Issues with 4 Molds and Chambering - Sizing Right?

[psychbiker]

The 4 molds I have for my Blackout AR are - 311365 PB, 311291 GC, Lee 312-155 GC, 311413 GC.

I've casted and sized to .310 A LOT of these boolits, like 30+ pounds. Plan was to use them for blackout and an M1A.

I made some dummy rounds for the blackout just now and struggled to get any to cycle. My manual lists COAL for all at 2.000 and above. There's no way that's happening. I was able to get a 311365 to chamber and eject at around 1.980". These fit and drop from a Sheridan gauge.

I'm using a Lee Taper Crimp.

Any ideas what could be the problem? Do I have to load these deeper? What about taper crimping? I run the bullet up in the ram and turn the crimp die until it stops, lower ram and then add a quarter turn.

Maybe size them to .309? I'd have to order a new sizer as I polished mine out to .310.

The 311291 did not chamber from the mag well either, it was awfully short. I think it's a good round for the M1A.

[r.tenorio671]

...in your other post you mentioned you have a Sheridan gauge, if it is the slotted version you can drop your loaded cartridge in it and see where exactly the issue is.

FWIW, when I use the unsized .310 AK bullets, the larger diameter of the bullet contacts the chambers leade sooner, requiring them to be seated deeper. If you seat deeper, you will need to decrease the powder charge correspondingly.

[psychbiker]

...in your other post you mentioned you have a Sheridan gauge, if it is the slotted version you can drop your loaded cartridge in it and see where exactly the issue is.

FWIW, when I use the unsized .310 AK bullets, the larger diameter of the bullet contacts the chambers leade sooner, requiring them to be seated deeper. If you seat deeper, you will need to decrease the powder charge correspondingly.

I do have the slotted gauge. Seating deeper and varying the crimp has worked for them to drop cleanly from the sheridan gauge. This doesnt mean they will chamber though in some cases.

I'm looking to borrow a 309 sizing die and see if thats the problem. I was able to load some 311365 to over 2.000" last night. Going to see if it chambers.

It may be an order of operations thing, too much crimp and not seating deep enough.

I've read maybe reaming it with a 'finish reamer' or a 'chamber reamer' may help. The plan is to shoot mostly cast bullets, especially now some insane ammo laws will be in play in 2017 here in california.

[r.tenorio671]

...in your other post you mentioned you have a Sheridan gauge, if it is the slotted version you can drop your loaded cartridge in it and see where exactly the issue is.

FWIW, when I use the unsized .310 AK bullets, the larger diameter of the bullet contacts the chambers leade sooner, requiring them to be seated deeper. If you seat deeper, you will need to decrease the powder charge correspondingly.

I do have the slotted gauge. Seating deeper and varying the crimp has worked for them to drop cleanly from the sheridan gauge. This doesnt mean they will chamber though in some cases.

I'm looking to borrow a 309 sizing die and see if thats the problem. I was able to load some 311365 to over 2.000" last night. Going to see if it chambers.

It may be an order of operations thing, too much crimp and not seating deep enough.

I've read maybe reaming it with a 'finish reamer' or a 'chamber reamer' may help. The plan is to shoot mostly cast bullets, especially now some insane ammo laws will be in play in 2017 here in california.

....IMHO, modifying your chamber by reaming it isn't the ideal way to go, especially for those times when you shoot factory ammo that is made to SAAMI specs. With deliberate measurements and adjustment of your dies, your handloads can be configured to meet the specs/dimensions that your chamber requires.

As the Sheridan gauges are cut with a chamber reamer to SAAMI specs (closer to minimum specs), when you take one of your loaded cartridges and drop it into your Sheridan you want to verify that it drops to the proper depth, i.e.; the case rim is at proper step mark, the shoulder corresponds to gauge, the trim length corresponds to gauge and bullet seating depth (which can be ogive type shape dependent) doesn't protrude too far into the leade section of the gauge preventing complete and full chambering. If you are sizing to .310 AND coating, the diameter of the bullet will be greater by the thickness of your coating, thereby decreasing the depth that it will fit into the chamber.

I would suggest you take a bullet from each mold and measure what the MAXIMUM COAL each would be then adjust as necessary to ensure proper fit to magazine and feeding from magazine. The Hornady OAL and Comparator tools are recommended to determine this and verified by your Sheridan once you construct a cartridge based on the results used. After finding that right combination, then you can begin determining powder charge weights, keeping in mind different powders will have different weight requirements and results for each of the bullets from each mold.

Good luck.

[psychbiker]

...in your other post you mentioned you have a Sheridan gauge, if it is the slotted version you can drop your loaded cartridge in it and see where exactly the issue is.

FWIW, when I use the unsized .310 AK bullets, the larger diameter of the bullet contacts the chambers leade sooner, requiring them to be seated deeper. If you seat deeper, you will need to decrease the powder charge correspondingly.

I do have the slotted gauge. Seating deeper and varying the crimp has worked for them to drop cleanly from the sheridan gauge. This doesnt mean they will chamber though in some cases.

I'm looking to borrow a 309 sizing die and see if thats the problem. I was able to load some 311365 to over 2.000" last night. Going to see if it chambers.

It may be an order of operations thing, too much crimp and not seating deep enough.

I've read maybe reaming it with a 'finish reamer' or a 'chamber reamer' may help. The plan is to shoot mostly cast bullets, especially now some insane ammo laws will be in play in 2017 here in california.

....IMHO, modifying your chamber by reaming it isn't the ideal way to go, especially for those times when you shoot factory ammo that is made to SAAMI specs. With deliberate measurements and adjustment of your dies, your handloads can be configured to meet the specs/dimensions that your chamber requires.

As the Sheridan gauges are cut with a chamber reamer to SAAMI specs (closer to minimum specs), when you take one of your loaded cartridges and drop it into your Sheridan you want to verify that it drops to the proper depth, i.e.; the case rim is at proper step mark, the shoulder corresponds to gauge, the trim length corresponds to gauge and bullet seating depth (which can be ogive type shape dependent) doesn't protrude too far into the leade section of the gauge preventing complete and full chambering. If you are sizing to .310 AND coating, the diameter of the bullet will be greater by the thickness of your coating, thereby decreasing the depth that it will fit into the chamber.

I would suggest you take a bullet from each mold and measure what the MAXIMUM COAL each would be then adjust as necessary to ensure proper fit to magazine and feeding from magazine. The Hornady OAL and Comparator tools are recommended to determine this and verified by your Sheridan once you construct a cartridge based on the results used. After finding that right combination, then you can begin determining powder charge weights, keeping in mind different powders will have different weight requirements and results for each of the bullets from each mold.

Good luck.

Thanks for the reply. I'm definitely ordering that OAL and comparator today. I also emailed a reputable reaming company and he said a .311 throater would be a good idea and his reasoning is the increased use of converted 223/556 cases. They thicker cases apparently and causing loading issues.

I size after the first coat then coat again. I'm going to try size a few again and see how they load, that may do it. I may not have to size to .310 either but everyone I read that shoots cast in blackout and 308 size to .310.

[gunfan2]

Since you mentioned the brass issue, what brass are you using? I have found when converting brass from R-P 223 brass that I have to anneal the brass in order for them to size properly and not spring back. Just a thought, and it doesn't take much of a difference in your chamber and your gauge that will prohibit the round from chambering in your gun!

[reloader64]

Take a fired unsized piece of brass and measure the inside neck diameter.
This will tell you how big your bullets can be.
Or take a bullet and insert it into a fired, unsized piece of brass. If it goes in easily, you can use it.
If you have to press it in, the bullet is too big for your chamber using that brass.

Brass thickness can and will vary mfg to mfg and lot to lot.

[reloader64]

I have the Lee 155 2r mold and after powder coating, the nose portion is to big to use in my rifle.
It will chamber, but good luck getting it back out.