headspace - bumping shoulders back

[paulnyc]

I have a Sako TRG-42 in 338 Lapua - I am reloading. Are there any articles on the net which explain how to measure headspace and set up the dies to "bump back the shoulder"?

Any help would be appreciated!

 

[H5N1]

Re: headspace - bumping shoulders back

I take a piece of fire formed brass, size it and put it in the gun and chamber it. Feel for the smoothness of the bolt close and adjust in 1/8th rotation down with the die until it closes smooth. The round should be able to rotate in the chamber. If you dont have it right it will make a shiny spot on the case head when you close the bolt. you will feel it when it is right. Just dont over do it.
This is how I do it anyway.

 

[Hummer]

Re: headspace - bumping shoulders back

That is a good method if you don't have gages. A Mo Gage is the ultimate followed by the RCBS precision mic. PM me and I will get you an address for Mo Gage in Connecticut.
A Mo gage will allow you to see just how far your shoulder goes forward on firing and let you adjust your dies and only set back shoulder .001" to .002".
If a GO headspace gage is inserted in a MO Gage it will read "0".
You have selected a outstanding rifle by the way.

 

[pmarauder]

Re: headspace - bumping shoulders back

I have your same set up..... what i do is anneal the necks every other firing on this big case. Sinclair sells headspace bushings ($9.00) that fit into your sinclair bullet comparator body (assuming you have a bullet comparator) This way you can measure the headspace of a fired case with your calipers. make sure you start with a fired case that is already a little tight on your chamber when you close the bolt. Or use a sharpie pen and color the shoulder of the case. Then chamber and close the bolt. What your looking for is just a small amount of "black" to be rubbeb off. that will be your exact head space for your chamber. then adjust your bump die accordingly..
Derek

 

[NukeMMC]

Re: headspace - bumping shoulders back

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hummer</div><div class="ubbcode-body">That is a good method if you don't have gages. A Mo Gage is the ultimate followed by the RCBS precision mic. PM me and I will get you an address for Mo Gage in Connecticut.
A Mo gage will allow you to see just how far your shoulder goes forward on firing and let you adjust your dies and only set back shoulder .001" to .002".
If a GO headspace gage is inserted in a MO Gage it will read "0".
You have selected a outstanding rifle by the way. </div></div>
+1 x 10^6 on the Mo's Gauge

I have 1 each for 223 and 308 and since I've had them, think they are as necessary as the press or dies when sizing brass. Mo can be reached at:
Mo DeFina MCS, Inc.
166 Pocono Road
Brooksfield, CT 06804
203-775-1013, FAX 203-775-9462
Store Calling Hours:
Tuesday thru Thursday: 10AM to 9PM
Friday: 6PM to 9PM
Saturday 10AM to 4PM

 

[ChrisGarrett]

Re: headspace - bumping shoulders back

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: paulnyc</div><div class="ubbcode-body">I have a Sako TRG-42 in 338 Lapua - I am reloading. Are there any articles on the net which explain how to measure headspace and set up the dies to "bump back the shoulder"?

Any help would be appreciated!

</div></div>

Get the Hornady headspace set of gages with holder, so you can measure all of your calibers that you reload for. While you're at it, get their bullet comparator inserts with their holder and then get the Hornady/Stoney Point modified cases for their measureing rod(s) in the calibers that you shoot and you'll be set for life.

You might drop ~$200 on them, but if you look hard enough, you'll find them on sale here or there.

They're the right tools for the important jobs we all do when reloading precision ammo.

Chris

 

[user]

Re: headspace - bumping shoulders back

Tag

 

[Ratbert]

Re: headspace - bumping shoulders back

How much does a MO gauge run? Anyone know if a 260 is available for it?

 

[btm_54]

Re: headspace - bumping shoulders back

Another option is:
larrywillis.com
He sells a headspace gage
you only have to buy one for all calibers.

 

[4Rail_Gunner]

Re: headspace - bumping shoulders back

I bEt it's MO money than the hornady headspace guage that fits in the bullet comparator tool