is different but I would think you should be able to cycle subsonic loads down to 180gr bullet weight with that. You had mentioned shooting a lot of 147gr bullets and I am pretty sure it will not cycle those subsonic unless you open it up. Opening it up will allow you to cycle the lighter bullets but on the other hand you shave more bullet and will require adjustable gas to shoot supersonic.

[320pf]

Originally Posted by JFettig

I measured my port and it is .083" according to my calipers, I think tp555 driled it to .08 if I remember correctly.

I'll look into AA#9. Not sure if I know anyone who has any. Until I buy or find some, I'll stick with supersonic loads and take your advice against opening it up. The plan was to open it to .090 max.

Thanks,
Jon

I have all on my 300-221 fireball barrels drilled out to 0.083. The gas ports in my rifles is in the pistol position and I can reliably shoot 165 gr bullets sub-sonic.

Pug is right on about the suggestion to use AA#9. That is the powder I use. I have also have some success with Alliant 2400.

You now have my curiosity peaked. I wonder if I can get my rifles to shoot 150-155 grain bullets in the sub-sonic realm? I think that I will give it a try this weekend.

320pf

[pug]

My notes from early on indicate that I was using H110 with the 150s. That was before I drilled out the port I am pretty sure. They list 150gr set to cannelure with 8gr H110 would cycle but not lock back. 8.2gr would cycle but not lock back. 8.5gr would cycle and lock but went supersonic after barrel warmed up. The only notes on #9 I kept seem to be for the 255gr hollow points. 8.9gr of #9 would push the 255gr HP at 1033 fps. Doesn't do you much good but thought I would throw it in there.

[JFettig]

I took some friends to the range to shoot up some of my ammo and I brought the whisper along to put a few more rounds through it... forgot the subs though.

I put about 10 rounds through it, 4 of them failed to eject, some failed to extract... I had my .223 AR with so I decided to pull the bolt carrier out of that and put it in this just for the hell of it and sure enough, it ran perfectly. I then tried to put the BC I had in the .300 in the .223, released the bolt and it would not go into battery all the way! It was hell to get it out! I think I found the culprit, I'll be sending that bolt carrier back to DPMS as soon as I get it back to my dealer.

If all goes well this week, I'll load up some more subs and see if I can get them to cycle.

Jon

[Ron458]

Jon, could you measure the bolt lugs? I wonder if they are longer & hitting the brl & extension inside. Need to keep an eye on the DPMS bolts! Ron

[JFettig]

Originally Posted by Ron458

Jon, could you measure the bolt lugs? I wonder if they are longer & hitting the brl & extension inside. Need to keep an eye on the DPMS bolts! Ron

Just measured the lugs out, .739 diameter on the bolt that works and .741-.742 on the bolt that doesn't. The other dims were all the same.(length of the lugs, depth of bolt face, etc.)

Both will chamber the dummy rounds just fine and they extract smoothly in my .300, I dropped in the one dummy I had made up in .223 and it closed real tight, I have a dirty chamber I see now, I'll clean that up tonight and see if I can figure something out. The chamber in the .300 is clean, not sure what the deal is. I'll take it out with the other carrier next time I go out and see if I can get any stoppages out of it.

Jon

[Ron458]

The extension has room for the .742 so it should be fine. Another idea would be to switch carriers to be sure it is the bolt. Let us know what you find out. Ron

[JFettig]

I picked up some #9,
What do you think of these charges from Acurate?
http://www.accuratearms.com/data/Per...0page%2076.pdf

I only have 220s right now, I figured I'd load a few in that area to chrono for next time I go out to the range.

Jon

[pug]

Loads look good to start with. As far as the bolt if you have a dial caliper run the step end down into the cup of the bolt face and measure the depth. See if the one giving trouble is equal or not as deep as the other.