Sorting boolits by weight?

[kappy]

I'm casting for a Finn Mosin (M39) with an RCBS mold. A friend of mine now has me weighing out my bullets.

First... I'm not sure how much I should expect my bullets to vary. The mold casts somewhere between a 195 and 200 grain bullet. I get the largest number of them in the 197-198 grain range.

My questions are...

1. How exacting should I be when I measure them? Right now, I'm going by the 1/2 grain. For instance, today I only loaded bullets weighing in between 197 and 197.5 grains. Should I be going by 1/4 grains? By a tenth of a grain?

2. And how much can I expect this to do in closing up my groups?

3. Finally... I've been indexing the seam of my bullets to a line on the case. I'm wondering if it's even worth doing, when I consider that I don't know which seam is which...

[kappy]

Oh... and since I'm feeling greedy... I'm using SR4759 (22 grains) ... anyone have another recommendation?

[sisiphunter]

in my experience...a heavish bullet like a 200 gr. for general use I would say a variance of 1/2 to 1 gr difference is fine. i am usually closer to the 1 gr variance...now for my 223 where the boolit omly weighs 55 gr a difference of 2 or 3/10 max...groups should definitly get better. as to how. well depends on how good or bad they were to start...with my old enfield i expect 2-3" groups at 100 m. with my scoped 223 i expect under 1" easily at 100m.

as for lining up a seam?? you mean when loading into the brass....no not necessary at all.

and sorry. dont load this cal. so no help there.

[WHITETAIL]

Kappy Welcome to the forum!
Keep checking back at this question.
I am sure there are guys and gals
that have an ans. for you.:guntootsmiley:

[happyret65]

I shoot the M-39 now after having a bad experience with the 91/30 rifles. If your RCBS mold is a 303 cal you will be okay. If not you need to cast with a mold in the .313 to .314 dia range to get the best results. I have two M-39s and both slug out at about .310. I shoot a flat base using a .313, 215 grain soft lead bullet and use 4759 powder. With no gas check I stay under the 1600 range. I try to get bullets close to the same weight. Hope this helps.

[kappy]

Thanks for the feedback.

I am also shooting the M39. I have a 91/30 which I've scoped... and am probably going to have rebarreled... I may go with .308?

My mold is for the 303. My slug is .310. I'm gas checking and lubing with Alox... which is doing a fairly decent job.

I shot about 40 rounds today. I'm getting... oh... about a 2.5" average group when I do my job decently. I don't know if that's good or not. The load was 22 grains of 4759.

I'm not sure what the speed is, but I'd imagine it's below 1700fps. My recipe book doesn't have many speeds listed.

Out of curiosity, happyret65, what's the best group you're getting with casting in the m39? Oh... and tell me that is not an awesome rifle! I get compliments on it every time I take it to the range.

[kappy]

in my experience...a heavish bullet like a 200 gr. for general use I would say a variance of 1/2 to 1 gr difference is fine. i am usually closer to the 1 gr variance...now for my 223 where the boolit omly weighs 55 gr a difference of 2 or 3/10 max...groups should definitly get better. as to how. well depends on how good or bad they were to start...with my old enfield i expect 2-3" groups at 100 m. with my scoped 223 i expect under 1" easily at 100m.

as for lining up a seam?? you mean when loading into the brass....no not necessary at all.

and sorry. dont load this cal. so no help there.

2-3? So I'm right in there at the moment. I asked someone at the range what I should be "shooting" for, and he said "a one hole group." He did have a bit of grin on his face at the time, though.

And thanks for the info on the seams. I thought that might have been a bit too anal retentive.

[MtGun44]

Isn't everyone ALWAYS shooting for a 1 hole group? Most are not going to get it, but it is
still the goal.

If you REALLY ARE trying for a one hole group, then you need to orient your brass, orient
your boolits, sort to 0.1 gr, etc. Even then - probably won't get there. How about breech
seating?! You could have a tool made up to line up the boolit and you could breech seat
each boolit and orient them each time, and use only one case, also oriented.

OR you could just sort them to around 1 grain which is 1/2% variation with a 200 gr boolit,
and load normally and have a lot of fun with a bit less accuracy.

Bill

[sqlbullet]

I mainly shoot semi-auto handguns and WWII and cold war era surplus arms (Garand, CETME, etc). I have no delusion that I am gonna get one hole groups from most of these guns.

I do weigh rifle bullets most of the time. Generally I do so at night while I watch a show with the wife and kids. Anything off by more than a grain I inspect, and almost always find a defect I hadn't previously seen.

Pistol bullets, I look at the base when the mold opens, and give them a quick once over when sizing them. If the base is bad, rounded corners, etc, it gets dropped in the sprue pile. If they are badly mis-shaped at sizing, they get rejected.

I shoot potato/apple sized objects at the smallest with cast bullets. Handguns I will shoot out to 50 yards or so at a potato. Hit them 40-50% of the time with my 10mm. Rifles generally out to 100 yards. Hit rates are about the same. In both cases this is standing or kneeling, no support.

If you are looking for one hole groups, then you better get out your scales.

[fredj338]

I only weigh hunting bullets or extreme accuracy bullets. The sizeof the bullet matters. In a 44 or 45, 1gr either way is going to be well within accuracy requriments. I weigh mostly to fund the ones that may have an internal void. They show up as 4-5gr lighter.

[kappy]

If you are looking for one hole groups, then you better get out your scales.
Yeah... I have no delusions there. Even with an expensive .223 bench rifle and scope, there are a lot of guys who won't get a one hole group.


I only weigh hunting bullets or extreme accuracy bullets. The sizeof the bullet matters. In a 44 or 45, 1gr either way is going to be well within accuracy requriments. I weigh mostly to fund the ones that may have an internal void. They show up as 4-5gr lighter.

I have a few like that. I was planning to shoot them anyway... but now that I know they likely have holes... I'll just reincarnate them.