What kind of tolerances are acceptable for accurate handloads in 45 ACP?

[Lone_Gunman]

I am new to reloading (have loaded a grand total of 100 rounds of 45 acp so far), so forgive me if this is a stupid question.

I am loading a 238 bullet over 4.8 grains of Win 231 to an OAL of 1.265 inches.

I am using the Lee pro auto disk to charge the cases with powder, and lee dies to seat and crimp the bullets.

When I measure the amount of powder being put in a case, it is usually 4.8 +/- 0.1 grains, but occasionally is as low as 4.6 grains. Is this a problem? Will a .1 to .2 grain difference in powder make a significant difference in accuracy shooting a handgun at 25 yards?

Also, the overall length of 1.265 is +/- .003 inches. Sometimes its as little as 1.262, sometimes 1.268. Is this a problem?

 

[The Bushmaster]

No. Unless you have radically modified your .45 ACP. The .45 ACP is very forgiving unless it is tweeked for absolute accuracy. My favorite loads for my Colt .45 ACP with mild modifications of Wilson Combat parts. is 6.0 grains of W-231 under a 185 grain Remington JHP (NOTE: This is a near maximum load. Aproach with caution). Bullet seating is 1.250. I have loaded 230 grain FMJ (ball) and seated the bullet at 1.280 with no problems...If they fit in the magazine and will chamber fully there should be no problem. My above mentioned loading with the 185 grain JHP holds a 2" or less at 25 yards. I also weigh every powder charge I drop. I would amagin that I'm within selected weight by +/-.1

 

[taliv]

we usually say "start 10% low and work up".

that should give you an idea of how much it takes to make a difference that can be dangerous.

 

[The Bushmaster]

Am I being chided??? 6.0 grains of W-231 is 11% below maximum powder weight by Winchester load manual...And .1 grain below Lyman's 48th edition. Also .3 grains below Sierra's 5th edition. Hence the near maximum load warning.

 

[YellowLab]

No scale out there is gonna have repeatable weights within .1 grain every time.

If you are off .3-.5 then start worrying, but the quoted tolerance for just about every scale out there is .1-.2gr so at worst your scale is within tolerance.

Fixed cavity measures will also suffer from how the powder lays in the cavity... some powders are worse than others (ball beeing the most repeatible, extruded or stick the worst).

 

[taliv]

heh, no chiding bushmaster. i was only responding to the original question

 

[The Bushmaster]

Oh...O K

 

[dmftoy1]

I don't know if this helps or not . ..but what I tend to do is shoot them over the chrony and if I'm getting a low standard deviation for two or three 10 shot strings then I figure I"m doing ok. I do try to be very consistent in my powder drops, etc but I think the measure I use says +/- .1 grain.

I do see the variation you're seeing in seating depth. It doesn't seem to affect accuracy too much.

Have a good one,
Dave

 

[Clark]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

Range report 4-3-04

Handloading:
.467" Lee Carbide die, large rifle primers.
Brass is pounded into sizing die further than can be pushed with shell
holder and then pounded out.
Brass is primed, charged, bullet seated, loaded ammo full length resized
to remove bullet base bulge.
Brass springs back to .469" and is interference fit in chamber, but lead in bullet springs back less.

Gun:
1903 Turk Mauser, Shilen .451" groove 26" bull barrel blank, 40X Leupold
scope. Throated until bolt just closes on 1.275" OAL 230 gr. FMJ. .469" reamer cut until bolt just closes on prepared case.
SAAMI chamber is .4796 to .4836" at rear and .474 to .478" at mouth.
SAAMI ammo is .470 to .476" at rear and .469 to .473" at mouth
SAAMI chamber and SAAMI ammo have, then, .001 to .0136" clearance
This rifle chamber is .469" at rear and .469" at mouth
This ammo is .469" at rear and .469" at mouth
This rifle and ammo have, then, 0 clearance, more like a 6mm PPC .262" neck

Computer calculation:
Quickload thinks it is 55 kpsi 1700 fps at muzzle, total drop = 6.9", 967 fps at target

Range results:
4" 20 shot group, rapid fire at 100m, everyone could hear the bullet hit the plywood target back, through hearing protectors. Plywood could be observed flying out the back of the target through the scope.

 

[Lone_Gunman]

Clark,

Huh?

 

[Clark]

I gave some 45acp tolerances in diameter that affect concentricity that I changed for accuracy.

 

[halvey]

When I measure the amount of powder being put in a case, it is usually 4.8 +/- 0.1 grains, but occasionally is as low as 4.6 grains. Is this a problem? Will a .1 to .2 grain difference in powder make a significant difference in accuracy shooting a handgun at 25 yards?

You will be ok. If +/- .1 or .2 grs of powder makes that much of a difference in accuracy, that is not a good gun.

Clark
Thanks for the data - good stuff to those who understand.