6mm cheat sheet info

[Hengehold]

Please add this cartridge to the list:

240 Tomahawk

Hornady Hagar brass

Case weight= 133.2 gr (fire formed & not resized)

H20 capacity = 36.2 gr

NK length= 0.170”

Shoulder angle= 40 degrees

 

[whatwind?]

bra, brx reamer

 

[Gabe22BR]

6TAC

.329” neck length
.273” taper to .272” at mouth
40* shoulder
.462” @ shoulder
.472” @ base/ .200” line
H2O capacity-39.8
1.560” max chamber length

 

[whatwind?]

updated

 

[snert]

6x50 Mo' Better (than the 6x47 Rem) 33.1 gr, 23 degree, .266 neck made from RWS 5.6x50 case.

Didn't see this added on the chart...

 

[SmokinJoe]

IMO one of the first things that should be stated in this thread is how the water capacity is measured, i.e. the method that should be used to make all the results as consistent as possible. The brand of brass should probably be stated also since there are significant variations in case capacity from one brand to another.

The way that I do a water capacity test is to take one or more primed cases, preferably fired cases, and weigh each one then mark the weight on the case. The weighed cases are then carefully filled with water then tapped a few times to hopefully get any trapped air out. When completely filled there should be a little swell of water above the mouth of the case. I use a tissue along the side of the mouth of the filled case to suck the extra water off leaving the water almost flat across the case mouth. Be sure to carefully dry the exterior of the filled case around the body and rim to prevent false weight results. The case is then weighed again and a record of that weight made. Then just subtract the original case weight and you have the water capacity.

 

[SmokinJoe]

Meant to preface my previous post with a big "Thank You" to whatwind? for creating this thread. It is probably useful to a lot of us. I checked 3 different cartridges from my brass this morning while taking the pictures and the 6CM and 243AI numbers I got match the chart pretty closely; all my brass is Lapua.

Another cartridge to add is the 6-250AI which had a water capacity of 50.1 grains made from Lapua 243, neck length approx .265 and shoulder angle is 40 degrees. Was interested to see that the 6CM had same water capacity so that will help with powder selection and load starting points

 

[whatwind?]

You’re welcome, i did have to some maths and research for neck lengths, it’s more of a guide to see the physics/ case capacities with each cartridge, I will update it again during week

 

[js2013]

Interesting. I wouldn’t have thought there’d be that big of a difference between the neck length of the 244 (376) and 6AI (320).

 

[denobravo]

i am just gathering info, please let me know what the correct numbers are, just gathering info for fun

		H2O	nk length	shlder ang
6x47 Rem		31.1	289	23
6x50 Mo Better		33.1	266	23
6x47		33
6PPC		33.74	280	30
6mm ARC		33.96	224	30
240 Tomahawk		36.2	170	40
6mm AR Turbo		37.45	185	40
6mm BR		39	320	30
6mm Grinch		39.05
6mm BRA (Lapua)		39.05	345	40
6 BRA (Alpha)		38.2	345	40
6mm BRG		39.35
6mm BRDX		39.5	283	40
6mm TAC		39.8	329	40	.462 shlder
6mm BRX		41	227	30
6mm Dasher		41.2	241	40
6GT (alpha)		43.3	299	35
6 GT (Horn)		44.9	299	35
6-250		44.5		26
6-250AI		50.1	265	40
6x47 Swiss Match		45.7	328	30
6x47L		47.75	310	30
6x47L AI		50		40
6xc		49.5	291	30
6creedmoor		51.1	281	30
Deep 6		51.2	351	26
243 wssm		53	278	37?
243 win		54	263	20
6 SLR		55	321	30
6 Comp Match		56	265	31
243 AI		57	267	40
244 Rem		57	376	26
6mm Rem AI		60.1	320	40
6-284		65	281	35
6saum		72	299	30

Base to shoulder;
6br. 1.071
6brdx 1.1647
6brx 1.171
6 dasher 1.1973

is very easy to get confused on the the specs for the 6 BR vs 6BRA. Simply put as I ascertain the reamer prints from JGS, the case wall on the 6 BR 30º is moved forward by .048 and the the neck shoulder junction is shortened by .004 and thus moving the shoulder angle back to 40º to form the 6 BRA 40º . The actual head space is .004shorter on the 6-BRA 40º than the 6-BR 30º.

all photos are off the internets, not mine

I cannot find ANY INFO on the 6mm TAC
could you point me in a direction for case dimensions, parent case etc