cartridge length

[remmag]

hey all
i have just loaded my first batch of bullets, 45 apc
in the lynman manual they show at the beginnning of the section on 45 apc a lover alll length of 1.275 and then at the end of each load group they show an oal measurement , this measurement is less than the 1.275 at the beginning ,on my loads 200 grain led bullet the oal is 1.235
is the one they show at the beginning the maximum and the one with each group the minimum cartridge length
i set my seating depth right at 1.265
i cant find anywhere in the manual it says minimum and maximum
thanks for any help

 

[EddieNFL]

The 1.275" on the description page is the supposed longest COAL a .45ACP can handle. The COALs listed with the load data is for an individual projectiles. For instance, the 185 jacketed SWC is 1.135. That may be the optimum COAL for accuracy, or it may not feed properly if shorter or longer. Also, loading longer could mean not enough bullet is in the case.

 

[Randy1911]

The 1.275 is the maxinmum SAAMI bullet length for that cartridge. Each bullet will have it's own optimum length. Example, a 230 gr RN FMJ bullet will be best at 1.260 - 1.270. However a 200 gr LSWC (a #68 H&G) will preform best at 1.250. The reason they list the bullet OAL is that different OAL can change the pressure of the cartridge. If you use a different OAL you need to work up your load carefully. But you should be doing that already.

 

[remmag]

i just measured my loaded rounds , they measure 1.270 and according to the book for a 200 grain led bullet using unique powder 6.0 grains the oal should be 1.235
do i need to seat the bullets down to that
if so ,when i seated using a lee die i put a light crimp on them (using the die that seats the bullet and crimps at the same time) can i seat the bullets down to 1.235 with that crimp on them
i am sorry for all the questions, i am new and these are the first rounds i have loaded
according to what i have read a light roll crimp was needed to shoot in an automatic and i am shooting a smith 45
thanks again

 

[rfwobbly]

remmag-
The "red lights" are at "pressure", "chamber fit", and "magazine fit". There may be additional "yellow lights" concerning feeding based on the bullet nose shape.

• You can always go longer without pressure fears, as long as you do not exceed the SAAMI max. If you exceed the max, then the rounds won't fit in the magazine.

• So the last test would be to drop one in your naked chamber and see if it spins freely.

Since the crimp on a 45ACP is a taper crimp, there should be no issue with seating the bullet slightly deeper by running them back through the press IF the crimp is properly applied and sized.

 

[remmag]

thanks for the responce
i will tell you ther is alot more to this than meets the eye, i have read up (i think) on crimping and have not read any thing on crimping being sized, would you mind explaining

and if there is anyone in the knoxville ,tn area that would be willing to give some pointers to that would be great
thanks again

 

[rcmodel]

You need to seat to the recommended OAL for the bullet you are using until you gain a better understanding of things.

Most lighter bullets have the full diameter running up to the ogive or nose taper of the bullet.
Seated too long, this full diameter will stick out of the case too far and run into the rifling in the barrel before they will fully chamber.

Take the barrel out of your gun and use it for a guage to check chambering freely.

You need to at least seat deep enough the bullet doesn't jam into the rifling before they are all the way in the chamber.

rc

 

[ka041a]

At +.035" I wouldn't be worried about shooting them. Depending on the firearm you're shooting, you should have enough freebore, so I think you're okay. I would certainly check that, though. The thing I would worry about is working on live rounds. Once the cartidge is loaded and crimped, i personally would use a bullet puller and start over again. Just my opinion...

 

[rfwobbly]

thanks for the response
i will tell you there is a lot more to this than meets the eye, i have read up on crimping and have not read any thing on crimping being sized, would you mind explaining

remag -
Certainly glad to help. The crimp on most auto cartridges is a taper crimp. The taper crimp is used to completely erase the "belling" you used to get the bullet into the case during the bullet seating process. Find the cartridge drawing in your reloading manual for the round you are working on, and look for a dimension right at the case mouth. Those dimensions come from SAAMI and are the MAXIMUM cartridge dimensions. If you want your reloaded cartridge to fit all chambers (especially your own) it's important then to be .001-.002" smaller than that number. When you go more than ~.002" then you start to get into trouble with disfiguring lead and plated bullets.

Remember, you're not trying to retain the bullet or mar the bullet's sides, you're simply trying to make sure the belling is completely gone. Doing things this way will make your reloads drop right in a "cartridge gauge" under its own weight, and from this you'll know the reloaded case will fit in any chamber.

Also remember that the ultimate test is your own barrel. You may have a super-tight chamber, or you may have a chamber that is loose for reliability or worn loose from age. What ever the case, you want YOUR finished round to drop into YOUR clean, naked (removed from the gun) barrel under it's own weight. You should not have to tap on the cartridge, push, "gently persuade", or any such foolishness.

IME, if the round fully seats in the chamber, usually you'll hear a faint ringing sound from the barrel. That's the mouth of the case contacting the end of the chamber exactly as God and John Moses Browning intended. Secondly, if the round will spin freely in that position, then you have some assurance that the ogive of the bullet is not engaging the rifling, which is always a safety concern.

So there you have it. Hope this helps!

 

[remmag]

RFwobbly
I took measurements off my loaded cases ,at the back they are .469.5 and at the very front they are 4.69.5, i will assume that indicates i have atleast taken the belling off the mouth of the case
i did seat 1 bullet down to 1.235 oal and it dropped fine in to my removed barrel with no problem and heard the sound you spoke of. it was however a little difficult to spin it but that seemed to be because of the contact from the rim of the case seating on the front part of the chamber
i did however notice the book showed the back of the case at .476 and the very front at the crimp to be .473. for the hell of it i measured a factory loaded round and at both the back and front the measurements were.470 indicating these had no crimp
question with my front and rear measurements being the same am i safe to seat the bullets with out taking them apart and starting over
also will you get different measurements as indicated above from different manufacturers
and thanks all for the help

 

[rfwobbly]

• So the SAAMI numbers for the case mouth are 0.473" (12.01mm) as per above. 0.473" minus .002" equals .471". If anything you are over-crimping, so you may well wish to back off a wee tad if you are using lead or plated bullets.

• Granted, spinning a test round is not the easiest thing sometimes. Grab it lightly with a small pair of pliers and slowly rotate it back and forth. Then when you pull the cartridge out, see if there are any marks on the ogive. This test may be aided by using a marking pen (Sharpie) to apply color to the nose of the bullet, then see if the color is removed.

• So your factory round is .470" all the way down, that does NOT mean they "have no crimp". It means the factory is using an un-tapered case which may be easier for them to manufacture. (Remember what I said? The SAAMI numbers are the "not-to-exceed" dimensions. So dimensions slightly smaller are a good thing.) In fact the .470" dimension means quite the opposite. It means the factory is applying a perfect crimp, and serves as proof that what I'm telling you is true.

• All manufacturers will use slightly different dimensions on their cartridges and cases. That stands to reason becasue they are making them in different factories on different machinery. However, none of them should ever be larger than the SAAMI dimensions. If they were, they wouldn't fit into your chamber.

Hope this helps!

 

[Walkalong]

You can throw SAMMI numbers out. What counts is your sizer, your bullet diameter, your brass diameter, etc.

Whatever the diameter ends up at about halfway down the part of the brass the bullet is seated in, taper crimp .001 to .002 down from that. A little more won't hurt, but won't help either.

• All manufacturers will use slightly different dimensions on their cartridges and cases. That stands to reason becasue they are making them in different factories on different machinery. However, none of them should ever be larger than the SAAMI dimensions. If they were, they wouldn't fit into your chamber.

Yep.

 

[remmag]

thanks guys
i will have to re-read everything again tomorrow and try to soak it up
i worked about 13 hours today and im too worn out to concentrate on it tonight
thanks again

 

[rfwobbly]

There's hardly anything the proper crimp and a little sleep won't fix.

 

[remmag]

Thanks for all the help. I have read through everything several times now nd it is making sense

 

[rfwobbly]

Remmy -

This is not explained anywhere that I know of. You have to understand that SAAMI standardizes the dimensions so that every ammo will go into every gun. So everything we discussed here is all inferred in the SAAMI numbers. Chambers can go no smaller than the SAAMI dimensions, and ammo can go no larger.

If you work with dimensions all day, then what the numbers say is intuitively obvious. But if you're in another line of work, then it might as well be hieroglyphics. So don't be too hard on yourself. We all came down the same path.

Glad we could help.

 

[remmag]

thanks alot for all the help