Lee 309-113f used for 7.62x39

[DrCaveman]

Anyone tried this?

I assume I should lap & beagle the mould at least enough to give me .311-312 diameter. Since i have never yet done any beagling, i like the opportunity to learn a new skill. Any other adjustments need to be made?

The gun it will shoot through is a CZ 527 carbine.

Thanks

[DrCaveman]

Also, can anyone comment as to why this boolit has a higher BC than the round nosed boolit of the same shape (120 gr)?

Also, go Ducks

[Nobade]

Watch the headspace on the cases you use. I did the same thing you are contemplating, and after a couple of loadings the cases got too short to fire. The pressure was so low the primer was shoving the cases into the chamber. If I loaded it hot enough to not do that, I had no accuracy (velocities upwards of 2200 fps at that point) Otherwise it works great, keep the speeds around 1800 fps and it shoots fine. But there is that headspace issue. I'd try Bullseye or something similar first and see if you can get the pressure up without too much speed.

[felix]

Yeah, Nobade is correct. However, BullsEye is too fast for that case volume for the purpose of what is needed for headspacing. It's a timing issue. Might work without overload for velocity desired, but 4756 is my preference. Herco is the same speed as 4756 but Herco can be finicky at the same required loading as 4756 to do the same job. It's an acceleration curve issue. ... felix

[runfiverun]

800-x might work well in this instance too,
it's bulky and just a step behind herco in burn rate.
it burns well in low pressure situations and gives a good gas volume.

[felix]

Agree. ... felix

[DrCaveman]

Interesting. Do you think this same low pressure issue could have caused my primer separation when using Lil gun with 160 gr spitzers?

Sounds like I should try some new powders. I was figuring I would use unique or 2400, but I havent really thought about the load yet. Also thought RL7 might work, but again, not thought it through nor researched it. 800-x is listed for many of my other favored calibers so maybe worth a try.

Thanks

[felix]

Yes, a low pressure at the wrong time issue. ... felix

[runfiverun]

800-x is an often overlooked powder with many good attributes.
it makes really good steel shot waterfowl loads and is excellent in the 44 mag too.

[Larry Gibson]

I'd start with well fire formed cases and NS only. Also if your cases use he LR primers use a LP primer with the least brisance such as the Remington LP primers. I fired 50 shots of 2.7 gr Bullseye under the 90 gr TL314-90-SWC in one R-P case with SP primers and had no reduction in headspace. Rifle was a Mini MK X Mauser. The headspace will only set back a bit if the firing pin blow/primer hardness does not bump the rim out from under the extractor. I don't recall that the CZ has a plunger ejector so the case headspace will/can only length to that allowed by the extractor.....IF the firing pin extrusion is correct and the extractor holds the case.

I shoot thousands of the 2.7 gr bullseys load through my 7.62x39 and find Unique a very good powder for the 311316 which is GC'd. I find the FB'd 32-20 bullets of 100 - 120 gr do well soft cast over 2.7 - 4 gr Bullseye keeping the velocity subsonic in the 800 - 1050 fps range.

Larry Gibson