2 rifle loading question

[remmag]

hey everyone
my first start into reloading ,rifle 7mm mag
1st question, when i run my brass through the full length sizer die, how can i ensure that i have done this to gain the correct headspace, if i need to i will get a headspace gauge, recommendations please

2cd
i am shooting a browning auto, i have ran 2 cases through the die,partially seated in the press and inserted into my gun chamber, let the action close to try to get a measurement for my coal, on 2 test cases i came up with 2 different measurements,1 st is 3.321.5 Scd is 3.327 a difference of.006.5
is this close enough to determine my coal, how much would you recommend i reduce this by for optimum performance

thanks

 

[rcmodel]

Use a candle flame or magic marker to smoke or color the case & bullet, then carefully chamber it.

Keep seating deeper until you stop getting rifling marks in the candle soot.

rc

 

[GooseGestapo]

I would use the "smoking the case neck" method of determining amount of sizeing , and size just enough that the cases will easily feed and chamber.

Secondly, I'd either seat the bullets to fit the magazine, or to recommended oal's. the very slight and questionable possible increase in accuracy dosen't justify the potential feeding and pressure issues with long seated bullets.

Your Browning will shoot well if the bullets are quality and rifle "likes" the particular load. I've seen a couple of BAR'S that would go 1.5moa for three shots. Good enough for any reasonable use.

I'd look to IMR4350 for best accuracy in the semi-auto, secondly, try RL22. I've gotten good results from H4831, too.

I used the 3.250"oal as a friends Savage M110 had a very short throat, with Sierra 140gr GameKings and Prohunters.

Be sure to also start at 10% below max and don't try to "hot-rod" the loads. The 7mmMag is excellent even slightly below factory full loads. Accuracy trumps a slight increase in velocity.

 

[remmag]

guys, i just rechecked my manual and the mas length is 3.290 so i would prabably be safest with that
the smoke test, do i smoke or marker the cases ,chamber and see if there is any markings on the case neck, is some marking allowable,
if you would please explain in detail, id hate to wreck my gun

the only use this rifle gets is deer hunting
and some practice at the range, cant afford factory shells anymore, $45.00 to $50.00 a box i awfull

 

[JimKirk]

You're loadfing for a BAR 7mm for both questions right?

Question #1
For the BAR you will need to run the sizing die all the way down until it touches the shell holder and then turn the die enough to take all the slack out of the press linkage, "cam over" on most presses. The belt headspaces the 7mm round, but I also like for the shoulder of the brass to touch at the same time as the belt. The easiest way to do this, is to smut the case with a candle or mark the shoulder with a Magic Marker to see if the shoulder is touching the chamber and how much it is. This is very tedious to do on an auto gun but it can be done, it just takes some Patience and trial and error.

Question #2
I am assuming that you are seating a bullet with the seating die and you're trying to get the COAL of the round that will feed and be accurate in the BAR. First the magazine may limit the length that you can use. If you magazine limit is shorter than the needed length to get closer to the rifling, then you are stuck using the length that the mag will allow.
No if the above is not true with your BAR, then you can smut or mark the bullet and keep seating the bullet until it does not touch the rifling. I would go for .015 or .020 off the rifling for the BAR.

Maybe this helped answer your questions !! Oh you don't need a headspace gauge if you use the above methods, but they sell them every day.

Jimmy K

I see we were all typing at the same time!!

 

[rcmodel]

Well, if all you want to do is kill a deer, I would completely forget about how far the bullet is from the rifling.

Most good hunting bullets will have a crimp cannulure, and that is where you should seat them for your auto-loader. A light crimp would not be a bad idea in a BAR.

rc

 

[remmag]

rc
i have always shot federal sierra game kings in the gun, i have not been able to find them (bullets only) with a cannulure, it has been suggested to just crimp the non cannulure bullets with a lee factory crimp die,
is this what you would suggest or would you switch bullets

thanks

 

[rcmodel]

I have crimped smooth .224 bullets with a Lee FCD and got very slightly better accuracy with a CZ-527 .223.
It won't hurt them I guess.

rc

 

[remmag]

i still would like someone to run through the smoke test for headspace

thanks

 

[Walkalong]

Smoking the cases will tell you when the shoulder is not hitting and there is enough clearance to chamber, but will not tell you anything about headspace.

For hunting I agree with rc and the others, forget about how far it is to the lands with the bullet. Load to fit the mag, or to the cannelure and crimp.

I too would rather size to headspace on the shoulder rather than the belt, but that is the next step once you have the basics down, if you want to try it. It will generally extend brass life, but isn't necessary. Since this is your first try at reloading, I would keep it basic. Size to fit a case gauge for shooting in your autoloader, or run the sizer down to touch the shell holder and a 1/4 turn or so more to take up slack as posted earlier.

Buy a good manual and start reading up.

Here is a short pictorial that covers some of what you asked. It might prove helpful, maybe not.

 

[remmag]

thanks walkalong
i have been reading manuals and it seems there was alot of (warnings) on headspace, i will do as the others suggested on bullet length

i was concerned as to whether or not i had my die properly set, i did do it as you said

i will by a case gauge from midway (wilson ) headspace and case length i beleive is my best option

just trying to pay attantion to safety and detail

thanks again

 

[Walkalong]

99% of the time if you size as much as the die allows, it will keep you out of trouble. The makers are pretty careful about that. The vast majority don't ever buy case gauges. You just don't know for sure though.

I am as guilty as any. I loaded .223 for years without using a case gauge. I only had one .223, and everything worked fine. (A big fat chambered Mini 14 which helped with sloppy sizing or ever so slightly buckled shoulders from crimping )

For a bolt gun I partial full length size mostly now. I used to neck size some, and still do with the .22 Hornet some, but for autos I have always full length sized. (With or without gauges)

 

[remmag]

thank you very much