13 replies to this topic

[Steve D.]

Hello Gang,

This question for AR with .223 Wylde chamber in 18" Shillen Brl. Most interested in Best Possibe Accuracy. Paper group shooting from 100-400 yds. is only use of gun.

Just curious why trim to 1.750 if it sounds like length spec up to 1.759 OK for chamber. Any advantage / problem in sizing to something like 1.754 / 1.755 ? My guess would be that 1.750 length brass leaves a little on the table in max. accuracy / bullet set-back from rifling? Just curious. Am starting to reload .223 now where only straight-wall pistol before this.

As always, I am all ears to hear from the masters in this forum.

Brass will be Ultra-Sonic clean, sized with RCBS F-L Sizer & Hornady stem with Tapered Expander Ball and little sizing wax. Then trimmed to whatever Length the Gurus here say on an RCBS trim-pro lathe with Inside and Outside Camfer. After a little adjusting the Trim-Pro 3-Way cutter head looks like it is doing a beautiful job on the 5-6 cases I have used to set it up with.

Have run a few and trimmed to 1.753 - 1.754 so far and they drop into Wilson case guage very nice with correct dimensions at head & mouth in relation to what guage surfaces call for. Looks like shoulder is getting set back about .002 - .003 from fired case and I think I am looking good in these dimensions so far.

Bullet to be seated with Forster B-R seater and light Lee FCD if needed. So far the neck tension feels like it will be pretty significant and may not need crimp at all. Have not started to seat any bullets until I am positive I will be trimming to correct length.

Standing by, Steve

[Steve D.]

Adding Question to my post...

Does that mean that all of the Load Manuals figure that you are starting with a casing length of 1.750 when they give the OAL for a given load as 2.220, 2.240, 2.260 etc?

If so, I guess it is inteneded that there are 10 Thousandths (1/100") more bullet out of the casing than would be the case if the Casing was 1.760 when it was reloaded, yes?

[Steve RA]

I doubt that everyone assumes you are starting with 1.750 cases. Case length can be varied, depending on chamber length. Overall length can vary according to way barrel throated but physically can't exceed maximum dimension that will fit in magazine.

[goat68]

Don't go much shorter or you could have a two piece case with half stuck in the chamber.

[Tom Freeman]

I trim to 1.740-745.

Its not that big of a deal.

Over sizing and pushing the shoulder back too far *is* a big deal.

[jakers]

Adding Question to my post...

Does that mean that all of the Load Manuals figure that you are starting with a casing length of 1.750 when they give the OAL for a given load as 2.220, 2.240, 2.260 etc?

If so, I guess it is inteneded that there are 10 Thousandths (1/100") more bullet out of the casing than would be the case if the Casing was 1.760 when it was reloaded, yes?

Case length does not have ANY effect on overall length.

[Alaskapopo]

I trim to 1.740-745.

Its not that big of a deal.

Over sizing and pushing the shoulder back too far *is* a big deal.

I would imagine you would have neck tension issues with brass that short.
Pat

[Tom Freeman]

I would imagine you would have neck tension issues with brass that short.

I have lots of issues, but neck tension isnt one of them. The difference in the amount of neck tension from 1.740 to 1.750 is nothing.

[Merlin Orr]

Adding Question to my post...

Does that mean that all of the Load Manuals figure that you are starting with a casing length of 1.750 when they give the OAL for a given load as 2.220, 2.240, 2.260 etc?

If so, I guess it is inteneded that there are 10 Thousandths (1/100") more bullet out of the casing than would be the case if the Casing was 1.760 when it was reloaded, yes?

Case length does not have ANY effect on overall length.

What about the bullet cannelure...?

[D.Hayden]

Adding Question to my post...

Does that mean that all of the Load Manuals figure that you are starting with a casing length of 1.750 when they give the OAL for a given load as 2.220, 2.240, 2.260 etc?

If so, I guess it is inteneded that there are 10 Thousandths (1/100") more bullet out of the casing than would be the case if the Casing was 1.760 when it was reloaded, yes?

Case length does not have ANY effect on overall length.

What about the bullet cannelure...?

Merlin.. do you really crimp to the cannelure.. or just asking for those that do?

It seem smost people just ignore the cannelure?

[Merlin Orr]

I actually have been doing the crimp at the cannelure.

Don't know any better...?

[Steve RA]

If you crimp to the cannelure, then case length will matter to the OAL. It is possible that you could get increased accuracy with a different OAL - which would mean not crimping in the cannelure. That, of course, assumes the same case length all the time.

[dskinsler83]

Loading for extreme accuracy in an at can be troublesome period

[dskinsler83]

Find out the full length of YOUR chamber and stay back about .003 off that THEN you can full length size which is what makes the neck length grow and trim to the .003 length below max length. Then you need to know what length you need to be touching rifling. Tools are out there for this measuring btw. Then and only then will you know if you will fit mag length or not. Then if you plan on using a mag then you adjust the OAL with bullet seating to fit mag and can buy .22cal bullets without cannulear just don't go below OAL on powder your using without using chrono and noting your signs of pressure Then do ladder testing